Association of Schistosoma haematobium infection with protection against acute Plasmodium falciparum malaria in Malian children.
Plasmodium falciparum and Schistosoma haematobium are co-endemic parasitic diseases with worldwide distribution. Evidence suggests interactions occur between helminthic and malaria infections, although it is unclear whether this effect is beneficial or harmful to the host. Malian children 4-14 years of age with asymptomatic S. haematobium infection (SP) (n = 338) were prospectively matched by age, sex, and residence to children without schistosomiasis (SN) (n = 338) who were cleared of occult intestinal parasites, and followed-up for one malaria transmission season (25 weeks). The time to the first clinical malaria infection, incidence of malaria episodes, and parasitemia were recorded. Age associated protection from malaria in children with schistosomiasis was observed. SP children (4-8 years of age) compared with SN children demonstrated delayed time to first clinical malaria infection (74 versus 59 days; P = 0.04), fewer numbers of malaria episodes (1.55 versus 1.81 infections; P = 0.03) and lower geometric mean parasite densities (6,359 versus 9,874 asexual forms/mm(3); P = 0.07) at first infection. No association between schistosomiasis and P. falciparum malaria was observed in children 9-14 years of age. We conclude that underlying schistosomiasis is associated with protection against clinical falciparum malaria in an age-dependent manner.
Lyke
Kirsten E
KE
Center for Vaccine Development, University of Maryland School of Medicine, Baltimore, Maryland 21201, USA. klyke@medicine.umaryland.edu
Dicko
Alassane
A
Dabo
Abdoulaye
A
Sangare
Lansana
L
Kone
Abdoulaye
A
Coulibaly
Drissa
D
Guindo
Ando
A
Traore
Karim
K
Daou
Modibo
M
Diarra
Issa
I
Sztein
Marcelo B
MB
Plowe
Christopher V
CV
Doumbo
Ogobara K
OK
D000208:Acute Disease; D000293:Adolescent; D017677:Age Distribution; D000367:Age Factors; D000818:Animals; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D019353:Endemic Diseases; D005243:Feces / Q000469:parasitology; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D016778:Malaria, Falciparum / Q000150:complications / Q000453:epidemiology* / Q000276:immunology / Q000652:urine; D008297:Male; D008302:Mali / Q000453:epidemiology; D010963:Plasmodium falciparum / Q000276:immunology*; D011446:Prospective Studies; D012307:Risk Factors; D012548:Schistosoma haematobium / Q000276:immunology*; D012553:Schistosomiasis haematobia / Q000150:complications / Q000453:epidemiology* / Q000276:immunology / Q000652:urine