Patterns of infection, incidence and reinfection with Schistosoma mansoni in Nile Delta Governorate: Kafr El Sheikh
Barakat, R.; Farghaly, A.; Morshidy, H.N.; el Sayed, M.K.; Masry, A.G.; Husein, M.H.; Miller, F.D.
Tropical and Geographical Medicine 47(6): 270-277
1995
ISSN/ISBN: 0041-3232 PMID: 8650738 Document Number: 445194
Two annual follow-up surveys of incidence, reinfection after treatment and reversion rates were estimated during a large prospective study of Schistosoma mansoni in the northern Nile Delta at Kafr El Sheikh Governorate, Egypt, based on a cohort established from a probability sample of the entire rural area. Infection was determined by stool examination using the Kato method to establish the geometric mean egg count (GMEC). The overall incidence rates for the first and 2nd annual follow-ups were 20.4 +or- 1.4 and 15.9 +or- 1.4%, respectively. The GMEC in positive cases were 35.6 +or- 1.2 and 31.0 +or- 1.6, respectively. Incidence was strongly associated with prevalence in the initial survey. Reinfection rates were high at 33.4 +or- 3.1 and 31.0 +or- 2.1%, respectively. Reinfection was associated with incidence. Reversion rates were highest in children 0 to 4 years old (61.2 +or- 18.1 and 78.5 +or- 7.0%, respectively) and increased from the first to 2nd follow-up (37.2 +or- 3.4 and 47.0 +or- 3.7%, respectively). Patterns of these rates according to village community and host age and sex are given for both follow-up examinations; comparison with limited data from previous studies suggests a stable pattern of transmission over time in the Nile Delta.