Endemic hepatitis C virus infection in a Sicilian town: further evidence for iatrogenic transmission

The prevalence of and risk factors for HCV and HBV infections in the general population and the predictive value of ALT screening in identifying anti-HCV positive subjects have been evaluated in a small Sicilian town. A random 1:4 sampling from the census of the general population was performed. Anti-HCV, HCV-RNA, HCV genotype, HBsAg, and anti-HBc were tested. The linkage between HCV infection and potential risk factors was evaluated by multiple logistic regression analysis. Among 721 subjects studied, 75 (10.4%) were anti-HCV positive. The HCV infection rate increased from 0.4% in subjects 10-29 years of age to 34% in those > 60 years of age. Among the 75 anti-HCV positive subjects, 66.7% were HCV-RNA positive and 36% had abnormal ALT, in contrast abnormal ALT levels were found in 4.3% of the 646 anti-HCV negative subjects (P < 0.01). HCV genotype 1b infected the majority (88.0%) of viremic subjects. Exposure to HBV infection (anti-HBc positivity) was found in 11.2% of subjects; HBsAg positivity was 0.7%. At multivariate analysis, two variables were associated with HCV infection: age > or = 45 years (OR 27.8; CI 95% = 11.0-70.2) and previous hospitalization (OR 2.5; CI 95% = 1.3-4.7). ALT testing had low positive predictive value (PPV = 49.1%) for HCV infection. The positive predictive value was good (88%) in people > or = 60 years of age, but minimal (16.7%) in those below 60. These findings indicate that HCV infection is common in the elderly, perhaps as a result of past iatrogenic transmission. The present low rate of HCV infection among the younger generations coupled with the low progression of the viral related liver damage does not support the projection of a future increasing incidence in the next decades of the burden of HCV-related chronic disease. HBV infection, formerly common in this area, is already in sharp decline. In an area of high HCV endemicity, screening of the general population by ALT cannot be used a surrogate marker to detect HCV infection in those susceptible to treatment.     

Prevalence of hepatitis C virus antibody among Korean adults.

To estimate the prevalence of hepatitis C virus (HCV) infection among Korean adults and to present the putative route of HCV transmission among them, serum samples from 4917 adults older than 20 years of age were tested for antibody to HCV (anti-HCV), and histories of blood transfusion and other pertinent information were obtained by self-administered questionnaires. The overall prevalence of anti-HCV was 1.7%; prevalence was 1.4% in subjects with normal levels of aspartate aminotransferase (AST) and alanine aminotransferase (ALT), 3.3% in those with slightly elevated and 5.9% in those with markedly elevated levels of the enzymes. The prevalence of anti-HCV increased with increasing age (P < 0.01), but was not associated with blood transfusion. The present study suggests that the prevalence of HCV infection was 1.4% and that the major routes of HCV transmission may be other than blood transfusion in healthy Korean adults.     

Prevalence of and risk factors for hepatitis C virus infection among blood donors in Chengdu, China

The objectives of the study were to estimate the prevalence of anti-hepatitis C virus (HCV) positivity among blood donors from Chengdu, China, and to determine risk factors associated with infection. In this study, data were collected from volunteer blood donors between July 2006 and June 2007. Anti-HCV test was performed in 119,518 donors. To identify risk factors associated with HCV infections a case-control study was conducted in 305 unique HCV-seropositive blood donors and 610 seronegative donors matched for age and sex. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using logistic regression. The population attributable risk (PAR) to risk factor was estimated according to the Bruzzi's formula. The prevalence of anti-HCV positivity was 0.53% (95% CI: 0.489-0.572%). The final multivariate model included the following independent HCV risk factors: razor sharing (OR=29.16; 95% CI: 12.89-66.00), blood transfusion (OR=20.84; 95% CI: 3.76-115.45), acupuncture (OR=8.01; 95% CI: 3.16-20.30), a history of hospitalization, injections >10 years earlier, a family history of hepatitis B, dental treatment, and ear piercing. The PAR of risk factors are 68.4%, 6.3%, 14.1%, 23.1%, 29.5%, 29.3%, 38.9%, and 27.8%, respectively, and the total PAR is 98.3%. Infection with HCV among blood donors in Chengdu is associated with iatrogenic risk factors and beauty treatment-related risk. Razor sharing is an important risk factor for HCV infection. These results indicate that infection control measures in healthcare settings may reduce the burden of HCV infection and there is a need for development of effective educational programs to improve HCV knowledge among beauty culture professionals, barber cosmetologists, and the general public to avoid risk behaviors.     

An epidemiological study of hepatitis C virus infection in a local district in Japan

Mass screening of anti-HCV in Iyo city, Japan was performed. Sera from 136 subjects were tested for anti-HCV by ELISA (Ortho Diagnostic Inc.). Anti-HCV was positive in 13 subjects (9.6%). The familial study for anti-HCV revealed 2 persons positive for anti-HCV in 2 families each, while only 1 person was positive in each of the 8 other families. Two females were positive for both anti-HCV and HBsAg, and all of their 3 children were negative for anti-HCV and positive for HBsAg. Positive rate of anti-HCV was higher in subjects who had a history of blood transfusion or "Chinese acupuncture" than that in those who did not. These results indicate that not only blood transfusion but also "Chinese acupuncture" and intrafamilial transmission are possible routes of HCV infection. The rate of vertical transmission of HCV is definitely lower than that of HBV.     

Molecular and epidemiological study on nosocomial transmission of HCV in hemodialysis patients in Brazil

An epidemiological and molecular study of hepatitis C virus (HCV) infection was carried out in Brazilian hemodialysis centers. A total of 1,095 patients in all 15 hemodialysis centers in the State of Goiás, Brazil, were studied. All patients were interviewed for possible risk factors to HCV infection and serum samples tested for anti-HCV by ELISA and for HCV RNA by nested RT-PCR of the 5' NC region. For sequence analysis, HCV RNA amplification for the NS5B region (nt 8,279-8,619) was performed. The phylogenetic tree was generated with MrBayes, and clusters with support values above 0.85 were considered epidemiologically related. Of the 1,095 patients, 180 were anti-HCV and/or HCV RNA positive, resulting in an overall prevalence of 16.4% (95% CI: 14.3-18.7). The prevalence of HCV infection in the dialysis centers ranged from 0% to 47.7%. Multivariate analysis of risk factors revealed that history of blood transfusion not screened for anti-HCV and length of time on hemodialysis were independently associated with HCV infection in this population. One hundred six samples could be amplified and sequenced in the NS5B region. Among them, plylogenetic tree analysis revealed that 69 sequences form 13 separated clusters, which were supported by credibility intervals ranging from 85% to 100%, indicating a very close relationship among the HCV isolates and therefore a likely transmission of the virus between patients. By combining phylogenetic analysis with epidemiological data, routes of transmission between the clustered-related-patients could be suggested. These findings provide evidence for nosocomial transmission of HCV in Brazilian hemodialysis centers.     

Molecular epidemiological and clinical aspects of hepatitis D virus in a unique triple hepatitis viruses (B,C, D) endemic community in Taiwan

The molecular epidemiological and clinical aspects of hepatitis D virus (HDV) in a unique HBV, HCV, and HDV triple virus endemic community in southern Taiwan were investigated. A total of 2,909 residents aged 45 or older were screened for hepatitis B surface antigen (HBsAg), anti-HCV antibody, and anti-HDV antibody (specifically for HBsAg-positive carriers). Factors that might be associated with HDV infection, viral nucleic acid detection, and genotyping of HBV, HCV, and HDV were investigated. The prevalence of HBsAg and anti-HCV were 12.6% (366/2,909) and 41.6% (1,227/2,909), respectively. For HBsAg carriers, 15.3% (56/366) were positive for anti-HDV assay. Living in a higher endemic district of HCV infection (odds ratio [OR] = 3.2; 95% confidence interval [CI] = 1.7-6.3), male gender (OR = 1.9; 95% CI = 1.1-3.6) and co-infection with HCV (OR = 1.8; 95% CI = 1.0-3.3) were significantly independent factors associated with HDV infection. The detection rate of HDV RNA among anti-HDV-positive patients was only 12.7% (7/55). The mean HBV titer of triple infection group was significantly lower than in the HBV/HDV co-infection group (2.23 vs 3.05 in log(10), copies/ml, P = 0.046). HCV RNA detection among the triple infection group showed 47.4% (9/19) viremia rate and viral loads of 579,121 IU/ml in median (16,803-1,551,190 IU/ml). The prevalent genotype of HBV was type B (23/25); HCV was 1b (7/9) and HDV was IIa/IIb (4/4). Only the presence of HCV RNA predicted the presence of elevated ALT significantly (OR = 25.0; 95% CI = 3.39-184.6). In conclusion, the geographical aggregation of HDV infection paralleled that of HCV infection in this community. HCV suppressed the replication of HBV among triple vital infection patients. HBV and HDV lapsed into a remission or nonreplicative phase in most cases, and HCV acted as a dominant factor in triple viral-infected individuals. Only the presence of HCV RNA was associated with elevated ALT values, but not HBV or HDV.     

A cost-effective algorithm for the diagnosis of Hepatitis C virus infection and prediction of HCV viremia in Cameroon

Conventional tests for antibody to Hepatitis C virus (HCV) and HCV RNA require considerable time before results are available, remain very expensive and are not adapted to many sub-Saharan African countries where HCV is endemic. The aim of this study was to evaluate the accuracy of an algorithm consisting of two HCV rapid tests to diagnose and predict HCV viremia in patients in Cameroon. Three hundred and twenty nine plasma samples were screened by two HCV rapid tests (ImmunoComb II HCV, PBS Orgenics and Hexagon HCV, Human). Previous evaluation of these samples for HCV antibodies (anti-HCV) by conventional third generation ELISA, considered as a reference test, indicated that 168 were anti-HCV negative and 161 positive. Among the 161 anti-HCV positive plasma, 114 (71%) were HCV RNA-positive by RT-PCR assay. The ImmunoComb II HCV test provided the more sensitive detection of anti-HCV (sensitivity: 99.4% with a 95% CI = 96-100%). Surprisingly, the second HCV rapid test, Hexagon HCV, showed a high capacity to identify non-viremic subjects amongst anti-HCV positive cases (93.6% [95% CI: 82-99%]). These results suggest an algorithm using ImmunoComb II HCV as a first test to screen anti-HCV positive subjects, and Hexagon HCV as a second test to discriminate between viremic and non-viremic HCV seropositive subjects.     

Hepatitis C virus infection among pregnant women in Yaounde,Cameroon: prevalence,viremia, and genotypes

Central Africa is considered to be an area of high endemic hepatitis C infection. To determine the prevalence of anti-HCV antibodies, HCV RNA, and the genotype distribution in Cameroon, 1,494 pregnant women attending antenatal care units in Yaounde, Cameroon were screened for HCV infection. Anti-HCV antibodies were detected with a 3rd generation ELISA (Monolisa anti-HCV plus version 2, BioRad, Richmond, CA). All anti-HCV antibody-positive sera were then tested with another 3rd generation ELISA (AxSYM) HCV version 3, Abbott Laboratories, Abbott Park, IL) and subsequently for HCV RNA (Amplicor HCV, Roche Diagnostics, Basel, Switzerland). Genotype was determined by phylogenetic analysis of the NS5b gene. Seventy-three pregnant women were found to be anti-HCV antibody positive by the first ELISA, but only 28 were anti-HCV positive by both ELISA. The prevalence of anti-HCV antibodies was thus 1.9% (28/1,494) (95% CI: 1.3-2.7%). 21/28 (75%) of the positive samples by both ELISA were HCV RNA positive. The 45 samples that were HCV antibody negative by the second ELISA were also HCV RNA negative. The HCV subtypes identified were 1a (24%), 2f (38%) and 4f (38%). In contrast to previous studies, anti-HCV antibodies were rare among pregnant women in Cameroon. The percentage of HCV seropositive pregnant women who had circulating HCV RNA was similar to that observed in Europe. Several HCV genotypes were found in Cameroon.     

Familial clustering of hepatitis B and C viruses in Korea.

In order to evaluate the familial clustering of hepatitis B virus(HBV) and hepatitis C virus(HCV) infections and to elucidate the possible routes of HCV transmission among Korean adults with chronic liver disease, 137 household contacts of 51 chronic carriers of HBsAg and 111 household contacts of 38 controls, and 181 household contacts of 96 anti-HCV positives and 102 household contacts of 76 anti-HCV negatives were tested from July 1990 to March 1994. Of 71 non-vaccinated household contacts of HBsAg carriers, 10 gave positive result for HBsAg(14.1%), but none of the household contacts of the controls were positive for HBsAg(p < 0.05). Familial clustering of HBV infection was found, when the offspring of carriers and controls were compared. A significantly higher percentage of the offspring of carriers were positive for HBV infection(54.6% vs 15.4%, p < 0.05) with OR of 6.6(95% Cl; 1.3-34.5). No evidence of familial clustering of HCV infection was found with 2.2%(4/181) anti-HCV positivity among the household contacts of index cases, similar to 1.0%(1/102) among those of controls. History of acute hepatitis(OR 3.2), transfusion(OR 3.2), and acupuncture(OR 2.5) were associated with an increased risk of HCV infection. In conclusion, HBV has strong familial clustering whereas HCV does not in Korea.     

Coxsackie B virus infections in women with miscarriage

Serum samples from 1,765 consecutive Sardinian blood donors, negative for hepatitis B surface antigen (HBsAg) and for antibodies to human immunodeficiency virus (HIV) (anti-HIV), were evaluated for the presence of antibodies to hepatitis C virus (anti-HCV) by second-generation ELISA. Anti-HCV was detected in 25 (1.45%) of the 1,765 donors examined. Anti-HCV was found in 15 of the 1,690 (0.9%) donors with normal alanine aminotransferase (ALT) and in 10 of the 75 (13%) donors with elevated ALT (P < 0.0001). Of the 15 anti-HCV-positive donors with normal ALT, only five (33%) were confirmed to be positive by second-generation RIBA, six (40%) were indeterminate, while four (27%) were RIBA negative. HCV RNA, as detected by polymerase chain reaction (PCR) using a set of primers from the 5′-noncoding region, was found in six of the 15 (40%) donors with normal ALT, including five RIBA, positive and one indeterminant. Of the 10 anti-HCV-positive donors with elevated ALT, all were RIBA positive and eight (80%) had detectable HCV RNA. Thus, among ELISA-reactive donors, those with elevated ALT had a significantly higher probability of being positive for secondgeneration RIBA and HCV RNA compared to those with normal ALT levels (P = 0.028). None of the 65 donors with elevated ALT but negative for anti-HCV by ELISA had detectable serum HCV RNA, as compared to eight of 10 anti-HCV ELISApositive donors (P < 0.0001). However, although negative for HBsAg, 12 of the 65 (18%) had serum HBV DNA by PCR. This study demonstrates that the combined use of second-generation ELISA and RIBA anti-HCV assays is highly effective in identifying HCV infection, whereas the specificity of ELISA alone for the screening of blood donors with normal ALT values appears to be limited. In contrast, in donors with elevated ALT levels, there is a positive correlation between second-generation assays (ELISA and RIBA) and HCV viremia. The high proportion of inapparent HBV infection in blood donors with elevated ALT levels underlines the importance of this test for the prevention of transfusion-associated viral hepatitis.     

Risk factors for hepatitis C virus infection among Koreans according to the hepatitis C virus genotype

To investigate risk factors for HCV infection according to the genotype, we studied 178 patients positive for HCV-PCR and 226 controls that were negative for the anti-HCV antibody. One hundred and twenty five controls (community control) were recruited from spouses of HCV-PCR-positive patients and the other 101 from hospital visitors (hospital control). HCV genotyping was performed by PCR, and epidemiological data were obtained from all participants. The distribution of HCV genotypes was as follows -- 1a (0.6%), 1b (39.9%), 2a (38.2%), 2b (0%), 3 (1.1%), and unclassified (20.2%). By multivariate analysis, blood transfusion (OR 2.90) and endoscopy (OR 2.80) were found to be risk factors for HCV genotype 1b versus the community control. Similarly, blood transfusion (OR 3.17) was found to be risk factors for HCV genotype 1b versus the hospital control. Blood transfusion (OR 2.75) and endoscopy (OR 3.57) were risk factors for HCV genotype 2a versus the community control, and blood transfusion (OR 4.55) and endoscopy (OR 2.16) were those versus the hospital control. Our results suggest that the risk factors for HCV infection are similar among the different genotypes. Blood transfusion and endoscopy were found to be associated with HCV infection.     

Hepatitis C virus in sickle cell disease

PURPOSE: To determine the prevalence of hepatitis C virus antibodies (anti-HCV) in patients with sickle cell disease. PATIENTS AND METHODS: Between 1983 and 2001, 150 patients from the Howard University Hospital Center for Sickle Cell Disease were screened for HCV antibody (52% women, 48% men, mean age 34 years). Frozen serum samples from 56 adult sickle cell patients who had participated in previous surveys (1983-92) of HIV and HTLV-1 serology and who were tested in 1992 for anti-HCV antibody--when commercial ELISA test (Ortho) became available--were included in this paper. Of the 150 patients in the study, 132 had sickle cell anemia genotype (SS), 15 had sickle cell hemoglobin-C disease (SC) and three had sickle beta thalassemia. Clinical charts were reviewed for history of blood transfusion, IV drug abuse, homosexuality, tattooing, iron overload, and alcohol abuse. RESULTS: Antibodies to HCV were detected in 53 patients (35.3%). Of the 55 patients who had frozen serum samples tested in 1992, 32 (58%) were reactive for anti-HCV, while only 21 of the 95 patients (22%) tested after 1992 were positive for HCV antibodies (P<0.001). Thirty-nine of 77 patients (51%) who received more than 10 units of packed red blood cells were positive for HCV antibody, and only 14 of 61 patients (23%) who received less than 10 units of packed red blood cells transfusion were positive for HCV antibodies (P<0.001). None of the 12 patients who never received transfusion were positive for HCV antibody. In the 53 anti-HCV positive patients, the mean alanine amino-transferase (ALT) value was 98- and 81 U/L, respectively, for males and females. These values were normal for the HCV-antibody negative patients. The aspartate amino-transferase (AST) and the total bilirubin were also higher in the anti-HCV positive patients compared to patients in the anti-HCV negative group. Forty-four patients (57.1%) who were transfused more than 10 units developed iron overload defined by a serum ferritin level higher than 1,000 ng/ml. A total of 20 of the patients with iron overload underwent liver biopsies. Seven of these 20 patients (35%) were HCV positive. These patients often had more severe liver disease and higher degree of iron deposition. CONCLUSION: The prevalence of HCV antibody and iron overload is directly related to the number of blood transfusions in patients with sickle cell disease. The prevalence of HCV infection has decreased significantly, since blood donor screening for HCV became available. Chronic HCV infection and iron overload place sickle cell patients at risk for significant liver disease.     

Community-based seroepidemiological survey of HCV infection in Catalonia, Spain.

The objective of this study was to investigate the prevalence of antibodies against the hepatitis C virus (anti-HCV) and the associated risk factors in a representative sample of the population of Catalonia, Spain. Serum samples from 2,142 subjects aged between 5 and 70 years, selected at random from urban and rural habitats, were studied. Multiple logistic regression analysis was carried out to determine variables associated independently with the presence of HCV antibodies. The age and gender standardized prevalence of anti-HCV was 2.5% (95% confidence interval, 1.8-3.2). Prevalence increased significantly with age (P < 0.001), but no other sociodemographic variables were associated with HCV infection. Tattoos (OR: 6.2), blood transfusions (OR: 5.0) intravenous drug use (OR: 4.9) and antecedents of hospitalization (OR: 2.3) were variables associated independently with infection. HCV infection affects mainly elderly people in Spain and spares children and adolescents. This suggests that major exposure to HCV may have occurred many years ago, when infection was more widespread than in recent years.     

Co-infection with hepatitis C virus and human immunodeficiency virus among patients with sexually transmitted diseases in Pondicherry, South India

Hepatitis C virus (HCV), which is usually transmitted by blood and blood products is emerging as an important agent in the list of sexually transmitted diseases (STDs). The present study was undertaken to document the burden of HCV infection in individuals with STDs in this tertiary care hospital in South India. One hundred serum samples collected from individuals with STDs were tested for antibodies to HCV by a third generation ELISA. All the samples were also screened for HIV infection. Six out of 100 individuals were found to possess antibodies against HCV (95% confidence interval [CI=1.3-10.7%). Fourteen out of 100 samples were positive for HIV (95% CI=7-20.9%). The seroprevalence of HCV in HIV positive individuals was 21.4% (3/14) whereas the corresponding figure for HIV negative individuals was only 3.5% (3/86). The difference was found to be statistically significant (p<0.01).     

Detection of hepatitis C virus antibody in non-A non-B liver diseases

Hepatitis C virus antibody (anti-HCV) was assessed in serum samples from patients with non-A, non-B liver diseases using an Ortho HCV ELISA kit. In patients with posttransfusion hepatitis, anti-HCV was found in 89% and the interval between onset and anti-HCV seroconversion was 51 to 168 (mean 80) days. Anti-HCV remained positive with fluctuating serum GPT levels in 88% of the patients in whom anti-HCV seroconversion was observed. In chronic liver diseases, anti-HCV was found in 70 to 100%, being more common in patients who had a history of blood transfusion. The average interval between transfusion and detectable anti-HCV was 21.5 years. Anti-HCV was also found occasionally in patients having normalized serum GPT level after the onset, HBV carrier with posttransfusion hepatitis and patients with autoimmune hepatitis. Decreasing anti-HCV titer was noted with the normalization of serum GPT levels in the patients who received interferon therapy. These findings suggest that anti-HCV is closely associated with blood transfusion and HCV infection plays an important role in non-A, non-B liver diseases. The improvement of the current HCV assay system seems to contribute to further evaluation of the clinical entity of HCV infection.     

Role of beauty treatment in the spread of parenterally transmitted hepatitis viruses in Italy

The aims of the study were to evaluate the role of beauty treatments in the spread of acute viral hepatitis B (HBV) and acute viral hepatitis C (HCV) in Italy. Data from the surveillance system for acute viral hepatitis (SEIEVA) during the period 1997-2002 were used. After exclusion of subjects <15 years or >55 years old and reporting intravenous drug use or blood transfusion, the association of acute HBV and HCV cases with beauty treatments (tattooing, piercing, manicure/chiropody, and barber shop shaving) was estimated comparing 2,964 hepatitis B and 598 hepatitis C cases with 7,221 hepatitis A cases, used as controls, by multiple logistic regression analysis. The population attributable risk (PAR) to beauty treatments was estimated according to Levin's formula. Beauty treatments were associated with acute HBV (OR = 1.8; CI 95% = 1.5-2.1) and acute HCV (OR = 1.7; CI 95% = 1.2-2.3). The strongest association was found with barber shop shaving for HBV (OR = 1.8; CI 95% = 1.5-2.2) and with tattooing for HCV cases (OR = 5.6; CI 95% = 2.8-11.0). The estimates of the population attributable risk (PAR) indicate that nearly 15% of all acute HBV (17.4% in males) and 11.5% of all acute HCV cases (16.4% in males) occurring in 15-55 year old subjects not exposed to intravenous drugs or blood transfusion in Italy are due to beauty treatments. It is concluded that certain beauty treatments play an important role in the spread of HBV and HCV infections in Italy.     

Detection of Antibodies to Hepatitis C Virus in Dried Blood Spot Samples from Mothers and Their Offspring in Lahore, Pakistan

Dried blood spot samples from mothers and their offspring attending the obstetric and pediatric departments of two hospitals in Lahore, Pakistan, were tested for antibodies to hepatitis C virus (HCV). The seroprevalence of HCV in the women was 6.7% (95% confidence interval [CI], 4.3 to 9.1), and that in the children was 1.3% (95% CI, 0.34 to 2.26). Four anti-HCV immunoglobulin G (IgG)-positive children had mothers that were anti-HCV IgG negative, which suggested that their infection was community acquired.     

1年以上血透患者HCV感染状况的调查

目的 研究1年以上的长期血液透析患者丙型肝炎（HCV）感染状况。方法 用ELISA法和RT－PCR法检测137例长期血透患者血清中的抗－HCV和HCVRNA,并且同时检测谷丙转氨酶（ALT）和谷草转氨酶（AST）,计算其变动率。结果 透析时间超过1年以上的137例患者中仅抗－HCV阳性8例,仅HCV－RNA阳性13例,抗－HCV与HCVRNA同时阳性者24例,感染率34．3％。且透析时间小于2年的,HCV感染率为15％,透析时间大于2年以上的其感染率增至37．6％。结论 血透患者中HCV的感染应引起重视,透析的年限越长,被HCV感染的机率就越大。酶学指证的变动率不能作为长期透析患者HCV感染的敏感指标。     

Prevalence of, and risk factors for Kaposi's sarcoma-associated herpesvirus infection among blood donors in Brazil: a multi-center serosurvey

Kaposi's sarcoma-associated herpesvirus (KSHV) is endemic in the Amazon and rare in southern regions of Brazil. However, geographical distribution and epidemiological correlates of infection in this large country are still poorly defined. To estimate the seroprevalence of, and risk factors for, KSHV infection in Brazil, a multi-center study was conducted among 3,493 first-time voluntary unpaid blood donors from Salvador, Sao Paulo and Manaus. Antibodies against KSHV were detected using a whole-virus ELISA validated prior to the serosurvey. Antibodies against the latency-associated nuclear antigen (LANA) were detected by immuno-fluorescence assay (IFA) among ELISA-positive sera and a random sample of ELISA-negative sera. Overall, seroprevalence of KSHV by whole-virus ELISA was 21.7% (95% confidence interval (CI): 20-23.4%) in men and 31.7% (95% CI: 29-34.3%) in women (P<0.0001). KSHV antibodies were detected by IFA-LANA in 3% (95% CI: 2-4.3%) of 867 ELISA-positive samples and in none of 365 randomly selected ELISA-negative samples. In multivariate analysis, KSHV seroprevalence by whole-virus ELISA was independently associated with female sex (odds ratio [OR]=1.6, 95% CI: 1.4-1.9); residence in the Amazon (OR=1.4, 95% CI: 1.2-1.8; compared to Salvador); Caucasian ethnicity (OR=1.3, 95% CI: 1.1-1.6) and herpes simplex virus type 2 (HSV-2) infection (OR=1.3, 95% CI: 1.1-1.6). KSHV seroprevalence did not significantly increase with age, nor was it associated with self-reported sexual behavior. KSHV seroprevalence is high among Brazilian blood donors, particularly from the Amazon region. This study supports the co-existence of sexual and non-sexual routes of KSHV transmission in this population.