G. Thomas Strickland

The role of parenteral antischistosomal therapy in the spread of hepatitis C virus in Egypt

BACKGROUND The population of Egypt has a heavy burden of liver disease, mostly due to chronic infection with hepatitis C virus (HCV). Overall prevalence of antibody to HCV in the general population is around 15-20%. The risk factor for HCV transmission that specifically sets Egypt apart from other countries is a personal history of parenteral antischistosomal therapy (PAT). A review of the Egyptian PAT mass-treatment campaigns, discontinued only in the 1980s, show a very high potential for transmission of blood-borne pathogens. We examine the relative importance of PAT in the spread of HCV in Egypt. METHODS The degree of exposure to PAT by cohort was estimated from 1961-86 Ministry of Health data. A cohort-specific exposure index for PAT was calculated and compared with cohort-specific HCV prevalence rates in four regions. FINDINGS HCV prevalence was calculated for 8499 Egyptians aged 10-50 years. A significant association between seroprevalence of antibodies to HCV and the exposure index (1.31 [95% CI 1.08-1.59]; p=0.007) was identified across four different regions. In all regions cohort-specific HCV prevalence was lowest in children and young adults than in older cohorts. These lower prevalence rates coincided with the gradual and final replacement of PAT with oral antischistosomal drugs at different points in time in the four regions. INTERPRETATION The data suggest that PAT had a major role in the spread of HCV throughout Egypt. This intensive transmission established a large reservoir of chronic HCV infection, responsible for the high prevalence of HCV infection and current high rates of transmission. Egypts mass campaigns of PAT may represent the worlds largest iatrogenic transmission of blood-borne pathogens.

Liver disease in Egypt: Hepatitis C superseded schistosomiasis as a result of iatrogenic and biological factors†

In Egypt, schistosomiasis was traditionally the most important public health problem and infection with Schistosoma mansoni the major cause of liver disease. From the 1950s until the 1980s, the Egyptian Ministry of Health (MOH) undertook large control campaigns using intravenous tartar emetic, the standard treatment for schistosomiasis, as community‐wide therapy. This commendable effort to control a major health problem unfortunately established a very large reservoir of hepatitis C virus (HCV) in the country. By the mid‐1980s, the effective oral drug, praziquantel, replaced tartar emetic as treatment for schistosomiasis in the entire country. This both reduced schistosomal transmission and disease and interrupted the “occult” HCV epidemic. It was evident when diagnostic serology became available in the 1990s that HCV had replaced schistosomiasis as the predominant cause of chronic liver disease. Epidemiological studies reported a high prevalence and incidence of HCV, particularly within families in rural areas endemic for schistosomiasis. Clinical studies showed 70% to 90% of patients with chronic hepatitis, cirrhosis, or hepatocellular carcinoma had HCV infections. Co‐infections with schistosomiasis caused more severe liver disease than infection with HCV alone. Schistosomiasis was reported to cause an imbalance in HCV‐specific T‐cell responses leading to increased viral load, a higher probability of HCV chronicity, and more rapid progression of complications in co‐infected persons. As complications of HCV usually occur after 20 years of infection, the peak impact of the Egyptian outbreak has not yet occurred. Efforts have been initiated by the Egyptian MOH to prevent new infections and complications of HCV in the estimated 6 million infected persons. (HEPATOLOGY 2006;43:915–922.)

Intrafamilial transmission of hepatitis C in Egypt

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. (HEPATOLOGY 2005.)

Hepatitis C vaccine: supply and demand

Despite difficulties associated with extreme variability and mutability of hepatitis C virus (HCV), several vaccines that prevent initial infection or viral persistence, or that clear viraemia in individuals with chronic HCV infections, are currently in development. At least one vaccine that may prevent chronic persistent infections will soon be available for testing. We review the widespread importance of HCV infection and disease, the immune response to HCV and correlates of protection, prevention strategies and vaccine candidates, and groups that will need the vaccine and provide suitable populations for assessing vaccine safety and efficacy. The evaluation of prophylactic vaccines is particularly problematic since distribution must focus upon individuals at high risk of exposure-for example, intravenous drug users and health-care providers in areas with high HCV prevalence. Although there is a huge need for therapeutic vaccines, further immunological hurdles must be cleared before one becomes available.

Comparison of tests for antibody to hepatitis E virus

The results of serologic tests for hepatitis E virus have varied widely from laboratory to laboratory, making interpretation of seroepidemiologic studies difficult. The present study compares serologic results with different antigens and tests developed in two laboratories for their ability to diagnose hepatitis E and measure antibody prevalence in a high risk population in Saudi Arabia. The results confirm that tests based upon open reading frame (ORF) 3 of HEV are of limited value for seroepidemiologic studies, whereas ORF2‐based antigens have broad utility and yield data that are reproducible in more than one laboratory. J. Med. Virol. 55:134–137, 1998.

Comparison of Second- and Third-Generation Enzyme Immunoassays for Detecting Antibodies to Hepatitis C Virus

ABSTRACT Supplemental assays, such as recombinant immunoblot assays (RIBA), are used to confirm detection of antibodies to hepatitis C virus (HCV). However, due to their expense, they are not widely used in developing countries. The purpose of our study was to compare the results of second- and third-generation (G2 and G3, respectively) enzyme immunoassays (EIAs) and to resolve discordant results by using a supplemental assay to assess the reliability of G2 and G3 EIAs to confirm anti-HCV antibody-positive results. We performed both G2 and G3 EIAs for anti-HCV antibodies on 1,134 serum samples collected during the 2nd year of a longitudinal community-based study in Egypt; 35 samples with discordant results were tested by Abbott Laboratories Micro-Particle Immunoassay (M-EIA) and RIBA. Viremia was determined with an in-house nested reverse transcriptase PCR (RT-PCR) to detect HCV RNA. Concordance between the two assays (G2/G3) was 96.9%; 87 (7.7%) samples were positive and 1,012 (89.2%) were negative by both assays. For 17 samples, the discordant results were G2 assay negative and G3 assay positive, and for 18 samples, the discordant results were G2 assay positive and G3 assay negative. Among the 17 G2 assay-negative and G3 assay-positive samples, 15 were M-EIA positive and 7 were PCR positive. Among the 18 G2 assay-positive and G3 assay-negative samples, 2 were M-EIA positive and none were PCR positive. RIBA results from 24 discordant samples showed 87.5% agreement with the G3 EIA, 12.5% agreement with the G2 EIA, and 95.8% agreement with M-EIA. Eleven samples were indeterminate by RIBA and excluded from this analysis. Based on RIBA results, the sensitivity of the G3 EIA was 99%, compared to 89.8% for the G2 EIA, while the specificity of the G3 EIA was 99.8%, compared to 98.9% for the G2 EIA. These results show that the reliability of the G3 EIA in screening these sera is excellent, and the G3 assay can be used in the absence of supplemental tests where resources are limited. RIBA appears not to have advantages over the less expensive M-EIA screening assay. The main disadvantage of RIBA is the occurrence of indeterminate results, especially among problematic samples. Samples giving discordant results in multiple assays are often indeterminate with the RIBA.

A Randomized Controlled Trial to Assess the Safety and Efficacy of Silymarin on Symptoms, Signs and Biomarkers of Acute Hepatitis

PURPOSE Milk thistle or its purified extract, silymarin (Silybum marianum), is widely used in treating acute or chronic hepatitis. Although silymarin is hepatoprotective in animal experiments and some human hepatotoxic exposures, its efficacy in ameliorating the symptoms of acute clinical hepatitis remains inconclusive. In this study, our purpose was to determine whether silymarin improves symptoms, signs and laboratory test results in patients with acute clinical hepatitis, regardless of etiology. METHODS This is a randomized, placebo-controlled trial in which participants, treating physicians and data management staff were blinded to treatment group. The study was conducted at two fever hospitals in Tanta and Banha, Egypt where patients with symptoms compatible with acute clinical hepatitis and serum alanine aminotransferase (ALT) levels >2.5 times the upper limit of normal were enrolled. The intervention consisted of three times daily ingestion of either a standard recommended dose of 140 mg of silymarin (Legalon, MADAUS GmbH, Cologne, Germany), or a vitamin placebo for four weeks with an additional four-week follow-up. The primary outcomes were symptoms and signs of acute hepatitis and results of liver function tests on days 2, 4 and 7 and weeks 2, 4, and 8. Side-effects and adverse events were ascertained by self-report. RESULTS From July 2003 through October 2005, 105 eligible patients were enrolled after providing informed consent. No adverse events were noted and both silymarin and placebo were well tolerated. Patients randomized to the silymarin group had quicker resolution of symptoms related to biliary retention: dark urine (p=0.013), jaundice (p=0.02) and scleral icterus (p=0.043). There was a reduction in indirect bilirubin among those assigned to silymarin (p=0.012), but other variables including direct bilirubin, ALT and aspartate aminotransferase (AST) were not significantly reduced. CONCLUSIONS Patients receiving silymarin had earlier improvement in subjective and clinical markers of biliary excretion. Despite a modest sample size and multiple etiologies for acute clinical hepatitis, our results suggest that standard recommended doses of silymarin are safe and may be potentially effective in improving symptoms of acute clinical hepatitis despite lack of a detectable effect on biomarkers of the underlying hepatocellular inflammatory process.

Prospective cohort study of mother‐to‐infant infection and clearance of hepatitis C in rural Egyptian villages

Although persistent transmission of hepatitis C virus (HCV) from infected mothers to their infants is reported in 4–8%, transient HCV perinatal infection also occurs. This prospective cohort study determined perinatal HCV infection‐ and early and late clearance‐rates in 1,863 mother‐infant pairs in rural Egyptian villages. This study found 15.7% and 10.9% of pregnant women had HCV antibodies (anti‐HCV) and HCV‐RNA, respectively. Among 329 infants born of these mothers, 33 (10.0%) tested positive for both anti‐HCV and HCV‐RNA 2 months following birth—29 (12.5%) having HCV‐RNA positive mothers and 4 (with transient infections) having mothers with only anti‐HCV. Fifteen remained HCV‐RNA positive at one and/or 2 years (persistent infections), while 18 cleared both virus and antibody by 1 year (transient infections). Among the 15 persistent cases, 7 cleared their infections by 2 or 3 years. At 2‐ to 6‐ and at 10‐ to 12‐month maternally acquired anti‐HCV was observed in 80% and 5% of infants, respectively. Four perinatally infected and one transiently infected infant were confirmed to be infected by their mothers by the sequence similarity of their viruses. Viremia was 155‐fold greater in mothers of infants with persistent than mothers of infants with transient infections. Maternal‐infant transmission of HCV is more frequent than generally reported. However, both early and late clearance of infection frequently occurs and only 15 (4.6%) and 8 (2.4%) infants born of HCV‐RNA positive mothers had detectable HCV‐RNA at one and 2–3 years of age. Investigating how infants clear infection may provide important information about protective immunity to HCV. J. Med. Virol. 81:1024–1031, 2009.

Incidence and risk factors for hepatitis C infection in a cohort of women in rural Egypt

A prospective cohort study of the incidence and risk factors for hepatitis C virus (HCV) infection was performed in 2171 pregnant women in three rural Egyptian villages who were HCV antibody (anti-HCV) and RNA (HCV-RNA) negative at baseline. During an average of 2.2 years follow up, 25 incident cases were observed, giving an estimated HCV incidence of 5.2/1000 person-years (PY). The infection rate correlated with community anti-HCV prevalence in pregnant women, while the perinatal incidence rate of 11.2/1000 PY was almost five times that of the non-perinatal rate (2.3/1000 PY). The data suggested iatrogenic perinatal risk factors were associated with infection in one village, while health education reduced infections in another. Among the 25 incident cases, eight were HCV-RNA negative when they were first found to be anti-HCV positive and one-third of the 15 viraemic cases with follow-up data available cleared their HCV-RNA after an average of 1.3 years. None of the 25 incident cases were jaundiced or had symptoms of hepatitis but elevated serum alanine aminotransferase levels confirmed hepatitis in nine. Our data suggest that asymptomatic HCV infections frequently occurred during the perinatal period but often cleared and that educating medical personnel on safe practices possibly reduced HCV transmission.

Sonographic studies of schoolchildren in a village endemic for Schistosoma mansoni

Parasitological, clinical, and sonographic examinations were performed on 309 school children in a village endemic for schistosomiasis mansoni. Data from the 255 denying treatment within the previous 2 years were analysed separately. On a single Kato examination 42% were uninfected; the remainder had light (26%), moderate (21%), or heavy (11%) infections with Schistosoma mansoni. Hepatomegaly (53%) and palpable spleens (35%) were common but clinical and parasitological findings often were unrelated. Abdominal sonography also demonstrated a high frequency of hepatomegaly (82%) and splenomegaly (49%). Sonographically determined liver span and spleen size correlated with the egg count. Sonographic lesions of periportal fibrosis of schistosomiasis mansoni with thickening of portal tracts and portal vein walls were frequently present and more common in infected than in uninfected children, and were correlated with the number of S. mansoni ova in the stool. Ultrasonographically detected periportal fibrosis was a reliable measurement of the prevalence and morbidity of schistosomiasis mansoni in this population, and provided very useful information, even when the parasitological and clinical findings were equivocal.