Tropical Health Matters

Mary E. Schmidt, M.D. has studied the malaria situation in Haiti for her MPH capstone project at the Johns Hopkins Bloomberg School of Public Health. She has shared the abstract of the project with us here.

Background:  Hispaniola is the only Caribbean island still endemic for malaria.  While the Dominican Republic continues to see improvement in the use of prevention measures and malaria rates, Haiti has been unable to organize, operate and fund a sustainable program.  The city of Jacmel in the South East District has the capacity to create a successful program.

Materials and Methods:  A literature review was performed of population based surveillance studies to understand the epidemiology of malaria in Haiti and the South East District. Individuals were interviewed to understand the Minister of Public Health and Population (MSPP) malaria policy and the current epidemiologic practices.  Haitian physicians and CBO workers were observed and interviewed to understand how malaria is diagnosed and treated, how patients are educated and the current community malaria prevention programs.

A literature review was performed of  materials from malaria experts, the World Health Organization (WHO), Pan American Health Organization (PAHO) and The Global Fund to better understand the components of a successful malaria elimination program.

Results:  This review focused on the current barriers of a malaria implementation program in Jacmel and the national system that would prevent a successful program.   The review led to the creation of a malaria elimination framework for Jacmel and the South East District.

The framework emphasizes a strong management and operations component.  The MSPP office communicates with finance, surveillance, the district health officer, and the operations team.  For a functional system, operations and management communicates with the MSPP oversight team and receives input from finance and surveillance in order to manage training, deployment, communications and local surveillance.

Monitoring and Evaluation is done on a district level and reported to district operations to help with managing the program and to the surveillance team.  Recommendations for policy development include focus on diagnostics, specific treatment, vector control, education and monitoring.  Barriers include funding and implementing an adequate operation and deployment team.

Conclusion:  The implementation of an effective malaria elimination program in Haiti will require MSPP leadership oversight and a strong operations and management team in each district.  The city of Jacmel in the South East District has the  interest and support from local CBOs and business leaders that make it the ideal location to implement the framework and create a sustainable program.

Recently we have seen some online discussion about mosquitoes biting 24/7, and while this is true, it is not all species of mosquitoes that bite all the time – only that anytime during the day/night one might be bitten, but by different types of mosquitoes, carrying different diseases at different times. Below is a chart that tries to draw some of the distinctions among the different types of mosquitoes.  It is not all inclusive. Some references are listed at the end. Finally there is an abstract about possible changes in malaria mosquito biting behaviors, although we should use caution in that this has not been verified universally.

Reference Links

• How Mosquitoes Work. http://science.howstuffworks.com/zoology/insects-arachnids/mosquito1.htm
• Be vigilant to different mosquito breeding grounds. http://www.fehd.gov.hk/english/safefood/images/Pestnews_9e.pdf
• Biological Notes on Mosquitoes. http://www.mosquitoes.org/LifeCycle.html
• Mosquito. From Wikipedia, the free encyclopedia. http://en.wikipedia.org/wiki/Mosquito
• Anopheles Mosquitoes. http://www.cdc.gov/malaria/about/biology/mosquitoes/
• Differentiate Culex, Anopheles and Aedes Mosquitoes. http://profwaqarhussain.blogspot.com/2012/10/differentiate-culexanopheles-and-aedes.html
• Flight performance of the malaria vectors Anopheles gambiae and Anopheles atroparvus. http://www.ncbi.nlm.nih.gov/pubmed/15266751

Effects of changing mosquito host searching behaviour on the cost effectiveness of a mass distribution of long-lasting, insecticidal nets: a modelling study. Malaria Journal 2013, 12:215 doi:10.1186/1475-2875-12-215. Olivier JT Briët (olivier.briet@unibas.ch). Nakul Chitnis (nakul.chitnis@unibas.ch)

Abstract: Background The effectiveness of long-lasting, insecticidal nets (LLINs) in preventing malaria is threatened by the changing biting behaviour of mosquitoes, from nocturnal and endophagic to crepuscular and exophagic, and by their increasing resistance to insecticides. \

Methods: Using epidemiological stochastic simulation models, we studied the impact of a mass LLIN distribution on Plasmodium falciparum malaria. Specifically, we looked at impact in terms of episodes prevented during the effective life of the batch and in terms of net health benefits (NHB) expressed in disability adjusted life years (DALYs) averted, depending on biting behaviour, resistance (as measured in experimental hut studies), and on pre-intervention transmission levels.

Results: Results were very sensitive to assumptions about the probabilistic nature of host searching behaviour. With a shift towards crepuscular biting, under the assumption that individual mosquitoes repeat their behaviour each gonotrophic cycle, LLIN effectiveness was far less than when individual mosquitoes were assumed to vary their behaviour between gonotrophic cycles. LLIN effectiveness was equally sensitive to variations in host-searching behaviour (if repeated) and to variations in resistance. LLIN effectiveness was most sensitive to preintervention transmission level, with LLINs being least effective at both very low and very
high transmission levels, and most effective at around four infectious bites per adult per year. A single LLIN distribution round remained cost effective, except in transmission settings with a pre-intervention inoculation rate of over 128 bites per year and with resistant mosquitoes that displayed a high proportion (over 40%) of determined crepuscular host searching, where some model variants showed negative NHB.

Conclusions: Shifts towards crepuscular host searching behaviour can be as important in reducing LLIN effectiveness and cost effectiveness as resistance to pyrethroids. As resistance to insecticides is likely to slow down the development of behavioural resistance and vice versa, the two types of resistance are unlikely to occur within the same mosquito population. LLINs are likely cost effective interventions against malaria, even in areas with strong resistance to pyrethroids or where a large proportion of host-mosquito contact occurs during times when LLIN users are not under their nets.

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Finally please note that one malaria intervention alone will not solve our problems so we need to apply a mix that includes Nets, Indoor Residual Spraying, Diagnosis with mRDTs, Appropriate treatment with Artemisinin-based Combination Therapy, Intermittent Preventive Treatment, one day a vaccine and others …

In 1978 the US Centers for Disease Control and Prevention reported that, “As of April 14, 1978, no cases of smallpox have been reported to the World Health Organization (WHO) from anywhere in the world since the last case had onset of rash on October 26, 1977, in Merka town, Somalia. However, a total of 2 years of effective surveillance must elapse before this last endemic area can be confirmed to be smallpox-free.” Thirty-five years later Somalia is linked with difficult efforts to eradicate another disease, polio.

Now unfortunately, “Somalia hadn’t had a case of polio for nearly six years. But in the past few months, the virus has come back,” according to National Public Radio (NPR)  In fact the 73 cases reported from Somalia so far this year, surpasses the 59 cases reported in the rest of the world. NPR further notes that, “Somalia has the rate of polio vaccination in the world after Equatorial Guinea, according to the World Health Organization.”

Thirty-five years ago, challenges hampering disease eradication were the natural environment. “During October and November surveillance in Somalia has been severely hampered by heavy rains that have made it difficult or impossible to travel by vehicle. Since work has had to be continued on foot, there have been some delays in reporting and incomplete search coverage in certain areas,” CDC reported.

Today it is human conflict, not the weather, that inhibits control. NPR’s report notes that, “The Somali government directs the campaigns, but it doesn’t control or have access to vast swaths of the country. Some of the most recent polio cases have occurred in areas that are considered off limits to vaccination teams.” Conflict in Pakistan in December-January also tried to create off limits areas by killing polio workers.

Because polio is a fecal-oral disease it spreads with people. Not surprisingly, cases are appearing in Somali refugee camps in Kenya.  All countries in the region are on alert as extra vaccination efforts will be needed. And as NPR observes, this may draw resources from countries like Nigeria that are very close to eliminating the disease.  Ironically the polio virus strain found in Somalia was traced to Nigeria.

Polio cannot be easily compared with malaria which has a vector, and also an larger arsenal of effective tools – insecticide treated nets, indoor residual spraying, chemo-prevention drugs, rapid diagnostic tests and effective medicines.  But the diseases face similar challenges that are more often human than deriving from the natural environment.  Human conflict deters malaria control in eastern Democratic Republic of the Congo, in the Central African Republic and in South Sudan.

Unlike for polio, we are not even close to numbering malaria cases in the dozens, but the as the recent Abuja Summit has shown, we must have the political will to rise above conflict and inefficient health systems and face down these devastating diseases.

(PS – fortunately as we can see in the attached map, malaria is not a pressing problem in Somalia.)

A Breakfast Briefing was given to African Ministers of Health and Foreign Affairs on 13th July 2013 in Abuja, Nigeria to review progress in Africa’s fight against malaria and to announce a new initiative to support 10 high-burden countries as part of the Special African Union Summit on HIV/AIDS, Tuberculosis and Malaria.

Dr Fatoumata Nafo-Traoré, Executive Director, Roll Back Malaria (RBM) Partnership in her welcome address) acknowledged the high level of commitment of partners and the high level of leadership from endemic countries over the past decade in the fight against malaria resulting on 44 countries seeing a > 50% reduction in malaria cases, but we cannot rest in the face of financial and technical challenges.

Dr Mustapha Sidiki Kaloko, the African Union Commission’s Commissioner for Social Affairs in his opening remarks reminded us that external funding has never been guaranteed, and as it is ebbing we need to scale up domestic financial support. The AU will work with all stakeholders to help close the $4b gap and not let gains reverse. In order not to lose momentum innovative domestic funding models are needed.

Joy Phumaphi, Executive Secretary of the African Leaders Malaria Alliance (ALMA) delivered the ALMA Scorecard update. She noted that the scorecard provides a roadmap and pushes countries to demonstrate results. Very positive results in terms of adopting policies that oppose artemisinin monotherapies and promote community case management are the norm now.

The challenge is the low scores on public sector management and effective use of existing resources. Efficiency gains could deliver up to 40% more services with available money. Continued scorecard success also depends on global attention remaining focused on Africa as post MDG goals are being set.

Dr Robert Newman, Director of the WHO Global Malaria Programme (WHO-GMP) introduced the new Larval Source Management (LSM) Manual. He told the gathering that the new LSM Manual was a result of advocacy by Nigeria’s Minister for Health.  IRS and ITNs have been success stories, but we need to use all available tools in appropriate manners. LSM has a unique niche where one finds discrete, fixed and definable water bodies as opposed to water in multiple diffuse sources like cattle foot prints on a rutted road that come and go over days.

Larvicides are expensive and labor intensive and need regular monitoring. People need to remember that environmental management is another larva control tool.  With all vector measures “commodities don’t deliver themselves”, but require commitment and action of people at all levels form the national to the community.

Dr Richard Kamwi, Hon. Minister of Health, Namibia, shared that in the 1990s there were 7,000 malaria deaths in his country annually, but only 4 in 2012. Namibia has a mixed strategy especially in the northern border area, and is close to pre-elimination.

Dr Robert Newman, Director of WHO-GMP gave a presentation on the Malaria Situation Room concept and explained that even though progress has been made and millions of lives saved, there are over 219 million cases of malaria annually and 660,000 deaths/ A disproportionate burden of malaria deaths even now is in African children under five years of age. We have responsibility for these children.  This burden is focused on 10 countries which account for 70% of malaria cases in Africa and 56% globally.

The Malaria Situation Room will be a way to collate data on funding, intervention, commodities and results.  International partners will continue to support all endemic countries, but malaria elimination will remain elusive unless more coordinated action is aimed at high burden areas.

With only 900 days left before the MDGs reach their target date (end of 2015), we want to anticipate and prevent problems like stock-outs, but wait to hear that there have been no antimalarials in clinics for over a month. We want to be proactive in the face of potential dis-investment to protect 10 years of progress which could be undone in only one malaria transmission season.

Dr Alexandre Manguale, Hon. Minister of Health, Mozambique noted that his country is one of the ten in the “situation room.” Mozambique has made great progress in case reduction in the south with support from the cross border Lubombo Spatial Development Initiative. The rest of the country poses special challenges with logistics and weather (flooding). Under these circumstances partners need to coordinate and be flexible in response to gaps and bottlenecks. Information gathered and shared through the situation room will make this possible.

At this point Dr Newman, Dr Nafo-Traoré and Dr Kaloko officially launched the Malaria Situation Room with a ribbon-cutting. Now the work begins to make this ‘room’ a pro-active place to eliminate malaria.

The International Certification Team (ICT) for Guinea Worm Disease Eradication held a debriefing meeting with the Honorable Minister of Health of Nigeria on Friday 12th July 2013.  The team of over a dozen international and national experts had been working in-country to review the certification report prepared by the Nigerian Guinea Worm Eradication Program (NIGEP) within the Federal Ministry of Health (FMOH) for three weeks to learn if claims that the last case of the disease occurred in 2008 and that measures were in place to detect any imported or locally transmitted case in the interim. (Photo shows Nigeria’s Honorable Minister for Health, Prof. C.O. Onyebuchi Chukwu at right, receiving report from ICT lead by Prof. Molyneux on left, with Nigeria’s WHO representative center.)

This ICT visit in 2013 marks 25 years since the launch of NIGEP at a time when there were over 650,000 cases found in over 6,000 villages/communities, the highest burden of the disease in Africa and likely the world at that time.  The leader of the ICT, Prof. David Molyneux, thanked all the partners over the past two and a half decades who made today’s good news briefing possible. Prof. Molyneux is also Chairman of the International Commission for the Certification of Dracunculiasis (guinea-worm disease) Eradication (ICCDE) based in WHO.

The Commission has certified that two of Nigeria’s neighbors, Benin and Cameroon, are already free of guinea worm. Niger to the north is also in the pre-certification phase, while active transmission is still occurring on a small scale in Chad. Prof. Molyneux explained that the concern about these neighbors to the north and northeast is the potential of imported cases through population migration, hence the need for continued strong surveillance as part of an overall national health surveillance system.

In the process of verifying information in the national report on guinea worm elimination and validating its contents the ICT visited 17 States and the Federal Capital Territory, 60 Local Governments, 136 villages and interviewed 1,630 people using standardized questionnaires. Prof. Molyneux said the team took each State into consideration as a separate entity since some are larger than whole countries that have previously been certified.

Surveillance that helped Nigeria document no new cases since 2008 included 1) regular reporting on multipurpose surveillance forms at all frontline clinics, 2) incorporation of case searches into community and house-to-house health activities such as national immunization days/child health days and ivermectin distribution for onchocerciasis control, and 3) radio advertisements/jingles that describe guinea worm and offer a reward of N25,000 (approximately $160) and subsequent follow-up of rumored reports that this stimulates. These activities need to continue as long as countries in the region may still harbor the disease.

The team also reviewed contributing factors to maintaining a guinea worm free Nigeria, in particular village water supplies. While they noted that access to safe water had increased in many rural villages, there was still a problem of maintaining various kinds of wells and water systems.  At the start of global guinea worm eradication efforts during the United Nations Water Decade (the 1980s) the importance of guinea worm being the main infectious disease transmitted only through poor water supplies was stressed.

The next steps after this informal briefing of the FMOH is transmission of the ICT report to the ICCDE. The decision of the ICCDE will then be sent to the Director General of WHO, who will then communicate the findings and recommendations to the Nigeria FMOH officially.  Hopefully before the end of 2013, Nigeria will be declared free of guinea worm, and as Prof. Molyneux said, strong vigilance and surveillance will need to stay in place, including cross-border collaboration to prevent reintroduction of the disease. (Photo shows two Nigeria Guinea Worm pioneers, Prof. Eka Braide on right and Prof Luke Edungbola on left who were among the original zonal coordinators for NIGEP)

Eradication of guinea worm will only be achieved once each endemic country is certified free of the disease.  The certification process is lengthy, thorough but absolutely necessary. Similar processes need to be strengthened for other infectious diseases.