Characterization of hepatitis C virus isolates from chronically infected patients

The function of the liver is to keep the human body in physiological equilibrium. This equilibrium is regulated by several metabolic pathways such as the production of plasma proteins and detoxification. Inflammation of the liver is known as hepatitis and as entity it has been recognized since the days of Hippocrates. The most important etiology of hepatitis is viral infection of the liver

HPV types, HIV and invasive cervical carcinoma risk in Kampala, Uganda: a case-control study

<p>Abstract</p> <p>Background</p> <p>While the association of human papillomavirus (HPV) with cervical cancer is well established, the influence of HIV on the risk of this disease in sub-Saharan Africa remains unclear. To assess the risk of invasive cervical carcinoma (ICC) associated with HIV and HPV types, a hospital-based case-control study was performed between September 2004 and December 2006 in Kampala, Uganda. Incident cases of histologically-confirmed ICC (N=316) and control women (N=314), who were visitors or care-takers of ICC cases in the hospital, were recruited. Blood samples were obtained for HIV serology and CD4 count, as well as cervical samples for HPV testing. HPV DNA detection and genotyping was performed using the SPF₁₀/DEIA/LiPA₂₅ technique which detects all mucosal HPV types by DEIA and identifies 25 HPV genotypes by LiPA version 1. Samples that tested positive but could not be genotyped were designated HPVX. Odds ratios (OR) and 95% confidence intervals (CI) were calculated by logistic regression, adjusting for possible confounding factors. </p> <p>Results</p> <p>For both squamous cell carcinoma (SCC) and adenocarcinoma of the cervix, statistically significantly increased ORs were found among women infected with HPV, in particular single HPV infections, infections with HPV16-related types and high-risk HPV types, in particular HPV16, 18 and 45. For other HPV types the ORs for both SCC and adenocarcinoma were not statistically significantly elevated. HIV infection and CD4 count were not associated with SCC or adenocarcinoma risk in our study population. Among women infected with high-risk HPV types, no association between HIV and SCC emerged. However, an inverse association with adenocarcinoma was observed, while decrease in CD4 count was not associated with ICC risk.</p> <p>Conclusions</p> <p>The ORs for SCC and adenocarcinoma were increased in women infected with HPV, in particular single HPV infections, infections with HPV16- and 18-related types, and high-risk HPV types, specifically HPV16, 18 and 45. HIV infection and CD4 count were not associated with SCC or adenocarcinoma risk, but among women infected with high-risk HPV types there was an inverse association between HIV infection and adenocarcinoma risk. These results suggest that HIV and CD4 count may have no role in the progression of cervical cancer.</p

Type-specific incidence, clearance and predictors of cervical human papillomavirus infections (HPV) among young women: a prospective study in Uganda

<p>Abstract</p> <p>Background</p> <p>While infections with human papillomavirus (HPV) are highly prevalent among sexually active young women in Uganda, information on incidence, clearance and their associated risk factors is sparse. To estimate the incidence, prevalence and determinants of HPV infections, we conducted a prospective follow-up study among 1,275 women aged 12-24 years at the time of recruitment. Women answered a questionnaire and underwent a pelvic examination at each visit to collect exfoliated cervical cells. The presence of 42 HPV types was evaluated in exfoliated cervical cells by a polymerase chain based (PCR) assay (SPF10-DEIA LiPA).</p> <p>Results</p> <p>Three hundred and eighty (380) of 1,275 (29.8%) women were followed up for a median time of 18.5 months (inter-quartile range 9.7-26.6). Sixty-nine (69) women had incident HPV infections during 226 person-years of follow-up reflecting an incidence rate of 30.5 per 100 person-years. Incident HPV infections were marginally associated with HIV positivity (RR = 2.8, 95% CI: 0.9 - 8.3). Clearance for HPV type-specific infections was frequent ranging between 42.3% and 100.0% for high- and 50% and 100% for low-risk types. Only 31.2% of women cleared all their infections. Clearance was associated with HIV negativity (Adjusted clearance = 0.2, 95% CI: 0.1 - 0.7) but not with age at study entry, lifetime number of sexual partners and multiplicity of infections. The prevalence of low-grade squamous intraepithelial lesions (LSILs) was 53/365 (14.5%). None of the women had a high-grade cervical lesion (HSIL) or cancer. Twenty-two (22) of 150 (14.7%) HPV negative women at baseline developed incident LSIL during follow-up. The risk for LSIL appeared to be elevated among women with HPV 18-related types compared to women not infected with those types (RR = 3.5, 95% CI: 1.0 - 11.8).</p> <p>Conclusions</p> <p>Incident HPV infections and type-specific HPV clearance were frequent among our study population of young women. These results underscore the need to vaccinate pre-adolescent girls before initiation of sexual activity.</p

Sequence analysis of the 5' untranslated region in isolates of at least four genotypes of hepatitis C virus in The Netherlands

The RNAs of hepatitis C virus (HCV) isolates from 62 patients with chronic HCV infection were analyzed by direct sequencing of the 5' untranslated region. Two important sequence motifs were recognized: one between positions -170 and -155 and the other between positions -132 and -117. These motifs are partly complementary. All three previously published genotypes were observed; 34 (55%) isolates were classified as type 1 (including prototype [from the United States] and HCV-BK [from Japan] sequences), 11 (18%) were classified as type 2 (including HC-J6 and HC-J8), and 12 (19%) were classified as type 3 (including EB1); one patient was infected with genotypes 1 and 2. Four (6%) isolates showed aberrant sequences and were therefore provisionally classified as genotype 4. These results indicate the significance of sequence variation among the 5' untranslated regions of different HCV genotypes and indicate that this region could possibly be used for consistent genotyping of HCV isolates

Rapid genotyping of hepatitis C virus RNA-isolates obtained from patients residing in Western Europe

Two rapid genotyping methods for hepatitis C virus (HCV), the line probe assay (Inno‐LiPA) and the subtype‐specific core amplification system [Okamoto et al., (1992b) Journal of General Virology 73:673‐679], were applied to 58 HCV isolates which were typed as type 1 (n=37) and type 2 (n=21) by sequence analysis of the 5′ untranslated region (5′UTR). The line probe assay targets the 5′UTR and recognized 12 subtype 1a, 25 subtype 1b, 18 subtype 2a, 2 subtype 2b and 1 subtype 2d in accordance with sequence analysis of this region. Subtype‐specific core amplification revealed 7 discrepancies among the 37 type 1 isolates when compared to LiPA. A different subtype was observed in 3 isolates (la versus 1b), 2 isolates remained untyped and 2 isolates showed a coinfection of subtype la and 1b. The first 5 discrepancies were confirmed by sequence analysis of the core region whereas the coinfection could not be confirmed. Of the 21 type 2 isolates only one could be typed by subtype‐specific core amplification. HCV RNA was detected in all 21 cases after the general first round of polymerase chain reaction (PCR). Direct sequencing of the core region indicated sequence variation as a source of failure. It is concluded that LiPA results are conclusive for typing of HCV. However, LiPA is hampered occasionally for subtyping by lack

Highly Effective Detection of Human Papillomavirus 16 and 18 DNA by a Testing Algorithm Combining Broad-Spectrum and Type-Specific PCR

The use of a single broad-spectrum human papillomavirus (HPV) DNA-based PCR test may fail to detect lower concentrations of HPV DNA due to competition between different genotypes in mixed infections. To improve HPV detection by PCR, broad-spectrum and type-specific (TS) PCRs were combined, with a focus on HPV-16 and HPV-18. Cervical and cervicovaginal cell samples were obtained from 1,113 healthy women (age range, 15 to 25 years) participating in an HPV-16/HPV-18 candidate vaccine efficacy trial. These samples were tested by a broad-spectrum SPF(10) PCR-DNA enzyme immunoassay, followed by a primer SPF(10)-based line probe assay (SPF(10) LiPA), and HPV-16- and HPV-18-TS PCRs. The results for the majority of the HPV-16/18 SPF(10) LiPA-positive samples were confirmed by TS-PCR (kappa values, 0.775 for HPV-16 and 0.785 for HPV-18). However, TS PCR revealed additional positive samples among those that contained other HPV genotypes due to competition. Conversely, SPF(10) LiPA identified HPV-16 or -18 in samples that remained negative by TS PCR as a result of sampling variation. Analysis of follow-up samples from more than 1,000 women confirmed that the combination of SPF(10)-LiPA with additional HPV-16- and HPV-18-TS PCR diminishes the rate of false-negative diagnosis. The combination of broad-spectrum and TS PCRs resulted in a novel testing algorithm. This combination of assays is more accurate than either method alone, and the novel algorithm offers a highly accurate and effective method for the analysis of HPV infections