Category Archives: Epidemiology

What to Observe on October 12th? Malaria’s Arrival in the Americas

Controversy exists about what historical event should be observed in the USA on 12th October. Ernest Faust explained many years ago that, “there is neither direct nor indirect evidence that the malaria parasites existed on this continent prior to the advent of the European conquerors,” while at the same time in the 16th through 18th Centuries, malaria was common in England, Spain, France, Portugal and other European nations that arrived in the “New World.” Initially, with the first voyage of Columbus the European explorers and settlers brought the disease, primarily Plasmodium vivax, while the slave trade brought P. falciparum.

National Geographic in its May 2007 issue provided the story “Jamestown, The Real Story.” This article reported that, “Colonists carried the plasmodium parasite to Virginia in their blood. Mosquitoes along the Chesapeake were ‘infected’ by the settlers and spread the parasite to other humans.” Thus malaria became one of many imported diseases that decimated the indigenous population. The spread of P. vivax in Jamestown was not surprising since the settlement was “located on marshy ground where mosquitoes flourished during the summer.”

Recent research has shown that the “Analysis of genetic material extracted showed that the American P. falciparum parasite is a close cousin of its African counterpart.” This research has documented two genetic groups in Latin America, related to two distinct slave routes run by the Spanish empire in the North, West Indies, Mexico and Colombia and the Portuguese empire to Brazil. Indigenous and remote rural populations of Bolivia, Colombia, Ecuador, Peru, Venezuela and Brazil remain at risk today.

In the South American continent the  native American population might have brought Melanesian strains of P. vivax before the Europeans arrived, but colonizers brought new strains from both Europe and Africa, as well as P. falciparum. Clearly, human migration has played an important role in malaria parasite dissemination through the Americas.

But back to the North American Continent where the USA is observing the historical implications of 12th October, Mark Blackmore reminds us that, “Anthropological and archeological data provide no indication of mosquito-borne diseases among the indigenous people of North America prior to contact with Europeans and Africans beginning in the fifteenth century” (Wing Beats Volume 25 Winter 2015). The spread of malaria by European colonizers is certainly not something to celebrate today.

The Weekly Tropical Health News 2019-06-29

Below we highlight some of the news we have shared on our Facebook Tropical Health Group page during the past week.

Polio Persists

If all it took to eradicate a disease was a well proven drug, vaccine or technology, we would not be still reporting on polio, measles and guinea worm, to name a few. In the past week Afghanistan reported 2 wild poliovirus type 1 (WPV1) cases, and Pakistan had 3 WPV1 cases. Circulating vaccine-derived poliovirus type 2 (cVDPV2) was reported in Nigeria (1), DRC (4) and Ethiopia (3) from healthy community contacts.

Continued Ebola Challenges

In the seven days from Saturday to Friday (June 28) there were 71 newly confirmed Ebola Cases and 56 deaths reported by the Democratic Republic of Congo’s Ministry of Health. As Ebola cases continue to pile up in the Democratic Republic of the Congo (DRC), with 12 more confirmed Thursday and 7 more Friday, a USAID official said four major donors have jump-started a new strategic plan for coordinating response efforts. To underscore the heavy toll the outbreak has caused, among its 2,284 cases, as noted on the World Health Organization Ebola dashboard today, are 125 infected healthcare workers, including 2 new ones, DRC officials said.

Pacific Standard explained the differences in Ebola outbreaks between DRC today and the West Africa outbreak of 2014-16. On the positive side are new drugs used in organized trials for the current outbreak. The most important factor is safe, effective vaccine that has been tested in 2014-16, but is now a standard intervention in the DRC. While both Liberia and Sierra Leone had health systems and political weaknesses as post-conflict countries, DRC’s North Kivu and Ituri provinces are currently a war zone, effectively so for the past generation. Ebola treatment centers and response teams are being attacked. There are even cultural complications, a refusal to believe that Ebola exists. So even with widespread availability of improved technologies, teams may not be able to reach those in need.

To further complicate matters in the DRC, Doctors Without Borders (MSF) “highlighted ‘unprecedented’ multiple crises in the outbreak region in northeastern DRC. Ebola is coursing through a region that is also seeing the forced migration of thousands of people fleeing regional violence and is dealing with another epidemic. Moussa Ousman, MSF head of mission in the DRC, said, ‘This time we are seeing not only mass displacement due to violence but also a rapidly spreading measles outbreak and an Ebola epidemic that shows no signs of slowing down, all at the same time.’”

NIPAH and Bats

Like Ebola, NIPAH is zoonotic, and also involves bats, but the viruses differ. CDC explains that, “Nipah virus (NiV) is a member of the family Paramyxoviridae, genus Henipavirus. NiV was initially isolated and identified in 1999 during an outbreak of encephalitis and respiratory illness among pig farmers and people with close contact with pigs in Malaysia and Singapore. Its name originated from Sungai Nipah, a village in the Malaysian Peninsula where pig farmers became ill with encephalitis.

A recent human outbreak in southern India has been followed up with a study of local bats. In a report shared by ProMED, out of 36 Pteropus species bats tested for Nipah, 12 (33%) were found to be positive for anti-Nipah bat IgG antibodies. Unlike Ebola there are currently no experimental drugs or vaccines.

Climate Change and Dengue

Climate change is expected to heighten the threat of many neglected tropical diseases, especially arboviral infections. For example, the New York Times reports that increases in the geographical spread of dengue fever. Annually “there are 100 million cases of dengue infections severe enough to cause symptoms, which may include fever, debilitating joint pain and internal bleeding,” and an estimated 10,000 deaths. Dengue is transmitted by Aedes mosquitoes that also spread Zika and chikungunya. A study, published Monday in the journal Nature Microbiology, found that in a warming world there is a strong likelihood for significant expansion of dengue in the southeastern United States, coastal areas of China and Japan, as well as to inland regions of Australia. “Globally, the study estimated that more than two billion additional people could be at risk for dengue in 2080 compared with 2015 under a warming scenario.”

Schistosomiasis – MDA Is Not Enough, and Neither Are Supplementary Interventions

Schistosomiasis is one of the five neglected tropical diseases (NTDs) that are being controlled and potentially eliminated through mass drug administration (MDA) of preventive chemotherapy (PCT), in this case praziquantel. In The Lancet Knopp et al. reported that biannual MDA substantially reduced Schistosomiasis haematobium prevalence and infection intensity but was insufficient to interrupt transmission in Zanzibar. In addition, neither supplementary snail control or behaviour change activities did not significantly boost the effect of MDA. Most MDA programs focus on school aged children, and so other groups in the community who have regular water contact would not be reached. Water and sanitation activities also have limitations. This raises the question about whether control is acceptable for public health, or if there needs to be a broader intervention to reach elimination?

Trachoma on the Way to Elimination

Speaking of elimination, WHO has announced major “sustained progress” on trachoma efforts. “The number of people at risk of trachoma – the world’s leading infectious cause of blindness – has fallen from 1.5 billion in 2002 to just over 142 million in 2019, a reduction of 91%.” Trachoma is another NTD that uses the MDA strategy.

The news about NTDs from Dengue to Schistosomiasis to Trachoma is complicated and demonstrates that putting diseases together in a category does not result in an easy choice of strategies. Do we control or eliminate or simply manage illness? Can our health systems handle the needs for disease elimination? Is the public ready to get on board?

Malaria Updates

And concerning being complicated, malaria this week again shows many facets of challenges ranging from how to recognize and deal with asymptomatic infection to preventing reintroduction of the disease once elimination has been achieved. Several reports this week showed the particular needs for malaria intervention ranging from high burden areas to low transmission verging on elimination to preventing re-introduction in areas declared free from the disease.

In South West, Nigeria Dokunmu et al. studied 535 individuals aged from 6 months were screened during the epidemiological survey evaluating asymptomatic transmission. Parasite prevalence was determined by histidine-rich protein II rapid detection kit (RDT) in healthy individuals. They found that, “malaria parasites were detected by RDT in 204 (38.1%) individuals. Asymptomatic infection was detected in 117 (57.3%) and symptomatic malaria confirmed in 87 individuals (42.6%).

Overall, detectable malaria by RDT was significantly higher in individuals with symptoms (87 of 197/44.2%), than asymptomatic persons (117 of 338/34.6%)., p = 0.02. In a sub-set of 75 isolates, 18(24%) and 14 (18.6%) individuals had Pfmdr1 86Y and 1246Y mutations. Presence of mutations on Pfmdr1 did not differ by group. It would be useful for future study to look at the effect of interventions such as bednet coverage. While Southwest Nigeria is a high burden area, the problem of asymptomatic malaria will become an even bigger challenge as prevalence reduces and elimination is in sight.

Sri Lanka provides a completely different challenge from high burden areas. There has been no local transmission of malaria in Sri Lanka for 6 years following elimination of the disease in 2012. Karunasena et al. report the first case of introduced vivax malaria in the country by diagnosing malaria based on microscopy and rapid diagnostic tests. “The imported vivax malaria case was detected in a foreign migrant followed by a Plasmodium vivax infection in a Sri Lankan national who visited the residence of the former. The link between the two cases was established by tracing the occurrence of events and by demonstrating genetic identity between the parasite isolates. Effective surveillance was conducted, and a prompt response was mounted by the Anti Malaria Campaign. No further transmission occurred as a result.”

Bangladesh has few but focused areas of malaria transmission and hopes to achieve elimination of local transmission by 2030. A particular group for targeting interventions is the population of slash and burn cultivators in the Rangamati District. Respondents in this area had general knowledge about malaria transmission and modes of prevention and treatment was good according to Saha and the other authors. “However, there were some gaps regarding knowledge about specific aspects of malaria transmission and in particular about the increased risk associated with their occupation. Despite a much-reduced incidence of malaria in the study area, the respondents perceived the disease as life-threatening and knew that it needs rapid attention from a health worker. Moreover, the specific services offered by the local community health workers for malaria diagnosis and treatment were highly appreciated. Finally, the use of insecticide-treated mosquito nets (ITN) was considered as important and this intervention was uniformly stated as the main malaria prevention method.”

Kenya offers some lessons about low transmission areas but also areas where transmission may increase due to climate change. A matched case–control study undertaken in the Western Kenya highlands. Essendi et al. recruited clinical malaria cases from health facilities and matched to asymptomatic individuals from the community who served as controls in order to identify epidemiological risk factors for clinical malaria infection in the highlands of Western Kenya.

“A greater percentage of people in the control group without malaria (64.6%) used insecticide-treated bed nets (ITNs) compared to the families of malaria cases (48.3%). Low income was the most important factor associated with higher malaria infections (adj. OR 4.70). Houses with open eaves was an important malaria risk factor (adj OR 1.72).” Other socio-demographic factors were examined. The authors stress the need to use local malaria epidemiology to more effectively targeted use of malaria control measures.

The key lesson arising from the forgoing studies and news is that disease control needs strong global partnerships but also local community investment and adaptation of strategies to community characteristics and culture.

Establishing Mobile Outreach Teams (MOTs) for strengthening Active Case Detection with Mobile Populations in Vietnam 2016-2020

Mobile migrant populations present a special challenge for malaria control and elimination efforts. Nguyen Ha Nam and colleagues* (Nguyen Xuan Thang, Gary Dahl, James O’Donnell, Vashti Irani, Sara Canavati, Jack Richards, Ngo Duc Thang, and Tran Thanh Duong) presented their study of this group at the recent Malaria World Congress. They are also sharing what they learned below.

Mobile Migrant Populations (MMPs) are a key population for containing the spread of malaria in the border areas between Cambodia and Vietnam. The number of imported cases in Viet Nam in 2017. 12,5% of such cases caught in Binh Phuoc and Dak Nong provinces and all of them came from Cambodia. The provinces bordering Cambodia and Vietnam have been had the highest malaria transmission intensity. This borders are frequented by MMPs who have proven difficult to target for surveillance and malaria control activities.

Mobile Outreach Teams (MOTs) provide a potential approach to target malaria elimination activities for MMPs who may not be strongly supported by the regular village-based and clinic-based health services. This work describes the implementation of MOTs in Binh Phuoc and Dak Nong Provinces, which are high-risk regions along the Viet Nam-Cambodia border. These activities were conducted as part of the Regional Artemisinin-resistance Initiative (RAI) in 2017. Each MOT was comprised of 2 Commune Health Staff and 1 Village Health Worker (VHW) from the village nearest to the outreach area.

In the first phase of the pilot, 3 communes of 2 districts in Binh Phuoc and 2 communes of 1 district in Dak Nong with highest malaria cases reported from NIMPE are selected as targeted areas. The Objectives were to …

  • Design/tailor Mobile Outreach Information Education and Communication/Behaviour change communication (BCC/ IEC) Toolkit
  • Intensify case detection and quality management by increasing the coverage of diagnostics and treatment for hard to reach populations
  • Strengthen outreach to high-risk and under-served populations through MOT scouting activities to locate unreached Mobile Communities and map their locations
  • Link MMPs with health facilities and Village Health Workers

All MOT members were provided with smartphones and were trained on how to use the EpiCollect5 app to track malaria cases, record mapping information and upload real-time reports of these malaria cases. MOTs conducted 5-day outreach activities every month. These activities began with scouting out locations of the MMP communities.

Once located, the MOTs geo-tagged the location of the community, conducted a short epidemiological survey on the community and screened for malaria using Rapid Diagnostic Tests and blood smear microscopy. Active malaria cases were provided with treatment according to the National guidelines, and Long Lasting Insecticidal Nets were distributed based on results of diagnosis and the survey.

This action has led to increased diagnosis and treatment of hard to reach MMPs with increased access by those communities to malaria services. Improved understanding and increased use of malaria prevention practices hard to reach MMP communities/households. Mapped of previously unreached MMP Communities and unofficial border crossing points with malaria transmission hotspots and highly frequented crossing identified. The number of MMPs were monitored by MOTs were 2,699 accounting for 5.18% of the population in the project sites (2,699/52,095).

These screened MMPs were almost located along the border among project communes in Bu Gia Map National Forest where have a lot of unofficial border crossers, timber camp communities, and other revolving communities. 1,977 targeted people were tested for malaria. This number was achieved 73.25% of mobile migrant people (1,977/2,699). This work highlights how MOTs can target the previously unreached populations of MMPs to strengthen malaria surveillance and active case responses to reduce malaria transmission in Viet Nam.

A system of real-time data collection of malaria cases from VHWs and MOTs using mobile phone uploads was established. Border screening and tracking hard to reach communities is a useful approach to implement to identify imported cases; however, it is labor-intensive, and misses subjects crossing at unofficial borders due to limited working time of MOTs (5 days a month).

Positive cases in Binh Phuoc province are maintained for keeping track after receiving treatment due to no confirmed cases detected in targeted communes in Dak Ngo province, though these communes mainly have numerous transient timber camps moving in deep forests, and highly mobile border-crossers moving between regions and countries frequently. Future work will combine routine support from District health staff and expand the role of VHWs with motorbike provision for each MOT in order to not only to improve their quality outreach activities but also develop stronger Active Case Detection in the next phase of the project.

*Team members represent the National Institute of Malariology, Parasitology and Entomology, Hanoi, Viet Nam; Health Poverty Action, London, UK; and the Burnet Institute, Melbourne, Australia.

References

  • Kheang ST, Lin MA, et al. Malaria Case Detection Among Mobile Populations and Migrant Workers in Myanmar: Comparison of 3 Service Delivery Approaches. 2018
  • Shannon Takala-Harrison,a Christopher G. Jacob, et al. Independent Emergence of Artemisinin Resistance Mutations Among Plasmodium falciparum in Southeast Asia. 2014.
  • Imwong M, Hien TT, et al. Spread of a single multidrug resistant malaria parasite lineage (PfPailin) to Vietnam. 2017.
  • Richard J Maude,corresponding author Chea Nguon, et al. Spatial and temporal epidemiology of clinical malaria in Cambodia 2004–2013. 2014.
  • Imwong M, Nguyen TN, et al.The epidemiology of subclinical malaria infections in South-East Asia: findings from cross-sectional surveys in Thailand–Myanmar border areas, Cambodia, and Vietnam. 2015.
  • Hannah Edwards, Sara E. Canavati, et al. Novel Cross-Border Approaches to Optimise Identification of Asymptomatic and Artemisinin-Resistant Plasmodium Infection in Mobile Populations Crossing Cambodian Borders. 2015.

Pilot Mapping, Real Time Reporting and Responding in High Risk Malaria Areas of Viet Nam

Viet Nam is among the Asia-Pacific countries focusing on eliminating malaria. Mapping helps target malaria interventions. Nguyen Xuan Thang and colleagues (James O’Donnell, Vashti Irani, Leanna Surrao, Ricardo Ataide, Josh Tram, An Le, Sara Canavati, Tran Thanh Duong, Tran Quoc Tuy, Gary Dahl, Gerard Kelly, Jack Richards, Ngo Duc Thang) presented their pilot mapping efforts at the Malaria World Congress in Melbourne recently and below share their experiences with us.

Viet Nam is focused on eliminating malaria by 2030. Viet Nam saw a 73% reduction in cases between 2013 and 2017 (NIMPE data), yet border provinces still have a high burden of malaria. However, some provinces still have a high burden of malaria. To achieve malaria elimination, it is essential to deploy targeted interventions in these locations.

Spatial Decision Support Systems (SDSS) can be used by National Malaria programs to integrate geographic elements in the management of malaria cases and facilitate targeted malaria interventions in these high-risk settings.

The objective of this work was to pilot a SDSS system for Binh Phuoc and Dak Nong Provinces in Viet Nam to facilitate ongoing surveillance and targeted malaria, as part of the Regional Artemisinin-resistance Initiative (RAI). This objective was achieved by:

  • Collecting data with cell phones

    Collecting baseline GIS data at household level and environmental characteristics associated with the area;

  • Establishing a routine data collection system that will be reported by mobile medical staff by mobile phone;
  • Integrating this data to form a spatial decision support system (SDSS);
  • Using the SDSS system for direct reporting to malaria control programs that provided strategic solutions for the prevention of disease spread and the elimination of malaria

Sample cell phone data screens

In Phase 1, a household and mapping survey was conducted in collaboration with commune, district and village health workers. Epicollect5 software was used on smartphones with GPS functionality to record mapping information (latitude and longitude) and general information on household members. During Phase 1, 10,506 households were surveyed and data was aggregated in a custom Geographic Information System (GIS) database.

The majority of the surveyed individuals were of the Kinh ethnicity (19,282; 35.4%), followed by M’Nong (4,669; 8.6%) and Mong (3,359; 6.2%). Data related to malaria among mobile populations were included in the GIS as a means to identify and describe groups at high risk for malaria e.g. forest-goers. The survey data were reviewed, cleaned and matched using the ID numbers, then aggregated with relevant administrative boundary data and linked on ArcGIS 10.2 software. This database is located in a custom GIS system and can be visualized as a spatial transmission model to support appropriate decision-making

Dots representing households

Phase 2 focused on ongoing surveillance with rapid case reporting and responses. Malaria cases diagnosed at public and local health facilities were entered into the system by Commune Health Officials. Village Health Workers were immediately notified and went to the patient’s home to undertake case investigation including further household mapping and active case detection activities. The Viet Nam National Institute of Malariology was also notified, and organized local officials to carry out an investigation into the sources of transmission (i.e. ‘hotspots’) and to implement timely interventions.

Dots representing cases

When the cases were identified, Village Health Workers went to the patient’s home to undertake operational procedures including geographic exploration, household mapping to identify the location and to identify the list of affected households. They also collected this data on EpiCollect5. Collated information on cases, transmission point, zoning of the target villages allowed for early detection of malaria outbreaks. The National Institute of Malariology can also issue guidelines when the hotspots are identified and when disease outbreaks occur

These activities are ongoing. In conclusion, a custom GIS database was developed using a household survey in Binh Phuoc and Dak Nong province of Viet Nam. Malaria cases were mapped to identify hotspots of malaria transmission and enable further active case detection and targeted interventions. This established GIS database aims to support routine case notification and to enhance the role of surveillance for active case detection and responses to achieve malaria elimination.

The authors are affiliated with the National Institute of Malariology, Parasitology, Entomology (NIMPE), Viet Nam; Burnet Institute, Australia; and Health Poverty Action, UK. Contact: xuanthang.nimpe@gmail.com

Agriculture and Promotion of Food Security Can Affect Malaria Transmission

The link between malaria and food security in a global context has been made. The influence of malaria on food security was examined. Now the connection between agriculture practices/food security and malaria is pursued below.

A common complaint with programs that distribute insecticide-treated bednets to prevent malaria is that the nets may be used for other purposes that the intended effort to prevent infected mosquitoes from biting people. All informants interviewed for a study in Western Zambia reported that ITNs are regularly used for fishing and the misuse is widespread. Unsustainable fishing practices, drought and population pressure were mentioned as reasons for fishery decline. The implication was that the use of free ITNs for fishing at least saved the population money in a time of declining fortunes.

A broader review of the ITNs for fishing issue was done through contacting expert witnesses across Africa. Mosquito net fishing (MNF) was found to be a broadly pan-tropical activity, particularly prevalent in sub-Saharan Africa. The authors found that, “Perceived drivers of MNF were closely related to poverty, revealing potentially complex and arguably detrimental livelihood and food security implications.”

The mosquito breeding potential of dams cuts across Africa with the number of dams located in malarious areas projected to increase according to Kibret and colleagues. This is because “The population at risk of malaria around existing dams and associated reservoirs, is estimated to increase from 15 million in 2010 to 21-23 million in the 2020s, 25-26 million in the 2050s and 28-29 million in the 2080s.” In addition, areas with dams but without malaria transmission at present, will likely transition to regions of unstable transmission due to climate change.

Likewise, a study in Ethiopia starts with the assertion that, “Dams are important to ensure food security and promote economic development in sub-Saharan Africa,” and then stresses the importance of understanding the consequences of these projects. The researchers found that “the mean monthly malaria incidence and anopheline larval density was generally higher in the dam villages than in the non-dam villages” in all the three dam settings studied. So while dams can increase agricultural production, the authors concluded that, “the presence of dams intensifies malaria transmission in lowland and midland ecological settings.”

Hydro-agricultural projects include dams and irrigation. Human bait mosquito captures volunteers in hydro-agricultural and river bank sites in Cameroon Akono et al. found that mosquito biting rates were higher in hydro-agricultural sites of less urbanized and urban settings than in natural river banks sites. An additional implication is that urban farming, an important component of food security, may influence mosquito and malaria prevalence.

Stoler and colleagues pursued this question of urban agriculture. The odds of self-reported malaria are significantly higher for women in Accra, Ghana who are living within 1 km of urban agriculture compared with all women living near an irrigation source, the association disappearing beyond this critical distance. Likewise in Kumasi, Afrane et al. learned that “adult and larval mosquito abundance and larval survival were high in the irrigated fields in the irrigated (urban) vegetable farm. This therefore, contributed significantly to adult mosquito populations and hence malaria transmission in the city.”

Even agricultural practices in smaller subsistence farms can foster malaria mosquito breeding. Practices found in southwest Nigeria include collection of pools of water in the farms for soaking cassava tubers, digging of trenches, irrigation of farms, and the presence of fish ponds.

Communities can perceive how agricultural practices may contribute to malaria. In Tanzania a fair number of rural respondents associated growing of rice with malaria. They also noted that the need to sleep on their farms at times meant they could not benefit from the mosquito nets hanging back in their house, some hours walk away. The idea of rice cultivation and malaria was tested in central Kenya. Mwangangi and co-researchers found that, “Rice fields and associated canals were the most productive habitat types,” for malaria mosquito breeding. Overall, Mboera et al. found, “evidence that malaria transmission risk varies even between neighbouring villages and is influenced by agro-ecosystems.”

Although we can establish the two-way link or intersection between malaria and food security, we can see that recommended joint or integrated programming may not always be optimal at various levels from the nation to the community. Greater collaboration between health and agricultural ministries and agencies is needed, supported by national policies that see malaria and food production as part of overall national development goals.

Improving the efficacy of reactive screen-and-treat for malaria elimination in southern Zambia

Global Health Day 2018 sponsored by the Johns Hopkins University Center for Global Health featured a poster presentation by several colleagues on Improving the efficacy of reactive screen-and-treat for malaria elimination in southern Zambia. Fiona Bhondoekhan, William Moss, Timothy Shields, Douglas Norris, Kelly Searle, Jennifer Stevenson, Harry Hamapumba, Mukuma Lubinda and Japhet Matoba (Southern Africa International Centers of Excellence in Malaria Research, the JHU Bloomberg School of Public Health, and the Macha Research Trust, Zambia) share their findings below.

Background: Malaria screen-and-treat (called Step D in Zambia) is a reactive case detection strategy in which cases detected at a health center trigger community health workers (CHWs) to screen for secondary malaria cases within a 140-meter radius of the index case household using PfHRP2 rapid diagnostic tests (RDTs). Few studies evaluated whether an evidence-based strategy using environmental features that characterize the immediate surroundings of a household, can improve the efficiency of secondary case identification.

Objective: This study utilized the Step D and extended the screening radius to 250-meters (termed Enhanced Step D or ESD) to assess which local environmental variables can guide CHWs to identify secondary cases more efficiently. As Zambia works toward eliminating malaria, more refined and targeted case detection strategies are required to find the untreated malaria cases that could serve as potentially asymptomatic sources of infection. This study can help guide and plan reactive case detection strategies in Zambia that allow community health workers/field teams to employ an evidence-based strategy to find malaria-positive secondary households situated near index case houses more efficiently.

Methods: Demographic information, malaria diagnosis, bed-net use and ownership, cooking energy source, and household floor material were obtained from surveys. Households were stratified into malaria positive and negative secondary households using RDT and qPCR results. ArcGIS was used to generate the following local environmental variables: screening radius (140 vs. 250-meters), number of animal pens within 100-meters, distance to nearest animal pen, distance and elevation difference between index and secondary houses, as well as the following large scale environmental variables: distance to main road and nearest stream category. Generalized estimating equations (GEE) estimated the cross-sectional effect for the difference in odds of a positive vs. negative secondary household for each predictor. For the secondary analysis GEE with the same model specifications was used to estimate the cross-sectional difference in odds of a positive vs. negative household for each environmental predictor. Model fit was evaluated with the Hosmer-Lemeshow goodness of fit test and significance was evaluated as a p-value of 0.05. Statistical analyses were carried out using STATA 14.2.

Results: Screening within the index households yielded an overall parasite prevalence of 8.6%, which was higher by qPCR (8.1%) than RDT (2.7%) as seen in Table 1. Secondary households had an overall parasite prevalence of 1.9% with similar differences by test used. Key results from regression analysis seen in Table 2 include a difference in prevalence according to screening radius as well as by proximity to the nearest stream. Secondary analysis produced similar results but showed statistically significant higher odds for households where animal pens were present.

Conclusion: Screening for secondary households within low-transmission setting in Zambia could be optimized by using both local-scale indicators such as the presence of animal pens and large-scale indicators such as streams as environmental guiding tools.

Acknowledgements: This research was supported in part the Bloomberg Philanthropies and the Johns Hopkins Malaria Research Institute, and the NIH-sponsored Southern and Central Africa ICEMR 2U19AI089680.

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.

Prof Lateef A Salako, 1935-2017, Malaria Champion

Professor Lateef Akinola Salako was an accomplished leader in malaria and health research in Nigeria whose contributions to the University of Ibadan and the Nigeria Institute for Medical Research (among others) advanced the health of the nation, the region and the world. His scientific research and his over 140 scientific publications spanned five decades.

His research not only added to knowledge but also served as a mentoring tool to junior colleagues. Some of his vast areas of interest in malaria ranged from malaria epidemiology, to testing the efficacy of malaria drugs to tackling the problem of malaria in pregnancy. He led a team from three research sites in Nigeria that documented care seeking for children with malaria the acceptability of pre-packaged malaria and pneumonia drugs for children that could be used for community case management. Prof Salako was also involved in malaria vaccine trials and urban malaria studies.

As recent as 2013 Prof Lateef Salako, formerly of NIMR said: “It is true there is a reduction in the rate of malaria cases in the country, but to stamp out this epidemic there is the urgent need for a synergy between researchers, the government, ministries, departments and agencies and involved in malaria control. That will enable coordinated activities that will produce quicker results than what obtains at the moment.”

At least one website has been set up where people can express their condolences.  As one person wrote, “Professor Lateef Salako was an exceptional student, graduating with distinction from medical school; an unforgettable teacher, speaking as a beneficiary of his tutelage; an exemplary scholar, mentoring many others; an accomplished scientist, making indelible contributions to knowledge. May his legacy endure.”

Readers are also welcome to add their own comments here about Prof Salako’s contribution to malaria and tropical health.

The Forest through the Trees: Themes in Social Production of Health

Recently Professor Ayodele S Jegede of the Faculty of Social Sciences, delivered the 419th Inaugural Lecture at the University of Ibadan, Ibadan, Nigeria, during the 2016/2017 academic session.  Below Prof. Jegede shares an abstract of his lecture.

Prof Ayodele S Jegede

Knowledge of individual actor’s behaviour is a reflection of the society as tree to the forest. As forest produces large quantities of oxygen and takes in carbon dioxide, society produces the needed resources for human beings to survive through culture. This inter-dependence between man and the environment is summarised by the Yoruba adage which says: “irorun igi ni irorun eye” (meaning: a bird’s peace depends on the peace enjoyed by the tree which harbours it).

Nigeria, a country with a population of about 187 million and a life expectancy of 53 years, 54% of the populace are living below the poverty line with limited access to health care services physically and economically. Although universal health coverage is vital to the achievement of the Sustainable Development Goals (SDGs) cultural perception of disease aside from loss of economic and low purchasing power makes people to attribute their illnesses to spiritual cause and therefore seek alternative health care services. This influences resistance to public health interventions in some African communities resulting in suspicion and distrust between health educators and the public.

Strengthening Health Information Systems

For instance, response to childhood immunizable diseases, mental illness, malaria and HIV/AIDS reported in this lecture was driven by how people define the diseases. Their response did result in delay in seeking modern health care until alternative care sources proved ineffective. This confirms W.I. Thomas (1929: 572) postulation that, “If men define situations as real, they are real in their consequences”.

Our stakeholders’ engagement interventions strategies strengthened by knowledge of how people construct their life, socially and culturally, proved to be a potent vaccine for preventing strain relationship between health workers and clients. Since society consists of individuals who constitute the stakeholders conducting health researches as well as management of epidemics and treatment during epidemics and disease episodes require appropriate ethical behaviours.

This suggests that adequate knowledge of the society is inevitable since a tree does not make a forest which confirms Marx Weber’s Action Theory postulation that an act does not become social unless it involves two or more persons. It is, therefore, that government should establish National Disease Observatory System (NDOS) to document diseases by type, location and related local practices for training health care professionals, clinical practice and emergencies preparedness.

Note also that the lecture was featured in the New Nigerian Newspaper with an emphasis on establishing a national disease observatory.  The Nigerian Tribune also featured the lecture stressing the importance of disease emergency preparedness.

Population Health: Malaria, Monkeys and Mosquitoes

On World Population Day (July 11) one often thinks of family planning. A wider view was proposed by resolution 45/216 of December 1990, of the United Nations General Assembly which encouraged observance of “World Population Day to enhance awareness of population issues, including their relations to the environment and development.”

A relationship still exists between family planning and malaria via preventing pregnancies in malaria endemic areas where the disease leads to anemia, death, low birth weight and stillbirth. Other population issues such as migration/mobility, border movement, and conflict/displacement influence exposure of populations to malaria, NTDs and their risks. Environmental concerns such as land/forest degradation, occupational exposure, population expansion (even into areas where populations of monkeys, bats or other sources of zoonotic disease transmission live), and climate warming in areas without prior malaria transmission expose more populations to mosquitoes and malaria.

Ultimately the goal of eliminating malaria needs a population based focus. The recent WHO malaria elimination strategic guidance encourages examination of factors in defined population units that influence transmission or control.

Today public health advocates are using the term population health more. The University of Wisconsin Department of Population Health Sciences in its blog explained that “Population health is defined as the health outcomes of a group of individuals, including the distribution of such outcomes within the group.” World Population Day is a good time to consider how the transmission or prevention of malaria, or even neglected tropical diseases, is distributed in our countries, and which groups and communities within that population are most vulnerable.

World Population Day has room to consider many issues related to the health of populations whether it be reproductive health, communicable diseases or chronic diseases as well as the services to address these concerns.