Category Archives: Surveillance

A malaria elimination framework that includes high prevalence countries, too

When the Nigeria Malaria Control Program changes its name to Nigeria Malaria Elimination Program (NMEP) a few years ago, people wondered whether this was getting too far ahead of the situation in one of the highest burden malaria countries in the world. The recently released Framework for Malaria Elimination by the Global Malaria Program of WHO shows that all endemic countries can fit into the elimination process.

Recent Webinar by WHO’s Global Malaria Program stressed that all countries have a role in malaria elimination

The Framework stresses that, “Every country can accelerate progress towards elimination through evidence-based strategies, regardless of the current intensity of transmission and the malaria burden they may carry.” The Three pillars of the malaria elimination framework have room for high burden countries. Pillar 1 states that, “Ensure universal access to malaria prevention, diagnosis and treatment.”

First it is important to understand that the Framework defines malaria elimination as the cessation of indigenous mosquito-borne transmission of malaria throughout a country. The Framework also observes that even within countries there are diverse transmission areas. Some are not amenable to malaria transmission, while others may be amenable but do not experience transmission.

It is important to realize that malaria transmission in most countries is characterized by diversity and complexity. Areas where transmission is occurring range from very low transmission zones where hotspots erupt to high levels of ongoing transmission. Thus even high burden countries may have variation that require development of intervention packages tailored to the specific transmission setting.

This stratification and development of appropriate intervention packages requires, “Excellent surveillance and response are the keys to achieving and maintaining malaria elimination; information systems must become increasingly ‘granular’ to allow identification, tracking, classification and response for all malaria cases (e.g. imported, introduced, indigenous).” This should lead to “subnational elimination targets as internal milestones.”

For high burden countries key components of Pillar 1 is, “Vector control strategies, such as use of insecticide-treated mosquito nets (ITNs/LLINs) and indoor residual spraying (IRS), together with case management (prompt access to diagnosis and effective treatment) are critical for reducing malaria morbidity and mortality, and reducing malaria transmission.”

Recommendations like ensuring political commitment, private sector involvement and establishment of an independent advisory committee are valuable at all stages of elimination. A challenge for high burden countries will be maintaining political commitment over many years. Early involvement of the private sector will boost coverage of major interventions. An independent advisory/monitoring group will help track data and progress.

It is important to put in place good monitoring systems to ensure that program coverage is well targeted, achieved and maintained. “Systematic tracking of programme actions over time, including budget allocations and adherence to standard operating procedures.” This enables accountability and enhances political commitment.

Finally the Malaria Atlas Project has mapped most recent data, and as we can see Nigeria does have a variety of transmission settings. We know now that the decision of Nigeria’s malaria program to update its name was appropriate. Hopefully not only the NMEP but also the various state malaria programs will look at their malaria transmission strata and plan according toward elimination.

Malaria, Dengue, Mosquitoes – evolving in the urban environment

As the world increasingly urbanizes, we need to address the role of urban ecosystems and the evolution of disease vectors and organisms.  Marina Alberti and colleagues explained that …

“Recent studies show that cities might play a major role in contemporary evolution by accelerating phenotypic changes in wildlife, including animals, plants, fungi, and other organisms. Many studies of ecoevolutionary change have focused on anthropogenic drivers, but none of these studies has specifically examined the role that urbanization plays in ecoevolution or explicitly examined its mechanisms.”

In their own study they looked at “five types of urban disturbances including habitat modifications, biotic interactions, habitat heterogeneity, novel disturbances, and social interactions.” The researchers learned that, “clear urban signal; rates of phenotypic change are greater in urbanizing systems compared with natural and nonurban anthropogenic systems.” They concluded that there is need to continually “uncover insights for maintaining key ecosystem functions upon which the sustainability of human well-being depends.”

Of particular concern in the area of tropical health are the unique urban manifestations of diseases like yellow fever, dengue and malaria. Although Zika virus, for example, was first discovered in forests, it has adapted to an urban cycle involving humans and domestic mosquito vectors in tropical areas where dengue is endemic. Musso and Gubler in their review further explain that although there may be sylvatic cycles of Dengue, “Arboviruses such as DENV have adapted completely to humans and can be maintained in large tropical urban centers in a mosquito-human-mosquito transmission cycle that does not depend on nonhuman reservoirs.”

Weaver et al. note that Zika in spreading to Asia, “emerged on multiple occasions into urban transmission cycles involving Aedes (Stegomyia) spp. Mosquitoes.” In addition it can be hypothesized that phenotypic changes in Asian lineage ZIKV strains made rare disease outcomes such as congenital microcephaly and Guillain-Barré more common and visible.

According to Estelle Martin and co-researchers, “Puerto Rico, a major metropolitan center in the Caribbean, has experienced increasingly larger and clinically more severe epidemics following the introduction of all four dengue serotypes.” They found that Dengue serotype 4 replaced earlier strains and that “this epidemic strain progressed rapidly, suggesting that the epidemic strain was more fit, and that natural selection may have acted on these mutations to drive them to fixation.”

In addition to virus evolution, mosquito changes have been documented by Caroline Louise and colleagues in “One of the world’s largest urban agglomerations infested by Ae. aegypti … the Brazilian megalopolis of Sao Paulo.”  They detected microevolution despite a short observational period and stress the implications of the “rapid evolution and high polymorphism of this mosquito vector on the efficacy of control methods.”

“The adaptation of malaria vectors to urban areas is becoming a serious challenge for malaria control,” is a major concern of Antonio-Nkondjio and co-workers. They found, “rapid evolution of pyrethroid resistance in vector populations from the cities of Douala and Yaoundé,” Members of this team also learned that the M form of Anopheles gambiae predominated in the centre of urban agglomerates in Cameroon. Previously it was known that larval habitats polluted with decaying organic matter as found in densely populated urban agglomerates, were unsuitable for Anopheles gambiae. The recent study showed that the “M form showed greater tolerance to ammonia (arising from organic matter) compared to the S form. This trait may be part of the physiological machinery allowing forest populations of the M form to colonize polluted larval habitats.”

The evolutionary response of vectors and disease organisms to urban environments needs continued monitoring. Urban disease control and elimination efforts must adapt to such adaptations in the disease process.

Towards Malaria Pre-Elimination in Rwanda: Active Case Investigation in a Low Endemic District

A poster entitled “Towards Malaria Pre-Elimination in Rwanda: Active Case Investigation in a Low Endemic District” was presented by members of Jhpiego’s Rwanda Team and colleagues:

Noella Umulisa, Angelique Mugirente, Veneranda Umubyeyi, Beata Mukarugwiro, Stephen Mutwiwa, Jean Pierre Habimana, and Corrine Karema, at the 65th annual meeting of the American Society of Tropical Medicine and Hygiene in Atlanta. The abstract follows …

case-detectionRwanda has seen an increase in malaria cases recently with an increase from 514,173 cases in 2012 to 1,957,402 cases in 2015. This change can be attributed to an increase in temperature, rainfall, and resistance to insecticides.

Despite this setback, Rwanda is aiming to reach the pre-elimination phase by 2018. In January 2015, 11 health facilities in Rubavu, a low endemic district, started implementing reactive active case detection after training 55 health care providers and 11 lab technicians on the topic. This strategy involves screening and treating individuals living in close proximity to passively detected cases, also known as index cases. Index cases can be used to identify population groups that are sources of infection.

cases-confirmed-investigatedFrom January 2015 to December 2015, 16,434 cases of Malaria were detected and treated at 11 health facilities in Rubavu District. Among these cases, 2,917(17.8%) index cases were investigated and 4,943 individuals (between 1 and 2 contacts for each index case) living in proximity of index cases were tested using rapid diagnostic tests by health care providers. Of these, 508 (10.3%) tested positive for malaria and were treated according to national guidelines.

These data shows that the number of investigated cases is still lower than the national guidelines of screening 5 individuals residing between 100 to 500 meters of every confirmed case. This low rate could be due to the increase of malaria cases in Rwanda which has placed a burden on health care providers and health facilities in areas like Rubavu which used to be low endemic malaria areas. Additionally, data gathered through supervision activities has indicated a need for additional training on screening investigations in order to adhere to national guidelines and conduct the investigations more efficiently.

Active case investigation could be improved by training and involving more health care providers such as community health workers who could reduce the burden on health center staff. The additional support for case investigation activities and improved training can help to achieve higher coverage of individuals located near index cases.

Epidemiology of Resurgent Malaria in Eastern Zimbabwe: Risk Factors, Spatio-Temporal Patterns and Prospects for Regaining Malaria Control

Mufaro Kanyangarara and her PhD thesis adviser, Luke Mullany, of the Johns Hopkins Bloomberg School of Public Health Department of International Health, have been looking into the challenges of controlling and eventually eliminating malaria in a multi-country context in southern Africa. We are sharing abstracts from her pioneering work. The first seen below provides an overview of the three components of the study.

Incidence 2012Despite recent reductions in malaria morbidity and mortality due to the scale up of malaria interventions, malaria remains a public health problem in sub-Saharan Africa, especially among children under five years of age, pregnant women and people living with HIV/AIDS. A recent resurgence in malaria, in areas where malaria control was previously successful, has brought to the forefront the importance of research to understand the epidemiology of malaria and the effectiveness of malaria control efforts in resurgent settings. Using cross-sectional surveys, routine data from health-facility based surveillance and freely available remotely sensed environmental data, this research examined the distribution of malaria and the impact of vector control in Mutasa, a rural district in Zimbabwe characterized by resurgent malaria.

Firstly, individual- and household level factors independently associated with individual malaria risk were identified using multilevel logistic regression models based on data from cross-sectional surveys conducted between October 2012 and September 2014. Secondly, geostatistical methods and remotely sensed environmental data were used to model the spatial and seasonal distribution of household malaria risk; then develop seasonal malaria risk maps with corresponding maps of the prediction uncertainty. Lastly, an evaluation of the effect of introducing an organophosphate for indoor residual spraying was conducted using routine health facility data covering 24 months before and 6 months after the campaign.

The results of multilevel model suggested that malaria risk was significantly higher among individuals who were younger than 25 years, did not sleep under a bed net, and lived close to the Zimbabwe-Mozambique border. The spatial risk maps depicted relatively increased risk of finding a positive household in low-lying areas along the Mozambique border during the rainy season. Lastly, the introduction of organophosphates to this pyretheroid resistant area resulted in a significant reduction in malaria incidence following spraying. These findings elucidate the heterogeneous distribution of malaria, identify risk factors driving malaria transmission and assess the quantitative impact of switching insecticide classes on health outcomes. Collectively, the findings provide evidence to guide country-specific decision making for regaining malaria control and underscore the need for strong between-country initiatives to curb malaria in Mutasa District and elsewhere.

Beyond Garki baseline results released, highlighting changes in malaria environment

Ilya Jones shares with us the latest update on Malaria Consortium’s Beyond Garki project that seeks to understand changes in malaria epidemiology and recommend effective strategies to improve control efforts ……

201506110316-malariometric-bannerOver the last 15 years, increased global investment in fighting malaria has contributed substantially to reduction in the prevalence of the disease in endemic countries around the world. With the development of new technologies and innovative approaches to disease control, there is more hope than ever that malaria will be eliminated in places where it used to be a major public health threat.

However, sustaining momentum requires a deep understanding of the changes in the frequency of the disease, determinants of transmission and impact of interventions in a changing environment. Understanding these changes is essential in order to tailor health interventions to be as effective as possible.

Malaria Consortium’s Beyond Garki project, funded by the UK government through the Programme Partnership Arrangement (PPA), seeks to understand changes in malaria epidemiology and recommend strategies to improve malaria control efforts. The project is named after the efforts of the World Health Organization and the government of Nigeria to study the epidemiology and control of malaria in Garki, Nigeria between 1969 and 1976. Beyond Garki began in Uganda and Ethiopia in 2012, with four survey rounds conducted to date. Additional studies were also carried out in Cambodia, and more studies are planned in Nigeria. Each survey tracks changes in malaria epidemiology over time and will ideally inform strategic decisions on the use of interventions.

The baseline results have been made available and will serve as a point of comparison for data obtained from subsequent survey rounds, which will be released in the autumn. However the results of the baseline survey are interesting in their own right. Some of the highlights are listed below:

  • Low to moderate malaria transmission intensity was observed in all sites. In Ethiopia, P. vivax was found to be a predominant malaria species, probably due to decline in transmission over recent years.
  • High coverage of insecticide treated nets (ITNs)was observed in three of four sites but it is still not at an ideal level.
  • ITN use rates among household members that had access were generally quite high. The studyNet use and infection also showed there is willingness to buy nets, at least in the Uganda sites.
  • In Uganda, a major vector of malaria, A. gambiae s.s., has developed resistance against pyrethroids.
  • Most human-vector contact still occurs indoors. However, there is a tendency of early biting of A. funestus s.l. in one of the sites in Uganda. More information is needed to determine the biting and resting habits of vector species in both countries.
  • The rate of malaria diagnosis using microscopy and rapid diagnostic tests (RDTs) has been strengthened in all sites. RDTs have been found to effectively predict negative malaria results, indicating that service providers should pay attention to other causes of fever when RDT negative results are reported for patients.
  • The level of use of intermittent preventive treatment of pregnant women (IPTp) needs to be strengthened in Uganda.

beyond garkiTo learn more about the project, the methods used to collect data, the findings and the recommendations, check out the dedicated microsite for Beyond Garki here, or read the baseline report here.

Moving toward Malaria Elimination in Botswana

elimination countriesThe just concluded 2015 Global Health Conference in Botswana, hosted by Boitekanelo College at Gaborone International Convention Centre on 11-12 June provided us a good opportunity to examine how Botswana is moving toward malaria elimination. Botswana is one of the four front line malaria elimination countries in the Southern African Development Community and offers lessons for other countries in the region. Combined with the 4 neighboring countries to the north, they are known collectively as the “Elimination Eight”.

The malaria elimination countries are characterised by low leves of transmission in focal areas of the country, often in seasonal or epidemic form. The pathway to malaria elimination requires that a country or defined areas in a country reach a slide positivity rates during peak malaria season of < 5%.

pathwayChihanga Simon et al. provide us a good outline of 60+ years of Botswana’s movements along the pathway beginning with indoor residual spraying (IRS) in the 1950s. Since then the country has expanded vector control to strengthened case management and surveillance. Particular recent milestones include –

  • 2009: Malaria elimination policy required all cases to be tested before treatment malaria elimination target set for 2015
  • 2010: Malaria Strategic Plan 2010–15 using recommendations from programme review of 2009; free LLINs
  • 2012: Case-based surveillance introduced

The national malaria elimination strategy includes the following:Map

  • Focus distribution LLIN & IRS in all transmission foci/high risk districts
  • Detect all malaria infections through appropriate diagnostic methods and provide effective treatment
  • Develop a robust information system for tracking of progress and decision making
  • Build capacity at all levels for malaria elimination

Botswana like other malaria endemic countries works with the Roll Back Malaria Partnership to compile an annual road map that identifies progress made and areas for improvement. The 2015 Road Map shows that –

  • 116,229 LLINs distributed during campaigns in order to maintain universal coverage in the 6 high risk districts
  • 200,721 IRS Operational Target structures sprayed
  • 2,183,238 RDTs distributed and 9,876 microscopes distributed
  • While M&E, Behavior Change, and Program Management Capacity activities are underway

Score cardFinally the African Leaders Malaria Alliance (ALMA) provides quarterly scorecards on each member. Botswana is making a major financial commitment to its malaria elimination commodity and policy needs. There is still need to sustain high levels of IRS coverage in designated areas.

Monitoring and evaluation is crucial to malaria elimination. Botswana has a detailed M&E plan that includes a geo-referenced surveillance system, GIS and malaria database training for 60 health care workers, traininf for at least 80% of health workers on Case Based Surveillance in 29 districts, and regular data analysis and feedback.

M&E activities also involve supervision visits for mapping of cases, foci and interventions, bi-annual malaria case management audits, enhanced diagnostics through PCR and LAMP as well as Knowledge, Attitudes, Behaviour, and Practice surveys.

Malaria elimination activities are not simple. Just because cases drop, our job is easier. Botswana, like its neighbors in the ‘Elimination Eight’ is putting in place the interventions and resources needed to see malaria really come to an end in the country. Keep up the good work!

Failure of malaria control efforts in northern Zambia

UNICEF, Zambia

UNICEF, Zambia

World Malaria Day 2014 was observed at the Johns Hopkins Bloomberg School of Public Health on Friday 25 April. 21 posters were presented. Below is the abstract of a third poster presented William Moss and colleagues from the Southern Africa International Centers of Excellence for Malaria Research.

Despite distribution of insecticide-treated bed nets, indoor residual spraying and case management with rapid diagnostic tests and artemisinin-based combination therapy, the burden of malaria remains high in northern Zambia.

RBM Impact Series Zambia

RBM Impact Series Zambia

Through passive case detection at health care facilities and active case detection through community-based surveys, we have documented persistently high parasite prevalence in Nchelenge District, Luapula Province, Zambia on the border of Lake Mweru with the Democratic Republic of Congo. Individual and household level risk factors for malaria were assessed and a spatial risk map constructed.

Pyrethroid resistance in local Anopheles funestus populations likely contributes to failure of current control efforts. Potentially contributing to malaria transmission is population movement from the lakeside to inland as fishing and agricultural seasons alternate.

Equally important may be cross-border movement between Nchelenge District, Zambia and Katanga Province in the Democratic Republic of Congo, suggesting the importance of epidemiological and entomological studies of cross-border malaria.

Resurgent Malaria in Eastern Zimbabwe

Mutasa District ZimbabweWorld Malaria Day 2014 was observed at the Johns Hopkins Bloomberg School of Public Health on Friday 25 April. 21 posters were presented. Below is the abstract of another poster presented William Moss and colleagues from the Southern Africa International Centers of Excellence for Malaria Research.

Eastern Zimbabwe has experienced recent large outbreaks of malaria after a history of successful control. Through passive case detection at health care facilities and active case detection through community-based surveys, we have documented seasonal malaria outbreaks in Mutasa District, Manicaland Province, Zimbabwe on the border with Mozambique.

We identified individuals with subpatent parasitemia who may be responsible for sustaining transmission during the dry season.

Pyrethroid resistance in local Anopheles funestus populations likely contributes to failure of current control efforts.

Potentially contributing to malaria transmission is population movement across the border with Mozambique.

* * * * * * *

Of interest, The Standard newspaper of Zimbabwe recently reported on this problem saying that, “Malaria burden remains high in border towns in Zimbabwe, especially in areas close to Mozambique, health experts have said. While the overall national statistics indicate a major decline from 5 000 deaths to 300 per year, border districts like Mudzi are still recording high cases.”

The feasibility of achieving and sustaining “malaria-free zones” in southern Zambia

World Malaria Day 2014 was observed at the Johns Hopkins Bloomberg School of Public Health on Friday 25 April. 21 posters were presented. Below is the abstract of a poster presented William Moss and colleagues from the Southern Africa International Centers of Excellence for Malaria Research.

miam_handbook_articleimageThe Government of Zambia is committed to creating “malaria-free zones” in southern Zambia. Through passive case detection at health care facilities and active case detection through community-based surveys, we have documented a dramatic decline in the burden of malaria in the catchment area of Macha Hospital, Choma District, Southern Province, Zambia from 2008 through 2013.

Macha Hospital:

Macha Hospital:

However, residual foci of transmission exist and the potential for repeated importation remains. We identified individuals with subpatent parasitemia and gametocytemia who may be responsible for sustained, low-level transmission and evaluated reactive case detection strategies to identify and treat these individuals using simulation models.

Factors associated with sustained insecticide-treated bed net use were evaluated in light of the declining burden of malaria. Parasite bar coding of 24 SNPs should permit the identification of imported parasites.

Results of a longitudinal analysis of changes in antibody responses to 500 Plasmodium falciparum antigens using a protein microarray should allow detection of residual transmission and document loss of humoral immunity in the absence of exposure.

iPhones for household malaria surveys in Sierra Leone

World Malaria Day 2014 was observed at the Johns Hopkins Bloomberg School of Public Health on Friday 25 April. 21 posters were presented. Below is the abstract of a poster presented by Suzanne Van Hull of Catholic Relief Services.iForm Builder picture on iPhone

Catholic Relief Services (CRS) and the Ministry of Health and Sanitation (MoHS) of Sierra Leone (SL) are co-implementing nationwide malaria prevention and treatment activities funded by the Global Fund to fight AIDS, Tuberculosis and Malaria. In order to track progress and impact, CRS and partners led the implementation of a malaria indicator survey (MIS) in early 2013 covering a nationally-representative sample of 6,720 households, inclusive of blood testing to determine prevalence of anemia and malaria. In early 2012, CRS also had the experience of using mobile technology for a Knowledge Attitude and Practices (KAP) study.

Fieldworkers used Apple 3GS iPhones for both surveys to collect data via the iFormBuilder platform, a web-based, software-as-services application with a companion app for the mobile devices allowing for timely data collection, monitoring, and analysis.

This was the first time that iPhones were used for a MIS, and lessons learned include: allowing at least four months to transform paper-based questionnaires into electronic format, giving the program enough time for pre-testing the tool and training data collectors/biomarkers/laboratory technicians, and involving key malaria stakeholders to ensure a nationally-led survey. Global Positioning Systems enabled the MoHS to make in-depth analyses on malaria trends based on geographic locations.

KAP survey on iPhoneOverall the benefits of an electronic versus a paper-based MIS questionnaire outweighed the challenges. The iPhone technology eliminated the need for paper transcribing, allowing for quicker data tabulation, real-time identification of mistakes, faster interviewing through skip patterns, and a close-to-clean dataset by the end of data collection saving time and money.

Survey results will be used to set evidence-based targets for all partners’ future malaria activities, especially the next 3 years of GF-supported malaria grants