Mathur K K, Harpalani G, Kalra N L, Murthy G G, Narasimham M V
Regional Office for Health & Family Welfare, Jaipur, India.
Indian J Malariol. 1992 Mar;29(1):1-10.
Barmer district of Rajasthan in Thar desert and hitherto a hypoendemic area for malaria came in the grip of a severe malaria epidemic during 1990. The epidemic occurred as an aftermath of floods, preceded by normal rains during 1988 and 1989 after a prolonged drought phase. The epidemic was spread over the whole district including Barmer town. Annual Parasite Incidence (API) and Annual falciparum Incidence (AFI) for the district touched record figures of 17.20 and 5.83 respectively while for the Barmer town they were 36.5 and 14.0 respectively. Out of the eight PHCs, Baitu PHC was the worst affected where the two indices touched all-time high figures of 55.3 and 19.6 per cent respectively. A total of 122 infants were reported positive for malaria, of which 103 were contributed by Baitu PHC alone. Eighty per cent infant positivity was spread over September and November, indicating a high rate of transmission. A total of 47 deaths due to cerebral malaria were reported. However, in view of the high infectivity among infants and paediatric groups there was a strong possibility of deaths among these groups which could not be verified. Entomological findings revealed that a sudden increase in An. culicifacies densities due to extensive breeding potential, as a sequel to floods, activated the transmission, which was maintained at a low level by An. stephensi, predominant in this desert region. Other factors which contributed to the intensity and extent of epidemic were the return of drought-migrated population from malarious areas, low cattle density, malaria non-immune population, inadequate and poor spray coverage and delayed radical treatment. Insecticide adult susceptibility tests revealed a high degree of resistance in An. stephensi against DDT and dieldrin.
拉贾斯坦邦塔尔沙漠地区的巴尔默县，一直以来是疟疾低发地区，却在1990年遭遇了严重的疟疾疫情。此次疫情是洪水过后出现的，在经历了长期干旱阶段后，1988年和1989年降雨正常。疫情蔓延至整个县，包括巴尔默镇。该县的年度寄生虫发病率（API）和年度恶性疟发病率（AFI）分别达到了创纪录的17.20和5.83，而巴尔默镇的这两个指标分别为36.5和14.0。在八个初级卫生保健中心（PHC）中，拜图初级卫生保健中心受影响最严重，这两个指标分别达到了55.3%和19.6%的历史最高水平。共有122名婴儿疟疾检测呈阳性，其中仅拜图初级卫生保健中心就有103名。80%的婴儿阳性病例集中在9月和11月，表明传播率很高。共报告了47例脑型疟死亡病例。然而，鉴于婴儿和儿童群体中的高感染性，这些群体中很有可能存在无法核实的死亡病例。昆虫学研究结果显示，由于洪水后广泛的繁殖潜力，库氏按蚊密度突然增加，激活了传播，而在这个沙漠地区占主导地位的斯氏按蚊将传播维持在低水平。导致疫情强度和范围的其他因素包括从疟疾流行地区返回的干旱迁移人口、低牛密度、对疟疾无免疫力的人群、喷洒覆盖不足和质量差以及根治治疗延迟。杀虫剂成蚊易感性试验显示斯氏按蚊对滴滴涕和狄氏剂具有高度抗性。
