title: Schistosomiasis mansoni in Kenya: relationship between infection and anaemia in schoolchildren at the community level.
abstract: 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.
authors.affiliation: Department of Medical Parasitology, London School of Hygiene and Tropical Medicine, UK.
authors.forename: R F
authors.initials: RF
authors.lastname: Sturrock
authors.forename: H C
authors.initials: HC
authors.lastname: Kariuki
authors.forename: F W
authors.initials: FW
authors.lastname: Thiongo
authors.forename: J W
authors.initials: JW
authors.lastname: Gachare
authors.forename: B G
authors.initials: BG
authors.lastname: Omondi
authors.forename: J H
authors.initials: JH
authors.lastname: Ouma
authors.forename: G
authors.initials: G
authors.lastname: Mbugua
authors.forename: A E
authors.initials: AE
authors.lastname: Butterworth
mesh_terms: 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
chemical_list: D000980:Antiplatyhelmintic Agents; D006454:Hemoglobins; D011223:Praziquantel