Biomedical subjects

M K El-Sayed

Publications and source records attributed to M K El-Sayed.

3 recordsLinked to original sources

PubMed2000

The epidemiology of schistosomiasis in Egypt: patterns of Schistosoma mansoni infection and morbidity in Kafer El-Sheikh.

This is a descriptive report of the Epidemiology 1, 2, 3 project in Egypt that made use of large probability sampling methods. These results focus on Schistosoma mansoni infection in the northern Nile Delta governorate of Kafr El Sheikh. A probability sample of 18,777 persons, representing the rural population of the entire governorate, was drawn. The sample was designed not to exclude villages based on location or presence of health care facilities and to include representation of the smaller ezbas or hamlets. The objective was to obtain detailed estimates on age- and sex-specific patterns of S. mansoni infection, and to provide a baseline for prospective studies. Stool specimens were examined by the Kato method. The estimated mean +/- SE prevalence of S. mansoni infection in the rural population was 39.3 +/- 3.3% in 44 villages and ezbas after weighing for the effects of the sample design. The estimated mean +/- SE geometric mean egg count per gram of stool (GMEC) was 72.9 +/- 7.3. Prevalence and GMEC varied considerably by village and ezba, with ezbas having a significantly higher prevalence. Villages and ezba-specific prevalence was strongly associated with GMEC (r2 = 0.61, P < 0.001). The prevalence of S. mansoni infection increased by age to 55.4 +/- 3.2% at age 16 without a significant change in the adult ages. There were no gender differences until age 6, after which males were consistently higher until middle age, when the differences converged. The age- and sex-specific pattern of GMEC varied widely; however, when the GMEC data were collapsed into 5-year age groups, the GMEC peaked at 81.5 +/- 12.1 eggs/g in the 10-14-year-old age group. These estimates provide the basis for evaluating control measures for reducing prevalence, intensity of infection, and transmission.

Adolescent↗

PubMed2000

Epidemiology 1, 2, 3: study and sample design.

Bad sample designs and selection bias have plagued studies on schistosomiasis, and as a result some believe that schistosomiasis is too focal, making it difficult to draw reliable samples. The Epidemiology 1, 2, 3 (EPI 1, 2, 3) sample design, although complex, demonstrates that sampling theory is readily applicable to epidemiologic studies of schistosomiasis. The EPI 1, 2, 3 sampling scheme was designed to achieve the smallest feasible standard errors given EPI 1, 2, 3 objectives and certain logistical constraints. The sample design is a multi-stage selection of villages (ezbas, which were stratified by size) and households within each of 9 purposely selected Egyptian governorates. Villages and households were systemically selected from census frames. The sampling of ezbas was especially difficult because of the lack of complete sampling frames and their wide variation in population size. Ultimately, ezbas were stratified by size and then randomly selected from each stratum. Sample sizes for villages and ezbas and individuals within ezbas were calculated based on EPI 1 and 2 objectives, respectively. No re-selection was made for non-respondents. A 20% subsample of the full sample was drawn for clinical and ultrasonographic examinations. The sample selected from individual governorates closely parallel the age structure of the 1986 census of the respective rural populations. Details of the study design and related methods are given below.

Egypt↗

PubMedDate not supplied

Who misses out with school-based health programmes? a study of schistosomiasis control in Egypt.

There has been a recent revival of interest in school-based health programmes in developing countries as a means of reducing the morbidity observed in school-aged children, of improving their physical growth and cognitive development, and of controlling transmission of disease in the community at large. This study used data collected from a large epidemiological survey of schistosomiasis in Egypt to examine what proportion of infected children missed treatment from an established national school-based schistosomiasis control programme simply because they did not attend school. It showed that children who were not enrolled in school had a higher prevalence of infection and were more intensely infected than children who attended school. At the extreme, over 80% of infected girls in one part of Egypt could not be treated by the existing school programme because they did not attend school. If these trends are similar in other countries where school-based programmes are being developed, school-based delivery may exacerbate existing inequalities in society and ways of expanding services to children who do not attend school regularly need to be explored.

Adolescent↗