Category Archives: Indoor Residual Spraying

Pesticide safety – lessons from the green revolution

In light of the current world food crisis the BBC has re-examined the experiences of the Green Revolution. This high tech approach to increasing farm output appears on the surface to be a success in the Punjab of India. The BBC’s David Loyn reported on the experiences of one farmer: “Before Mr Singh’s father died young of cancer in 1992, none here suspected that the technology that had brought wealth to these farmlands in the 1970s might have a downside as well.”

Mr. Loyn looked more closely into the issue of the pesticides required by these crops. “The sprays all have instructions demanding that they should only be used with face masks and protective clothing. But the farm workers here do not use protective equipment, and they spray far more than the recommended amount. The cause of cancer is always a contentious issue, but a new study from the Punjabi University at Patiala ruled out other potential factors like age, alcohol intake and smoking, concluding that the way the sprays are used is causing cancer.”

Around a dozen insecticides are approved for use in Indoor Residual Spraying. WHO cautions that, “When implementing IRS, it is critical to ensure that adequate regulatory control is in place to prevent unauthorized and un-recommended use of public health pesticides.” Safety should be a major concern –

Another major consideration when selecting an insecticide is safety. Insecticides recommended by WHO are deemed safe for public health use under the recommended conditions of use. Concerns over the safety of DDT, a persistent organic pollutant, have also been comprehensively addressed in the framework of the Stockholm Convention on Persistent Organic Pollutants (POPs). The Convention bans the use of DDT, except for public health purposes. Therefore, DDT can be used for IRS where it is indicated, provided that stringent measures are taken to avoid its misuse and leakage outside public health.

lrg-102-img_1606_ethiopia_lowres-sm.jpgIn a comparison of the cost advantages of various insecticides that can be used for IRS, Walker (2000) emphasizes that safety measures must be included in the cost calculations. Even in the re-treatment of ITNs, WHO recommends that, “The use of rubber gloves is essential; mouth and nose masks should be worn when dipping large numbers of nets, especially with emulsifiable concentrate formulations.” The document also stresses that people who pack, mix and spray insecticides should also wear protective devices/clothing.

We hope that with proper care, supervision and protection of malaria workers, the community members they serve and the environment, we will see the history of today’s malaria control efforts written without the downside as experienced in the Green Revolution.

United Nations – ambitious plans for 2010

buttonwhite_fr.gifWorld Malaria Day is time for hope, and the United Nations Secretary-General, Ban Ki-moon, is not disappointing. The BBC reports that, “In a video message for a UN World Malaria Day event, the Secretary-General announces an initiative offering household sprays and bed nets treated with insecticide “to all people at risk, especially women and children in Africa” by the end of 2010.”

This is an almost unbelievable though desirable goal, much over the 80% RBM targets for 2010. The Secretary-General prefers to call this goal “bold, but achievable.” Even with help from GFATM, PMI, the World Bank Booster program, UNITAID and others, many countries are struggling to meet the 2005 target of 60% coverage of vulnerable populations with ITNs and medicines. The new UN malaria envoy, Ray Chambers has done the math –

  • 500 million additional people
  • 250 million additional ITNs/LLINs
  • less than 1,000 days to achieve this
  • “That’s four-to-five times what we’ve done in the past”

While this effort will push us toward eradication, Chambers is realistic in stating that the goal of complete elimination of the disease will depend on vaccine development, which is still some years away.

Reuters News also adds a note of realism by quoting a statement from the U.S. National Institutes of Health which said that malaria has proven to be “remarkably resilient, resurging because of the emergence of drug-resistant parasites and insecticide-resistant mosquitoes.” Reuters also mentions the unknowns created by global warming for consideration. These concerns add a sense of urgency that simple mentioning of 2010 may not confer.

Ironically, targeting these new malaria intervention and coverage goals comes on the heels of concern that African countries, where malaria is endemic, are unlikely to meet the Millennium Development Goals, which include malaria reduction. Clearly there are serious challenges in terms of finance and health systems issues to achieving universal overage in under 1,000 days – we hope all partners will heed this challenge on World Malaria Day and work together to meet it.

A Gold Standard for IRS

The VOICES website features a success story on corporate responsibility and contribution to malaria control in Ghana – the efforts by AngloGold Ashanti to organize state of the art indoor residual spraying in the district of Ghana where they have their mining operations.  The case study showed that from the start in early 2005 until near the end of 2006, hospital cases of malaria in the district droped by 50%.  Recent updates show continued progress as seen in the attached chart.

obuasi-malaria-control-program.jpgThe IRS program in Obuasi district started its fifth round of bi-annual spraying in March 2008. Since the start of the program, major drops in clinic attendance for malaria have been seen. Some parasitological studies were done at baseline and once since the start, and showed a similar trend, but these surveys need to be done more regularly to provide definitive proof of the intervention’s effectiveness.

A recent report to Ghana’s National Malaria Coordinating Committee on the project showed 1) positive community acceptance, 2) wide use of a variety of education and information channels, 3) the addition of larviciding, and 4) the functioning of a Malaria Control Center that monitors activities, provides training and receives visitors from partners around the region. The project has created 128 jobs in the community. Other mining companies in the country are apparently considering a similar venture into corporate responsibility.

The Obuasi model is expensive relative to what typical government programs can afford, in part because ecological conditions require bi-annual spraying. The Malaria Center is an additional cost, but a valuable contribution to the national malaria control effort. The US President’s Malaria Initiative is in the process of building on the Obuasi experience and expanding IRS into five districts further north where once a year spraying will be appropriate and thereby test the feasibility of wider IRS use as part of the Ghana National Malaria Control Program.

Ghana had applied to the Global Fund for IRS activities in Round 7, but was unsuccessful. If IRS is going to be rolled out fully in the ecologically appropriate districts (at least 50), the levels of funding support possible from GFATM are needed. Hopefully partners will rally to ensure that Ghana is successful in its malaria proposal for Round 8.

Revisionist Malaria History – the case of IRS

A new report on the implementation of Indoor Residual Spraying (IRS) by the World Health Organization begins with the following ‘historical’ perspective: “In the 1950s and 1960s the WHO led malaria eradication campaign eliminated the risk of malaria infection for about 700 million people mainly in Europe, Asia and Latin America within a period of about 20 years using IRS as a major tool. In the 1980s, following the global consensus to replace malaria eradication campaign by a long term control program, use of IRS was significantly reduced. In Africa, the intervention was abandoned except in some countries in southern and eastern Africa where IRS remained the corner stone of the malaria control strategy.” The report goes on to expound on the return of IRS and its potential for success throughout Africa.

lrg-87-img_1544a_ethiopia_lowres_sm.jpgThe above statement makes it sound like the world community just woke up one day and decided, “Let’s stop IRS”, with little reference to problems faced by famed Malaria Eradication Program (MEP). Fortunately Randall Packard has also recently published a book on the history of malaria that helps set the record straight on the MEP.

Technically the MEP was launched in 1955 and came to an official close in 1969, but even before it started, its main technical intervention, IRS with DDT, had already shown signs of mosquito resistance. A number of factors including low levels of economic development, poor health system infrastructure and donor fatigue led to the close of MEP. It truly was a daunting task given the limited tools and difficult environment in many countries.

Today there are more tools, but some are more expensive, e.g. ACT compared to chloroquine. There is also a greater choice of insecticides, though again, cost is a consideration. The new WHO report brushes on some of these challenges, especially the low levels of health system capacity in some of the most endemic countries. But as Packard points out these tools alone are not enough unless programs address the basic underlying social and economic factors that continue to ‘protect’ the persistence of this killer disease.

Island getaway … from malaria?

A press release yesterday announced that, “Research in Zanzibar, Tanzania has found a remarkable fall in the number of children dying from malaria. Within a three-year period (2002 to 2005), malaria deaths among the islands’ children dropped to a quarter of the previous level and overall child deaths to half.”

Zanzibar is an island, and that makes control of any disease special. Mabaso, Sharp and Lengeler conducted a historical review of malaria control in Africa and looked especially at IRS efforts between the 1940s and 1960s. They noted that, “IRS was not taken to scale in most endemic areas of the continent with the exception of southern Africa and some island countries such as Reunion, Mayotte, Zanzibar, Cape Verde and Sao Tome.” Malaria has returned to some of these islands, and the authors warn that IRS by itself is not a magic bullet.

dscn9483sm.JPGA key feature of the effort in Zanzibar was the use of ACTs and LLINs together. These interventions have been supported by both the US President’s Malaria Initiative and the Global Fund to Fight AIDS, TB and Malaria, which has provided assistance for both treatment and LLINs specifically to Zanzibar in Rounds 1 and 4.

Progress on Bioku Island in Equatorial Guinea is happening, but not at the same rate as Zanzibar. Marathon Oil has helped with IRS and ExxonMobil with nets. Marathon reports that annual insecticide spraying campaigns started February 2004., and the program achieved “44% reduction of malaria parasites in children and 95% reduction in malaria transmitting mosquitoes.” Researchers have also documented “42% fewer infections occurring in 2006 compared with baseline (2004)” and reduction associated with recent house spraying or net use. They also stressed the need for comprehensive monitoring of coverage and correct use of IRS and ITNs, as there were variations in mosquito populations on the island.

Sao Tome also experienced a drop in malaria prevalence after a successful pilot ITN program. Currently Sao Tome is using GFATM money to implement a mixed method strategy and scale up free distribution of insecticide-bed nets, community-based management of malaria, provision of information, education and communication (IEC) about malaria, Intermittent Preventive Treatment (IPT), and artemisinin-based combination therapies (ACTs).

While disease control on an island may appear simple, the process is obviously a microcosm of the challenges faced on the mainland. Lessons from the eradication days show that one strategy alone may not yield long term results. Hopefully Zanzibar’s lessons of mixed approaches to malaria control will guide other national malaria control programs.

Environmental Management of Malaria

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.

safe-and-reliable-water-for-the-community.jpgThe 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.

IRS – does the community accept?

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.”

remove-hh-items-before-irs.jpgWHO 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.

de-globalizing pregnant African women

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.

DDT – an emotional or an epidemiological response?

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.

Revising Ghana’s Malaria Strategy

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.