Schistosomiasis mansoni in Kenya: relationship between infection and anaemia in schoolchildren at the community level.
Haematological surveys were carried out in 3 schools in 2 areas where Schistosoma mansoni is endemic in Machakos District, Kenya, before and after a treatment campaign using praziquantel. Earlier clinical impressions of differences in the levels of anaemia between the 2 areas were not confirmed. Although individual haemoglobin levels and haematocrits often fell below international norms, significant anaemia with abnormal red blood cell morphology was rare (< 5%), but varied between schools. Altitude could have accounted for some of these differences, but other factors, including diet and parasitism, were involved. Anaemia was associated with splenomegaly and, to a lesser extent, hepatosplenomegaly. Epidemic malaria (mainly Plasmodium falciparum) appeared to be the main cause of parasite-induced anaemia. There was no significant association with the scarce hookworm infections (mainly Necator americanus); nor did the much commoner S. mansoni cause severe anaemia at the community level, but haemoglobin levels dropped as its intensity increased. Treatment with praziquantel eliminated this trend except in a few subjects with splenomegaly alone (probably due to malaria) or with schistosomal hepatosplenic disease. Possible pathogenic mechanisms are reviewed, including the consumption of red blood cells by adult schistosomes as a possible cause of anaemia.
Sturrock
R F
RF
Department of Medical Parasitology, London School of Hygiene and Tropical Medicine, UK.
Kariuki
H C
HC
Thiongo
F W
FW
Gachare
J W
JW
Omondi
B G
BG
Ouma
J H
JH
Mbugua
G
G
Butterworth
A E
AE
D000293:Adolescent; D000740:Anemia / Q000097:blood / Q000150:complications* / Q000453:epidemiology; D000980:Antiplatyhelmintic Agents / Q000627:therapeutic use; D002648:Child; D002675:Child, Preschool; D004909:Erythrocyte Indices; D004912:Erythrocytes / Q000473:pathology; D005260:Female; D006400:Hematocrit; D006454:Hemoglobins / Q000032:analysis; D006725:Hookworm Infections / Q000097:blood / Q000150:complications / Q000453:epidemiology; D006801:Humans; D007630:Kenya / Q000453:epidemiology; D008288:Malaria / Q000097:blood / Q000150:complications / Q000453:epidemiology; D008297:Male; D011223:Praziquantel / Q000627:therapeutic use; D012555:Schistosomiasis mansoni / Q000097:blood / Q000150:complications* / Q000188:drug therapy / Q000453:epidemiology; D013163:Splenomegaly / Q000150:complications
D000980:Antiplatyhelmintic Agents; D006454:Hemoglobins; D011223:Praziquantel