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Archive for "Elimination"



Climate &Ecosystems &Elimination &Environment &Equity &Gender &Genetics &Monitoring &Mosquitoes &Research &Surveillance Bill Brieger | 25 Apr 2024

Drought, Malaria, and Climate Equity

The 2024 World Malaria Day Theme of “Gender, Health Equity, and Human Rights” cannot be divorced from the inequities of climate change wherein the countries that contribute the least to the problem suffer the most, including the deleterious effects of changing malaria geographics. The current severe drought in Zambia, Zimbabwe, and Malawi is a case in point.

As a recent headline in VOA news states, “UN officials in Zambia to assess worst drought in 20 years.” The government has declared a drought officially where it “has affected a total of 8 provinces across the country with highest impacts in Southern, Central, Eastern, North-western, Western, and Lusaka Provinces.”

Drought should not be confused with a “normal” dry season. What we are seeing in Southern Africa now is an extended dry period in what should have been the rainy season. A study in Mali suggests that adult malaria-carrying mosquitoes “have endured the dry season by aestivating—the hot-weather equivalent of hibernating.” Unfortunately, an extended dry period of a drought may be more difficult to endure for the adults, but possibly the eggs are more resistant. Additional studies paint a more complicated picture.

Weather cycles intensify with climate change. El Niño, which can lead to droughts also produces warming in higher elevations so there tends to be an increase in malaria transmission in areas in the highlands.

Research in Zambia published just two years ago reported increasing trends of malaria in areas covering over 47% of all health facilities, while a declining trend was seen in areas covering 27% of health facilities. The decreasing trend was noticeable in the south, where malaria risk is lowest, and current drought conditions higher. The authors stress the need for continued geographic surveillance and implementation of control strategies geared to the conditions in each area.

A systematic review of the effects of climate change identified “vector borne disease (including malaria, dengue and West Nile Virus)” as a major concern as well as “nutrition-related effects (including general malnutrition and mortality, micronutrient malnutrition, and anti-nutrient consumption),” which compromises the ability of children to fight disease. The review found different impacts of drought ranging from increase mortality a year after a drought, to the disappearance of some vector species. The lesson is that each country needs to monitor their situation carefully. For Zambia, UNICEF reports that, “significant number are children, at risk of food insecurity, acute malnutrition, and disease.”

Research on drought effects on malaria arose from a study that examined the effects of drought on malaria infection (genetic) complexity and transmission in lizards (Plasmodium mexicanum and Sceloporus occidentalis). The authors noted that, “relationship between rainfall and parasite prevalence is somewhat more ambiguous.” Thus, the authors recommended that more information is needed about human malaria parasites and drought since “drought may cause shifts in human disease outcomes independent of any changes to prevalence.”

The United Nations challenges us by observing that, “Due to the complex relationship between malaria and climate change, gaps in knowledge still exist in the mechanisms of the linkage.” Changes in temperature, rainfall, and humidity need to be monitored for effects on vectors, parasites, and human movement. The current situation requires a more nuanced and complex approach to interventions if malaria elimination can be achieved while also preventing gender discrimination, promoting health equity and preserving human rights.

Dracunculiasis Guinea Worm &Elimination &Eradication Bill Brieger | 27 Feb 2024

Guinea Worm Is Still with Us in 2024

Almost 40 years ago efforts got underway to eradicate another human infectious disease from the face of the earth. Smallpox eradication. Defined as the total elimination of the disease from every country, had been successful, facilitated by the basic technology of an effective vaccine. There were difficult times with the organization and management aspects of smallpox eradication, but the organizers of the campaign were able and willing to adapt their strategies as they learned more about the epidemiological, social, and cultural aspects of the disease.

Praise has been given to guinea worm efforts because of the start contrast between 3.5 million cases in the mid-1980s to only 13 so far verified in 2024. Interestingly, progress has been inching, as one author put it, toward zero for at least 10 years, long after the earlier target date of 1995. Clearly a disease that was theoretically “simple” to eliminate through the provision of clear, safe water supplies, was not so simple after all.

Despite his recent health and family challenges President Jimmy Carter has never waivered from his support to eradicate guinea worm as reported by CNN.  The Carter Center’s 2023 report showed a remarkable reduction in Guinea worm cases, bringing the ancient parasitic disease closer to being eradicated.  Alix Boisson-Walsh provides details in a Lancet Infectious article entitled “Diseases Guinea worm disease inched closer to eradication in 2023.”  The Carter Center shared these highlights for 2023:

  • Eradication of Guinea worm disease remains in sight with only 13 provisional human cases reported worldwide in 2023.
  • The Carter Center announced Thursday. The number matches the lowest annual total of human cases ever reported, following 13 cases in 2022 and 15 in 2021.
  • When The Carter Center assumed leadership of the global Guinea Worm Eradication Program in 1986, an estimated 3.5 million human cases occurred annually in 21 countries in Africa and Asia.
  • The grisly parasitic disease has been reduced by 99.99% since eradication efforts began and is poised to become the second human disease and the first parasitic disease eradicated in history.
  • Reports of animal infections slightly increased due to expanded surveillance in Angola and Cameroon.
  • All figures for humans and animals are provisional until officially confirmed, typically in March. Guinea worm is poised to become the second human disease in history to be eradicated, following smallpox, as well as the first parasitic disease and the first without a medicine or vaccine. Community-based and innovative behavioral change and local mobilization are the key drivers of success.

Building on seven World Health Assembly resolutions and hosted by The Carter Center, Reaching the Last Mile, the UAE, and the WHO, representatives of impacted countries (Angola, Chad, Ethiopia, Mali, South Sudan, Sudan, Democratic Republic of the Congo, and Cameroon) and organizations renewed their commitment to eradicating the debilitating disease by 2030 by signing the Abu Dhabi Declaration on the Eradication of Guinea Worm Disease, in 2022 and pledged to commit resources, energy, and policy initiatives to eradicate Guinea worm disease.

Four decades of disease eradication work may seem like a long time, but like smallpox, guinea worm has been around for millennia. CDC notes that, “In 1959, the World Health Organization (WHO) started a plan to rid the world of smallpox,” and “the 33rd World Health Assembly declared the world free of this disease on May 8, 1980.”

Malaria eradication efforts started, stalled and resumed beginning with the National Malaria Eradication Program in the USA on July 1, 1947. Subsequently, “the World Health Organization (WHO) submitted at the World Health Assembly in 1955 an ambitious proposal for the eradication of malaria worldwide.” We are still aiming for 2030 and beyond to rid the world of malaria country-by-country.

In 1998 Walter R. Dowdle outlined three indicators that were considered to be of primary importance in eradicating a disease. These included “an effective intervention is available to interrupt transmission of the agent, practical diagnostic tools with sufficient sensitivity and specificity are available to detect levels of infection that can lead to transmission, and humans are essential for the life-cycle of the agent, which has no other vertebrate reservoir and does not amplify in the environment.” In 2000, Aylward and colleagues also posed three criteria including “(1) biological and technical feasibility, (2) costs and benefits, and (3) societal and political considerations.”  Andrews and Langmuir post the awkward reality that “If … the decline in new cases is halted by circumstances which slow it down to a fluctuating equilibrium at some point approaching but not quite reaching zero, the disease may be declared administratively to be under control, though it is certainly not eliminated.”

The persistence of low-level human transmission of guinea worm may appear encouraging when compared to he initial estimate of 3.5 million infections, but we hope that the political and social commitment will persist so that the dwindling cases will eventually reach zero. Additional effort is needed now that one of Dowdle’s criteria has been breached, another vertebrate reservoir (domestic dogs, cats and others who share unsafe water sources with humans). The costs and benefits can be questioned as eradication is drawn out over time. Guinea worm has always epitomized the concept of NTDs wherein not just the disease but the people who suffer from it are neglected. Eradication will only come when that neglect stops.

Elimination &MDA &NTDs &poverty &Schistosomiasis &Trachoma &Vector Control Bill Brieger | 13 Jun 2023

Eliminating NTDs as a Public Health Problem May Not Be Enough

The concept and goal of eliminating a disease appears simple on the surface, but complications ensue when the words “as a public health problem” are added.  We know that the distinction exists between eradication and elimination with the former being globally and the latter being nationally or regionally. The sum total action of eliminating a disease from all endemic countries therefore results in total global eradication.

The challenge comes when we try to qualify the concept of elimination. The US CDC defined elimination of disease as, “Reduction to zero of the incidence of a specified disease in a defined geographical area as a result of deliberate efforts; continued intervention measures are required.” Thus, there is no more transmission.  Following from this eradication is defined as, “Permanent reduction to zero of the worldwide incidence of infection caused by a specific agent as a result of deliberate efforts; intervention measures are no longer needed.” Penn Medicine summarized this as, “Elimination means stopping the transmission of a disease in a specific geographic area or country, but not worldwide. Elimination is a crucial step in the path toward eradication, requiring constant monitoring and interventions to keep serious diseases at bay.”

The foregoing definitions seem straightforward, but what does elimination as a public health problem or a disease of public health concern mean? The World Health Organization recently “congratulate(d) Benin and Mali for eliminating trachoma as a public health problem. Concerning another neglected tropical disease (NTD), lymphatic filariasis (LF), global control programs are aiming “to reduce the prevalence of infection below target thresholds and to alleviate the suffering of people affected by lymphoedema and hydrocele.” Wiegand and colleagues in The Lancet Global Health note that, “For schistosomiasis, the criterion for elimination as a public health problem (EPHP) is defined as less than 1% prevalence of heavy-intensity infections (ie, ?50 Schistosoma haematobium eggs per 10 mL of urine or ?400 Schistosoma mansoni eggs per g of stool).” They take issue with the fact that such definitions mean that morbidity still exists, though at very levels, so elimination of transmission has not really occurred for any of these NTDs.

Because the social, environmental, and behavioral conditions that favor transmission may still exists, one cannot guarantee that incidence such diseases may not increase again. All three diseases, LF, Schistosomiasis, and Trachoma have been tackled primarily through preventive chemotherapy, is simply put, using mass drug administration (MDA) over a period of years until active surveillance determines that “infection (is) below target thresholds.” Trachoma does have its SAFE strategy which includes water, sanitation and hygiene interventions, but drugs can reduce the disease without long term achievements in such activities have become sustainable.

Prada et al. in the Journal of Infectious Diseases warn that there can be resurgence of a disease that was documented to be eliminated as a public health problem. They explain that the transmission assessment survey held after several MDA rounds for LF may not be enough to guarantee that low levels of transmission and eventual elimination are achieved. They conclude that, “The risk of resurgence after achieving current targets is low and is hard to predict using just current prevalence. Although resurgence is often quick (<5 years), it can still occur outside of the currently recommended post-intervention surveillance period of 4–6 years,” and recommend monitoring beyond this period.

Toor and co-researchers suggest for NTD programs that, “as case numbers drop and elimination comes into prospect, transmission reduction through other interventions, such as vector control and sanitation, becomes crucial in reducing the probability and speed of resurgence, particularly when MDA or screening programs are halted. Surveillance activities for detecting elimination and resurgence become increasingly important to ensure that successes are maintained.”

Ultimately, unless the context of NTD transmission is addressed, elimination will be an elusive goal. Therefore, as WHO advocated on the recent World NTD Day, “Everybody, including leaders and communities, to confront the inequalities that drive NTDs and to make bold, sustainable investments to free the world’s most vulnerable communities affected by NTDs from a vicious cycle of disease and poverty.”

Elimination &Health Systems &NTDs &Polio &Surveillance &Trachoma Bill Brieger | 29 May 2022

When is Disease Elimination not Elimination?

A May 28th press release from the World Health Organization states that, “Togo eliminates trachoma as a public health problem.” The article explains that …

Validation of trachoma elimination as a public health problem in Togo was based on evidence. Several population-based trachoma surveys were conducted starting from 2006 to 2017. The 2017 survey using WHO recommended methodology found that the prevalence of key indicators was below the WHO trachoma elimination threshold. There was also evidence that Togo’s health system is able to identify and treat new cases of late complications of trachoma.

This raises the question, is Trachoma gone from Togo or does trachoma continue to exist at some low level whereby, as WHO notes, Togo has joined, “12 other countries that have been validated by WHO for having eliminated trachoma as a public health problem.”

This description of disease elimination contrasts sharply with the global concerns when “health authorities in Malawi have declared an outbreak of wild poliovirus type 1 after a case was detected in a young child in the capital Lilongwe. This is the first case of wild poliovirus in Africa in more than five years.” Wild polio virus had been declared eliminated in Africa, and just one case in one country grabs international attention.

Would one case of trachoma tomorrow receive the same concern in Togo? Apparently not according to the WHO definition, “Elimination of trachoma as a public health problem is defined as: (i) a prevalence of trachomatous trichiasis (TT) “unknown to the health system” of < 1 case per 1000 total population; and (ii) a prevalence of trachomatous inflammation-follicular (TF) in children aged 1–9 years of < 5%, in each formerly endemic district.”

So, while no cases of smallpox, guinea worm or polio would be tolerated after elimination has been declared, parents of a child who develops trachoma in Togo tomorrow would be told that your child’s case is only 1 in a 1000 and not of concern to public health. The caveat is though that “the health system (must be) able to identify and manage incident TT cases.” Presumably, if such management capacity does not exist, the disease in question could spread and elimination would be eliminated.

Another Neglected Tropical Disease, Lymphatic Filariasis, faces the same challenge in terms of elimination status. WHO explained in its guidance that, “In 1997, the 50th World Health Assembly resolved to eliminate LF as a public-health problem (resolution WHA50.29). In response, WHO proposed a comprehensive strategy for achieving the elimination goal that included interrupting transmission in endemic communities and implementing interventions to prevent and manage LF-associated disabilities The LF guidance stresses “Effective monitoring, epidemiological assessment and evaluation are necessary to achieve the aim of interrupting LF transmission,” or in a word Surveillance. There is clear concern for “absence of transmission” and worries about “recrudescence.”

While polio has a vaccine and guinea worm relies on providing safe community water, LF and Trachoma elimination depends on mass drug administration (MDA) at planned intervals until such time as transmission is reduced. All require a strong health system to implement, but the challenges of maintaining MDAs until such time as elimination has been validated is somewhat more challenging. In this context the communication is extremely important. Just because WHO validates the elimination of a disease as a public health problem, does not give policy makers license to ignore that disease. Advocacy is continually needed such that even after apparent elimination, neglected diseases will not be forgotten and health systems themselves not neglected.

Agriculture &Children &Climate &Coordination &Development &Elimination &Environment &Epidemiology &Food Security Bill Brieger | 15 Apr 2022

Malaria elimination challenges around the world

In the past week, news has featured challenges to malaria elimination around the globe. Starting in Papua New Guinea which accounted for accounted for 86% of all cases in the Western Pacific Region in 2020. While there are 39% fewer cases in the region since 2000, there was an increase of 300,000 cases between 2019 and 2020. It is mainly in the six countries of the Greater Mekong subregion where progress has been steady.

Moving east to the Brazilian Amazon, one finds wildcat gold mining operations are not only destroying Native American ecosystems but are carving huge holes in the earth which are perfect breeding conditions for mosquitoes. This means that malaria cases among the Yanomami indigenous people living in the Brazilian Amazon have increased by more than 12 times since 2014.

Also within South America, one finds that although Paraguay was certified by the World Health Organization (WHO) as free of local transmission of malaria in 2018, experts are warning that travelers entering the country from areas with malaria transmission could easily reintroduce the disease. Hence vigilance is urged.

Crossing next to sub-Saharan Africa, one reads of studies showing an increasing link between malaria and agriculture across the region. As population expands in the region, more food, water and agricultural commodities are required. Irrigation and deforestation to clear land for agriculture increase the risk of childhood malaria in sub-Saharan Africa. The experts recommend that African ministries of agriculture, health, and environment need to collaborate on safer development policies and practices, not only to curb malaria, but the devastating effects of climate change.

Finally continuing back to Asia, one finds what might be termed an epidemiological conflict between Nepal, which is nearing malaria elimination for 2025, and its southern neighbor India, which is a source of imported malaria. Although the number of indigenous cases is nearing zero, health authorities fear that imported cases of of malaria from India are so high that local transmission could be reignited.

Malaria is clearly a global health problem. Collaboration and coordination across continents is needed to eliminate the scourge.

Elimination &Monkeys &Zoonoses Bill Brieger | 09 Jan 2022

Humans, Monkeys, and Malaria in Costa Rica: Implications for Elimination

A just-published article by Andrea Chaves and colleagues entitled, “Presence and potential distribution of malaria-infected New World primates of Costa Rica”, Specifically their results state that, “PCR analysis for the Plasmodium presence was conducted in 384 samples of four primates …

  • Howler monkey [n?=?130]
  • White-face monkey [n?=?132]
  • Squirrel monkey [n?=?50]
  • red spider monkey [n?=?72]),

… from across Costa Rica. Three Plasmodium species were detected in all primate species (P. falciparum, P. malariae/P. brasilianum, and P. vivax). Overall, the infection prevalence was 8.9%, but each Plasmodium species ranged 2.1–3.4%. The niche model approach showed that the Pacific and the Atlantic coastal regions of Costa Rica presented suitable climatic conditions for parasite infections. However, the central pacific coast has a more trustable prediction for malaria in primates.”

Last year, Tobias Mourier et al. reported another human/non-human primate connection in Brazil. According to them, “Analysis of the P. simium genome confirmed a close phylogenetic relationship between P. simium and P. vivax, and suggests a very recent American origin for P. simium. The presence of the DBP1 deletion in all human-derived isolates tested suggests that this deletion, in combination with other genetic changes in P. simium, may facilitate the invasion of human red blood cells and may explain, at least in part, the basis of the recent zoonotic infections.

The connection between human and primate malaria also flows toward humans as traditional human plasmodium infections decrease in prevalence in Malaysia. Lai are co-researchers explain that, “The incidence of zoonotic malaria Plasmodium knowlesi infection is increasing and now has been the major cause of malaria in Malaysia.”

In fact, the 2021 World Malaria Report noted that, “Malaysia had no cases of human malaria for 3 consecutive years, but in 2020 reported 2607 cases of P. knowlesi, a zoonotic malaria.” The report does not specify efforts to handle this issue.

These studies raise a continuing question about the feasibility of eliminating malaria in countries when those plasmodium species that infect humans also infect other primates and vice versa. As we have noted before, monkeys do not use bednets. As long as primate Plasmodium reservoirs exist, our ability to eliminate the disease will remain elusive.

Elimination &Vaccine Bill Brieger | 23 Aug 2021

Malaria Vaccine Approval Nearing

Over the coming three days the Malaria Vaccine Implementation Programme (MVIP) Advisory Group in its capacity as SAGE/MPAG Working Group will conduct a full evidence review of the RTS,S/AS01 malaria vaccine and develop proposed recommendations for Strategic Advisory Group of Experts (SAGE) on Immunization and MPAG. This comes on the heels of the recent 74th World Health Assembly Resolution that, “Urges Member States to step up the pace of progress through plans and approaches that are consistent with WHO’s updated global malaria strategy and the WHO Guidelines for malaria. It calls on countries to extend investment in and support for health services, ensuring no one is left behind; sustain and scale up sufficient funding for the global malaria response; and boost investment in the research and development of new tools.”

The large scale pilot intervention of the RTS,S/AS01 malaria vaccine started two years ago in selected districts in three countries countries: Ghana, Kenya and Malawi.  For example, “Two years on from the launch of a pilot programme, more than 1.7 million doses of the world’s first malaria vaccine have been administered in Ghana, benefitting more than 650,000 children with additional malaria protection.” WHO says that, “Insights generated by the pilot implementation will inform a WHO recommendation on broader use of the vaccine across sub-Saharan Africa,” which will then be considered by global advisory bodies for immunization and malaria, i.e. the SAGE and MPAG.

WHO is asking the Working Group to address the following question, “Does the additional evidence on the feasibility, safety and impact of the RTS,S/AS01 vaccine support a WHO recommendation for use of the vaccine in children in sub-Saharan Africa beyond the current pilot implementation?” WHO has set the following meeting objectives:

  1. To examine and provide input to the Grading of Recommendations Assessment, Development and Evaluation (GRADE) evidence profiles of the quality of the evidence used to inform the recommendations;
  2. To review and interpret the evidence, with explicit consideration of the overall balance of benefits and harms;
  3. To formulate recommendations – in alignment with the endorsed 2019 RTS,S Framework for Decision – taking into account benefits, harms, values and preferences, feasibility, equity, acceptability, resource requirements and other factors, as appropriate.

Hopefully decisions will be forthcoming soon so that planning can get underway to address immunization as part of the overall malaria elimination effort.

Capacity Building &CHW &Community &Elimination &Health Education &Indoor Residual Spraying &IPTp &ITNs &Malaria in Pregnancy &World Malaria Day &Zero Malaria Bill Brieger | 25 Apr 2021

Twenty Years of Malaria Day Observances: Jhpiego at the Forefront

In 2001 the first Africa Malaria Day (AMD) was observed. The opportunity to mark progress and exhort increased efforts for the continent continued through 2007. Then in 2008, the concept of World Malaria Day (WMD) took over, though it could not be denied that the bulk of malaria morbidity, mortality and intervention still was focused on African countries. Other countries have made progress such as the recent certification of malaria elimination in Argentina and El Salvador, but twenty years after the first AMD/WMD, Africa is still leading the way for creative, sustained intervention against the disease, despite threats to resources from economic downturns and new pandemic diseases.

Below we go straight to Africa to share activities and observances of WMD 2021 from Jhpiego’s African Malaria Technical Officers. After reading through, please watch “Jhpiego Leaves No One Behind | World Malaria Day, 2021″ on YouTube.

“Saramed” from Guinea reports that Guinea, like other countries in the world, celebrates World Malaria Day under the theme: ” Zero Malaria, Draw a Line on Malaria “. We are currently conducting the following activities:

  • Lectures and debates on malaria in medical faculties and health schools;
  • Animation of debate programs on malaria in public and private radios and televisions of the country,
  • Advocacy and sensitization of religious and other influential people
  • Carrying out a package of activities (administration of IPT to pregnant women who have missed their ANC appointment, community distribution of LLINs, screening and treatment of confirmed cases, awareness raising on malaria) in high incidence localities.

These activities is in line with the WHO approach of “high burden, high impact”.

Noella Umulisa reports that the WMD celebration took place in Eastern Province, in Bugesera district in the Mareba sector. Due to COVID-19 pandemic ,only 100 persons were invited to the event.This year’s the national theme is “Zero Malaria starts with me”.

Key activities during the event included …

  • Visit of breeding sites under sentinel surveillance
  • Visit of indoor residual spraying (IRS) sites
  • Launching of the Awareness of the population using drones on the ongoing IRS campaign in this time of COVID-19
  • Song by CHWs
  • Certificate to Integrated Vector Management (IVM) Training of Trainers who will train others up to village level
  • Speech of the Director General ,the guest of honor.

From Burkina Faso, Yousseff Sawadogo and Moumouni Bonkoungou shared photos of the celebration that featured a giant Insecticide-Treated  Net, a speech by the US Ambassador, a malaria song composed by a nurse, an official speech by the President of the National Assembly, and national recognition given to one of the current Jhpiego staff members, Thiery Ouedraogo, who at one time also served as director of the national malaria control program. He was decorated by the country’s authorities as a knight of the order of merit.

Bright Orgi from Jhpiego’s TiPToP malaria in pregnancy project in Nigeria ?? shared photos from a series of compound meetings in the community to mark WMD 2021. The meetings focused on malaria prevention and treatment. Provided opportunities to rural communities to ask questions on malaria issues. Here we can see that observance of WMD must be taken to the people who actually suffer from malaria and need to be actively involved in its solution. Deo Cibinda from the Democratic Republic of the Congo share photos of a national celebration, seen to the left.

Finally, As Kristen Vibbert noted, “These are such amazing World Malaria Day stories. I’m so heartened to see all of these great country efforts to remind everyone of how the fight against malaria must continue despite the Covid-19 pandemic.”  Charles Wanga tweeted, “We know how to defeat #malaria. But that’s not enough. We must do more to save pregnant women and children from the deadly scourge. This #WorldMalariaDay and everyday, because@Jhpiego leaves no one behind in our fight to #EndMalaria for good in Africa, and everywhere”

Anemia &Diagnosis &Elimination &Epidemiology &Genetics &Integrated Vector Management &IPTp &Malaria in Pregnancy &Plasmodium knowlesi Bill Brieger | 26 Oct 2020

Malaria News Today 2020-10-26: Haiti, India, Malaysia, Cape Verde

Recent news and abstracts explore malaria on three continents. Genetic aspects of malaria are studied in Haiti as well in Malaysia. Use of fish to control malaria carrying mosquitoes are successful in India. The movement toward malaria elimination is examined in Cape Verde. Finally, Non-invasive diagnostic tests are recognized/rewarded by NIH. Read more by following the links below.

NIH Awards Prize to Hemex Health’s Non-Invasive Sickle Cell, Malaria, Anemia Rapid Test (“SMART”) Diagnostic Technology

Researchers from Hemex Health, Medtronic plc, Case Western Reserve University, and the University of Nebraska Medical Center’s International Foundation Against Infectious Disease in Nigeria (IFAIN) were awarded 3rd place and $100,000 in the NIH Technology Accelerator Challenge.  Code named, SMART (Sickle, Malaria, Anemia, Rapid Test), the system includes non-invasive diagnostics for sickle cell, malaria, and anemia. The project seeks to build on Hemex Health’s Gazelle® platform, which currently includes minimally invasive tests (using a drop of blood) for malaria, the detection and quantification of hemoglobin variants, as well as for total hemoglobin for anemia determination.

The non-invasive test will screen for anemia, malaria, and sickle cell disease using an optical finger sensor similar to the way blood oxygen is measured. An advantage of combining the non-invasive and minimally invasive diagnostics is, when needed, more diagnostic information and confirmation is available on the same platform. The goal is a one-minute, $0.25 non-invasive malaria, sickle cell, and anemia test. “The world desperately needs easy-to-use diagnostic technologies with the flexibility needed to meet viruses and diseases in every corner of the planet,” said Ms. White.

Controlling Mosquitoes: Ramanathapuram district inches closer to malaria-free status

Steps taken by the Ramanathapuram district administration to control mosquito breeding for the last five years has enableed the district inch closer to being declared a ‘malaria-free district, with only one malarial fever case having been reported till September, this year. Last year, the district reported 43 cases.

One of the initiatives is to bring guppy fish from the Ayyankulam tank in Tiruvannamalai district and let them into all wells and tanks of the districts in 3:1 ratio (3 familes/one male). The fish thrives, eating the mosquito larvae and eggs and the incidence of malaria came down in the district.

Updates on malaria epidemiology and profile in Cabo Verde from 2010 to 2019: the goal of elimination

Located in West Africa, Cabo Verde is an archipelago consisting of nine inhabited islands. Malaria has been endemic since the settlement of the islands during the sixteenth century and is poised to achieve malaria elimination in January 2021. The aim of this research is to characterize the trends in malaria cases from 2010 to 2019 in Cabo Verde as the country transitions from endemic transmission to elimination and prevention of reintroduction phases. All confirmed malaria cases reported to the Ministry of Health between 2010 and 2019 were extracted from the passive malaria surveillance system.

A total of 814 incident malaria cases were reported in the country between 2010 and 2019, the majority of which were Plasmodium falciparum. Cabo Verde has made substantial gains in reducing malaria burden in the country over the past decade and are poised to achieve elimination in 2021. However, the high mobility between the islands and continental Africa, where malaria is still highly endemic, means there is a constant risk of malaria reintroduction. Characterization of imported cases provides useful insight for programme and enables better evidence-based decision-making to ensure malaria elimination can be sustained.

Genetic analysis reveals unique characteristics of Plasmodium falciparum parasite populations in Haiti

With increasing interest in eliminating malaria from the Caribbean region, Haiti is one of the two countries on the island of Hispaniola with continued malaria transmission. While the Haitian population remains at risk for malaria, there are a limited number of cases annually, making conventional epidemiological measures such as case incidence and prevalence of potentially limited value for fine-scale resolution of transmission patterns and trends. In this context, genetic signatures may be useful for the identification and characterization of the Plasmodium falciparum parasite population in order to identify foci of transmission, detect outbreaks, and track parasite movement to potentially inform malaria control and elimination strategies.

This study evaluated the genetic signals based on analysis of 21 single-nucleotide polymorphisms (SNPs) from 462 monogenomic (single-genome) P. falciparum DNA samples extracted from dried blood spots collected from malaria-positive patients reporting to health facilities in three southwestern Haitian departments (Nippes, Grand’Anse, and Sud) in 2016.

437 of the 462 samples shared high levels of genetic similarity–at least 20 of 21 SNPS–with at least one other sample in the dataset. These results revealed patterns of relatedness suggestive of the repeated recombination of a limited number of founding parasite types without significant outcrossing. These genetic signals offer clues to the underlying relatedness of parasite populations and may be useful for the identification of the foci of transmission and tracking of parasite movement in Haiti for malaria elimination.

Epidemiology of malaria among pregnant women during their first antenatal clinic visit in the middle belt of Ghana

A total of 1655 pregnant Ghanaian women aged 18 years and above with a gestational age of 13–22 weeks, who attended an antenatal care (ANC) clinic for the first time, were consented and enrolled into the study. A structured questionnaire was used to collect socio-demographic and obstetric data and information on use of malaria preventive measures. Venous blood (2 mL) was collected before sulfadoxine-pyrimethamine administration. Malaria parasitaemia and haemoglobin concentration were determined using microscopy and an automated haematology analyser, respectively.

One out of five pregnant women attending their first ANC clinic visit in an area of perennial malaria transmission in the middle belt of Ghana had Plasmodium falciparum infection. Age???25 years, multigravid, educated to high school level or above, and in household with higher socio-economic status were associated with a lower risk of malaria parasitaemia. Majority of the infections were below 1000 parasites/µL and with associated anaemia. There is a need to strengthen existing malaria prevention strategies to prevent unfavourable maternal and fetal birth outcomes in this population.

Genetic diversity of circumsporozoite protein in Plasmodium knowlesi isolates from Malaysian Borneo and Peninsular Malaysia

Understanding the genetic diversity of candidate genes for malaria vaccines such as circumsporozoite protein (csp) may enhance the development of vaccines for treating Plasmodium knowlesi. Hence, the aim of this study is to investigate the genetic diversity of non-repeat regions of csp in P. knowlesi from Malaysian Borneo and Peninsular Malaysia.
The phylogenetic analysis revealed indistinguishable clusters of P. knowlesi isolates across different geographic regions, including Malaysian Borneo and Peninsular Malaysia.

The csp non-repeat regions are relatively conserved and there is no distinct cluster of P. knowlesi isolates from Malaysian Borneo and Peninsular Malaysia. Distinctive variation data obtained in the C-terminal non-repeat region of csp could be beneficial for the design and development of vaccines to treat P. knowlesi.

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.

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