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Borders &Conflict &COVID-19 &Ebola &Epidemic &One Health &Yellow Fever Bill Brieger | 10 May 2023

Outbreaks Emergency Preparedness And Response In Uganda

Solomon Afolabi, a graduating MPH student from the JHU Bloomberg School of Public Health examined the challenge of epidemics and outbreaks in Africa with special reference to Uganda as an example. The abstract of his report is found below.

According to the WHO, preparedness for emergency health conditions like infectious disease outbreaks should be an ongoing action supported by adequate funding, resources, partnerships, and political will that is executed at all levels to keep it sustained. Emergency preparedness is a framework that identifies practical in-country health emergency preparedness principles and elements by acknowledging lessons learned from previous response activities for priority planning, implementation, and reinforcing operational capacities.

Uganda is an ecological hotspot for various infectious diseases making the country liable to outbreaks. In the last two decades, multiple significant outbreaks have occurred, prominent of which are from yellow fever, Ebola virus disease, and COVID-19 global pandemic. Efforts to build a strategic framework for emergency outbreak preparedness and to strengthen the national operational capacity led to the establishment of the Ugandan National Institute of Public Health (UNIPH) in 2013.

This paper presents a blend of literature that takes account of the successes, challenges faced, and gaps identified in the preparedness and response capacities to the infectious disease outbreaks experienced in the last two decades. It also reviewed how the national efforts had fared in operational readiness for an emergency response to epidemics, building a resilient health system, practicing the One-Health human-animal-environment interface, and in government, community, and individual capacities to contribute effectively to strengthen the national emergency preparedness and response to these frequent disease outbreaks. The findings revealed that Uganda’s outbreak preparedness had made much progress over two decades, from the overwhelming Sudan strain Ebola virus outbreak in 2000-2001 to a similar episode from the same species in 2022 to 2023.

The response measures that feature the activation of a national response plan by the MoH were well coordinated locally to swiftly lead to the activation of NTF, NRRT, DTF, DRRT, and VHTs for immediate mobilization and deployment of operational resources to affected districts. The response was strengthened by well-organized local coordination by the MoH and development partners (WHO, CDC, UN agencies, etc.). The immediate setting up of treatment and isolation centers, provision of Ebola kits, training of more health workers, and coverage of 10 high-risk districts ensured a significant impact.

The provision of more than 5000 doses of vaccines with the support of WHO and partners was a global capacity milestone impact, and the country was declared Ebola-free in a record 69 days. Uganda’s current national emergency preparedness and response plan has received commendations locally and from global international partners, having progressively built capacity from lessons learned in just over a decade of responding to frequent infectious disease outbreaks and using the recommendations proffered accordingly.

This sustained momentum of preparedness supported the swift transition to contain COVID-19 and laid a good foundation for their strengthened readiness for an emergency response to outbreaks.

Asymptomatic &Borders &Children &Elimination &Indoor Residual Spraying &IRS &Migration &Mosquitoes &Pharmacovigilence Bill Brieger | 08 Oct 2020

Malaria News Today 2020-10-08: the role of travel, asymptomatic disease and gut microbiome from AJTMH

The American Journal of Tropical Medicine and Hygiene has several new articles on malaria. Abstracts are shared. Two articles examine the role of travel in malaria transmission, both cross-border and rural-urban. Another considers the effect on pharmacokinetics of lumefantrine due to gut bacteria. In Uganda indoor spraying has reduced transmission, but asymptomatic cases remain among children. The challenges of asymptomatic malaria to elimination efforts is also examined in India. Links to the articles are found below.

Evidence of Microbiome–Drug Interaction between the Antimalarial Lumefantrine and Gut Microbiota in Mice

The antimalarial drug lumefantrine exhibits erratic pharmacokinetics. Intersubject variability might be attributed, in part, to differences in gut microbiome–mediated drug metabolism. We assessed lumefantrine disposition in healthy mice stratified by enterotype to explore associations between the gut microbiota and lumefantrine pharmacokinetics. Gut microbiota enterotypes were classified according to abundance and diversity indices from 16S rRNA sequencing. Pharmacokinetic parameters were computed using noncompartmental analysis. Two distinct enterotypes were identified.

Maximal concentration (C max) and total drug exposure measured as the area under the drug concentration–time curve (AUC0–24) differed significantly between the groups. The mean and standard deviation of C max were 660 ± 220 ng/mL versus 390 ± 59 ng/mL (P = 0.02), and AUC0–24 was 9,600 ± 2,800 versus 5,800 ± 810 ng × h/mL (P = 0.01). In healthy mice intragastrically dosed with the antimalarial drug lumefantrine in combination with artemether, lumefantrine exposure was associated with gut bacterial community structure. Studies of xenobiotic–microbiota interactions can inform drug posology and elucidate mechanisms of drug disposition.

Malaria Transmission, Infection, and Disease following Sustained Indoor Residual Spraying of Insecticide in Tororo, Uganda

Tororo, a district in Uganda with historically high malaria transmission intensity, has recently scaled up control interventions, including universal long-lasting insecticidal net distribution in 2013 and 2017, and sustained indoor residual spraying (IRS) of insecticide since December 2014. We describe the burden of malaria in Tororo 5 years following the initiation of IRS. We followed a cohort of 531 participants from 80 randomly selected households in Nagongera subcounty, Tororo district, from October 2017 to October 2019. Mosquitoes were collected every 2 weeks using CDC light traps in all rooms where participants slept, symptomatic malaria was identified by passive surveillance, and microscopic and submicroscopic parasitemia were measured every 4 weeks using active surveillance. Over the 2 years of follow-up, 15,780 female anopheline mosquitos were collected, the majority (98.0%) of which were Anopheles arabiensis.

The daily human biting rate was 2.07, and the annual entomological inoculation rate was 0.43 infective bites/person/year. Only 38 episodes of malaria were diagnosed (incidence 0.04 episodes/person/year), and there were no cases of severe malaria or malarial deaths. The prevalence of microscopic parasitemia was 1.9%, and the combined prevalence of microscopic and submicroscopic parasitemia was 10.4%, each highest in children aged 5–15 years (3.3% and 14.0%, respectively). After 5 years of intensive vector control measures in Tororo, the burden of malaria was reduced to very low transmission levels. However, a significant proportion of the population remained parasitemic, primarily school-aged children with submicroscopic parasitemia, providing a potential reservoir for malaria transmission.

Malaria Diagnosed in an Urban Setting Strongly Associated with Recent Overnight Travel: A Case–Control Study from Kampala, Uganda

Malaria is frequently diagnosed in urban Kampala, despite low transmission intensity. To evaluate the association between recent travel out of Kampala and malaria, we conducted a matched case–control study. Cases were febrile outpatients with a positive malaria test; controls were febrile outpatients with a negative test. For every two cases, five controls were selected, matching on age. Data were collected on recent overnight travel out of Kampala (past 60 days), destination and duration of travel, and behavioral factors, including sleeping under an insecticide-treated net (ITN) during travel. From July to August 2019, 162 cases and 405 controls were enrolled. The locations of residence of cases and controls were similar. More controls were female (62.7% versus 46.3%, P < 0.001). Overall, 158 (27.9%) participants reported recent overnight travel.

Travelers were far more likely to be diagnosed with malaria than those who did not travel (80.4% versus 8.6%, OR 58.9, 95% CI: 23.1–150.1, P < 0.001). Among travelers, traveling to a district not receiving indoor residual spraying of insecticide (OR 35.0, 95% CI: 4.80–254.9, P < 0.001), no ITN use (OR 30.1, 95% CI: 6.37–142.7, P < 0.001), engaging in outdoor activities (OR 22.0, 95% CI: 3.42–141.8, P = 0.001), and age < 16 years (OR 8.36, 95% CI: 2.22–56.2, P = 0.03) were associated with increased odds of malaria. Kampala residents who traveled overnight out of the city were at substantially higher risk of malaria than those who did not travel. For these travelers, personal protection measures, including sleeping under an ITN when traveling, should be advocated.

Prevalence of Asymptomatic Malaria Parasitemia in Odisha, India: A Challenge to Malaria Elimination

The prevalence of malaria in India is decreasing, but it remains a major concern for public health administration. The role of submicroscopic malaria and asymptomatic malaria parasitemia and their persistence is being explored. A cross-sectional survey was conducted in the Kandhamal district of Odisha (India) during May–June 2017. Blood samples were collected from 1897 individuals for screening of asymptomatic parasitemia. Samples were screened using rapid diagnostic tests (RDTs) and examined microscopically for Plasmodium species. Approximately 30% of randomly selected samples (n = 586) were analyzed using real-time PCR (qPCR), and the genetic diversity of Plasmodium falciparum was analyzed.

The prevalence of Plasmodium species among asymptomatic individuals detected using qPCR was 18%, which was significantly higher than that detected by microscopy examination (5.5%) or RDT (7.3%). Of these, 37% had submicroscopic malaria. The species-specific prevalence among asymptomatic malaria-positive cases for P. falciparum, Plasmodium vivax, and mixed infection (P. falciparum and P. vivax) by qPCR was 57%, 29%, and 14%, respectively. The multiplicity of infection was 1.6 and 1.2 for the merozoite surface protein-1 gene (msp1) and (msp2), respectively. Expected heterozygosity was 0.64 and 0.47 for msp1 and msp2, respectively. A significant proportion of the study population, 105/586 (18%), was found to be a reservoir for malaria infection, and identification of this group will help in the development of elimination strategies.

Travel Is a Key Risk Factor for Malaria Transmission in Pre-Elimination Settings in Sub-Saharan Africa: A Review of the Literature and Meta-Analysis

By sustaining transmission or causing malaria outbreaks, imported malaria undermines malaria elimination efforts. Few studies have examined the impact of travel on malaria epidemiology. We conducted a literature review and meta-analysis of studies investigating travel as a risk factor for malaria infection in sub-Saharan Africa using PubMed. We identified 22 studies and calculated a random-effects meta-analysis pooled odds ratio (OR) of 3.77 (95% CI: 2.49–5.70), indicating that travel is a significant risk factor for malaria infection.

Odds ratios were particularly high in urban locations when travel was to rural areas, to more endemic/high transmission areas, and in young children. Although there was substantial heterogeneity in the magnitude of association across the studies, the pooled estimate and directional consistency support travel as an important risk factor for malaria infection.

Borders &Ebola Bill Brieger | 18 Aug 2019

Ebola Crisis Takes a Turn: Increased US Intervention Necessary

As part of the course on Social and Behavioral Foundations in Primary Health Care, Allan Ciciriello posted in the class blog. We have shared his thoughts below.

Confirmed and probable Ebola virus disease cases by week of illness onset by Kivu region health zone. Data as of 13 August 2019

Historically, the 2018 – 2019 Ebola outbreak is the biggest the Democratic Republic of the Congo has ever seen. As a whole, it is also the second largest documented epidemic of the disease on record. The epicenter of the eruption is located in the Kivu region, which has also been in the midst of a conflict between the Congolese military and rebel groups, which has prevented necessary assistance from making its way into the country. Due to the decline of the situation over the past year, culminating with a confirmed case of Ebola in the capital city of Goma, the World Health Organization officially announced it as a Public Health Emergency of International Concern in July 2019.

The spread of the virus to bordering countries is a matter of great importance in the global health community. This includes the nations of Burundi, Rwanda, South Sudan, and Uganda. Given that Goma is a major transportation hub connecting these territories together, it is imperative that the transmission of Ebola be stopped quickly in the Kivu region.

Ebola virus disease in the Democratic Republic of the Congo – Operational readiness and preparedness in neighbouring countries
Recently, the World Health Organization has claimed the current funding is not enough to sustain response activities on a multi-national scale. The United States, who played a large role in the 2014 – 2015 outbreak of Ebola, has had limited participation this time around. This is largely due to the ability of the global health community to respond more adequately to the disease through large improvements in technical capabilities. Security factors with the military conflict have also prevented the United States from getting on the ground in the Democratic Republic of the Congo. However, due to recent changes in the situation, the Congolese government and the World Health Organization cannot efficiently resolve the epidemic without additional help from UN partners, most notably the United States.
‘We won’t get to zero cases of Ebola without a big scale-up in funding,’ UN relief chief warns

The United States must change its current policies on intervening in the Democratic Republic of the Congo Ebola outbreak. Most important is contributing additional funding to sustain the World Health Organization’s role in halting the spread of the virus within the current borders, while also supporting the surrounding nations’ prevention efforts. USAID is a critical source of backing in this ongoing battle, and without them it is likely to falter. I would also reconsider the hesitancy of placing United States government personnel on the frontlines, because as the problem gets more dire the harder it will be to act from within the country. The CDC is another key player in this game, and I would advise the US take advantage of the United Nations Organization Stabilization Mission in the Democratic Republic of the Condo’s (also known as MONUSCO) peacekeeping forces to get public health workers back on the frontline with guaranteed protection from rebel militias.

Borders &Diagnosis &Ebola &Elimination &Integrated Vector Management &ITNs &Mosquitoes &NTDs &Snakebite &Trachoma &Urban Bill Brieger | 04 Aug 2019

Tropical Health Update 2019-08-04: Ebola, Malaria Vectors, Snakebite and Trachoma

In the past week urban transmission in Goma, a city of at least 2 million inhabitants in eastern Democratic republic of Congo, was documented as a gold miner came home and infected his wife and child. To get a grip on the spread of the disease, DRC is considering another vaccine, not without some controversy. WHO provides detailed guidance on all aspects of response. On the malaria front we have learned more about malaria vectors, natural immunity and reactive case detection.

Ebola Challenges: Vaccines, Urban Transmission

The current Ebola vaccine being deployed to over 150,000 people in North Kivu and Ituri Provinces was itself an experimental intervention during 2016 when it was first used in the largest ever outbreak located in West Africa. BBC reports that, “World Health Organization (WHO) data show the Merck vaccine has a 97.5% efficacy rate for those who are immunised, compared to those who are not.”

The proposed addition of a Johnson and Johnson vaccine would be in that same experimental phase if introduced in DRC now. It has been proven safe as well as effective in other primates. The challenge is that even though the Merck vaccine supplies are near 500,000, this is not enough to cover the potential needs in an area with over 10 million people, although Merck is still producing more. At present, BBC says, “Those pushing for the use of the new Johnson & Johnson vaccine, had proposed using it to create a protective wall, vaccinating people outside the outbreak zone.” In addition, the new national response team is concerned that “Only about 50% of cases of Ebola in the Democratic Republic of Congo are being identified.”

Finally, there is the issue of community mistrust of government workers and challenging logistics. “There are also concerns that the new vaccine – which requires two injections 56 days apart – may be difficult to administer in a region where the population is highly mobile, and insecurity is rife.”

If efforts at vaccination are needed soon in Goma, up to 2 million doses might be needed. Reuters reports that, “Congolese authorities were racing to contain an Ebola epidemic on Thursday, after a gold miner with a large family contaminated several people in the east’s main city of Goma before dying of the hemorrhagic fever.” Readers may recall that the West Africa outbreak of 2014-16 in Guinea, Sierra Leone and Liberia accelerated greatly after infected people went to major cities in search of help.

The miner is the second ‘imported case into Goma, which borders Rwanda, but because his family lives there, he has already infected his wife and one of his 10 children. Contacts are being traced and monitored, but this urban and border threat is one of the factors that led WHO to finally declare the current outbreak a public health emergency.

Malaria

As we move toward malaria elimination Reactive Case Detection (RCD) has been proposed as an integral part of these efforts with the hopes that is can be conceived of as a way of gradually decreasing transmission, according to an article in Malaria Journal. In fact, the value of RCD may be limited as follows:

  • RCD alone can eliminate malaria in only a very limited range of settings, where transmission potential is very low
  • In other settings, it is likely to reduce disease burden and help maintain the disease-free state in the face of imported infections

Another article looks at “natural exposure to gametocytes that can result in the development of immunity against the gametocyte by the host as well as genetic diversity in the gametocyte.” The researchers learned that there can be variations in immune response depending on season and geography. This information is helpful in planning malaria elimination interventions.

On the vector front a baseline susceptibility testing was conducted in 16 countries in sub-Saharan Africa for neonicotinoids. “The target site of neonicotinoids represents a novel mode of action for vector control, meaning that cross-resistance through existing mechanisms is less likely.” The findings will help in the preparation for rollout of clothianidin formulations as part of national IRS rotation strategies by PMI and other partners.

Researchers also called on us to learn more about malaria vectors in other parts of the world. In order to eliminate Plasmodium falciparum from the Caribbean and Central America program planners should consider local vector characteristics such as An. albimanus. They found that, “House-screening and repellent IRS are potentially highly effective against An. albimanus if people are indoors during the evening.”

Vectors are also of concern on the edges of malaria transmission, particularly in South Africa, one of the ‘elimination eight’ countries of the Southern Africa Development Community. Researchers examined the, “potential role of Anopheles parensis and other Anopheles species in residual malaria transmission, using sentinel surveillance sites in the uMkhanyakude District of northern KwaZulu-Natal Province.” They found Anopheles parensis is a potential but minimal vector of malaria in South Africa “owing to its strong zoophilic tendency.” On the other hand, An. arabiensis was found to be the major vector responsible for residual malaria transmission in South Africa. Since these mosquitoes were found in outdoor-placed resting traps, interventions are needed to control outdoor-resting of vector populations.

NTDs of Concern

During the week, the member states of the African Union renewed their commitment to fight and permanently eliminate Neglected Tropical Diseases. Africa.com reported that, “Achievements to date include 1 billion people treated against at least one NTD and 37 countries have completed the removal of at least one NTD.”

Although some reports have discounted the idea of trachoma in Namibia, there may be reason to re-examine the situation. On Twitter Anthony Solomon notes that Namibia needs #trachoma prevalence surveys. A just-completed joint Ministry of Health & Social Services/@WHO mission found active trachoma & trichiasis in Zambezi & Kunene Regions.

The Times of India draws attention to snakebite. It says that “Under-reported and inadequately treated, fatalities in India are estimated at close to 50,000 a year, the world’s highest.”

Overall we can see that the concept of ‘neglect’ has several uses. There is neglect if half of Ebola cases are undetected. There is neglect if we do not understand malaria vectors in low transmission areas. Finally, there is neglect if we do not conduct up-to-date disease surveys to determine whether a disease is present or not. Elimination of tropical diseases is challenging when key processes are neglected.

Agriculture &Borders &Ebola &Essential Medicines &Integrated Vector Management &ITNs &Larvicide &Mosquitoes &Schistosomiasis &Severe Malaria &Vaccine &Vector Control Bill Brieger | 15 Jul 2019

The Weekly Tropical Health News 2019-07-13

In the past week more attention was drawn to the apparently never-ending year-long Ebola outbreak in the northeast of the Democratic Republic of the Congo. Regarding other diseases, there is new information on the RTS,S malaria vaccine, river prawns have been found to play a biological control role in schistosomiasis, and an update from the World Health Organization on essential medicines and diagnostics. New malaria vector control technologies are discussed.

Second Largest Ebola Outbreak One Year On

Ronald A. Klain and Daniel Lucey in the Washington Post observed raised concern that, “the disease has since crossed one border (into Uganda) and continues to spread. In the absence of a trajectory toward extinguishing the outbreak, the opposite path — severe escalation — remains possible. The risk of the disease moving into nearby Goma, Congo — a city of 1 million residents with an international airport.”

They added their voices to a growing number of experts who are watching this second biggest Ebola outbreak in history and note that, “As the case count approaches 2,500 with no end in sight, it is time for the WHO to declare the outbreak a public health emergency of international concern — a ‘PHEIC’ — to raise the level of global alarm and signal to nations, particularly the United States, that they must ramp up their response.” They call for three actions: 1) improved security for health workers in the region, 2) stepped up community engagement and 3) extended health care beyond Ebola treatment. The inability to adequately respond to malaria, diarrheal diseases and maternal health not only threated life directly, but also threated community trust, putting health workers’ lives at risk.

Olivia Acland, a freelance journalist based in DRC, reporting for the New Humanitarian describes the insecurity and the recent “wave of militia attacks in the Democratic Republic of Congo’s northeastern Ituri province has left hundreds dead and roughly 300,000 displaced in recent weeks, triggering a new humanitarian crisis in a region.” Specifically, “Ituri, a fertile region rich in gold deposits, has been an epicentre of conflict in Congo for decades. Between 1999 and 2003, around 60,000 people were killed here, as a power struggle between rebel groups escalated into ethnic violence,” related to traditional tensions between Hema cattle herders and Lendu farmers with roots in Belgian colonization.

Updates from the DRC Ministry of Health report on average 11 new Ebola cases per day in the past week. So far over 160,000 people have been vaccinated, and yet the spread continues. The Ministry also describes new protocol contains three vaccinations strategies that can be used depending on the environment in which confirmed cases are found including:

  • Classic Ring: The classic strategy of vaccinating contacts of confirmed cases and contact contacts.
  • Enlarged ring: It is also possible to vaccinate all inhabitants of houses within 5 meters around the outbreak of a confirmed case.
  • Geographical Ring: In an area where team safety can not be guaranteed, they can vaccinate an entire village or neighborhood.

Malaria Vaccines, Essential Drugs and New Vector Control Technologies

Halidou Tinto and colleagues enrolled two age groups of children in a 3-year extension of the RTS,S/AS01 vaccine efficacy trial: 1739 older children (aged 5–7 years) and 1345 younger children (aged 3–5 years). During extension, they reported 66 severe malaria cases. Overall they found that, “severe malaria incidence was low in all groups, with no evidence of rebound in RTS,S/AS01 recipients, despite an increased incidence of clinical malaria in older children who received RTS,S/AS01 compared with the comparator group in Nanoro. No safety signal was identified,” as seen in The Lancet.

WHO has updated the global guidance on medicines and diagnostic tests to address health challenges, prioritize highly effective therapeutics, and improve affordable access. Section 6.5.3 presents antimalarial medicines including curative treatment (14 medicines) for both vivax and falciparum and including tablets and injectables. Prophylaxis includes 6 medicines including those for IPTp and SMC. The latest guidance can be downloaded at WHO.

Paul Krezanoski reports on a new technology to monitor bednet use and tried it out in Ugandan households. As a result. “Remote bednet use monitors can provide novel insights into how bednets are used in practice, helping identify both households at risk of malaria due to poor adherence and also potentially novel targets for improving malaria prevention.

In another novel technological approach to vector control, Humphrey Mazigo and co-researchers tested malaria mosquito control in rice paddy farms using biolarvicide mixed with fertilizer in Tanzanian semi-field experiments. The intervention sections (with biolarvicide) had lowest mean mosquito larvae abundance compared to control block and did not affect the rice production/harvest.

Prawns to the Rescue in Senegal Fighting Schistosomiasis and Poverty

Anne Gulland reported how Christopher M. Hoover et al. discovered how prawns could be the key to fighting poverty and schistosomiasis, a debilitating tropical disease. They found that farming the African river prawn could fight the disease and improve the lives of local people, because the African river prawn is a ‘voracious’ predator of the freshwater snail, which is a carrier of schistosomiasis.

The researchers in Senegal said that, “market analysis in Senegal had shown there was significant interest among restaurant owners and farmers in introducing prawns to the diet.” The prawn could also for the basis of aquaculture in rice paddies and remove the threat of schistosomiasis from the rice workers.

—- Thank you for reading this week’s summary. These weekly abstractings have replaced our occasional mailings on tropical health issues due to fees introduced by those maintaining the listserve website. Also continue to check the Tropical Health Twitter feed, which you can see running on this page.

Borders &Diagnosis &Elimination &Environment &Gender &Health Education &Health Workers &Indoor Residual Spraying &IRS &ITNs &Mosquitoes &Plasmodium/Parasite &Vector Control Bill Brieger | 07 Jul 2019

The Weekly Tropical Health News 2019-07-06: Eliminating Malaria in Low Transmission Settings

This week started with articles that drew attention to the challenges of malaria in low transmission areas and with low density infections. Malaria Journal has provided several insightful articles toward this end.

Being an island has certainly helped Zanzibar make progress toward malaria elimination as witness the fact that malaria prevalence has remained below 1% for the past decade. Not only does Zanzibar still face threats of infection from the mainland, it may also experience an upsurge locally if residual transmission and the role of human behavior and community actions are not well understood. April Monroe et al. conducted in-depth interviews with community members and local leaders across six sites on Unguja, Zanzibar as well as semi-structured community observations of night-time activities and special events to learn more.

While there was high reported ITN use, there were also times when people were exposed t mosquitoes while being outdoors during biting times. This could be around the house, or at special night events like such as weddings, funerals, and religious ceremonies. Men spent more time outdoors than women. Clearly appropriate interventions and needed and should be promoted in culturally appropriate ways in order to further reduce and eventually eliminate transmission.

Angela Early and colleagues presented findings on a diagnostic process of deep sequencing for understanding the dynamics and complexity of Plasmodium infections, but stress that knowing the lower limit of detection is challenging. They present “a new amplicon analysis tool, the Parallel Amplicon Sequencing Error Correction (PASEC) pipeline, is used to evaluate the performance of amplicon sequencing on low-density Plasmodium DNA samples.”

The authors learned that, “four state-of-the-art tools resolved known haplotype mixtures with similar sensitivity and precision.” They also cautioned that, “Samples with very low parasitemia and very low read count have higher false positive rates and call for read count thresholds that are higher than current default recommendations.” Better understanding of the genetic mix of plasmodium infections as countries move toward low transmission and elimination is crucial for selecting appropriate interventions and evaluating their outcomes.

Hannah Edwards and co-researchers examined conditions for malaria transmission along the Thailand-Myanmar border in areas approaching malaria elimination. While prevalence may be less than 1%, residual transmission still occurs. Transmission occurs not only around residences but in the forests where people work. The researchers therefore looked at the behavior of both humans and insects. Overall, they found that, “Community members frequently stayed overnight at subsistence farm huts or in the forest. Entomological collections showed higher biting rates of primary vectors in forested farm hut sites and in a more forested village setting compared to a village with clustered housing and better infrastructure.”

While mosquitoes preferred to bite inside huts, their threat was magnified by those who did not use long lasting insecticide-treated nets (LLINs). While out in the farms and forests, people tended to wake early and increase their likelihood of being bitten. The authors discuss the challenges of dual residences in terms of LLIN ownership and even concerning the potential access to indoor residual spraying. The definition for universal net coverage needs to expand from one net per two people to include adequate nets wherever people are located.

The Amazonian area of Brazil is another area working toward malaria elimination, in particular, Plasmodium vivax. Felipe Leão Gomes Murta et al. also looked at the human side of the equation and identified misperceptions by both community members and health workers that could inhibit elimination efforts. They found, “many myths regarding malaria transmission and treatment that may hinder the sensitization of the population of this region in relation to the use of current control tools and elimination strategies, such as mass drug administration (MDA),” and LLINs.

Problematic perceptions included mention by both groups that the use of insecticide-treated nets, may cause skin irritations and allergies. Both community members and health professionals said malaria is “an impossible disease to eliminate because it is intrinsically associated with forest landscapes.” They concluded that such perceptions can be a barrier to control and elimination.

Efforts to eliminate malaria from low transmission settings are an essential to the overall global goals. These four articles tell us that close attention to and better understanding of humans, parasites and mosquitoes is still needed to achieve these goals.

Borders &Diagnosis &Ebola &Elimination &Eradication &Health Systems &Measles &Surveillance &Vaccine &Yaws Bill Brieger | 22 Jun 2019

The Weekly Tropical Health News Update 2019-06-22

For almost 20 years we have been maintaining an email list where current news and articles have been shared with those interested in tropical health and malaria. The listserve host we have been using is changing to a paid model. While there are still some free listserve options, these are cumbersome to produce. Since we are already maintaining this blog, we thought it best to provide a weekly summary of key news events through this medium.

Mapping Plasmodium Vivax

The Malaria Atlas Project has published in The Lancet a global burden of Plasmodium Vivax mapping study. The authors describe the contribution of this study as: “Our study highlights important spatial and temporal patterns in the clinical burden and prevalence of P vivax. Amid substantial progress worldwide, plateauing gains and areas of increased burden signal the potential for challenges that are greater than expected on the road to malaria elimination. These results support global monitoring systems and can inform the optimisation of diagnosis and treatment where P vivax has most impact.”

Ebola Spread from DRC to Uganda

Since the major ongoing outbreak of Ebola Virus Disease in North Kivu and Ituri Provinces of the Democratic Republic of Congo (DRC) started nearly a year ago, there has been concern that the disease might spread to neighboring countries like Uganda, Rwanda, South Sudan and the Central African Republic. This fear same true recently when a family affected by Ebola crossed from DRC into Uganda to connect with relatives in Kasese District Uganda. Uganda has had many years’ experience dealing with Ebola and was able to contain the situation.

A press release this week noted that, “As of today (21 June 2019), Uganda has not registered any new confirmed Ebola Virus Disease (EVD) case in Kasese District or any other part of Uganda since the last registered case one week ago. There are no new suspect cases under admission. Currently, 110 contacts to the confirmed Ebola cases in Kagando and Bwera are being followed up daily. A total of 456 individuals have been vaccinated against EVD using the Ebola-rVSV vaccine in Kasese District, Western Uganda.”

Although many people expected that the meeting of the “International Health Regulations (2005) Emergency Committee} for Ebola virus disease in the Democratic Republic of the Congo would finally declare the current outbreak a Public Health Emergency of International Concern (PHEIC) because it crossed a border, the result was noting that the challenge was still an emergency only for DRC. WHO did note that there were serious funding gaps and support from other countries for the DRC’s predicament. Ironically, such gaps make it more likely that Ebola can spread more widely.

As of 21 June 2019, the DRC reported a total of 2,211 cases since the start of the epidemic last year, of which 2,117 have been confirmed and 94 are probable. There have been 1,489 deaths. To date 139,027 persons have been vaccine with the Merck rVSV-ZEBOV vaccine.

Progress toward Eliminating Malaria – the E-2020 Countries

The process of eliminating malaria from the world needs to start in a step-by-step fashion. WHO explained that, “Creating a malaria-free world is a bold and important public health and sustainable development goal. It is also the vision of the Global technical strategy for malaria 2016-2030, which calls for the elimination of malaria in at least 10 countries by the year 2020.”

Actually, WHO identified 21 countries, spanning 5 regions, that could defeat malaria by 2020. The progress report charts the effort. During the recent World Health Assembly two countries received recognition for being certified malaria-free, Argentina and Algeria. This week WHO also announced that 5 more countries have not had malaria cases in the past year. There was also release of a downloadable report on progress toward the 2020 target for selected countries.

Reconsidering Yaws Eradication

In the 1950s and 1960s the world focused on the possibility of eradicating Yaws through screening and treatment interventions. Like the early malaria eradication programs from the same period, the Yaws effort slowed, stopped and experienced a resurgence. The Telegraph reported that, “Between 1952 and 1964, Unicef and the WHO screened some 300 million people for the illness, in a coordinated programme which treated more than 50 million cases. Yaws was on the brink of being wiped out and reports of the disease dropped by 95 per cent.” WHO continues to work on treatment strategies with azithromycin and for resistant cases, benzathine benzylpenicillin injection.

WHO noted that there were 80,472 cases reported in 2018, although this figure is likely to be much higher in actuality. The challenge of case detection exists but may be overcome, according to the Telegraph with a new molecular rapid diagnostic test which detects yaws within 30 minutes, and thus could allow on-the-spot diagnosis in remote regions.

Measles Cases Continue to Increase

The problem of measles in the DRC may not be receiving much attention because of the Ebola epidemic. Ironically, Outbreak News Today reports that, “In a follow-up on the measles outbreak in the Democratic Republic of the Congo (DRC), UN health officials report an additional 7500 suspect cases in the past 2 weeks, bringing the total cases since the beginning of the year to 106,870. The death toll due to the measles outbreak has reached 1815 deaths (case fatality ratio 1.7%).”

Vaccine coverage challenges in the DRC result from health systems weaknesses. Unfortunately, a global study has shown that increasing cases in the Global North are not due to weak systems, but ‘vaccine hesitancy.’ The Guardian reports that a global survey has revealed the scale of the crisis of confidence in vaccines in Europe, “showing that only 59% of people in western Europe and 50% in the east think vaccines are safe, compared with 79% worldwide.” The Guardian observes that, “In spite of good healthcare and education systems, in parts of Europe there is low trust in vaccines. France has the highest levels of distrust, at 33%.”

For more news and daily updates check our other services, a closed/private Facebook Group and a Twitter feed. For those who do not use social media, please check here each weekend to find a summary of some of the stories we have shared during the week.

Borders &CHW &Climate &Elimination &IPTi &Sahel &Surveillance &Vector Control Bill Brieger | 26 Sep 2018

Hopefully Malaria Elimination will not be the SaME

The Sahel Malaria Elimination Initiative (SaME) has been launched, but builds on a long history of cooperation in the region. Efforts by eight Sahelian countries to share lessons and strategies mirrors the Elimination Eight group on the opposite end of the continent.

The few rainy season months in the Sahel offer optimum malaria transmission, which SaME is tackling

The Roll Back Malaria (RBM) Partnership to End Malaria announced that in Dakar on 31st August 2018, the health “ministers from Burkina Faso, Cabo Verde, Chad, Mali, Mauritania, Niger, Senegal and The Gambia established a new regional platform to combine efforts on scaling up and sustaining universal coverage of anti-malarials and mobilizing financing for elimination.” The group plans a fast-track introduction of “innovative technologies to combat malaria and develop a sub-regional scorecard that will track progress towards the goal of eliminating malaria by 2030.” This will build on the existing country scorecard that has been developed and implemented by AMLA2030 for all countries in the region and tracks roll out of key malaria and health interventions. The Sahel Malaria Elimination Initiative will be hosted by the West African Health Organization, a specialised agency of the Economic Community of West African States (ECOWAS).

RBM explains that while the eight countries will work together, they do not have a homogenous epidemiological picture or experience with malaria programming. The Sahel experiences 20 million annual malaria cases, according to RBM, and “the Sahel region has seen both achievements and setbacks in the fight against the disease in recent years.” These eight have a highly variable malaria experience. Burkina Faso and Niger continue to be among the countries with high malaria burdens. Cabo Verde is on target for malaria free status by 2020. The Gambia, Mauritania and Senegal are reorienting their national malaria program towards malaria elimination. A benefit of this epidemiological and programmatic diversity is that countries can learn important lessons from each other.

The SaME Initiative will use the following main approaches to accelerate the combined efforts towards the attainment of malaria elimination in the sub-region:3

  • Regional coordination
  • Advocacy to keep malaria elimination high on the development and political agenda
  • Sustainable financing mechanisms
  • Cross-border collaboration and ensuring accountability
  • Fast-track the introduction of innovative and progressive technologies
  • Re-enforcing the Regional regulatory mechanism for quality of malaria commodities and introduction of new tools.
  • Establish malaria observatory, regional surveillance, and best practice sharing

Collaboration across borders on vector control is an example of needed regional coordination. According to Thomson et al., climate variations have the potential to significantly impact vector-borne disease dynamics at multiple space and time scales. Another challenge to vector control in the region is the issue of how mosquitoes repopulate areas after an extended dry season. Huestis et al. examined the response of Anopheles coluzzii and Anopheles gambiae to environmental cues in season change in the Sahel.

Seasonal Malaria Chemoprevention Round 3 of 2018 in Burkina Faso

In addition to a history of cooperation, Sahelian countries share a unique malaria intervention, Seasonal Malaria Chemoprevention (SMC) that as the name implies, built on the reality of highly seasonal transmission in the region. SMC grew out of over five years of research in several African settings to test the effect of what was originally termed Intermittent Preventive Treatment for Infants (and later children) or IPTi.

Like IPT for pregnant women, SMC would be given monthly for at least 3-4 months, but unlike IPTp, SMC would consist of a combination two medicines, amodiaquine plus sulfadoxine-pyrimethamine (AQ+SP), which required a three daily doses (SP alone as used in IPTp consists on one dose). SMC could not therefore, be delivered effectively as a clinic-based intervention, but “should be integrated into existing programmes, such as Community Case Management and other Community Health Workers schemes.” Access to SMC by pre-school aged children as delivered by CHWs was found to be more equitable than sleeping under an LLIN. SMC has been recommended for school-age children, a neglected group that bears a substantial burden of malaria.

Closely linked to surveillance is modeling the spatial and temporal variability of climate parameters, which is crucial to tackling malaria in the Sahel. This requires reliable observations of malaria outbreaks over a long time period. To date efforts are mainly linked to climate variables such as rainfall and temperature as well as specific landscape characteristics. Other environmental and socio-economic factors that are not included in this mechanistic malaria model.

The Sahel Malaria Elimination initiative offers a unique collaborative opportunity for countries to improve on the quality of proven interventions like SMC and test and take to scale new strategies like school-based malaria programs. Regional coordination can produce better, timelier and longer-term surveillance and better understanding of and actions against malaria vectors. Readers will surely be anticipating the publishing of the regular progress malaria elimination scorecards as promised by SaME leadership.

Advocacy &Borders &Children &Conflict &Costs &Epidemiology &Funding &Human Resources &Leadership &Monitoring &Mortality &NTDs &Partnership &Surveillance Bill Brieger | 03 Feb 2018

African Leaders Malaria Alliance Recognizes Country Achievements, Adds NTDs to its Scorecard

The 30th African Union (AU) Heads of State Summit at its headquarters in Addis Ababa, Ethiopia provided an important opportunity to bring the challenges of infectious diseases on the continent to the forefront. Led by the African Leaders Malaria Alliance (ALMA), two major activities occurred, raising greater awareness and commitment to fighting neglected tropical diseases (NTDs) and recognizing the contributions countries have made in the fight against malaria.

For many years ALMA has maintained Scorecard for Accountability and Action by monitoring country progress on key malaria interventions. It later added key maternal and child health indicators.  At the AU Summit ALMA announced that NTD indicators would be added to the scorecards which are reported by country and in summary.

The scorecard will now “report progress for the 47 NTD-affected countries in sub-Saharan Africa in their strategies to treat and prevent the five most common NTDs: lymphatic filariasis, onchocerciasis, schistosomiasis, soil-transmitted helminths and trachoma. By adding NTDs to the scorecard, African leaders are making a public commitment to hold themselves accountable for progress on these diseases.”

In the press release Joy Phumaphi, Executive Secretary ofALMA, explained that, “Malaria and NTDs both lay their heaviest burden on the poor, rural and marginalised. They also share solutions, from vector control to community-based treatment. Adding NTDs to our scorecard will help give leaders the information they need to end the cycle of poverty and reach everyone, everywhere with needed health care.” This will be an opportunity to demonstrate, for example, that, “In 2016, 40 million more people were reached with preventive treatment for at least one NTD than the year before.”

The combination is based on the logic that NTDs and malaria are both diseases of poverty. Malaria and several NTDs are also vector-borne. Also community platforms are a foundation for delivering needed drugs and supplies to tackle these diseases. Ultimately the decision shows that Heads of State are holding themselves accountable for progress in eliminating these diseases.

At a malaria-focused side meeting of the AU Summit Dr. Kebede Worku (Ethiopia’s State Minister of Health) shared that his government has been mobilizing large amount of resources to the fight against malaria which has led to the shrinking of morbidity and mortality since 2005. He also stressed that Africans should be committed to eliminate malaria by the year 2030. “Failing to do so is to repeat the great failure of 1960s faced at the global malaria fighting.”

The highlight for the malaria community at the Summit was the recognition of six countries that have made exemplary progress in the past year. The 6 countries that are leading the way to a Malaria-Free Africa by 2030 are Algeria, Comoros, Madagascar, the Gambia, Senegal, and Zimbabwe, recognized by ALMA for their sharp decline in malaria cases. Madagascar, the Gambia, Senegal and Zimbabwe Reduced malaria cases by more than 20 percent from 2015 to 2016. Algeria and Comoros are on track to achieve a more than 40 percent drop in cases by 2020.

H.E . Dr. Barnabas Sibusiso Dlamini, the Prime Minister of the Kingdom of Swaziland, whose King and Head of State is the current chair of ALMA, warned all endemic countries that, “When we take our eyes off malaria, the cost for our countries is huge. Yet if we increase our efforts to control and eventually eliminate malaria, the yield we get from it is tremendous. It is time that we dig deep into our pockets and provide malaria programmes with the needed resources.”

Mentioning the need for resources raises a flag that calls on us to be a bit more circumspect about progress. IRINNews notes that this is a critical time in the fight against malaria, when threatened funding cuts could tip the balance in an already precarious struggle. IRIN takes the example of Zambia to raise caution. They report that the results of malaria control and the government efforts have been uneven. While parasite prevalence among small children is down almost by half in some areas, many parts of the country have seen increases in prevalence

IRIN concludes that, “For now, the biggest challenge for Zambia will be closing the gap in its malaria elimination strategy, which will cost around $160 million a year and is currently only about 50 percent funded – two thirds from international donors and one third from the Zambian government. Privately, international donors say the government must spend more money on its malaria programme if it is to succeed.” Cross-border transmission adds to the problem.

Internal strife is another challenge to malaria success. “The recent nurses’ strike which lasted for five months may have cost Kenya a continental award in reducing the prevalence of malaria during the 30th African Union Summit in Ethiopia on Sunday.” John Muchangi in the Star also noted that, “However, Kenya lost momentum last year and a major malaria outbreak during the prolonged nurses’ strike killed more than 30 people within two weeks in October.”

Finally changes in epidemiology threaten efforts to eliminate malaria in Africa. Nkumana, et al. explain that, “Although the burden of Plasmodium falciparum malaria is gradually declining in many parts of Africa, it is characterized by spatial and temporal variability that presents new and evolving challenges for malaria control programs. Reductions in the malaria burden need to be sustained in the face of changing epidemiology whilst simultaneously tackling significant pockets of sustained or increasing transmission. Many countries like Zambia thus face both a financial and an epidemiological challenge.

Fortunately ALMA is equipped with the monitoring and advocacy tools to ensure that its members recognize and respond to such challenges. The Scorecards will keep the fight against the infectious diseases of poverty on track.

Borders &Mapping Bill Brieger | 01 Oct 2015

High Resolution Malaria Risk Mapping in Mutasa District, Zimbabwe: Implications for Regaining Control

Mufaro Kanyangarara and her PhD thesis adviser, Luke Mullany of the Johns Hopkins Bloomberg School of Public Health Department of International Health, have been looking into the challenges of controlling and evCategorical maps of predicted household malaria risk and uncertaintyentually eliminating malaria in a multi-country context in southern Africa. We are sharing abstracts from her pioneering work including the following which explores high resolution risk mapping in Zimbabwe near the Mozambique border.

Background: In Zimbabwe, more than half of malaria cases are concentrated in Manicaland province, where malaria continues to rebound despite intensified control strategies. The objectives of this study were to develop a prediction model based on high-resolution environmental risk factors and obtain seasonal malaria risk maps for Mutasa District, one of the worst affected districts in Manicaland Province.

Methods: Household RDT status was obtained from ongoing community-based surveys in Mutasa District from October 2012 through April 2015. While environmental variables were extracted from remote sensing data sources and linked to household RDT status. Logistic regression was used to model the probability of household positivity as a function of the environmental covariates. Model prediction performance and overall model fit were examined. Model predictions and prediction standard errors were generated and inverse distance weighting was used to generate smoothed maps of malaria risk and prediction uncertainty by season.

Results: Between October 2012 and April 2015, 398 households participated in the household surveys. Ninety-six individuals representing 66 households tested RDT positive. Household malaria risk was significantly higher among households sampled during the rainy season and further from the Mozambique border, while malaria risk was lower in sparsely populated areas as well as households located at higher elevations during the rainy season. The resulting maps predicted elevated risk during the rainy season particularly in low-lying areas bordering with Mozambique. In contrast, the risk of malaria was low across the study area during the dry season with foci of malaria scattered along the northern, western and south-eastern peripheries of the study area.

Conclusion: This study provides evidence for the significant heterogeneity of malaria, which was strongly linked to elevation, house density and proximity to the Mozambique border. These findings underscore the need for strong cross-border malaria control initiatives to complement country specific interventions.

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