Tropical Health Matters

A recent WHO publication, Preventing Disease through Health Environments, addresses environmental factors responsible for malaria spread and control. Malaria contributed 10% to the environmental burden of disease for children aged 0-14 years worldwide. Specifically, “An estimated 42% of the global malaria burden, or half a million deaths annually, could be prevented by environmental management.” According to the document, There are three main approaches to the environmental management of malaria:

• Modify the environment. This approach aims to permanently change land, water or vegetation conditions, so as to reduce vector habitats.
• Manipulate the environment. This approach temporarily produces unfavourable conditions for vector propagation and therefore needs to be repeated.
• Modify or manipulate human habitation or behaviour. This approach aims to reduce contact between humans and vectors

Although some elements of individual and household behavior are involved in environmental control, it would be be an exercise in victim blaming to assume that individuals and households can take the main responsibility for taking environment measures. Water supply, drainage, road construction, river and stream control and other environmental measures are the responsibility of institutions and governments. Unfortunately such infrastructural improvements are costly, and one does not see them addressed in major malaria control programs like GFATM and PMI.

The World Bank has noted that, “Malaria affects millions in the East Asia and Pacific (EAP) region and impedes economic development, particularly affecting the rural poor. In the early 1900s malaria was controlled in many parts of the region using environmental management (EM) for vector control. EM is where the environment is modified or manipulated to reduce malaria transmission by attacking local vector mosquitoes and requires an understanding of the ecology of these species. Today malaria control is based on drugs and insecticides…” Because of questions of sustainability and resistance, the possibility of a return to environmental management is raised.

The World Bank’s Malaria Booster Program document does consider some elements of environmental management, but many of these fall more in line with integrated vector control measures in country examples like IRS, larviciding, and larvivorous fish. Some mention is made of filling spots of standing water. The larger infrastructural issues are not addressed. This is not to say that wider World Bank projects don’t address such issues, but what is needed is a more integrated approach that the malaria control potential of infrastructural projects is assessed and planned. Other development partners need to join in this effort.

The Agencia de Informacao de Mocambique reported that, “spraying campaigns have often failed to attain the desired results because people refuse to allow the Ministry of Health teams to spray their homes. The last spraying campaign, intended to cover 47 of Mozambique’s 128 districts, only met 37 per cent of its target.” The Ministry of Health reported that, “much of the low coverage is due to people simply refusing the health workers access to their homes.” Similarly the President’s Malaria Initiative (PMI) identified that only 50% of targeted homes were covered in a 2006 IRS campaign in Mozambique.

The World Health Organization confirms that part of the decline in the use of IRS to control malaria has been low community acceptance. “Community acceptance of house spraying and cooperation, for exam­ple, by allowing access and removing some household contents prior to spray­ing, are critical for the program to be successful. Repeated spraying of houses commonly generates fatigue and refusal by householders. Reduced acceptability has been an impediment to effective IRS implementation in vari­ous parts of the world.”

WHO identifies other factors that reduce community acceptance including, “Some insecticide formulations are less acceptable because of their smell or because they leave unattractive deposits on walls.” IRS may also make community members feel uncomfortable and suspicious of spray teams, such as when household possessions are moved to enable spraying, as seen in the drawing from a WHO Eastern Mediterranean Office publication.

One was to overcome these problems is enhancing community participation and improving the capacity of the health system: “Acceptance and cooperation by house owners are higher with better health education and more involvement in planning. The cost for personnel is much reduced although the local health service or a community-based organization may have to give the spray workers some financial or other compensation. The health services, however, have to be strengthened in order to provide health education as well as the supervision and evaluation of activities.”  Similarly, PMI suggested that a “well-run … spraying program has been able to keep refusals below 5-10% over the course of 11 rounds of spraying” through involving community leaders and string health education efforts. Therefore, IRS, like any other public health intervention, needs a strong community involvement and health education component to succeed.

The Sixtieth Session of the World Health Assembly (WHA) endorsed the creation of Malaria Day to bring global awareness to what has been to date Africa Malaria Day Resolution (A60/12). This follows on the heels of creation of Malaria Awareness Day in the US to compliment Africa Malaria Day. In the process the WHA wound up officially excluded Intermittent Preventive Treatment for pregnant women (IPTp) from the list of key interventions to being simply an activity that is implemented in Africa. This follows elevation by the WHO’s Global Malaria Program of IRS to a key global strategy and demonstrating that pregnant women in Africa are no longer important to the global fight against malaria – just a regional anomaly.

One excuse for demoting IPTp is supposed sulfadoxine-pyrimethamine (SP) resistance. Interestingly it is the same WHO along with researchers who have found that SP for IPTp is effective even at rates of 50% resistance among non-immune children under five years of age. No less an authority than peer reviewed Lancet articles have recently made the case for continuing IPTp with SP. Maybe the WHA has been tricked by people who don’t realize that even in a ‘global’ malaria program, the greatest burden of malaria falls on children and pregnant women in Africa.

The issue of DDT for malaria control continues to raise emotions. Even though the World Health Organization has endorsed the use of DDT for indoor residual spraying (IRS), people make emotional claims that the banning of DDT has causes millions of deaths, because of political wrangling over its safety. A common response to the situation is to blame Rachel Carson.

The WHO position paper on IRS traces the history of its use in malaria control dating back to the 1950s, a time of optimism for eradicating malaria. While acknowledging that changing opinion about DDT safety was involved in its discontinued use, the position paper points out other serious constraints including “lack of government commitment and financing to sus­tain these efforts over the long term and to concerns about insecticide re­sistance and community acceptance.” A major reason why malaria eradication efforts of the 1950s and 1960 failed in Africa was the lack of health system infrastructure to maintain continued IRS.

The early success of IRS was not just a matter of health infrastructure, but also of epidemiology. Greater success was recorded in areas where malaria was seasonal/epidemic – areas where IRS did not have to be maintained year round.

Issues of epidemiology and entomology, not emotion are leading groups like the Malaria Consortium to encourage dialogue on appropriate use of IRS, especially in highly endemic areas with year round transmission. In particular, Kolaczinski et al. note “In high transmission settings, IRS must be implemented indefinitely and at high quality to achieve control. As current infrastructure limitations and unpredictable funding make this unlikely, each country must carefully consider the role of IRS.” In short each country must examine its own financial and epidemiological situation and make a rational choice. A combination of strategies, including ITNs, is available as no one intervention fits all circumstances. Kolaczinski and colleagues also point to the need for better costing data to aid national malaria programs in making such hard decisions.

There are donors who can help make the financial decisions easier in the short run. PMI is pledging to make IRS available in all 15 of its countries in an appropriate manner based on “environmental assessments.” The Global Fund also acknowledges the use of IRS. The GFATM malaria grant to Liberia is an example of a grant proposal that includes IRS, and IRS is being implemented in Yemen. Now that IRS has been added to the current arsenal of anti-malaria weapons, it is time to stop complaining and start fundraising to guarantee adequate supplies as well as well trained and equipped malaria control staff who will apply IRS in a safe and epidemiologically sound manner.

Ghana, like other countries in the region, is reported to be revising its national malaria strategy. Most countries developed a new strategy document around 2001, at the beginning of the Roll Back Malaria Partnership, that reflected the goals of achieving 60% coverage of the core interventions (ITNs, IPT and appropriate and timely case management).  This level was supposed to have been achieved by 2005, and then new targets of 80% coverage took effect for the 5-year period starting 2006.  Many changes occurred between 2001 and 2006 including the availability of artemisinin-based combination therapy (ACT), long-lasting insecticide treated nets (LLINs), and the re-emergence of indoor residual spraying (IRS).

Some shifts in policy have occurred, and it is natural for a new strategy to be developed to account for these. The Global Fund for Fighting AIDS, TB and Malaria (GFATM) noted that Ghana switched to ACTs, and now the country needs to embody this in their malaria strategy. Ghana was given permission to use artesunate-amodiaquine as its ACT rather than the pre-qualified drug artemether-lumefantrine.  Drug quality issues resulted in serious side effects that eroded the public trust. The Food and Drugs Board took action, and as the GFATM noted, the PR worked hard “to overcome the bad publicity around the launch of ACTs.” Therefore the new malaria strategy needs a strong health education component to overcome and remaining public skepticism about the intentions and quality of the national malaria control effort.

Another challenge of the new malaria strategy will be to prevent the diversion of nets into the private sector. This problem likely arose in part due to the fact that cost was a major issue that prohibited net ownership before the start of the GFATM grant.

Ghana is also considering IRS, which is possible now that Ghana has been designated a PMI country. The challenge with IRS is determining the appropriate insecticide because of varying resistance of vectors in different regions of the country.

Overall the biggest challenge in revising the malaria strategy is determining Ghana’s own national malaria control needs and then coordinating the input of donors to meet those needs rather than developing a strategy based solely on what the donors expect.

A recent posting by Christine Afandi summed up succinctly most of the human health concerns about DDT.  While not downplaying human health effects, a bigger issue is, how can we keep DDT confined to the walls of homes? Shortly after Uganda announced its intentions to use DDT, neighboring Rwanda made the opposite decision and expressed concern that DDT use in Uganda would pollute its neighbor’s environment.  How could this happen if countries follow WHO guidelines and use DDT only for indoor residual spraying (IRS)? Unfortunately, the answer is simple: leakage.

The newer donor programs are often focusing heavily on getting commodities out to communities at the expense of strengthening the management and oversight systems that ensure these commodities are used properly.  Hence, one finds ACTs intended for public clinic use being sold in private pharmacies and drug shops. Stories about chemicals abound: pesticides intended for cocoa trees being used to kill and harvest fish; supplies of ‘abate’ intended for guinea worm control gone missing.

Leakage of malaria medicines costs individual lives by denying free treatment to poor children. Leakage of DDT supplies into the commercial and agricultural sectors threatens the whole environment. The question must be addressed: are malaria control programs and public health systems capable of safely managing and controlling DDT supplies?  Until that question can be answered with strong assurance, IRS programs should be kept on the back burner.