Abstract. This investigation's objective was to identify risk factors for hepatitis C virus (HCV) in a village in Upper Egypt with a moderately high prevalence (8.7%) of antibodies to HCV (anti-HCV). A representative sample of 6,012 (63%) of the 9,581 village inhabitants was included in the study. A questionnaire solicited information regarding risk factors for infection, and blood samples were tested for anti-HCV. Parenteral risks identified in age-adjusted analysis included blood transfusions, dental procedures, hospital admission, surgery, complicated deliveries, history of injection therapy for schistosomiasis, and history of frequent injections. Circumcision was pervasive and was not associated per se with ant-HCV; however, circumcision by an informal, rather than formal, health care provider was associated with anti-HCV among young men and boys. The results did not reveal any unique community-acquired exposures that caused HCV infections: inhabitants who had tattoos, who smoked goza, who were shaved by a community barber, or who had their ears pierced were not at greater risk for anti-HCV than those who did not. Risks identified in multivariate analysis for both those older and younger than 30 years included prior parenteral therapy for schistosomiasis and blood transfusion; for those 30 or younger, circumcision by an informal rather than formal health care provider, and frequent injections; and for those older than 30, never attending college, invasive medical procedures, and complicated deliveries. Selecting for those with blood transfusion, prior parenteral therapy for schistosomiasis, and invasive medical procedures would identify less than half of those infected. Inclusion of frequent injections would identify 80% of those infected with HCV, but as a result of the pervasive use of injections, it would not discriminate from those uninfected. Nonetheless, general reduction of these exposures and assuring sterile practices are logical goals for intervention.
The incidence of hepatitis C (HCV) infection and associated risk factors were prospectively assessed in a cohort of 6,734 Egyptians from 2 rural villages who were negative for antibodies to HCV (anti-HCV). Initial and follow-up sera were tested for anti-HCV by enzyme immunoassay (EIA), and possible incident cases were confirmed by using the microparticle enzyme immunoassay (MEIA) and tested for HCV RNA. All follow-up serum samples converting from negative to positive without detectable HCV-RNA were further tested by recombinant immunoblot assay. Over an average of 1.6 years, asymptomatic anti-HCV seroconversion occurred in 33 people (3.1/1,000 person-years [PY]), including 28 (6.8/1,000 PY) in the Nile Delta village (AES), where prevalence was 24% and 5 (0.8/1,000 PY) in the Upper Egypt village (baseline prevalence of 9%). The strongest predictor of incident HCV was having an anti-HCV-positive family member. Among those that did, incidence was 5.8/1,000 PY, compared (P < .001) with 1.0/1,000 PY; 27 of 33 incident cases had an anti-HCV-positive family member. Parenteral exposures increased the risk of HCV but were not statistically significant; 67% of seroconverters were younger than 20 years of age, and the highest incidence rate (14.1/1,000 PY) was in children younger than 10 who were living in AES households with an anti-HCV-positive parent. In conclusion, young children would especially benefit from measures reducing exposures or preventing infection with HCV. T he prevalence of antibodies to hepatitis C virus (anti-HCV) in Egypt, 14% to 18% of the population, is among the highest in the world. 1-6 Studies of risk factors for infection have focused on prevalent infection, identifying historical risk factors that may no longer contribute to HCV transmission, such as the mass treatment campaigns for schistosomiasis with parenteral tartar emetic 3 and blood transfusions. 7,8 Information on the current magnitude of transmission and risk factors for transmission of HCV in communities in Egypt and other countries is scarce.Studies of the incidence of HCV have generally been restricted to special or high-risk populations, such as blood donors and intravenous drug users (IVDU). 2,9-11 IVDU are rare in the rural Egyptian communities that are most affected by HCV. [4][5][6] In areas with a high HCV prevalence, and thus a large reservoir of infection, the risk of incident infection should be relatively high, increasing the importance of, and opportunity for, the identification of current risk factors for transmission. The purpose of this report is to estimate a recent incidence of HCV infection and to identify risk factors for such infections in 2 community-based cohorts with anti-HCV prevalence of 24% and 9%. 4,5 Patients and MethodsStudy Population. One half of households in villages in the Nile Delta, Aghour El Soughra (AES), 40 km north of Cairo, and all households in Upper Egypt, Sallam, 350 km south of Cairo, were systematically recruited in 1997 to obtain interview data and blood samples for epidemiological stud...
Hepatitis E virus (HEV) is enterically transmitted and causes self-limiting acute viral hepatitis (AVH) primarily in less developed countries. A prospective cohort study to assess incidence of, and risk factors for, seroconversion to HEV (anti-HEV) was conducted in two Egyptian villages with a 67.7% anti-HEV prevalence. Nine hundred and nineteen villagers who were initially anti-HEV-negative were followed for 10.7 months. Thirty-four (3.7%) had strong anti-HEV serologic responses at follow-up giving an estimated anti-HEV incidence of 41.6/1,000 person-years. No significant associations were found between anti-HEV seroincidence and demographic and socioeconomic factors, source of water, household plumbing or sanitation, hand and vegetable washing, ownership of animals, jaundice and many other variables. None of the seroconverting subjects gave a history compatible with AVH during the interval. We hypothesize that both zoonotic and anthroponotic transmission of avirulent (possibly genotype-3) HEV is occurring extensively in these rural villages. An alternative explanation for the lack of morbidity among anti-HEV incident cases could be initial asymptomatic infections occur during early childhood with subsequent antibody titer boosting without illness upon re-exposure to the virus.
Abstract. The prevalence of antibody to hepatitis C virus (anti-HCV) was determined in a cross-sectional survey in a village in Upper Egypt. Exposure and demographic characteristics were obtained through a questionnaire. Antibody to hepatitis C virus was assessed using a second generation enzyme immunoassay, and the presence of HCV RNA was tested using a reverse transcriptaseϪpolymerase chain reaction. Collection of blood samples was targeted at those Ն 5 years old, and obtained from 62.8%. This report describes the community, the HCV infection characteristics of the subjects, and evaluates some factors associated with presence of anti-HCV. Of the 6,031 participants, 522 (8.7%) were anti-HCV positive. Prevalence was higher among males than females (11.3% versus 6.5%; P Ͻ 0.001). It was greater among those Ͼ 30 years of age than among those Յ 30 years of age (20.0% versus 3.6%; P Ͻ 0.001). Those who were less educated, farmed, provided health care, and were currently married had a significantly higher anti-HCV prevalence than those who were not; however, these associations were not significant after adjusting for age. Although active infections with Schistosoma haematobium were not associated with anti-HCV, a history of past infection was (age-adjusted risk ratio [RR] ϭ 2.1, 95% confidence interval [CI] ϭ 1.8, 2.4); 134 persons who had a history of receiving parenteral anti-schistosomal therapy had a higher age-adjusted RR (3.0; 95% CI ϭ 2.5, 3.7) for anti-HCV than those who did not. Hepatitis C virus RNA was detected in 62.8% of the anti-HCV positive subjects, without significant variation by age, gender, education, or marital status. The prevalence of anti-HCV in Upper Egypt is high, albeit lower than in Lower Egypt, with continuing but limited transmission indicated by the lower prevalence in residents Յ 30 years old.
Acquired immunity to human schistosomiasis correlates with increased serum levels of schistosome antigen-specific IgE. Since interleukin (IL)-4 stimulates IgE production, the hypothesis that Th2-associated cell-mediated immunity participates in protection to reinfection was studied in a cohort of adolescent boys 12-18 months after chemotherapeutic cure in Upper Egypt. Initial Schistosoma haematobium prevalence was 51% and posttreatment incidence was 44%. Water contact was similar between putatively resistant and susceptible patients. Resistant persons had a 3.5- to 14-fold greater frequency of schistosome adult worm antigen (SWAP)-specific lymphocytes secreting IL-5 or IL-4 (by ELISPOT) and IL-5 or IL-4 production in peripheral blood lymphocyte culture supernatants (P < .05 to < .001, n = 48) versus susceptible subjects (n = 38). In contrast, SWAP-induced interferon-gamma and IL-10 production and lymphocyte proliferation were similar between the 2 groups. Schistosome egg antigen and streptolysin O each stimulated similar cytokine production in susceptible and resistant persons. Thus, enhanced SWAP-driven IL-4 and IL-5 production correlates with immunity to reinfection in adolescents exposed to urinary schistosomiasis.
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