Cambodia's deadliest disease on the comeback trail

Cambodia¹s deadliest disease‹malaria‹appears to be making a big comeback in Cambodia, according to a new study by the National Malaria Centre (CNM). The study, released late last month, points to three recent epidemic outbreaks of malaria that took place earlier this year in Pursat, and in the Oral and Phnom Srouc districts of Kompong Speu province. Indicating that more than half of all of Cambodian children living in high-risk areas currently show clinical signs of the disease, the report goes on to sound the alarm bell about the possibility of future epidemic outbreaks of the disease. Even as recently as one year ago, medical officials in Cambodia were optimistic about the chances of bringing the spread of malaria under control. Between 1992 and 1995, the number of people who died from malaria every year in Cambodia fell by close to half, from 1,204 to 620. That decrease was seen as a sign that medical authorities were winning their battle against malaria, which had claimed a steadily rising death toll through the 1980s and early 1990s. Since, 1992, the CNM has been introducing effective new techniques for treating and preventing malaria‹including the use of insecticide-treated mosquito nets‹and providing extensive training to provincial medical practitioners. So what went wrong? Ironically, the CNM report says that the epidemic outbreaks are related to the decrease of what has been a very different sort of health risk in Cambodia‹the Khmer Rouge. With the high number of rebel defections over the past year, and the corresponding reclamation of territory by government forces, more and more people are venturing into extremely high-risk areas. In Kompong Speu, for example, there have been large numbers of people living as displaced persons in camps in parts of the province where the risk of malaria is low, thus losing their natural immunity to the disease. But in late 1996, the local Khmer Rouge leadership went over to the government side. The report goes on to say that‹fueled by rumors about a government move to grant concessions to logging companies‹a large number of displaced persons subsequently left the camps to return to land that they abandoned to the rebels, which often happened to be located in high-risk malaria areas. ³Massive malaria outbreaks occurred shortly after their arrival, and as there were no private drug sellers available, these outbreaks caused many deaths,² the report says. Dr Mey Bouth Denis, a CNM malariologist, adds that the Khmer Rouge¹s demise has meant that large numbers of men have begun venturing into forest areas formerly held by the rebels, to work as loggers and gem miners, or to hunt, thus exposing themselves to an extremely high risk of malaria. Last month¹s CNM report estimates that up to 20 percent of Cambodia¹s population‹approximately two million people‹risk contracting the disease in this way. Dr Mey Bouth Denis says that such mobility makes it tougher for the center to figure out what types of malaria are occurring where, and also makes it difficult to choose an appropriate localized method treatment that will avoid making particular strains of the disease more drug-resistant. ³There¹s lots of movement with the population. People go to places where there are jobs‹in the forests, in rubber plantations, in mining areas‹and when they move around (with malaria), it is a treatment problem,² he says. But the portion of the population considered to be at highest constant risk of exposure to malaria are the close to 500,000 Cambodians‹many of them from ethnic minority groups‹who live in remote forest villages. Dr Stefan Hoyer, a malaria project officer from the World Health Organization, says that there are some such villages which show all-time record rates of the diseases for all of Cambodia, Laos and Vietnam. Late last year, in a mission led by the CNM, Hoyer studied the incidence of the disease in Ka Chok village, in Ratanakkiri province, finding that more than 41 percent of all inhabitants and 60 percent of children showed signs of malaria parasites. ³We found, as far as I know, the highest malaria index ever measured in Vietnam, Laos and Cambodia,² he says. ³When we had discovered the record-breaking parasite rates in Ka Chok, we knew that every minority village in the densely forested southern Annamese mountain chain would be suffering to about the same extent.² Moreover, according to Hoyer, many of the villagers who were previously treated for malaria had been re-infected. ³Re-infection has occurred on an intense scale,² he says. As a result, the CNM‹which is also responsible for the treatment of Dengue fever‹focuses much of its attention on finding ways of controlling the spread of malaria in remote forest villages. CNM vice director Dr Doung Socheat says that the center¹s major breakthrough has been the adoption of insecticide-treated mosquito nets as the main method of malaria prevention in Cambodia. Other methods include the use of insect repellents and preventive drugs‹misuse of which leads to drug resistant strains of the disease‹but Dr Doung Socheat says that widespread distribution of free mosquito nets in rural areas has proven to be the most effective means of controlling the disease. ³(Preventative malaria drugs) are not effective for our people, because people don¹t take the drug treatments properly,² he says. ³The people when they take drugs think that it is enough, and they allow mosquitoes to bite them. But it is not enough. The drugs are not strong enough if there is repeated exposure, and all they will do is reduce the severity of the infection. ³And we can use repellents, but people are always in the forest, and they don¹t keep putting it on. ³But after we started giving out the nets, the number of cases of malaria went down,² Dr Doung Socheat says. ³We don¹t know the exact percentage, but it definitely went down.² Dr Doung Socheat, for his part, is wary about citing malaria statistics, explaining that the figures at his disposal are from government health facilities only, and do not include malaria cases treated by so-called ³private sector² health practitioners in Cambodia. ³We don¹t know how many people go through private sector,² Dr Doung Socheat says. ³We¹ve asked the private sector for their reports, but we do not have the numbers yet, and we do not have the money or the staff to get those numbers ourselves.² A related problem, Doung Socheat continues, is that the ³private-sector² label can include self-appointed medical practitioners with little or no knowledge of modern treatment methods. ³Private sector do not follow treatment protocols properly. We don¹t really know what they do for treatment.² As part of its community health education program, which is aimed primarily at inhabitants of Cambodia¹s most malaria-prone regions, the center distributes a variety of instructional materials that it has devised. The material includes T-shirts that feature a picture of a mother and her infant sleeping under a mosquito net, and a message about preventing malaria and Dengue fever. The T-shirts are handed out to people who are able to answer quiz questions about preventing these two diseases. Dr Doung Socheat, says that his favorite instructional item is a calendar that he himself designed. It comes with a permanent picture of a model wearing one of the center¹s T-shirts, and holding a mosquito net. Each of the monthly calendar pages highlights significant health-related dates, and includes disease prevention messages. Doung Socheat says that he got the idea for the calendar after noticing the popularity of posters of film stars and the like. ³I saw that people would hang up pictures of beautiful women‹film stars‹and keep them up,² he says. ³I thought, why can¹t we do that? So we produced the calendar. People hang the picture of the woman up on the wall, and they see the message every day. ³If it was a poster, maybe they read it once, and then throw away. The message is not very complex, and people understand it.²