Mohamed M K, Rakhaa M, Shoeir S, Saber M
Department of Community, Environmental and Occupational Medicine, Faculty of Medicine, Ain Shams University, Cairo, Egypt.
J Egypt Public Health Assoc. 1996;71(1-2):79-111.
This study examines the relative importance of risk factors for viral hepatitis C infection and estimates the magnitude of HCV problem among Egyptians. It is a continuation of a recently performed cross-sectional study conducted on more than 5000 Egyptians. Serum samples (1945) were analyzed for liver enzymes (SGPT and SGOT) to evaluate the status of liver affection. One hundred and sixty nine samples (103 confirmed HCV seropositives and 66 seronegative) were analyzed for PCR HCV RNA to estimate the frequency of HCV viraemia among those individuals. Rates for HCV seropositivity by ELISA test in mass screening were corrected using predictive value of a positive test at prevalence between 5-50%. Attributable risk and population attributable risk estimates were calculated for those significant factors in logistic regression analysis. Overall number of HCV infected individuals was estimated for age groups of 15-65 years and the numbers of HCV related liver complications were estimated. HCV PCR RNA was positive for 50% of ELISA-seropositive samples and for 13.8% of the seronegative samples. However, only 5% of those individuals with HCV seropositivity and 3.7% of those with PCR RNA positivity Showed SGPT serum levels above 1.5 normal. The overall age, sex and urban/rural adjusted rate of true HCV seropositivity is estimated to be 15.6% among working Egyptians between 15-65 years. Attributable risk due to injections for the treatment of bilharziasis is estimated to be 47% (95% CL = 38%-55%) among exposed males. Blood transfusion was estimated to be responsible for 87% (95% CL = 57%-96%) of cases among previously transfused females. Population attributable risk for injections for treatment of bilharziasis among working urban and rural males is estimated to be 15% and 11% respectively. Blood transfusion and sharing contaminated needles contributed by 24% of cases (for each) among working urban females. Previous hospitalization contributed by 36% of cases among working rural females and by 10% among working urban males. As for the national estimate of cases of HCV seropositivity we estimated more than 5 million individuals with an expected number of chronic hepatitis of varying degrees of 3.5 millions. HCV viraemia with high probability for transmission is present in more than 50% of those individuals and liver cirrhosis cases expected to develop within an average of 20 years of infection are in the range of 350-700 thousand cases. The major proportions of population attributable risk are due to other undefined risk factors associated with age, male sex, living in rural areas and in lower and upper Egypt. Further research is needed to elucidate those factors prevailing in these areas, associated with increased risk of HCV infection.
本研究探讨了丙型病毒性肝炎感染危险因素的相对重要性，并估算了埃及人群中丙型肝炎问题的严重程度。它是最近对5000多名埃及人进行的横断面研究的延续。分析了1945份血清样本中的肝酶（谷丙转氨酶和谷草转氨酶），以评估肝脏病变状况。对169份样本（103份确诊的丙肝血清阳性样本和66份血清阴性样本）进行了丙肝病毒RNA聚合酶链反应（PCR HCV RNA）检测，以估算这些个体中丙肝病毒血症的发生率。在大规模筛查中，通过酶联免疫吸附测定（ELISA）检测得出的丙肝血清阳性率，利用患病率在5%-50%之间时阳性检测的预测值进行了校正。对逻辑回归分析中的那些显著因素计算了归因风险和人群归因风险估计值。估算了15-65岁年龄组中丙肝感染个体的总数以及与丙肝相关的肝脏并发症数量。丙肝病毒RNA聚合酶链反应检测显示，50%的ELISA血清阳性样本以及13.8%的血清阴性样本呈阳性。然而，丙肝血清阳性个体中只有5%、PCR RNA阳性个体中只有3.7%的谷丙转氨酶血清水平高于正常水平的1.5倍。据估计，15-65岁在职埃及人中，经年龄、性别和城乡调整后的真实丙肝血清阳性总体发生率为15.6%。在暴露的男性中，因注射治疗血吸虫病导致的归因风险估计为47%（95%可信区间=38%-55%）。在既往接受过输血的女性中，输血被估计导致了87%（95%可信区间=57%-96%）的病例。在职城乡男性中，因注射治疗血吸虫病导致的人群归因风险估计分别为15%和11%。在职城市女性中，输血和共用受污染针头各导致了24%的病例。既往住院在在职农村女性病例中占36%，在在职城市男性病例中占10%。至于全国丙肝血清阳性病例的估计数，我们估计超过500万人，不同程度的慢性肝炎预期病例数为350万。超过50%的这些个体存在高传播可能性的丙肝病毒血症，预计感染后平均20年内发展为肝硬化的病例数在35万至70万例之间。人群归因风险的主要部分归因于与年龄、男性性别、生活在农村地区以及埃及上下埃及相关的其他未明确的危险因素。需要进一步研究以阐明这些地区中存在的、与丙肝感染风险增加相关的因素。
