Malaria in Yemen on the Rise [Archives:1997/51/Health]

December 22 1997

Another parasitic disease which is on the rise again is carried by protozoans is transmitted by the Anopheles mosquito. Current forms of treatment have become insecure because of drug resistance developed by the microorganism. It is endemic in the tropics and coastal areas of countries having similar climatic or subtropical conditions. The entire Red Sea and Hadramaut coasts are fertile areas for this disease because of the climate. Mosquito larva need the coastal areas to develop and become adults. The parasite has different varieties, each capable of reproducing asexually in man and sexually in the mosquito; reproduction occurs in the blood cells and liver cells of man which break open and in the lining of the insect’s gut. The disease is transmitted as the insect bites a person who was previously infected or if it already harbours the protozoan, by biting a healthy subject.
Clearly the process of eradicating the disease has two alternatives; either by treating the subject so as to reduce the liability that he will harbor the protozoan or by eliminating the vector, in this case the mosquito. Risks of spreading are magnified as infected subjects travel to and from countries where the mosquito is still present and where they can act as new sources of protozoans for the mosquito. The symptoms arise when the plasmodium present in the blood cells, multiply causing the cell to burst open. The lysis is synchronous and this causes shivering, feeling cold, having fits of high temperature and sweating. The fever cycle varies according to the plasmodium; 48 hours for P. vivax, 72 hours for P. malariae. P falciparum causes bursts of fever at smaller time intervals . Prevention begins by knowing the culprit illustrated to the right: its resting position is classical, with the hind legs held up. The egg , larva and pupae representing the different stages in the development of the adult have characteristic shapes. The egg is not evenly surfaced as in the Culex mosquito and the larva lies relatively parallel to the water surface unlike the Culex variety which is suspended vertically. Most people don’t know that for the parasite to get into the blood it is not only introduced directly by the mosquito but travels directly from the liver where it is stored in the parenchymal cells and completes a sub-cycle of invading other cells there, under the merozoite form (see diagram). Today with the advent of resistance to chloroquinine therapy people are taking drugs like Fansidar distributed in Britain after having followed a quinine course. The prophylactic to take is Paladrin, twice weekly if there is the threat of an attack, but that is not advised for people who have already had malaria and have build up some antibodies against the disease.
The disease has its rarer forms like that entering the brain tissue in children causing cerebral malaria that is fatal and flash malaria in adults where symptoms reach their climax in ten to fifteen minutes as the person collapses, goes through the tremors and sweating and then quickly comes back to himself looking slightly pale. There is the malignant forms which carries on in waves of fever for several months and is usually lethal and Blackwater fever common in tropical Africa which manifests itself by the presence of blood exuding from the urethra and shooting pains in the marrow of the long bones. Until recently many western doctors hadn’t heard of this latter form. Malaria is for the most part chronic with onsets of flu like symptoms once every few years depending on the stress level of that individual. Statistics taken from the Yemen 1996 year book shows a higher percentage of cases at coastal centers like Hodeidah and Hajjah and smaller figures for the interior regions of Dhamar and Taiz, a sign that the occurrence of the ailment is on the increase due to the above mentioned factors. Last year Hodeidah had 75,410 cases, much more than the statistics for other infectious diseases of the area, like dysentery and infectious hepatitis with only 830 cases. Sanaa, although in the interior also has had a comparable amount of cases; 72,654 were reported. This may be due to the migration of infected workers from the coast to the city, untreated sewage dumps, rainfall accumulating as puddles in the city and the lack of awareness among carriers who do not treat themselves completely. Many patients, as soon as they feel better abandon the treatment course. These people do not follow up on the treatment by doing blood tests. This is why the percentage of malaria, 47 % is the highest among the transmissible diseases in Yemen.
Martin Dansky, Yemen Times