MALARIA: Staying the course on malaria research

JOHANNESBURG, 28 June 2011 (IRIN)

 Photo: Wendy Stone/IRIN
Lack of testing leads to frequent misdiagnosis in Africa

 Funding for malaria research and development has quadrupled in the past 16 years - new drugs, diagnostics and insecticides have been developed and a vaccine is in the final stage of testing - but the constantly adapting malaria parasite means the pipeline of new products and technologies needs to keep flowing.
A new report, "Staying the Course? Malaria Research and Development in a Time of Economic Uncertainty", analyses the progress that unprecedented levels of funding has achieved in recent years and warns that the future of the global fight against malaria depends on better coordination among a larger number of donors and ensuring that the money is more evenly spread.
Currently, the lion's share of research and development (R&D) funds goes to developing new drugs (38 percent), vaccines (28 percent) and basic research (23 percent), while research into diagnostic tests receives a paltry 1 percent of funding, and product development for controlling malaria-carrying mosquitoes (vector control) just 4 percent.
Partly this is because developing and testing new drugs and vaccines is much more costly than developing diagnostics and vector control products, but David Bell, head of the malaria diagnostics programme at the non-profit Foundation for Innovative New Diagnostics (FIND), believes it also reflects donor preferences.
"It's easy to sell the idea of a drug or vaccine because it saves lives. A diagnostic test also saves lives by stopping a child being given the wrong drug and ensuring they receive the right drug... but it's harder to sell that to donors," he told IRIN on the phone from Geneva.
Bell described his field as "grossly underfunded". This has slowed the development of new diagnostic tools and made it difficult to ensure the quality of existing tests for detecting malaria - in sub-Saharan Africa, where the use of diagnostic tests is not widespread, patients presenting with a fever are often misdiagnosed with malaria and treated for the wrong disease.
The report, published by the global health non-profit, PATH, and the Roll Back Malaria Partnership, estimates that funding for diagnostic tests needs to quadruple and remain at US$50 million per year for the next four years.
Some of the most pressing needs are for the development of rapid tests for less common types of malaria; a way to screen pregnant women with low levels of malaria parasites that can still harm a foetus; and more sensitive tools for detecting a potential resurgence of the disease in areas with low prevalence.
"The problem in areas where mortality [from malaria] is very low because interventions have worked, is that people lose interest and there's a danger we'll see a rebound in malaria, so we need to have these new tools to manage that," said Bell.

Vector control neglected
Spraying insecticides and treated bed nets have yielded impressive results in reducing the malaria burden in many parts of the world, but vector control has been neglected in recent years - just when resistance to the one class of insecticides licensed for use with bed nets, pyrethroids, has become widespread.
"There are very few locations [in Africa] where there isn't [pyrethroid] resistance," said Janet Hemmingway, CEO of the non-profit research group, Innovative Vector Control Consortium (IVCC). "If resistance is sufficiently strong, a treated bed net is of no more use than an untreated one."
Developing a new active ingredient is a seven-year process because of the need for long-term toxicology reports, but IVCC is looking at several agricultural insecticides to determine whether they could be "re-purposed" for malaria control.
"We know there's nothing ideal, but there could be something that would hold the fort for a few years while we get some new active [ingredients] through [the process]," said Hemmingway.
IVCC is also developing a simple point-of-use test to determine whether a net has been treated properly, and another for monitoring insecticide resistance in mosquitoes - but even with a five-year, $50 million grant from the Bill & Melinda Gates Foundation, and a further $28 million from other donors, they still face a $100 million funding shortfall.

More donors needed
Total funding for malaria R&D reached $612 million by 2009, up from $121 million in 1993, but nearly three-quarters of that amount was provided by nine organizations, most of them public and philanthropic, and just two organizations - the Gates Foundation and the US National Institutes of Health (NIH) - accounted for half of all funding, and most of the increase in funding in recent years.
According to the report, funding for malaria R&D only needs to increase by 2 percent per year to meet the goals agreed by the international malaria community in the 2008 Global Malaria Action Plan (GMAP). After 2016, earlier investments should start paying off and funders can begin to scale back their contributions. However, this best-case scenario depends on donors coordinating with each other to ensure funds are distributed more evenly.
The Roll Back Malaria Partnership hopes to achieve this during two donor meetings later in 2011. "We need to ensure the main donors are aware of the poor distribution of funds," said executive director Awa Marie Coll-Seck.
"We're hoping new donors will come along - it's important to diversify," she said, insisting that the goal of eradicating malaria from the world, set out in the GMAP, was still within reach.
"All the elements are in the pipeline - a vaccine, insecticides, diagnostics. The more results we see, the more we think it is possible," Coll-Seck told IRIN. "But the malaria parasite is always changing and adapting; you need to always be developing new tools to stay ahead of it."
http://www.irinnews.org/report.aspx?reportID=93090

MALARIA: Precaution and funding of vector control must be based on evidence

Richard Tren & Donald Roberts : 18 May 2011
Malaria Journal
In their paper "Status of pesticide management in the practice of vector control: a global survey in countries at risk of malaria or other major vector-borne diseases," van den Berg et al. make some generally accepted and valid arguments about the need for improved management of public health insecticides (PHIs). Given the importance of vector control, it would be beneficial for malaria control program managers and staff to be trained in proper insecticide use and management, if only to slow the spread of insecticide resistance. However the authors reveal an anti-insecticide bias and an ideological approach to disease control that could potentially undermine disease prevention efforts.
In stating "All chemical pesticides are inherently toxic to humans and precaution is required to minimize exposure and adverse health effects," the authors are creating opportunities for scaremongering. The needs for research and for improved procedures to minimize exposures to both disease-carrying insects and insecticides are self-evident. Yet, invoking "precaution" at the level of warning residents their houses are being sprayed with a harmful chemical to minimize adverse health effects should be based on proof of such adverse effects. Such proof does not exist, as exemplified by the circular logic displayed by the first author in another paper in which he and co-authors argue residents should be warned of possible harm from DDT exposures. In that paper the authors trumpeted "precaution" by justifying a claim of adverse health effects with the statement, "The very fact that there are so many precautions built into the WHO guidelines shows that IRS chemicals are considered hazardous." Such rationalizations reveal clear intent to expand the precautionary principle to restrain PHI use in disease control programs. Reasonable people know existence of safety measures (which often result from mere claims of potential dangers) does not imply IRS chemicals are dangerous. On the other hand, reasonable people accept that prudent safety standards are important. Warning residents that DDT and other PHIs are dangerous is neither prudent nor good public health policy because it would result in spraying refusals, an outcome that would increase risks of malaria transmission.
The authors conclude with the statement that support for vector control by donors and funding agencies should be contingent on them pursuing an IVM approach. We disagree strongly. Support for vector control programs should be based on the evidence of disease control efficacy. If a program that relies heavily on IRS delivers the best results in terms of disease reduction, then that is what should be supported. Though IVM should embrace effective methods of malaria control, such as IRS, we believe that IVM is far too often interpreted as adopting any and every vector control method except the spraying of insecticides. This is proven by the highly biased track record of funding malaria control programs without PHIs by the UN Environment Programme and Global Environment Facility. Making IVM a condition of funding elevates ideology above evidence and has no place in disease control programs.
In summation, the authors reveal intent to invoke the precautionary principle over disease control programs and use power of the purse strings to pressure governments away from critically important uses of PHIs to control malaria and other insect-borne diseases. The disease control community must continue to resist the anti-PHI agenda.
http://www.malariajournal.com/content/10/1/125/comments#506690

MALARIA: Amazon Malaria Initiative meeting

May 11 2011
For the next two days, Belize is hosting health officials from 13 South American countries on San Pedro. They are attending the Amazon Malaria Initiative meeting which affords countries of the region an opportunity to share experiences on interventions in the prevention and control of malaria.

Of special interest at this meeting is the use of Long Lasting Insecticide Treated Bed Nets. Belize has been participating in the initiative for the last several years now, and according to Dr. Jose Marenco, Head of Belize's Vector Control Unit, the Amazon countries bring with them a wealth of information on the topic of Malaria.

Dr. Jose Marenco- Head of Vector Control Unit
"Belize has been participating in this initiative for several years now. The relationship has intensified over the last 2 years actually. So it was decided that there was a need to have a meeting to review the strategy for the implementation of impregnated insecticide treated nets. It's something that Belize doesn't have much experience in. And so when we were approached about hosting the meeting, we found it important so we embraced the idea, and so we have 13 countries from South America coming to Belize to share their experience in the implementation of insecticide treated bed nets. So we have a couple of our associates from the Ministry of Health and Red Cross - we invited also - to share, listen and learn during these 2 days. Red Cross has distributed bed nets during times of disaster; we appreciate that very much. Ministry of Health has, since 2009, implemented bed net distribution also, but we do it not in a very systematic way. So learn a lot, not just to distribute them, but to monitor them, to see their residual effect - even the disposal at the end of the lifetime of the bed nets. Certainly, as we continue bringing malaria incidence down, this initiative can help us to keep the achievements so far."
http://www.7newsbelize.com/sstory.php?nid=19620

MALARIA: Status of pesticide management in the practice of vector control

Henk van den BergJeffrey HiiAgnes SoaresAbraham MnzavaBirkinesh AmeneshewaAditya DashMikhail EjovSoo Hian TanGraham MatthewsRajpal YadavMorteza Zaim
Credits/Source: Malaria Journal 2011, 10:125

Status of pesticide management in the practice of vector control: a global survey in countries at risk of malaria or other major vector-borne diseases
It is critical that vector control pesticides are used for their acceptable purpose without causing adverse effects on health and the environment. This paper provides a global overview of the current status of pesticides management in the practice of vector control.

Methods:
A questionnaire was distributed to WHO member states and completed either by the director of the vector-borne disease control programme or by the national manager for vector control.
In all, 113 countries responded to the questionnaire (80% response rate), representing 94% of the total population of the countries targeted.

Results:
Major gaps were evident in countries in pesticide procurement practices, training on vector control decision making, certification and quality control of pesticide application, monitoring of worker safety, public awareness programmes, and safe disposal of pesticide-related waste. Nevertheless, basic conditions of policy and coordination have been established in many countries through which the management of vector control pesticides could potentially be improved.
Most countries responded that they have adopted relevant recommendations by the WHO.

Conclusions:
Given the deficiencies identified in this first global survey on public health pesticide management and the recent rise in pesticide use for malaria control, the effectiveness and safety of pesticide use are being compromised. This highlights the urgent need for countries to strengthen their capacity on pesticide management and evidence-based decision making within the context of an integrated vector management approach.

http://7thspace.com/headlines/382496/status_of_pesticide_management_in_the_practice_of_vector_control_a_global_survey_in_countries_at_risk_of_malaria_or_other_major_vector_borne_diseases.html

MALARIA: What do we know about larvicides?

Bill Brieger 16 Nov 2010
In SciDec.net we read that, “Cuba has announced plans to build biolarvicide factories in Brazil and several African countries in a bid to tackle malaria and dengue fever.” The move is based on apparent successes of efforts such as those in Angola where the Director-general of Labiofam says that, “Angola, for instance, has reduced malaria incidence by 50 per cent, and some areas have seen a 70 per cent fall,” with similar results in Accra, Ghana.
WHO says that larviciding is “indicated only for vectors which tend to breed in permanent or semi-permanent water bodies that can be identified and treated, and where the density of the human population to be protected is sufficiently high to justify the treatment with relatively short cycles of all breeding places.” What actual documented evidence is there from Angola and elsewhere in Africa about the use and effectiveness of larviciding?
An article on the history of malaria control in Liberia reviews early efforts to use synthetic insecticides for indoor residual spraying and larviciding. Unfortunately, “These projects encountered a spate of difficulties that foreshadowed the general retreat from malaria eradication efforts across tropical Africa by the mid-1960s.” What has changed now that we are in the days of rolling back malaria?
A newly published article on mosquito larval source management in areas experiencing flooding in The Gambia concluded that …
The intervention was associated with a reduction in habitats with late stage anopheline larvae and an 88% reduction in larval densities. The effect of the intervention on mosquito densities was not pronounced and was confounded by the distance of villages to the major breeding sites and year. There was no reduction in clinical malaria or anemia. Ground applications of non-residual larvicides with simple equipment are not effective in riverine areas with extensive flooding, where many habitats are poorly demarcated, highly mobile, and inaccessible on foot.
A key approach to the use of larvicides may be integrated vector management, where there is not reliance on one control measure alone. In the Kenyan highlands researchers found that, “Vector control with microbial larvicides enhanced the malaria control achieved with ITNs alone. Anti-larval measures are a promising complement to ITN distribution in the economically important highland areas and similar transmission settings in Africa.”
Larviciding was found to have a positive effect in reducing childhood malaria in Tanzania where “larviciding reduced malaria prevalence and complemented existing protection provided by insecticide-treated nets. Larviciding may represent a useful option for integrated vector management in Africa, particularly in its rapidly growing urban centres.”
The two promising articles from Kenya and Tanzania would be strengthened if large scale operations like those described for Angola were better documented and published because as was seen in Liberia many years ago it was the basic operational issues that limited program effectiveness.
Devine and Killeen report in discuss some of the practical issues of larviciding in Malaria Journal and note that, “The effective operational implementation of these campaigns is difficult, time consuming, and expensive,” in part because of “The myriad and cryptic nature of aquatic habitats and the difficulty in identifying and targeting the most productive of these (which) makes maximizing that impact very challenging.”
Devine and Killeen recommend a “new auto-dissemination methodology” based on a “detailed characterization of oviposition behaviour and of the effective transfer distances between feeding, resting and aquatic resources.” Again, these are good ideas, but what of evaluation of current large scale approaches underway? In addition, as RTI suggests programs must establish “baseline information on the acute, intermediate, and chronic effects of chemicals used in malaria vector control on workers and the general population.”
The basic question remains - what can we learn about the right conditions for larvicide use as a major tool in integrated vector management for malaria? All partners in rolling back malaria have a responsibility for helping this learning process by documenting and publishing their experiences. Maybe the proceedings of the recent Labiofam Conference in Havana will be published soon.
http://www.malariafreefuture.org/blog/?p=1082

MALARIA: need to know about ecology of the mosquito

A global commitment to malaria eradication must also involve a long-term commitment to vector ecology. This is the message of the authors of a Policy Forum article published in this week's PLoS Medicine, who emphasize that malaria eradication efforts will not be successful until a better understanding of the ecology and evolution of the mosquito vectors is gained.
Gerry Killeen from the Ifakara Health Institute in Dar es Salaam, Tanzania and colleagues say that existing front-line vector control measures (such as insecticide-treated nets and residual sprays) cannot break the transmission cycle of Plasmodium falciparum in the most intensely endemic parts of Africa and the Pacific.
They argue that malaria eradication will require urgent strategic investment into understanding the ecology and evolution of the mosquito vectors that transmit malaria rather than sole investment in established means of preventing malaria transmission.
They particularly emphasize the need to understand the private lives of mosquitoes in the broader environment outside of houses where they spend most of their lives: most of what we know is based on waiting for them to come to us rather than us following them as they struggle to survive and reproduce, the authors say.
doi:10.1371/journal.pmed.1000303

MALARIA: India' Mumbai statistics

Mumbai: The mill land in and around South Mumbai may be expensive in the realty market, but it is also proving to be a dangerous breeding ground for mosquitoes causing malaria. Alarmed by this development, the Brihanmumbai Municipal Corporation (BMC) has now decided to rope in firemen to conduct fogging operations in mill compounds.
According to the civic health department records, 1,418 cases of malaria have been reported in the city’s private and public hospitals since June 1. On Friday alone, 63 patients with malaria were admitted to the city’s hospitals. The disease has also claimed four lives since June 1, said civic health authorities.
The figures also throw up an interesting fact that most patients, who tested positive, were migrants working at construction sites. “Construction sites pose a huge problem as they are breeding spots for mosquitoes. Also, the workers suffering from malaria are from the north and north-eastern states like Orissa, West Bengal, which come under the ‘the malaria belt’,” said an officer from the civic health department.
According to doctors in the city, there are an equal number of cases of both strains of malaria - vivax as well as falciparum. However, what is worrying is that the vivax strain, which hitherto had been milder than falciparum, is showing signs of increasing severity. “Nowadays, we are seeing patients with vivax also getting serious. In the last fortnight, I have seen about 20-odd patients - half of them suffering from vivax - who have required hospitalisation,” said Dr Pradip Shah, consultant physician, Fortis Hospitals at Mulund.
“My advice to patients is to keep their surroundings hygienic and see to it that no water collection occurs near their buildings, as this is where the female anopheles mosquitoes breed.”
According to the civic body, Kurla has been identified as the worst-hit locality. “I am treating about four fresh cases of malaria, mostly vivax strain, every day,” said Dr Sharad Menon, Kurla-based paediatrician. Fortunately, vivax strain is easier to pick up, so the diagnosis is easy, he added.
The BMC has taken several measures to tackle the mosquito-borne menace. “Many times, construction workers don’t allow the BMC staff to enter construction sites for fogging. We are planning to rope in firemen for this task,” said Manisha Mhaiskar, additional municipal commissioner.
“The BMC surveillance officers in every ward office will also go door-to-door and screen patients with high fever for malaria. The surveillance officers will then go back after 15 days and check the patient again for malaria symptoms, as that is how long it takes for the parasite to fully mature and start affecting a person.”
Mhaiskar assured that the BMC is doing everything possible to control the menace. “The civic body has distributed brochures on malaria to private practitioners as these cases reach the clinics first,” she said.
http://www.dnaindia.com/mumbai/report_expensive-mill-land-cause-of-malaria-in-south-mumbai_1401355

MALARIA: Getting the mosquito to do the work

Malaria pathogens are transmitted to humans by the bite of female Anopheles mosquitoes. The juvenile stages of these mosquitoes develop in a variety of water bodies and are key targets for vector control campaigns involving the application of larvicides. The effective operational implementation of these campaigns is difficult, time consuming, and expensive. New evidence however, suggests that adult mosquitoes can be co-opted into disseminating larvicides in a far more targeted and efficient manner than can be achieved using conventional methods.
A recent field trial with the dengue vector, Aedes aegypti, exploited the obligate behaviours of adultmosquitoes to transfer a potent larvicide between resting and oviposition sites.
An impressiveimpact on the juvenile population was mediated by 1) a highly effective and persistent insecticide, 2)the predictability of sites where adult mosquitoes could be exposed, 3) a limited aquatic habitat and 4) sufficient mosquito density. The use of adult females as larvicide-disseminating vehicles resulted in the very precise targeting of the insecticide; only those aquatic habitats visited by adults were contaminated and, the more popular the site, the greater the number of transfer events.
http://www.malariajournal.com/content/9/1/142