Summer 1997 (5.2)
An Ancient Scourge in Azerbaijan
by Dr. C.W. Oliver
It's mosquito time again in Azerbaijan. The female Anopheles mosquitoes in search of blood now seem to have found an endless supply of donors in the hundreds of thousands of Azerbaijanis who have fled their homelands in the Armenian-occupied Nagorno-Karabakh region.
Left: Typical sleeping tower for railway workers to escape mosquitoes and malaria in the Karabakh region at the turn of 19th century.
It's banquet time for these micro-vampires who utilize blood to supply the extra protein needed to facilitate ovulation and produce their next generation. Unfortunately, in exchange for their supper (they only feed between dusk and dawn), they can transmit a parasite to humans (Plasmodium vivax) which causes one form of the debilitating disease known as malaria, an ancient scourge on the rise again.
Refugees are easy prey because of their typically deplorable living conditions which usually lack screening or other hygienic amenities. In addition, they are usually located in the worst environs in close proximity to standing waters, ideal breeding grounds for the Anopheles mosquito. The health status of refugees who acquire malaria is further exacerbated because their immune systems are already weakened by years of poor nutrition and complementary infections from lack of sanitation. Vivax malaria, because of its chronic, debilitating nature, has been a serious impediment to local economies in endemic areas, particularly those dependent on agricultural labor.
Hardest hit are the refuges living in the marshy lowland regions of the interior and along the southern border near Iran. Thousands of cases of malaria have been reported in the refugee camps since 1993, while probably more cases outside the camps have gone unreported. In the past, few humans had lived in these harsh environs. They knew that malaria and other dangerous tropical diseases were endemic in the region. The ancients even wrote about malaria, calling it "the returning fever."
Symptoms and Treatment
Although the form of malaria found in Azerbaijan is not the life-threatening kind that exists in sub-Saharan Africa, vivax malaria can cause debilitating chronic disease characterized by febrile episodes, headache, lymphadenopathy, body aches and general malaise. Fever is periodic (every two days) with intermittent chills and profuse sweating. The distinguishing feature of vivax malaria is the relapse. The parasite has the propensity to aestivate (hide out) in the liver. Even years later, it can induce another bout of malaria when it moves back into the bloodstream. Currently in Azerbaijan, the treatment regimen of choice against vivax malaria is a course of chloroquine for the first phase (the blood stage), followed later by primaquine to prevent relapses from the liver phase.
Prevention is Possible
With the malaria season rapidly approaching again after a long winter in Azerbaijan, policy makers and medical relief agencies will undoubtedly be faced with the recurring dilemma of what can be done to prevent or control the next outbreak.
The epidemiological profile of malaria in Azerbaijan, given its seasonal and marginal endemicity, suggests that with the right approach, malaria can be successfully controlled and prevented through a committed health care system, an informed public and a modest commitment from a unified donor community.
Past measures of malaria control, such as widespread spraying of insecticides and distribution of antimalarial drugs, have been relatively ineffective, expensive and potentially dangerous. Mosquitoes are increasingly resistant to pesticides. In some countries, malaria parasites have already become resistant to drugs such as chloroquine and fansidar, especially if the drugs are not taken according to the prescribed schedule. Fortunately, there are safer, more cost-effective measures available today.
In 1993, the World Health Organization convened member countries in Amsterdam to develop a new Global Malaria Strategy based on the difficult lessons learned over the past decades. Some of the more salient recommendations for the prevention and control of malaria include:
Use of insecticide-treated netting materials. Anopheles mosquitoes typically feed each evening after dusk and before dawn. Permethrin, a synthetic analogue to pyrethrum (a derivative from the chrysanthemum flower), makes a safe, cheap and effective insecticide for impregnating netting materials, which can be used around sleeping areas and on windows, doors or roof eaves. The netting material can be treated either via hand dipping or incorporated into the fiber during manufacture. In the former case, the nets need to be re-dipped with permethrin prior to each malaria season. In most projects throughout the world, the netting material has been imported, since this has been the most cost-effective approach.
Rapid diagnosis and case management. Suspected cases need to be handled immediately, since patients who are not treated correctly have the ability to reinfect others via the mosquito, in vivax malaria, additional attention must be given to treat the multiple phases of the disease. Much of the difficulty in adequately addressing the malaria problem in Azerbaijan stems from a shortage of laboratory equipment and drugs, as well as appropriate training of personnel (due to the lack of resources in an overburdened health care delivery system). Lack of awareness and poor living conditions among the refugee population (who often have no access to health care are other major contributing factors.
Micro-environmental improvements and prevention education. Mosquitoes need water to breed. Draining pools of standing water would eliminate their breeding sites. Fewer mosquitoes would mean a reduction in transmission of malaria. In order for the local community to contribute toward addressing the malaria problem, it needs to understand how malaria is transmitted, what can be done to reduce transmission and exposure, and where to go to seek adequate treatment.
All of these measures require a commitment of cooperation and education form the local community, and must be deployed in an integrated fashion. Under the huge economic constraints faced by Azerbaijan, particularly with regard to the provision of health care for a large refugee population, there is still great need for humanitarian assistance toward that end from the international donor community. The first step in demonstrating that malaria can be effectively controlled and prevented would be the design and implementation of a community based intervention trial. Ideally, a pilot project would be implemented in an area with a large, concentrated population of humans and mosquitoes such as one of the larger refugee camps. Once successfully demonstrated, such a model could readily be replicated in other endemic areas. This could also be a humble first step toward sustainable development in the 21st century.
Cheaper diagnostic techniques for malaria. Genetically-engineered immunololgic tests are on the horizon that will enable health care personnel to provide an accurate diagnoses in five minutes. Such a test would require only a single drop of blood and a few reagents. This would eliminate the need for laborious, expensive and time-consuming microscopy.
Malaria vaccine. Although huge investments have already been made, it is unlikely that an effective vaccine will be available in the near future. Not enough basic research regarding malaria and related mechanisms of cell-mediated immunity has yet been carried out. Yet, as was the case with small-pox, the development of an effective malaria vaccine may be the only hope for the global eradication of this disease. Mosquitoes disdain border formalities, and the parasite has a long head start over medical science. After all the malaria plasmodium has spent 3 million years developing its on stealth-like methods for evading detection in its human host. On the same scale, it's as if our counter-attack began only this morning.
No malaria cases have been reported in Baku yet this year. The mosquitoes buzzing around Baku tend to be of the culicine family (Aedes aegypti), which are incapable of transmitting malaria, although they can transmit arboviruses such as dengue fever in Asia and yellow fever in Africa. Distinguishing between the two subfamilies of mosquitoes is possible. typically, the larger, malaria-carrying anopheles is poised at a 45-degree angle to the surface on which it rests. They also tend to have wing markings.
Visitors to endemic areas should first consult with a travel physician, who will most likely recommend a course of prophylaxis to begin two weeks prior to arrival. Lately, the drug of choice has been mefloquine (larium) which should be continued weekly during the visit and for two weeks after departure.
From 1993-95, Dr. Oliver was the Tropical Diseases Advisor from Johns Hopkins School of Hygiene & Public Health assigned to advise the U.S. Agency for International Development (USAID) on its global tropical disease programs. He has spent most of the past 20 years developing international public health programs in Africa and Asia, and most recently in Azerbaijan with Relief International.
For further information, contact Dr. Oliver at: firstname.lastname@example.org or visit the malaria Web site of USAID's Environmental Health Project at: http://www.access.digex.net/~ehp/webliog.html
From Azerbaijan International (5.2) Summer 1997.
© Azerbaijan International 1997. All rights reserved.