학술논문
Patterns of malaria indices across three consecutive seasons in children in a highly endemic area of West Africa: a three times-repeated cross-sectional study
Document Type
Report
Author
Source
Malaria Journal. May 28, 2014, Vol. 13
Subject
Language
English
ISSN
1475-2875
Abstract
Author(s): Denis-Luc Ardiet[sup.2] , Bertrand Graz[sup.1,2] , Thomas Szeless[sup.1] , Anne Mauris[sup.1] , Jacques Falquet[sup.2] , Ogobara K Doumbo[sup.3] , Amagana Dolo[sup.3] , Ousmane Guindo[sup.3] , Mahamadou S Sissoko[sup.3] , [...]
Objectives To study the manifestations of Plasmodium infection, and its relations with the malaria disease, especially when comparing dry and rainy seasons in a hyperendemic area of West Africa. Methods The study was carried out in an area where malaria transmission is high, showing important seasonal variations. One thousand children, representing the total child population (1-12 year old), were observed transversally at the end of three consecutive seasons (dry/rainy/dry). The usual indicators, such as parasite density, splenomegaly, anaemia, or febrile disease were recorded and analysed. Results The prevalence of Plasmodium falciparum was high in all age groups and seasons, constantly around 60%. The high transmission season (rainy) showed higher rates of anaemia and spleen enlargement and, in the youngest children only, higher parasite densities. There were also differences between the two dry seasons: in the first one, there was a higher rate of fever than in the second one (p < 0.001). Low parasite density ( Conclusions These data confirm previous hypotheses of a strong difference in malaria infection and disease between dry and rainy seasons. The most relevant seasonal indicator was not mainly parasite rate and density but anaemia, spleen enlargement, prevalence and possible origin of fever. Recommendations In any situation (i.e. fever or not) and especially during the dry season, one must consider that detection of parasites in the blood is only evidence of a Plasmodium infection and not necessarily of a malaria disease. In such a situation, it seems suitable to obtain, through national malaria teams, a well-defined situation of transmission and prevalence of Plasmodium infection following zones and seasons, in order to adapt control strategies. For researchers, a systematic management of data separately for dry and rainy season appears mandatory. Keywords: Plasmodium infection, Malaria disease, Season, Endemicity, Malaria indices, Epidemics, Epidemiology, Diagnosis
Objectives To study the manifestations of Plasmodium infection, and its relations with the malaria disease, especially when comparing dry and rainy seasons in a hyperendemic area of West Africa. Methods The study was carried out in an area where malaria transmission is high, showing important seasonal variations. One thousand children, representing the total child population (1-12 year old), were observed transversally at the end of three consecutive seasons (dry/rainy/dry). The usual indicators, such as parasite density, splenomegaly, anaemia, or febrile disease were recorded and analysed. Results The prevalence of Plasmodium falciparum was high in all age groups and seasons, constantly around 60%. The high transmission season (rainy) showed higher rates of anaemia and spleen enlargement and, in the youngest children only, higher parasite densities. There were also differences between the two dry seasons: in the first one, there was a higher rate of fever than in the second one (p < 0.001). Low parasite density ( Conclusions These data confirm previous hypotheses of a strong difference in malaria infection and disease between dry and rainy seasons. The most relevant seasonal indicator was not mainly parasite rate and density but anaemia, spleen enlargement, prevalence and possible origin of fever. Recommendations In any situation (i.e. fever or not) and especially during the dry season, one must consider that detection of parasites in the blood is only evidence of a Plasmodium infection and not necessarily of a malaria disease. In such a situation, it seems suitable to obtain, through national malaria teams, a well-defined situation of transmission and prevalence of Plasmodium infection following zones and seasons, in order to adapt control strategies. For researchers, a systematic management of data separately for dry and rainy season appears mandatory. Keywords: Plasmodium infection, Malaria disease, Season, Endemicity, Malaria indices, Epidemics, Epidemiology, Diagnosis