[Quality control during ultrasonographic evaluation of morbidity due to Schistosoma haematobium in Niger].
Within the framework of a campaign to control urinary schistosomiasis in Niger, a quality control audit was performed on ultrasonographic assessment of morbidity due to Schistosoma haematobium. The purpose of this audit was to determine variance and reproductibility of epidemiological data provided by two trained independent observers. Three parameters were studied, i.e.,: interobserver variability on matched data, interobserver variance at the community level on the same or different subjects, including some after treatment with praziquantel, and intra-observer variance. A total of 1750 ultrasound examinations were carried out on 1416 inhabitants from 10 hyperendemic villages (70 p. 100 schoolchildren) according to a slightly modified version of the WHO Cairo protocol. Inter-observer variance at the individual level was high for some elementary abnormalities of the bladder. Variance was around 20 p. 100 for the 2 main indicators, i.e. presence of at least one bladder lesion and dilatation of the upper urinary tract. At the community level, inter-observer variance was moderate and the two observers' global assessment of morbidity due to Schistosoma haematobium was the same. Variations of morbidity related to level of endemicity were given perceived in parallel. Similar findings were noted for the intra-observer variability at the individual or community level. Ultrasound examination is supposed to furnish reliable morbidity data for selecting communities at risk and scheduling treatments during schistosomiasis control programs. The results of this study show that the level of inter- and intra-observer variance in ultrasonographic assessment in Niger is compatible with this critical role.
Campagne
G
G
Centre Hospitalier de la Côte Basque, Bayonne, France. gerard.campagne@wanadoo.fr
Garba
A
A
Barkire
H
H
Vera
C
C
Boulanger
D
D
Chippaux
J P
JP
D002648:Child; D005260:Female; D006801:Humans; D008297:Male; D009017:Morbidity; D009548:Niger / Q000453:epidemiology; D015588:Observer Variation; D011786:Quality Control; D012553:Schistosomiasis haematobia / Q000000981:diagnostic imaging* / Q000453:epidemiology*; D014463:Ultrasonography; D001743:Urinary Bladder / Q000000981:diagnostic imaging