Intestinal schistosomiasis in mothers and young children in Uganda: investigation of field-applicable markers of bowel morbidity

Abstract

To control intestinal schistosomiasis at a national level in sub-Saharan Africa, there is a need for field-applicable markers to measure morbidity associated with this disease. The purpose of this study was to determine whether fecal calprotectin or fecal occult blood assays could be used as morbidity indicators for intestinal schistosomiasis. The study was carried out in Uganda with a cohort of young children (n = 1,327) and their mothers (n = 726). The prevalence of egg-patent schistosomiasis was 27.2% in children and 47.6% in mothers. No association was found between schistosomiasis infection and fecal calprotectin in children (n = 83, odds ratio [OR] = 1.08, P = 0.881), although an inverse relationship (n = 58, OR = 0.17, P = 0.043) was found in mothers. Fecal occult blood was strongly associated with Schistosoma mansoni infection in children (n = 814, OR = 2.30, P < 0.0001) and mothers (n = 448, OR = 1.95, P = 0.004). Fecal occult blood appears to be useful for measuring morbidity associated with intestinal schistosomiasis and could be used in assessing the impact of control programs upon disease.

Figure 1.

Locations of the study sites in Uganda. 1 = location of the surveyed villages in Buliisa District on Lake Albert, and 2 = location of the villages in Mayuge District on Lake Victoria.

Figure 2.

Numbers of children and mothers tested for fecal occult blood and calprotectin, and questioned about blood in stool, diarrhea, and abdominal pain on Lakes Albert and Victoria in Uganda. The percentages of those examined who were positive for Schistosoma mansoni are shown in parentheses. Calprotectin analysis was not carried out separately for each lake system; only total numbers of mothers and children tested are shown.

Figure 3.

Fecal occult blood (FOB) (negative, weak positive, and strong positive) and Schistosoma mansoni infection intensity (negative, light infection, and medium/heavy infection), Uganda. Column widths represent a ratio of 80:11:10 of children with negative, weak positive, and strong positive FOB results and a ratio of 39:6:5 of mothers with negative, weak positive, and strong positive FOB results.