Prevalence Of Active Hepatitis C Virus Infection Research Articles

Dynamic changes in the prevalence of markers of hepatitis C virus infection among the conditionally healthy population of the Tyva Republic

The aim is to determine the dynamic changes in the prevalence of hepatitis C virus (HCV) infection among various age groups of the conditionally healthy population of the Tyva Republic over the past 11 years.Material and methods. 1163 serum samples collected in 2019 from the healthy volunteers living in the Tyva Republic of were tested for HCV markers. The study included people of 10 age cohorts: less than 1 year, 1-4, 5-9, 10-14, 15-19, 20-29, 30-39, 40-49, 50-59 years, and 60 years or older. Anti-HCV antibodies were detected using commercially available enzyme immunoassay. HCV RNA was detected in anti-HCV positive samples by means of RT-PCR. The dynamic changes in HCV prevalence were assessed based on a comparison of the results with data of the seroservey of the same design conducted in this region in 2008 in similar age cohorts of healthy volunteers (n=910).Results and discussion. The prevalence of anti-HCV antibodies among general population of the Tyva Republic in 2019 was 2.0%. This indicator slightly decreased by 1.7 times over 10 years (3.3% in 2008, p =0.1629). The prevalence of active HCV infection in the Tyva Republic also decreased not significantly (1.1% in 2019 vs. 1.3% in 2008, p = 0.6901). The proportion of people with active infection among anti-HCV positives in 2019 was 56.5%.The decrease in the prevalence of HCV infection over 11 years was associated with a significant reduction in the detection rates of hepatitis C markers in age cohort 40-49 years (0.9% in 2019 vs. 3.6% in 2008 for HCV RNA, p<0.05, and 1.8% in 2019 vs. 9.1% in 2008 for anti-HCV, p<0.05, respectively). The highest rates of detection of anti-HCV and HCV RNA were observed among participants aged 60 years and over (8.0% and 7.0%, respectively, in 2019 and 11.0 and 6.3%, respectively, in 2008), which significantly exceeded detection rates in other age groups, both in 2008 and 2019 (<0.05).Conclusion. A decrease in the prevalence of HCV infection in general population of the Tyva Republic was observed over last 11 years, primarily due to a decrease in the proportion of unidentified cases of infection among people aged 40-49 years. At the same time, the proportion of unidentified cases of HCV infection in persons aged 60 years and older remains consistently high, which is apparently due to insufficient screening coverage in this age cohort. This age-associated risk cohort should be benefited from the inclusion in HCV screening program.

ESTIMATION OF PREVALENCE OF HEPATITIS C VIRUS INFECTION BY SEROLOGICAL TEST AND REAL TIME RT-PCR TEST AMONG SUSPECTED VIRAL HEPATITIS CASES ATTENDING TERTIARY CARE HOSPITAL, KOLKATA

Objective: Hepatitis C virus (HCV) infection is a major public health problem in India and worldwide. Majority remain asymptomatic until they develop serious complications like liver cirrhosis or hepatocellular carcinoma with fatal outcome. Hence, early diagnosis of active HCV infection and prompt initiation of treatment is important. Treatment with directly acting antivirals (DAAs) resulted in high sustained virological response (SVR) rates of >95% globally. This study was done to estimate seroprevalence and prevalence of active HCV infection among study population. After initiation of treatment, SVR rates were estimated. Methods: This was hospital-based, cross-sectional, and observational study. Screening was done by third-generation Enzyme-linked immunosorbent assay to detect anti-HCV antibody, then confirmatory real-time reverse transcription-polymerase chain reaction (RT-PCR) test was done for detection of active cases and determining their viral load. Treatment of 12-week duration was initiated by DAAs and followed up to estimate SVR by doing real-time RT-PCR after 12 weeks of treatment completion. Result: Among 17,752 consecutive non-repetitive blood samples, seroprevalence was 1.78%. The prevalence of active cases was 1.52%. HCV active infection was prevalent more among male (64.21%) and among 40–60 years age group. History of multiple blood transfusion (58%) was the most common risk factor, followed by multiple sex partners (13.3%). Coinfections with Hepatitis B virus and Human immunodeficiency virus were seen in 13.65% of cases. About 92% of patients completed their treatment. SVR was 97.87%. Conclusion: High SVR of 97.87% is evidence-based data that support that proper treatment can eliminate HCV infection. Detection by real-time RT-PCR and highly effective DAA has made a paradigm shift to approach of HCV diagnosis and management in recent times

Prevalence and risk factors for hepatitis C virus infection among HIV positive patients at the Lagos University Teaching Hospital, Nigeria

Background: Worldwide, an estimated 58 million people have chronic hepatitis C virus (HCV) infection, with about 1.5 million new infections occurring per year. About 2.3 million people living with HIV globally have serological evidence of past or present HCV infection. The aim of this study was to determine the prevalence of active HCV infection and associated risk factors among HIV positive patients attending the HIV clinic, Lagos University Teaching Hospital (LUTH), Idi-Araba, Lagos, Nigeria.
 Methodology: A cross sectional study was conducted to determine the prevalence of and risk factors for HCV infection among randomly selected HIV positive patients at the LUTH HIV clinic. Socio-demographic, clinical and laboratory data were collected from the participants using a structured questionnaire. Blood samples were collected and tested for HCV antibodies with an enzyme linked immunosorbent assay (CTK Biotech USA) and HCV RNA was detected using reverse transcriptase polymerase chain reaction assay.
 Results: One hundred and ninety-five HIV infected participants were recruited into the study of which 134 (68.7%) were females and 61 (31.3%) were males. The mean age of participants was 40.1±7.8 years. Of the 195 participants, 5 tested positive for antibody to HCV, giving a seroprevalence rate of 2.6% (95% CI = 0.8-5.9%). Of the 5 seropositive participants, HCV RNA was detected in 1 (20.0%), giving a prevalence of 0.5% (1/195) for active HCV infection. The seroprevalence of HCV in males of 4.9% (3/61) and females of 1.5% (2/134) was not significantly different (OR=3.41, 95% CI=0.56-20.98%, p=0.18). The mean log10 HIV viral load was significantly higher among participants seropositive for HCV (5.1±0.9 log copies/ml) than those seronegative (2.7±1.2 log copies/ml) (p < 0.001). The mean duration of antiretroviral therapy was significantly lower among participants seropositive for HCV (2.6±1.3 years) than those seronegative (5.6±3.1 years) (p=0.004). The seroprevalence of HCV was significantly higher in those with CD4 count <350 cells/mm3 (8.5%) than those with CD4 count >350cells/mm3 (p=0.02). The seroprevalence of HCV in the HIV-positive participants was significantly associated with sexual partners (p=0.0473), with highest seroprevalence in those with ≥ 3 sexual partners (OR=11.625, 95% CI=1.049-128.83). Other risk factors were not significantly associated with seroprevalence of HCV (p>0.05), while risk factors associated with active HCV infection could not be evaluated with the only one HCV RNA positive participant
 Conclusion: Although the prevalence of active HCV infection in HIV infected individuals in this study was apparently low (0.5%), screening with HCV antibody test and confirmation with HCV RNA PCR assay are recommended.

Prevalence of active HCV infection and genotypic distribution among the general population of district Mardan, Pakistan.

Hepatitis C virus (HCV) is the serious global public health burden of liver disease. Approximately 170 million people in the world are infected with (HCV). In Pakistan, where the disease has high occurrence rate. The present study envisages an up-to-date prevalence of HCV and genotypic distribution in the general population of Mardan District, Khyber Pakhtunkhwa (KP), Pakistan. The blood samples from 6,538 individuals including 3,263 males and 3,275 females were analyzed for hepatitis C surface antigen by Immuno-chromatographic test (ICT), Enzyme-linked immunosorbent assay (ELISA), and reverse transcription-polymerase chain reaction (PCR). It was found that 396 (12.13%) out of 3263 individuals contained antibodies in their blood against HCV, while among the different age groups, the highest incidences of HCV antibodies were found in the 31-40 age group (11.01%). The ICT positive samples were further screened by nested PCR to determine the existence of active HCV-RNA. It was identified that 7.11% (3263) of the total population (6538) tested was positive, among which the 461 (14.07%) females possessed antibodies in their blood against HCV. Our data showed total HCV infection in the investigated population was 5.78%. Higher percentage of HCV prevalence was detected in males than females in the age group 31-40 and 41-50. To compare the prevalence of HCV genotypes age-wise in male and female genotype 3a was found most prevalent genotype followed by 1a, 2a and 3b, respectively.

Evaluation of Incidence, Genotypes, and Risk Factors Associated with Newly Diagnosed Hepatitis C Cases in Khyber Pakhtunkhwa (KPK), Pakistan

Hepatitis C is a global health concern brought on by the hepatitis C virus (HCV). The risk factors of the disease include injection drug users, contaminated medical instruments, blood transfusion, organ transplant, major surgery, dialysis, dental surgery, and acupuncture. The aim of the current study was to identify the prevalence of active HCV infection, genotypes, and their associated risk factors in newly infected patients of Khyber Pakhtunkhwa (KPK), Pakistan. A total of 230 HCV cases and 245 control subjects were enrolled. Our findings revealed that disease infection rates were higher in female patients (52.6%) than male patients (47.4%). Moreover, the disease was more prevalent in the age group 30–40 years (39.6%). The highest incidence was found in the southern region (51.30%), followed by the northern region (27.82%), and central region (18.26%). In our data set, dental surgery, major surgery, disease in family, barber community, blood received, needles, abroad travel, injection drug users, acupuncture, and organ transplantation were determined as the major associated risk factors of the disease. Odds ratio were significantly higher (10.91%) for those who used acupuncture as compared to those who did not. Similarly, odds were significantly higher (10.03%) for those who had HCV in their family, dialysis (9.377%), dental surgery (7.618%), major surgery (6.813%), barber community (5.328%), and blood received (2.252%) as compared to the control group. Also, the most frequent genotype was 3a (63%), followed by an un-typeable genotype (11.30%).

Trends in the Prevalence of Hepatitis C Virus Infection based on the Insurance Status in the United States from 2013 to 2018.

With the recent improvement in the treatment of hepatitis C virus (HCV) infection, a better understanding of the infection burden is needed. We aimed to (a) estimate the trends in the national prevalence of HCV infection based on the type of health insurance coverage and (b) identify at-risk populations for HCV infection in the United States (US) general population. Population-based analyses using the National Health and Nutrition Examination Survey (2013-2018) were performed with a focus on HCV infection. We analysed the prevalence of HCV infection based on the health insurance status before the direct-acting antiviral (DAA) era (2013-2014) and during the DAA era (2015-2018). The age-adjusted prevalence of active HCV infection (HCV RNA [+]) was 0.92% (95% confidence interval, 0.71%-1.19%) in the US non-institutionalized civilian population. Although the prevalence of active HCV infection has remained stable, the prevalence of resolved HCV infection has increased after the introduction of DAA. In terms of health insurance coverage, the prevalence of active HCV infection decreased, and the prevalence of resolved HCV infection increased among individuals who had health insurance, especially private health insurance. The independent risk factors of active HCV infection were 40-69years group, male, less than high school education, unmarried, below poverty status, being born in the US, history of blood transfusion and not having private health insurance. The burden of active HCV infection has decreased among individuals who had health insurance, especially private health insurance, during the DAA era.

Prevalence and undiagnosed fraction of hepatitis C infection in 2018 in Spain: results from a national population-based survey.

A national strategy against hepatitis C virus (HCV) was implemented in Spain in 2015 with the aim of reducing associated morbidity and mortality. In order to improve our understanding of the epidemiology of HCV, we analysed the prevalence of HCV antibodies and active infection overall and by age and sex in the general population aged 20-80 years. We also aimed to report the undiagnosed fraction. A national population-based seroprevalence survey was conducted in 2017-2018. A representative sample from the general population was selected using two-stage sampling. The prevalence of total HCV antibodies and of HCV RNA was calculated using inverse probability weighting based on bootstrapping. Overall, we approached 17496 persons; 9103 agreed to participate and met the eligibility criteria and 7675 were aged 20-80. We obtained a prevalence of HCV antibodies of 0.85% [95% confidence interval (CI): 0.64-1.08%] and of active infection of 0.22% (95% CI: 0.12-0.32%). The prevalence of active HCV infection was highest in men aged 50-59 (0.86%; 95% CI: 0.28-1.57%) and in men aged 60-69 years (0.72%; 95% CI: 0.27-1.28%). Prevalence was below 0.20% in the remaining age groups. The undiagnosed fraction for active HCV infection was 29.4%. This study shows that prevalence of HCV in the general population in Spain is low and reflects the impact of scaling up treatment with direct acting antivirals, together with other prevention strategies, from 2015 onwards. The data reported can guide subsequent public health actions.

Prevalence and characteristics of hepatitis C virus infection detected by extended screening of working-age adults in Madrid (Spain).

Hepatitis C virus (HCV) infection is a leading cause of liver-related morbidities and mortality. Antiviral treatment is highly successful but only a fraction of infected subjects are aware of their HCV status; therefore, prevalence studies are essential to identify HCV-infected individuals. Our aim was to analyze the prevalence and characteristics of HCV infection among working-age adults in Madrid (Spain). Extended screening for HCV infection was performed by measuring HCV antibodies in blood collected preoperatively from individuals requiring surgical treatment of work-related injuries or at baseline from subjects suffering occupational exposures to biological fluids. HCV RNA was measured in HCV antibody-positive subjects unaware of their HCV status. Serum aminotransferases were measured in all participants. During a six-year period (2013-2018), 16,734 consecutive patients were studied. Two hundred and twenty-eight (1.4%) were HCV antibody-positive [191 (83.8%) males; 37 (16.2%) females; median (SD) age: 49.2 (7.5) years], 94 (41.2%) were unaware of their HCV status, and 41 (17.9%) had detectable HCV RNA [mean (SD) log10 UI/mL: 5.6 (1.1)]. Most HCV antibody-positive subjects were born during the 1945-1965 period (birth cohort group), and the prevalence of active HCV infection was higher in this group (56.1% vs 43.9%; p = 0.194). Overall, 62 (27.8%) participants had elevated serum aminotransferases, including 22 (57.9%) with active HCV infection (p < 0.001). Screening for HCV infection in working-age adults detected a significant proportion of HCV-infected individuals with viremia and normal transaminase levels, who were unaware of their infection status. Extended screening for HCV infection is warranted.

Differences in inpatient and outpatient hepatitis C virus prevalence and linkage to care rates in a safety net hospital hepatitis C screening program.

Routine screening for hepatitis C virus (HCV) infection is crucial in identifying the 50% of infected persons unaware of their infection. We added an inpatient screening initiative to our successful outpatient HCV screening program in an urban, safety-net hospital. From March 2017 to December 2019, HCV screening was performed in inpatient and outpatient settings at Grady Health System. We compared care cascade outcomes, including anti-HCV testing, RNA testing, and linkage to care (LTC) between these settings. A total of 29751 patients were tested for anti-HCV: 8883 inpatients and 20868 outpatients. The anti-HCV population was predominantly Black (76.2%) and male (67.9%). The total anti-HCV prevalence was 8.9%, with 14% of inpatients and 6.7% of outpatients testing positive. RNA testing was performed on 86%. The prevalence of active HCV infection was 59.3% in those that were anti-HCV positive; inpatient prevalence was 66%, and outpatient was 53.8%. Of those with active infection, 67.5% were linked to care (57.3% of inpatients and 77.8% of outpatients). We found significant differences in prevalence of anti-HCV and LTC rates between inpatients and outpatients during an HCV screening program. Higher anti-HCV prevalence among inpatients may be due a higher prevalence of non-birth year HCV risk factors. LTC rates were lower in the inpatient setting despite a robust linkage strategy. The striking prevalence of HCV in both settings warrants continued screening, expansion to additional settings, and novel strategies to improve inpatient linkage rates, especially in the setting of new universal HCV screening guidelines.

Prevalence and Risk Factors of Hepatitis C Virus (HCV) in Tehsil Batkhela District Malakand, KPK, Pakistan

Background: Prevalence of Hepatitis C viral infection and its major risk factors has been found out in population of Batkhela, Khyber Pakhtunkhwa, Pakistan by taking number of volunteers from the interested area. HCV prevalence has not been researched in recent time here in this area, so that’s why we contributed.&#x0D; Materials and Methods: Ab rapid test cassette serum/plasma (USA) kit has been used for the mentioned purpose following by ELISA and finally PCR to find out active infection of virus. ICT positive individuals were reconfirmed by ELISA and then ELISA positive samples were carefully investigated by RT-PCR for Hepatitis C Virus.&#x0D; Results: The study population was of 770 volunteers belonging to the mentioned area of research, 453 males and 317 females. The overall prevalence was found to be 5.32% of HCV in Batkhela. This prevalence ratio was 3.12% in males and 2.20 % in females. 3rd generation ELISA was used to refine ICT positive samples which showed that 37 of the ICT positive samples had antibodies detected by ELISA. To find out active HCV infection, ELISA positive samples were refined by real time PCR which showed 2.98% of prevalence of active HCV infection in Batkhela based on HCV RNA in their blood.&#x0D; Principle Conclusion: Overall prevalence was found 5.32%, contaminated reused syringes and blades at Barbour’s shop, blood transfusion, surgical operations and unhygienic food in stalls etc were found significant risk factors for acquiring HCV infection. Body weakness and pale yellow skin color was common symptom in HCV positive volunteers. Safe sexual activities, blood screening before donation and sterilizing surgical equipment’s can protect us from Hepatitis C Virus.

Prevalence of infection with hepatitis C virus in Venezuela, as assessed with an immuno-assay based on synthetic peptides.

Information on infection with hepatitis C virus (HCV) in South America is scarce. The seroprevalences of antibodies to HCV among urban, rural and Amerindian populations from Venezuela, and the genotypes of the HCV isolates recovered, were therefore determined. A total of 2592 sera were tested with an immuno-assay which was developed in-house and based on synthetic peptides. Each reactive sample was then re-tested, using other enzyme immuno-assays and a reverse-transcription, nested PCR, and any sample confirmed positive (in any test) was considered HCV-positive. Genotypes were determined by analysis of RFLP. Overall, 39 (1.5%) of the samples were found HCV positive. The results of the immuno-assays indicated that the seroprevalence of HCV markers among the Amerindians investigated (23/1082, or 2.1%) was significantly higher than that among the other subjects (16/1510, or 1.1%; P = 0.02). No such difference was observed in the numbers of subjects confirmed positive by PCR, however (6/1082 v. 10/1510), and some of the anti-HCV reactivity observed among Amerindians may have been the result of cross-reactivity with parasitic infections. The relative low prevalence of active HCV infection (16/2582, or 0.6%) and the HCV genotypes observed (mainly genotype 1) are in agreement with the results of previous studies indicating that HCV is not autochthonous to South America. However, it is clear that the virus may now be found even in isolated Amerindian populations. The in-house, synthetic-peptide-based immuno-assay seems to be a valuable tool for epidemiological studies.

Prevalence of Hepatitis C Virus in the Population of Albania for the Period 2007-2010

BACKGROUND: Hepatitis C is a blood-borne, infectious, viral disease that is caused by a hepatotropic virus called Hepatitis C virus (HCV).AIM: The aim of this study is to determine the prevalence of active HCV infection (HCV–RNA) in the cases that were anti-HCV positive.MATERIAL AND METHODS: Plasma of 301 high-risk for HCV infection consecutive from University Hospital Centre “Mother Theresa” Tirana-Albania, during January 2007 to December 2010 was included in this study. To identify the presence of HCV RNA, the samples were examined by Cobas Amplicor HCV test (qualitative method).RESULTS: From 301 samples analyzed in total, 214 of them resulted positive for the presence of HCV-RNA's, corresponding to a prevalence of 71.1%, with 95% CI interval [65.8 - 75.9] for value of χ2 = 52.7 p value &lt;0.0001. Divide by the sex 56% were males and 44% females, with statistically significant difference between them for value χ2 =4306 p value=0.0380. Among the age groups the highest prevalence was observed in the age groups &gt; 25 years with a significant difference with other age groups for p value &lt;0.001.CONCLUSION: Among tested samples, 71.1 % were confirmed to be positive for HCV –RNA infections. The prevalence of male was highest compared to female. For males and females infected the prevalence was highest in the age group of &gt; 25 years.

Prevalencia de los marcadores de infección de los virus de las hepatitis en pacientes portadores del VIH en el sur de España

To determine: (a) The prevalence of active infection by the hepatitis C virus (HCV) and hepatitis B virus (HBV) in HIV-infected patients, as well as previous exposure to hepatitis A virus (HAV), HBV and HCV. (b) The proportion of patients who have been vaccinated against HAV and/or HBV. (c) The HCV genotype distribution and the percentage of patients who have started treatment against HCV infection. All HIV-infected patients who attended the Infectious Diseases Unit of a tertiary care hospital in Southern Spain between September 2008 and February 2009 were included in a prospective cross-sectional study. A total of 520 patients were included. Three hundred and fifty-eight (69%) patients had positive HCV antibody, while 71% of them showed detectable HCV-RNA. The HCV genotype distribution was: 153 (62%) genotype 1, 49 (20%) genotype 3, and 45 (18%) genotype 4. One hundred and thirteen (36.5%) subjects had received treatment against HCV. The prevalence of active HBV infection was 4.4%, while the exposure to HBV was 54.8%. Four hundred and thirty-seven (84%) patients had positive markers of infection of HAV. Of the patients eligible to be vaccinated, 25.6% and 22.3% patients were vaccinated against HAV and HBV, respectively. The current prevalence of active HCV infection remains high in our area. There were no changes in the HCV genotype distribution. The number of patients with indication for HBV and HAV vaccination and receive these vaccines is low.

Rising burden of Hepatitis C Virus in hemodialysis patients

AimHigh prevalence of Hepatitis C virus (HCV) has been reported among the dialysis patients throughout the world. No serious efforts were taken to investigate HCV in patients undergoing hemodialysis (HD) treatment who are at great increased risk to HCV. HCV genotypes are important in the study of epidemiology, pathogenesis and reaction to antiviral therapy. This study was performed to investigate the prevalence of active HCV infection, HCV genotypes and to assess risk factors associated with HCV genotype infection in HD patients of Khyber Pakhtunkhwa as well as comparing this prevalence data with past studies in Pakistan.MethodsPolymerase chain reaction was performed for HCV RNA detection and genotyping in 384 HD patients. The data obtained was compared with available past studies from Pakistan.ResultsAnti HCV antibodies were observed in 112 (29.2%), of whom 90 (80.4%) were HCV RNA positive. In rest of the anti HCV negative patients, HCV RNA was detected in 16 (5.9%) patients. The dominant HCV genotypes in HCV infected HD patients were found to be 3a (n = 36), 3b (n = 20), 1a (n = 16), 2a (n = 10), 2b (n = 2), 1b (n = 4), 4a (n = 2), untypeable (n = 10) and mixed (n = 12) genotype.ConclusionThis study suggesting that i) the prevalence of HCV does not differentiate between past and present infection and continued to be elevated ii) HD patients may be a risk for HCV due to the involvement of multiple routes of infections especially poor blood screening of transfused blood and low standard of dialysis procedures in Pakistan and iii) need to apply infection control practice.

Prevalence of active hepatitis c virus infection in district mansehra pakistan

Prevalence of active hepatitis C virus (HCV) infection in apparently healthy inhabitants of District Mansehra, Pakistan was surveyed during September, 2009 to May, 2010. Subjects of different age and gender groups were analyzed through random blood sampling from people of three areas viz; Tehsil Mansehra, Tehsil Balakot and Tehsil Oghi. Sum of 400 individuals, 300 male and 100 females with age groups from 10 years to 50 and above were included in the study. All the individuals were screened for antibodies against HCV. The positive samples thus screened, were subjected to polymerase chain reaction (PCR) analysis for detection of HCV-RNA. The results showed that 3.5% of the people of District Mansehra are actively infected with HCV whereas 7% of the population in general, has the presence of antibodies against HCV in their blood. It was also concluded that the prevalence of active HCV infection was high 4% in males as compared to females (2%). The prevalence of HCV proportionality increases with the increase in age of the people. Its incidence was highest (7.69%) in the people of the age group of 51 years and above, whereas no sign of infection was recorded for the age group of 10-20 years.

Prevalence of infection with hepatitis C virus in Venezuela, as assessed with an immuno-assay based on synthetic peptides

Information on infection with hepatitis C virus (HCV) in South America is scarce. The seroprevalences of antibodies to HCV among urban, rural and Amerindian populations from Venezuela, and the genotypes of the HCV isolates recovered, were therefore determined. A total of 2592 sera were tested with an immuno-assay which was developed in-house and based on synthetic peptides. Each reactive sample was then re-tested, using other enzyme immuno-assays and a reverse-transcription, nested PCR, and any sample confirmed positive (in any test) was considered HCV-positive. Genotypes were determined by analysis of RFLP. Overall, 39 (1.5%) of the samples were found HCV positive. The results of the immuno-assays indicated that the seroprevalence of HCV markers among the Amerindians investigated (23/1082, or 2.1%) was significantly higher than that among the other subjects (16/1510, or 1.1%; P = 0.02). No such difference was observed in the numbers of subjects confirmed positive by PCR, however (6/1082 v. 10/1510), and some of the anti-HCV reactivity observed among Amerindians may have been the result of cross-reactivity with parasitic infections. The relative low prevalence of active HCV infection (16/2582, or 0.6%) and the HCV genotypes observed (mainly genotype 1) are in agreement with the results of previous studies indicating that HCV is not autochthonous to South America. However, it is clear that the virus may now be found even in isolated Amerindian populations. The in-house, synthetic-peptide-based immuno-assay seems to be a valuable tool for epidemiological studies.