Hepatitis C virus infection in a community in the Nile Delta: risk factors for seropositivity.

The purpose of this study was to identify risk factors for hepatitis C virus (HCV) infection in a rural village in the Nile Delta with a high prevalence of antibodies to HCV (anti-HCV). One half of the village households were systematically selected, tested for anti-HCV, and interviewed: 973 of 3,999 (24.3%) subjects were anti-HCV-positive (reflecting prior HCV infection but not necessarily current liver disease), with nearly equal prevalence among males and females. Anti-HCV prevalence increased sharply with age among both males and females, from 9.3% in those 20 years of age and younger to >50% in those older than 35, suggesting a cohort effect with reduced transmission in recent years. Multivariate regression was used to estimate independent effects of risk factors on seropositivity. Among those over 20 years of age, the following risk factors were significantly associated with seropositivity: age (P <.001); male gender (odds ratio [OR] = 2.5, 95% CI = 1.3-4.7); marriage (OR = 4.1, 2.4-6.9); anti-schistosomiasis injection treatment (OR = 2.0, 1.3-2.9); blood transfusion (OR = 1.8, 1.1-2.9), invasive medical procedure (surgery, catheterization, endoscopy, and/or dialysis) (OR = 1.5, 1.1-1.9); receipt of injections from "informal" health care provider (OR = 1.3, 1.0-1.6); and cesarean section or abortion (OR = 1.4, 1.0-1.9). Exposures not significantly related to anti-HCV positivity in adults included: history of, or active infection with, Schistosoma mansoni, sutures or abscess drainage, goza smoking in a group, and shaving by community barbers. Among those 20 years old or younger, no risk factors were clearly associated with anti-HCV positivity; however, circumcision for boys by informal health care providers was marginally associated with anti-HCV (OR = 1.7, 1.0-3.0). Prevention programs focused primarily on culturally influenced risks in rural Egyptian communities are being implemented and evaluated.

Hepatitis C virus (HCV) infection in a community in the Nile Delta: population description and HCV prevalence.

This report describes a cross-sectional survey of the prevalence of antibodies to hepatitis C virus (anti-HCV) in a rural Egyptian community in the Nile Delta. One half of the village households were systematically selected and examined by questionnaire and testing sera for anti-HCV and HCV RNA. Blood samples were obtained from 3, 888 (75.4%) of 5,156 residents >/=5 years of age; an additional 111 samples were obtained from children younger than 5 years. Overall, 973 (24.3%) of 3,999 residents were anti-HCV-positive, and the age- and gender-adjusted seroprevalence was 23.7%. Anti-HCV prevalence increased sharply with age, from 9.3% in those 20 years of age and younger to >50% in those older than 35 years. Currently or previously married individuals were more likely to be seropositive than those never married, controlling for age (Mantel-Haenszel risk ratio = 1.8; 95% CI: 1.3, 2.6). Of the 905 anti-HCV-positive samples tested, 65% were also positive for HCV RNA. Active schistosomal infection was not associated with anti-HCV status; however, history of antischistosomal injection therapy (reported by 19% of anti-HCV positives) was a risk for anti-HCV (age-adjusted risk ratio = 1.3; 95% CI: 1.2, 1.5). This study, the largest community-based survey to date, supports earlier reports of high levels of anti-HCV among adults in rural areas of Egypt, although many of those who are seropositive will not have active liver disease. The large reservoir of HCV infection in the community provides an opportunity to investigate risk factors for transmission, the natural history of infection and effectiveness of preventive methodologies, and raises concern about the prospect of an increasing incidence of chronic liver disease in the coming decades.

Quality control for parasitologic data.

Accuracy of data is of paramount concern for all research. The task of providing objective assurances of accuracy of parasitologic data for a large, multi-center epidemiologic research project in Egypt (Epidemiology 1, 2, 3 [EPI 1, 2, 3]) presented a unique set of challenges undertaken jointly by the Ministry of Health's Qalyub Center for Field and Applied Research with technical assistance from Tulane University (New Orleans, LA). The EPI 1, 2, 3 project was part of large bilateral research program, the Schistosomiasis Research Project, undertaken jointly by the governments of Egypt and the United States. This paper describes the nature of the quality control system developed to accomplish this task, presents results and discusses the findings.

The epidemiology of schistosomiasis in Egypt: Qalyubia Governorate.

The primary objectives of this study, carried out in Qalyubia Governorate in Egypt (south-central Nile Delta), were to continue tracking historical trends of infection prevalence of Schistosoma mansoni and S. haematobium, determine whether satellites (ezbas) of mother villages differed significantly with respect to schistosomiasis transmission, and to asses schistosomiasis-induced morbidity on a population basis using ultrasonography. Our study revealed that S. haematobium has virtually disappeared from Qalyubia governorate, and that S. mansoni prevalence continues to decline slowly (17% in 1991 compared with 19% in 1990). The prevalence of intestinal schistosomiasis was actually higher in the mother villages than in the ezbas of the same villages, indicating that prevalence based on surveys of villages alone did not (at least for Qalyubia) cause underestimates of true prevalence. (A mother village is the large village in an area that includes hamlets or ezbas. In many areas, the infection rate in ezbas is significantly higher than in the larger central village.) Ultrasonographic studies revealed that less than 3% of the population had stage 2 or stage 3 periportal fibrosis, commonly associated with chronic schistosomiasis mansoni. This low level of morbidity was consistent with earlier data from Qalyubia, which also showed a low level of S. mansoni-induced morbidity in this governorate.

HAV and HEV infection in hospitalised hepatitis patients in Alexandria, Egypt.

A total of 202 serum and stool samples from acute hepatitis patients attending the Fever Hospital of Alexandria, Egypt, have been studied to reveal markers of hepatitis virus infection. Anti-HAV IgM were detected in 21 out of 202 sera (10.4%), whereas 201 sera (99.5%) had anti-HAV IgG. The first age attack was in the class-age 0-9 years with 64.7% of anti-HAV IgM positive sera. Among 202 patients, anti-hepatitis E IgG (sample/over cut off > 1.0) was identified in 90 patients (44.5%). The anti-HEV seropositivity ranged from 17.6% to 60.0% in the different age groups, with the highest level in the class-age 20 29 years. Anti-hepatitis E IgM were identified in 49 patients with the first age attack in the class-age 10-19 years (39.4%). HAV RNA was identified by nested PCR in 7 samples out of 15, whereas HEV RNA was present in 4 out of 75 stool samples. Direct DNA sequence of the latter PCR products confirmed the presence of the HEV genome; comparison of the sequences of the isolates from Egypt with those in data banks revealed the highest homology to the Burma strain. Our data confirm that HAV and HEV are common causes of acute sporadic hepatitis in Alexandria but with different peak age positivity. Occasionally, but not infrequently, dual infections (HAV-HEV and HEV-enteric viruses) were also found. The risk analysis indicates that patients living in rural areas are exposed to a higher risk of hepatitis E infection compared to the urban population, whereas the presence of anti-HEV IgG was significantly associated with consumption of common village water and use of indoor dry pit and oral therapy for schistosomiasis.

Evidence of hepatitis E virus replication on cell cultures.

Several human and animal cell lines have been used to grow hepatitis E virus. The strain SAR-55 was adapted only on PLF/PLC/5 cell line without any visible cytopathic effect. The growth of the SAR-55 was monitored by examining the positive and the negative strands of HEV-RNA. Stool samples, obtained from hospitalised acute hepatitis patients at the Fever Hospital of Alexandria (Egypt), were used to confirm the susceptibility of PLF/PLC/5 cells. After more than one-week's cultivation, three stool samples out of 17 IgM anti-HEV positive and 1 from 52 IgG anti-HEV positive patients showed a specific RT-PCR amplification product. The nucleotide sequences of the methyltransferase region of the genome in the isolates revealed the maximum homology with Burma strain with several point mutations.

Microbiological quality of coastal sea water of Alexandria, Egypt.

The aim of the present study was to evaluate the quality of the seawater in Alexandria, Egypt. Samples were collected in 6 different points: Kayet Bay, El Shatby, Camp Cesar, Sporting, Beir Massoud and El Max. In total, 24 samples were analyzed. For each point the analysis included estimation of the following parameters: Esherichia coli, total coliform and fecal streptococci, Yersinia, Shigella, Salmonella, bacteriophages and enteric viruses. Just one sample (El Max) was positive for the presence of Salmonella, neither Shigella or Yersinia were isolated from any of the analyzed points. E. coli was identified in 10 samples while the ratio between total coliform and fecal streptococci showed variable results with the exception of El Max that resulted constantly high. Three samples were positive for the presence of enteric viruses: El Shatby, Beir Massoud and Sporting. The analysis of phages showed a variable pollution values.

PIP: The bacteriological virological parameters were evaluated on seawater samples taken at different points on the coast of Alexandria, Egypt. Samples were collected at 6 different points: Kayet Bay, El Shatby, Camp Cesar, Sporting, Beir Massoud, and El Max. A total of 24 samples were analyzed by estimation of the following parameters: Escherichia coli, total coliform and fecal streptococci, Yersinia, Shigella, Salmonella, bacteriophages, and enteric viruses. The virological analysis included the isolation and identification of cytopathogenic enteroviruses and three phages: somatic coliphage, F-specific, and B 40-8. The bacteriophage analysis was performed by the plaque assay method using the double-layer method, whereas the membrane filtration method was used to estimate bacterial populations in the samples. During the summer period no E. coli could be isolated from any point during the study, whereas in autumn E. coli were identified in all the points except for Sporting. E. coli was identified in 65% of the qualitative analyses. The limit was exceeded in 12 samples out of 24; for fecal streptococci, in 15 samples out of 24. The ratio over 4.4 relating to fecal coli and fecal streptococci indicated human fecal pollution. The El Max sample was positive for the presence of Salmonella; neither Shigella nor Yersinia were isolated from any of the analyzed points. In the El Max sample (autumn period), total coliform and fecal streptococci exceeded the European Community (EC) limit, whereas the ratio was 10, confirming human fecal pollution. E. coli was identified in 10 samples, while the ratio between total coliform and fecal streptococci showed variable results with the exception of El Max, which was constantly high. Three samples were positive for the presence of enteric viruses: El Shatby, Beir Massoud, and Sporting. The enteric viruses were confirmed by a secondary passage on cell culture. The analysis of phages showed variable pollution values.

Recent trends in the prevalence and distribution of schistosomiasis in the Nile delta region.

In 1983, a survey of 71 villages in the Nile delta demonstrated that the overall prevalence of Schistosoma mansoni and S. haematobium infections was 39% and 5%, respectively. Recent increased availability of praziquantel, combined with Egyptian Ministry of Health-sponsored media efforts to educate the public about schistosomiasis, prompted us to determine the current status of S. mansoni and S. haematobium infections in the delta and evaluate any changes that may have occurred since the previous survey. The same villages that participated in the 1983 survey were resampled in 1990. Stool and urine samples were requested from all occupants over the age of two years in a 5% sample of houses within each village. Stool (Kato) thick smears and urine sediments were read qualitatively at the rural health station. Field-prepared Kato smears and a 20% sample of urine specimens were forwarded to the Ministry of Health Laboratory, where quantitative readings were also performed. Analysis of samples obtained from 17,310 persons revealed that S. mansoni prevalence had decreased to 23% and that S. haematobium prevalence had decreased to 3% (P < 0.001). The highest levels of schistosome infection were found in governates located in the eastern section of the delta. The observed changes in the prevalence of S. mansoni and S. haematobium suggest that control measures are having a favorable impact on schistosomiasis transmission in this region.

Immune responses and immunoregulation in relation to human schistosomiasis in Egypt. III. Immunity and longitudinal studies of in vitro responsiveness after treatment.

Immune responsiveness of schistosomiasis patients was assayed longitudinally, before and for two years after chemotherapeutic treatment with praziquantel, by in vitro peripheral blood mononuclear cell (PBMN) proliferation upon exposure to phytohaemagglutinin (PHA), or soluble schistosomal antigenic preparations from eggs (SEA), adult worms (SWAP) or cercariae (CAP). Parallel faecal and urine examinations documented the infection status of the patients during this time. Treatment resulted in substantially increased responsiveness to the schistosome-derived materials but not to PHA or C. albicans extract. The responses to SEA, SWAP, and CAP often remained elevated for one to two years after treatment. However, those patients who became reinfected had significantly lower PBMN responses to SEA or CAP at the time of the last blastogenesis assay before the observation that they were again stool-positive for Schistosoma mansoni eggs. No other demonstrable differences (such as age, sex, household location, pre-treatment intensities of infection or occupation) were observed between those who remained uninfected for at least two years (resistant?) and those who became reinfected during this time (susceptible?).

Immune responses and immunoregulation in relation to human schistosomiasis in Egypt. II. Cimetidine reversal of histamine-mediated suppression of antigen-induced blastogenesis.

The effect of histamine on cell-mediated immune responses of chronic schistosomiasis patients was tested by peripheral blood mononuclear cell (PBMN) reactions to phytohemagglutinin-P (PHA) and soluble schistosomal antigenic preparations derived from eggs (SEA) or adult worms (SWAP). PBMN responses to PHA were suppressed by exogenous histamine (10(-5)M), and the addition of cimetidine (CIM) (10(-4)M), an H2-receptor antagonist, reversed this suppressive effect. Histamine primarily suppressed PBMN responses to suboptimal and optimal PHA concentrations. Exogenous histamine (10(-5)M) also suppressed PBMN responses of 27 schistosomiasis patients to SEA and SWAP, respectively. The addition of CIM (10(-4)M) to suppressed cultures reversed the effect of exogenous histamine. Most importantly, the addition of CIM to schistosomal antigen-induced cultures, without exogenous histamine, significantly increased patients' PBMN responses to SEA and SWAP. The mean optimal increase in SEA responses of 19 patients was 390%. With SWAP-induced responses of 21 patients this increase was 165%. The use of 10(-4)M diphenhydramine (DPH), an H1-receptor antagonist, resulted in general suppression of both PHA-induced and schistosomal antigen-induced PBMN responses. Lower concentrations of DPH lead to variable responses but did not result in consistent abrogation of the histamine-induced suppression. These data imply that an histamine-induced, H2-receptor-mediated suppressor circuit often helps modulate antigen-specific responsiveness of PBMN from patients with chronic schistosomiasis.

Immune responses and immunoregulation in relation to human schistosomiasis in Egypt. I. Effect of treatment on in vitro cellular responsiveness.

Cell mediated immune reactivity of chronic schistosomiasis patients was tested in vitro by peripheral blood mononuclear cell (PBMN) responses against phytohemagglutinin P (PHA), Candida albicans extract, soluble schistosomal antigenic preparations derived from eggs (SEA), adult worms (SWAP) and cercariae (CAP), before and after treatment of the patients with parziquantel. The patient population was from villages in the Qalyub province, Egypt, that are endemic for Schistosoma mansoni and S. haematobium. Patients were studied immediately before, and at 1, 3, 6, and 9 months after chemotherapy. Egg counts were done on stool and urine specimens taken simultaneously with blood samples. There was a significant increase in PBMN responses to SWAP and CAP but not to SEA, PHA or C. albicans in 27 patients (age 8-65) 1 month after treatment. Eleven patients treated 1.5 years previously did not show such elevated responses 1 month after re-treatment. Three months after treatment higher mean responses were observed to SWAP, CAP, SEA, and PHA, but not to C. albicans in 24 patients (age 6-26). Significant increases in PBMN responses to SWAP and CAP, but not to SEA, PHA or C. albicans were obtained at 6 months after treatment in 12 patients (age 6-30). By 9 months after treatment in a group of 11 patients (age 8-25) SWAP and CAP responses were still elevated as were SEA and C. albicans induced reactivities. The PBMN responses of 10 patients were followed longitudinally at pretreatment, 3-, 6-, and 9-month post-treatment times. In general, elevated responses were maintained throughout this period to the schistosomal preparations. Unrelated responses occasionally fluctuated but were not consistently altered over time.