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Background: New oral treatments with very high cure rates have the potential to revolutionize global management of hepatitis C virus (HCV), but population-based data on HCV infection are missing in many low and middle-income countries (LMIC). Methods: Between 2004 and 2009, dried blood spots were collected from age-stratified female population samples of 9 countries: China, Mongolia, Poland, Guinea, Nepal, Pakistan, Algeria, Georgia and Iran. HCV antibodies were detected by a multiplex serology assay using bead-based technology. Results: Crude HCV prevalence ranged from 17.4% in Mongolia to 0.0% in Iran. In a pooled model adjusted by age and country, in which associations with risk factors were not statistically heterogeneous across countries, the only significant determinants of HCV positivity were age (prevalence ratio for ≥45 versus <35 years = 2.84, 95%CI 2.18-3.71) and parity (parous versus nulliparous= 1.73, 95%CI 1.02-2.93). Statistically significant increases in HCV positivity by age, but not parity, were seen in each of the three countries with the highest number of HCV infections: Mongolia, Pakistan, China. There were no associations with sexual partners nor HPV infection. HCV prevalence in women aged ≥45 years correlated well with recent estimates of female HCV-related liver cancer incidence, with the slight exception of Pakistan, which showed a higher HCV prevalence (5.2%) than expected. Conclusions: HCV prevalence varies enormously in women worldwide. Medical interventions/hospitalizations linked to childbirth may have represented a route of HCV transmission, but not sexual intercourse. Combining dried blood spot collection with high-throughput HCV assays can facilitate seroepidemiological studies in LMIC where data is otherwise scarce. [ABSTRACT FROM AUTHOR]

Background: Acquisition of genital human papillomavirus (HPV) infection is common among the young, sexually active population. Genital HPV infections do not always lead to seroconversion. We aimed to assess the association between cervico-vaginal high risk (hr) HPV DNA and type-specific antibodies in an ethnically diverse cohort of young women. Methods: Women of Dutch, South-Asian Surinamese, African Surinamese, Ghanaian, Moroccan and Turkish origin participating in a large-scale multi-ethnic population-based cohort (the HELIUS study) provided vaginal self-samples and blood samples, and completed a questionnaire regarding demographics, lifestyle and sexual health. Vaginal swabs were tested for HPV using the highly sensitive SPF10-PCR DEIA/LiPA25 system (version1). Serum samples were tested for typespecific L1 antibodies against 7 hrHPV types (16,18,31,33,45,52,58) with multiplex serology. We assessed the association between vaginal HPV DNA and type-specific seropositivity with logistic and linear regression, using generalized estimating equations (GEE). We determined whether this association varies by ethnicity by adding an interaction term. Results: We selected 532 women who completed the questionnaire, provided a vaginal swab and a blood sample. Their median age was 27 years (interquartile range 24-31 years). Prevalence of DNA of any of the 7 hrHPV was 22 %; HPV-52 was most common. Prevalence of antibodies against one or more hrHPV types was 24 %; HPV-16 seropositivity was most common. In multivariable logistic regression analysis using GEE, adjusting for other determinants, vaginal HPV DNA detection was associated with type-specific HPV seropositivity (OR 1.53, 95 % CI 1.06-2.20). In multivariable linear regression analysis using GEE, the geometric mean of type-specific antibody reactivity was 1.15 (95 % CI 1.04-1.27) times higher in women positive for HPV DNA compared to HPV DNA-negative women. There was little evidence that ethnicity modified the association between HPV DNA, and type-specific seropositivity, or with antibody reactivities (p =0.47 and p = 0.57, respectively).Conclusions: In this multi-ethnic group of young women in Amsterdam, cervico-vaginal hrHPV DNA detection was an independent determinant of type-specific HPV seropositivity. [ABSTRACT FROM AUTHOR]

Background: The role of Merkel cell polyomavirus (MCV) infection in the etiology of non-melanoma skin cancers, other than Merkel cell carcinoma, is unclear. Previously, we reported a significant association between seropositivity to MCV capsid antigen and MCV DNA-positive cutaneous squamous cell carcinoma (SCC). Here we present associations between SCC and seroreactivity to MCV T-antigen (T-Ag) oncoprotein, as well as MCV DNA detected in eyebrow hairs. Findings: A clinic-based case--control study, including 171 SCC cases and 300 controls without skin cancer, was conducted at Moffitt Cancer Center in Tampa, Florida. Multiplex assays were used to measure serum antibodies against MCV small and large T-Ag and MCV DNA in both eyebrow hairs and SCC tumors (n = 144). Odds ratios (ORs) and 95 % confidence intervals (CIs) were estimated using logistic regression to evaluate the associations between MCV and SCC. No significant association was observed between seroreactivity to MCV full-length large or small T-Ag and SCC, overall [ORlarge T-Ag = 0.99 (0.48-2.08), ORsmall T-Ag = 0.31 (0.06-1.62)] or when comparing tumor MCV DNA-positive cases to controls [ORlarge T-Ag = 1.06 (0.38-2.93)]. Only presence of MCV DNA in eyebrow hairs was significantly associated with MCV DNA-positive SCC [OR = 4.05 (2.01-8.18)]. Conclusion: MCV infection is unlikely to play a direct role in SCC. [ABSTRACT FROM AUTHOR]

Background Helicobacter pylori infection that is usually acquired in childhood and lasts for lifetime is mostly asymptomatic but associated with severe gastrointestinal disease including cancer. During chronic infection, the gastric mucosa is histologically changing. This forces H. pylori to permanent adaptation in its gastric habitat by expression of different proteins which might be reflected in distinctive antibody patterns. Methods To characterize dynamics of the immune response to H. pylori we analysed 1797 sera of a cross-sectional study representative for the German population (age range 1-82 years) with multiplex serology, a fluorescent bead-based antibody binding assay that allows simultaneous and quantitative detection of antibodies. Fifteen recombinant, affinity-purified H. pylori proteins (UreA, GroEL, Catalase, NapA, CagA, CagM, Cagd, HP0231, VacA, HpaA, Cad, HyuA, Omp, HcpC and HP0305) were used as antigens. Results H. pylori seroprevalence (positivity for at least three antigens) was 48% and increased with age from 12% in children <15 years to 69% in females and 90% in males >65 years. Prevalences were highest (>83%) for Omp, VacA and GroEL. For 11 proteins, seroprevalence was higher in males than females (P < 0.05) from age 55 onwards. For all antigens, the median prevalence increase per age decade was stronger in males (8.4%, range 3.8-12.9%) than females (6.1%, range 3.4-10.8%). However, among seropositives the median number of antigens recognized increased from children <15 years to individuals >65 years stronger in females (P = 0.02). Antibody reactivities to GroEL, HyuA, CagM, Catalase, NapA and UreA also increased stronger in females (average 1.7-fold/decade, SD 0.5) than in males (1.5-fold/decade, SD 0.4). Conclusion H. pylori antibody response accumulates qualitatively and quantitatively with age. This may reflect a lifelong stimulation of the immune response by chronically active infection. [ABSTRACT FROM AUTHOR]

Background Several assays are used to measure type-specific serological responses to human papillomavirus (HPV), including the bead-based glutathione S-transferase (GST)-L1 multiplex serology assay and virus-like particle (VLP)-based ELISA. We evaluated the highthroughput GST-L1, which is increasingly used in epidemiologic research, as a measure of cumulative HPV infection and future immune protection among HPV-unvaccinated women. Methods We tested enrollment sera from participants in the control arm of the Costa Rica Vaccine Trial (n = 488) for HPV16 and HPV18 using GST-L1, VLP-ELISA, and two assays that measure neutralizing antibodies (cLIA and SEAP-NA). With statistical adjustment for sampling, we compared GST-L1 serostatus to established HPV seropositivity correlates and incident cervical HPV infection using odds ratios. We further compared GST-L1 to VLPELISA using pair-wise agreement statistics and by defining alternate assay cutoffs. Results Odds of HPV16 GST-L1 seropositivity increased with enrollment age (OR = 1.20 per year, 95%CI 1.03-1.40) and lifetime number of sexual partners (OR = 2.06 per partner, 95%CI 1.49-2.83), with similar results for HPV18. GST-L1 seropositivity did not indicate protection from incident infection over 4 years of follow-up (HPV16 adjusted OR = 1.72, 95%CI 0.95- 3.13; HPV18 adjusted OR = 0.38, 95%CI 0.12-1.23). Seroprevalence by GST-L1 (HPV16 and HPV18, respectively) was 5.0% and 5.2%, compared to 19.4% and 23.8% by VLPELISA, giving positive agreement of 39.2% and 20.8%. Lowering GST-L1 seropositivity cutoffs improved GST-L1/VLP-ELISA positive agreement to 68.6% (HPV16) and 61.5% (HPV18). Conclusions Our data support GST-L1 as a marker of cumulative HPV infection, but not immune protection. At lower seropositivity cutoffs, GST-L1 better approximates VLP-ELISA. [ABSTRACT FROM AUTHOR]

Background: In the Netherlands, there are strong disparities in Chlamydia trachomatis (CT) prevalence between ethnic groups. The current study aims to identify whether socioeconomic status, sexual risk behavior and sexual healthcare seeking behavior may explain differences in CT seroprevalence between ethnic groups.Methods: We used 2011-2014 baseline data of the HELIUS (HEalthy LIfe in an Urban Setting) study, a multi-ethnic population-based cohort study in Amsterdam, the Netherlands, including participants from Dutch, African Surinamese, South-Asian Surinamese, Ghanaian, Moroccan and Turkish origin. For this analysis, we selected sexually active, heterosexual participants aged 18-34 years old. CT seroprevalence was determined using a multiplex serology assay. The CT seroprevalence ratios between different ethnicities are calculated and adjusted for potential indicators of socioeconomic status, sexual risk behavior and sexual healthcare seeking behavior.Results: The study population consisted of 2001 individuals (52.8% female) with a median age of 28 years (IQR 24-31). CT seropositivity differed by ethnicities and ranged from 71.6% (African Surinamese), and 67.9% (Ghanaian) to 31.1% (Turkish). The CT seroprevalence ratio of African Surinamese was 1.72 (95% CI 1.43-2.06) and 1.52 (95% CI 1.16-1.99) of Ghanaian as compared to the Dutch reference group, after adjustment for socioeconomic status, sexual risk behavior and sexual healthcare seeking behavior.Conclusions: Indicators of socioeconomic status, sexual risk behavior, and sexual health seeking behavior could not explain the higher CT seroprevalence among African Surinamese and Ghanaian residents of Amsterdam. [ABSTRACT FROM AUTHOR]

Background: Despite intensive study of high-risk mucosal human papillomaviruses (HPV), little is known of the epidemiology of cutaneous HPV. As part of a study of cutaneous squamous cell carcinoma and HPV among organ transplant recipients (OTR) from London and Oxford, we investigated the seroprevalence and risk factors for 34 HPV types (detected using Luminex technology) among 425 Caucasian OTR without skin cancer., Results: Overall, 86% of participants were seropositive to at least one HPV: 41% to mucosal alpha types, 33% to cutaneous alpha types, 57% to alpha types, 56% to beta, 47% to gamma types and 45% to other types (nu, mu, HPV101 and 103). In both centres, the most common types were HPV6 (33% and 26% for London and Oxford respectively), HPV8 (24% and 18%), HPV15 (26% and 29%), HPV17 (25% and 21%), HPV38 (23% and 21%), HPV49 (19% and 21%), HPV4 (27% and 23%), HPV65 (30% and 25%), HPV95 (22% and 20%), HPV1 (33% and 24%) and HPV63 (28% and 17%). The seroprevalence of 8 HPV types differed significantly (P < 0.05) between London and Oxford. Those individuals seropositive to multiple types of one genus were more likely to be seroreactive to multiple types of another genus. As expected, antibodies against mucosal alphaHPV types were more frequent in younger patients and among women. Sunbed use and sunbathing was associated with seropositivity to multiple gammaHPV (P-trend = 0.007) and self-history of abnormal smear was related to seroactivity to multiple betaHPV (P = 0.01). Skin type and other self reported markers of exposure to ultraviolet radiation were not consistently associated with any HPV types. No other distinguishing epidemiological features of transplant recipients with antibodies against single or multiple HPV types were identified., Conclusion: Findings for mucosal HPV types were in line with results from previous studies. We observed differences in HPV seroprevalence between organ transplant recipients from two geographically close centres but no clear risk factor was found associated with cutaneous HPV seropositivity among organ transplant recipients. These findings have implications for interpretation of future seroepidemiology studies addressing the association between HPV and cutaneous SCC in OTR populations.

Background: The natural history of cutaneous HPV is unclear and in particular, seroprevalence among individuals with different levels of immune function and ethnicity is unknown. As part of a study of cutaneous squamous cell carcinoma (SCC) and HPV among organ transplant recipients (OTR) from London, we investigated the seroprevalence and risk factors for 34 HPV types (detected using Luminex technology) among 409 OTR patients without skin cancer (243 Caucasians and 166 non-Caucasians), 367 individuals with end stage renal failure on dialysis (222 Caucasians and 145 non-Caucasians) and 152 immunocompetent (IC) individuals without skin cancer (102 Caucasians and 50 non-Caucasians) to compare the HPV seroprevalence in patients with differing immune status and ethnicity. In total, seroprevalence data from 928 individuals, all from London, was available., Results: Overall, no difference between HPV seroprevalence by immune status was observed (P = 0.3) among Caucasian or among non-Caucasian individuals, with seroprevalence varying from 87% to 94% across different immune status and ethnic groups. Those individuals seropositive to multiple types of one genus were more likely to be seroreactive to multiple types of another genus, independent of immune status or ethnicity. Lower seroprevalence for gammaHPV 4, and to a lesser extent gammaHPV 48, were observed among OTR compared to IC and dialysis patients. Higher seroprevalence against antibodies to betaHPV 93 were detected more frequently in non-Caucasians than Caucasians whereas muHPV 1 and, to a lesser extent, gammaHPV 4 were found more frequently among Caucasians - these findings were independent of immune status. Within non-Caucasian subgroups, the seroprevalence of 8 HPV (alpha-mucosal HPV16 and 13, alpha-cutaneous HPV7 and 2, betaHPV8, 17, 23 and 38) was significantly (P < 0.02) higher in Black compared to Asian patients. HPV16 being sexually transmitted, this might suggest a potential sexual route of transmission for some beta HPV types., Conclusion: We did not observe major disturbance in antibody response between immunocompetent, dialysis and OTR individuals, but significant differences in HPV seroprevalence were identified according to ethnicity. Further research is needed to clarify the natural history of cutaneous HPV, particularly given the growing research interest in its possible role in the pathogenesis of cutaneous SCC.