Seasonality as a determinant of the efficacy of praziquantel in population-based chemotherapy: lessons from the practice.

During October-November 1991, 1356 male farmers, 18-40 years old from a village in Fayoum Governorate, Egypt, were examined for Schistosoma haematobium infection. The prevalence of infection was 22.2%. Infected farmers were treated immediately with praziquantel at the recommended dose of 40 mg/kg body weight in a single, oral dose. Twelve weeks after treatment 86/262 (32.8%) infected farmers were negative for S. haematobium eggs in urine. In another study conducted in a satellite village in the Nile Delta (Beheira Governorate) where S. mansoni infection is prevalent, all residents of both sexes between 5 and 50 years of age (n = 858) were examined for S. mansoni. The prevalence of S. mansoni was 69.0%. Infected subjects were treated with the same dose of praziquantel during January-February 94, with an overall resultant efficacy of 85.5% (471/551) and 97.2% (103/106) in 18-40 years old males 8-10 weeks post treatment. The high cure rate in the second study was probably because treatment took place 2 months after the end of the high transmission season.

Comparison between the prospect Cryptosporidium Microtiter Assay and the immunofluorescent test in the diagnosis of cryptosporidiosis.

The immunofluorescent test utilizing rabbit antisera against Cryptosporidium oocysts isolated from dairy calves was compared with the proSpect Cryptosporidium Microtiter Commercial Assay which is an enzyme immunoassay utilizing monospecific antibody to Cryptosporidium specific antigen (CSA). The former test proved to be by far more sensitive than the latter one in diagnosing human cases positive for cryptosporidiosis by the modified acid fast stain.

Evaluation of GiardEIA kit for giardiasis diagnosis.

Giardia lamblia is recognized as one of the most common agents for diarrhea world wide. To date, microscopical examination of stool samples is the gold standard for giardiasis diagnosis. However, intermittence of the Giardia cycle and some medications may cause temporary disappearance of cysts from stools, thus giving false negative results. In the present study, we evaluated a commercially available enzyme immunoassay kit (GiardEIA) for the detection of Giardia copro-antigens and compared the results with those of the merthiolate-iodine-formaldehyde concentration (MIFC) microscopical examination technique. Sixty-nine fecal samples from children 2-12 years old were emulsified and allowed to react with a Giardia specific antibody, then with an enzyme conjugated antibody and the reaction was developed colorimetrically. Seventy-four percent of the parasitologically positive Giardia cases were also positive by GiardEIA while 26% of the microscopically negative cases were positive by the assay. GiardEIA gave negative results with 82% and 100% of stools with helminthic and protozoan (other than Giardia) infections, respectively. Similarly, no cross-reactivity was found with any of the bacterial agents including Shigella flexneri, pathogenic E. coli, Klebsiella spp. and Salmonella typhi. GiardEIA is a simple assay that can diagnose 24 samples in less than an hour without the need for any special equipment and can be useful in epidemiological surveys and in giardiasis outbreaks.

Microbiologic and clinical study of acute diarrhea in children in Aswan, Egypt.

Children with diarrhea presenting to a Government Rehydration Center in Aswan, Egypt, were investigated to determine the etiology and clinical presentation of acute childhood diarrhea in southern Egypt. Among 126 outpatients and 25 inpatients with diarrhea (mean age 18 months), enterotoxigenic Escherichia coli (ETEC) (17% of cases), Cryptosporidium (9%), Salmonella spp. (7%), Campylobacter jejuni/coli (7%), and Shigella spp. (5%) were the most common enteropathogens identified during the high incidence season of July. Enteropathogens were isolated as often from inpatients as outpatients, except for Salmonella spp. and Cryptosporidium, which were recovered more often from inpatients. Salmonella-infected children, in particular, were more ill, feverish, and dehydrated on presentation than other children, resulting in more frequent hospitalization. Except for Salmonella-infected children, children with acute diarrhea usually presented without severe dehydration, which may have been due to frequent initiation of oral rehydration therapy (ORT) by mothers trained by local health care providers. A potential environmental source of ETEC was identified in clay water storage containers commonly used in this area.