Prevalence and characteristics of hepatitis B and C virus infections in treatment-naïve HIV-infected patients

Hepatitis B vaccination coverage in Germany: systematic review

BACKGROUND

Despite being considered as a low prevalence country for hepatitis B (HBV), some populations in Germany are at higher risk of infection. In the context of the World Health Organization's (WHO) viral hepatitis elimination goals, a valid epidemiological data base is needed to plan and monitor the national response. Prevention strategies include general and targeted HBV vaccination programmes.

OBJECTIVE

The aim of this work was to estimate the HBV vaccination coverage (VC) in the general population (GP) and different population groups in Germany from available evidence and to identify current evidence gaps for future research.

METHODS

We conducted a systematic review on HBV VC in the general population and populations at high risk of HBV exposure or severe infection in Germany. We included eligible publications (01/01/2017 to 06/06/2020) from databases Embase, Pubmed and Livivo, from a previous scoping review (including data published 01/01/2005-17/03/2017), from the national surveillance system and screened the reference lists of all publications at full text level. Risk of bias was assessed using the Hoy et al. tool.

RESULTS

We included 68 publications of 67 studies and assigned them to one or more suitable population groups. Twenty-one studies contained data among children/adolescents and three among adults from the GP (VC 65.8-90.5% and 22.9-52.1%, respectively), one among travelers (VC 89.0%), 13 among immunocompromised populations (VC 7.8-89.0%), 16 among populations with occupational risk and 16 with non-occupational risk of HBV exposure (VC 63.6-96.5% and 4.4-84.5%, respectively).

CONCLUSION

Comprehensive evidence at low risk of bias was identified for children/adolescents. However, 25 years after including HBV in the national immunisation schedule, VC in Germany is still below the 95%-goal defined by WHO. For people at occupational risk of HBV exposure, VC was mostly reported to be over the WHO goal of 80%, but quality of evidence was heterogenous and should be improved. For people at non-occupational risk of HBV exposure, evidence was sparse and of low quality. The low VC highlights the need for future research to plan vaccination programmes targeting these populations.

Prevalence of Hepatitis B, C, and D in Germany: Results From a Scoping Review

Background: One of the five strategic directions in the World Health Organization global health sector strategy on viral hepatitis 2016-2021 is to generate strong strategic information for focused action to understand the viral hepatitis epidemic and focus the response. Knowledge of national prevalence is a cornerstone of strategic information. Germany is considered to be a low prevalence country for viral hepatitis B, C, and D, however the prevalence is likely to be higher among at-risk groups. Methods: The aim of this work was to give a detailed overview of the prevalence of viral hepatitis B (HBsAg, anti-HBc), C (anti-HCV, HCV RNA), and D (anti-HDV, HDV RNA) in different population groups in Germany. Therefore, we analyzed the results of a comprehensive literature search on various aspects of the epidemiological situation of hepatitis B, C, and D in Germany. Eligible publications including information on hepatitis B, C, and D prevalence were extracted from the overall spreadsheet table and summarized and analyzed based on virus and different population groups. A quality appraisal was performed using a checklist developed by Hoy et al. to assess risk of bias in prevalence studies. Results: Overall, 51 publications were identified through the literature search. The overall prevalence of HBsAg in the general (and proxy) population ranged from 0.3 to 1.6%. Among at-risk groups, including clinical populations and health care workers, the HBsAg prevalence ranged from 0.2% (among rheumatic patients) to 4.5% among HIV positive patients. The overall prevalence of anti-HCV in the general (and proxy) population ranged from 0.2 to 1.9%. Among at-risk groups, including clinical populations and health care workers, the anti-HCV prevalence ranged from 0.04% (among health care workers) to 68.0% among people who inject drugs. Conclusions: The hepatitis B and C prevalence in the general population in Germany is low. Prevalence is high to very high among at-risk populations, however for some groups evidence was incomplete or missing completely. To reach the elimination goals in Germany and implement a targeted response, more research among at-risk groups is needed.

The epidemiology of Hepatitis B, C and D in Germany: A scoping review

BACKGROUND

Germany is considered to be a low prevalence country for viral Hepatitis B, C and D (HBV, HCV, HDV). However, the burden of disease can be high among subpopulations. To meet the world Health Organization (WHO) viral hepatitis (VH) elimination goals, a national strategy was developed by the German government in 2016. We performed a scoping review to understand the baseline epidemiological situation in Germany regarding burden of disease, sequelae and care of HBV, HCV and HDV as a reference to monitor the progress of the national VH elimination and to identify further knowledge gaps and research needs.

METHODS

The protocol of the systematic review was prepared following the PRISMA statement guidelines for scoping reviews. Relevant search terms were used to identify eligible studies according to the research questions. We searched six online databases for original work published between January 2005 and March 2017. Based on the identified references, a matrix was developed presenting the eligible literature by targeted population group and outcome category.

RESULTS

104 publications were eligible for extraction covering 299 outcome results. The population groups targeted in the identified studies included the general population and proxy populations, a range of clinical populations, people who inject drugs, men who have sex with men, healthcare workers, people in prisons and different migrant/mobile populations. Other vulnerable populations (e.g. sex workers) were not targeted. Overall, good evidence was found for HBV and HCV prevalence and HBV vaccination coverage in the GP and proxy populations. Evidence for these outcomes was weaker in populations at risk for VH. For HBV and HCV incidence and mortality, we identified large evidence gaps in all population groups. Outcomes on VH sequelae and care were mainly covered by studies in clinical populations of people living with viral hepatitis. For HDV the overall evidence available was scarce.

CONCLUSIONS

We created a comprehensive evidence-based overview on the current epidemiological situation of viral hepatitis in Germany. We identified knowledge gaps for further research and established a baseline for future monitoring of viral hepatitis elimination goals in Germany.

Molecular Characterization of Near Full-Length Genomes of Hepatitis B Virus Isolated from Predominantly HIV Infected Individuals in Botswana

The World Health Organization plans to eliminate hepatitis B and C Infections by 2030. Therefore, there is a need to study and understand hepatitis B virus (HBV) epidemiology and viral evolution further, including evaluating occult (HBsAg-negative) HBV infection (OBI), given that such infections are frequently undiagnosed and rarely treated. We aimed to molecularly characterize HBV genomes from 108 individuals co-infected with human immunodeficiency virus (HIV) and chronic hepatitis B (CHB) or OBI identified from previous HIV studies conducted in Botswana from 2009 to 2012. Full-length (3.2 kb) and nearly full-length (~3 kb) genomes were amplified by nested polymerase chain reaction (PCR). Sequences from OBI participants were compared to sequences from CHB participants and GenBank references to identify OBI-unique mutations. HBV genomes from 50 (25 CHB and 25 OBI) individuals were successfully genotyped. Among OBI participants, subgenotype A1 was identified in 12 (48%), D3 in 12 (48%), and E in 1 (4%). A similar genotype distribution was observed in CHB participants. Whole HBV genome sequences from Botswana, representing OBI and CHB, were compared for the first time. There were 43 OBI-unique mutations, of which 26 were novel. Future studies using larger sample sizes and functional analysis of OBI-unique mutations are warranted.

Time course of cellular HIV-DNA and low-level HIV viremia in HIV-HCV co-infected patients whose HCV infection had been successfully treated with directly acting antivirals

This longitudinal study described cellular HIV-DNA changes and their correlation with HIV low-level plasma viremia (LLV) in HIV-HCV co-infected patients on successful antiretroviral and anti-HCV therapy by treatment with direct-acting antivirals (DAA). Thirty-nine patients were examined prior to the start of DAA (T0), after week 12 (T1) and 24 weeks (T2) of anti-HCV therapy. Cellular PBMC HIV-DNA was analysed as an absolute value and as the percentage of increase or decrease from T0 to T2. Patients were classified as having undetectable plasma HIV viraemia (UV) or LLV in the year before the start of anti-HCV treatment and within the T0-T2 study period. Thirty-five patients (89.7%) of the 39 subjects enrolled had the same plasma HIV viraemia control in the year before HCV treatment and in the T0-T2 interval. The HIV-DNA value at T0 and at T2 was higher in patients with LLV than in subjects with UV (p = 0.015 and p = 0.014, respectively). A similar proportion of patients with LLV and UV experienced an increase or decrease of HIV-DNA from T0 to T2. The percentage increase in HIV-DNA value (262.8%) from T0 to T2 was higher compared to the decrease (43.5%) in patients with UV (p = 0.012), and it was higher compared to the percentage increase in HIV-DNA value reported in subjects with LLV (262.8 versus 49%, p = 0.026). HIV-HCV co-infected patients experienced a multifaceted perturbation of cellular HIV-DNA levels within a 24-week period during anti-HCV treatment; the extent of the phenomenon was greater in subjects with UV. Fast HCV-RNA clearance seemed to have a greater influence on the cellular reservoir than on plasma HIV-RNA.

Are the testing needs of key European populations affected by hepatitis B and hepatitis C being addressed? A scoping review of testing studies in Europe

AIM

To investigate whether or not key populations affected by hepatitis B and hepatitis C are being tested sufficiently for these diseases throughout the European region.

METHODS

We searched MEDLINE and EMBASE for studies on HBV and HCV testing in the 53 Member States of the World Health Organization European Region following PRISMA criteria.

RESULTS

136 English-language studies from 24 countries published between January 2007 and June 2013 were found. Most studies took place in 6 countries: France, Germany, Italy, the Netherlands, Turkey, and the United Kingdom. 37 studies (27%) addressed HBV, 46 (34%) HCV, and 53 (39%) both diseases. The largest categories of study populations were people who use drugs (18%) and health care patient populations (17%). Far fewer studies focused on migrants, prison inmates, or men who have sex with men.

CONCLUSIONS

The overall evidence base on HBV and HCV testing has considerable gaps in terms of the countries and populations represented and validity of testing uptake data. More research is needed throughout Europe to guide efforts to provide testing to certain key populations.

Hepatitis E virus infection in the liver transplant recipients: Clinical presentation and management

Hepatitis E virus (HEV) is an emerging pathogen and an increasingly recognized cause of graft hepatitis, especially in the post-orthotopic liver transplantation immunocompromised population. The exact incidence and prevalence of HEV infection in this population remains unclear but is certainly greater than historical estimates. Identifying acute HEV infection in this population is imperative for choosing the right course of management as it is very difficult to distinguish histologically from acute rejection on liver biopsy. Current suggested approach to manage acute HEV involves modifying immunosuppression, especially discontinuing calcineurin inhibitors which are the preferred immunosuppressive agents post-orthotopic liver transplantation. The addition of ribavirin monotherapy has shown promising success rates in clearing HEV infection and is used commonly in reported cases.

Prevalence of non-HIV cancer risk factors in persons living with HIV/AIDS: a meta-analysis

OBJECTIVE

The burden of cancer among persons living with HIV/AIDS (PLWHA) is substantial and increasing. We assessed the prevalence of modifiable cancer risk factors among adult PLWHA in Western high-income countries since 2000.

DESIGN

Meta-analysis.

METHODS

We searched PubMed to identify articles published in 2011-2013 reporting prevalence of smoking, alcohol consumption, overweight/obesity, and infection with human papillomavirus (HPV), hepatitis C virus (HCV) and hepatitis B virus (HBV) among PLWHA. We conducted random effects meta-analyses of prevalence for each risk factor, including estimation of overall, sex-specific, and HIV-transmission-group-specific prevalence. We compared prevalence in PLWHA with published prevalence estimates in US adults.

RESULTS

The meta-analysis included 113 publications. Overall summary prevalence estimates were current smoking, 54% [95% confidence interval (CI) 49-59%] versus 20-23% in US adults; cervical high-risk HPV infection, 46% (95% CI 34-58%) versus 29% in US females; oral high-risk HPV infection, 16% (95% CI 10-23%) versus 4% in US adults; anal high-risk HPV infection (men who have sex with men), 68% (95% CI 57-79%), with no comparison estimate available; chronic HCV infection, 26% (95% CI 21-30%) versus 0.9% in US adults; and HBV infection, 5% (95% CI 4-5%) versus 0.3% in US adults. Overweight/obesity prevalence (53%; 95% CI 46-59%) was below that of US adults (68%). Meta-analysis of alcohol consumption prevalence was impeded by varying assessment methods. Overall, we observed considerable study heterogeneity in prevalence estimates.

CONCLUSION

Prevalence of smoking and oncogenic virus infections continues to be extraordinarily high among PLWHA, indicating a vital need for risk factor reduction efforts.

The prevalence of hepatitis B virus infection markers and socio-demographic risk factors in HIV-infected patients in Southern Brazil

INTRODUCTION

Hepatitis B virus (HBV) and human immunodeficiency virus (HIV) infections are two of the world's most important infectious diseases. Our objective was to determine the hepatitis B surface antigen (HBsAg) and hepatitis B core antibody (anti-HBc) prevalences among adult HIV-infected patients and identify the associations between socio-demographic variables and these HBV infection markers.

METHODS

This study was performed from October 2012 to March 2013. Three hundred HIV-seropositive patients were monitored by the Clinical Analysis Laboratory of Professor Polydoro Ernani de São Thiago University Hospital, Santa Catarina, Brazil. The blood tests included HBsAg, anti-HBc immunoglobulin M (IgM) and total anti-HBc. Patients reported their HIV viral loads and CD4+ T-cell counts using a questionnaire designed to collect sociodemographic data.

RESULTS

The mean patient age was 44.6 years, the mean CD4 T-cell count was 525/mm3, the mean time since beginning antiretroviral therapy was 7.6 years, and the mean time since HIV diagnosis was 9.6 years. The overall prevalences of HBsAg and total anti-HBc were 2.3% and 29.3%, respectively. Among the individuals analyzed, 0.3% were positive for HBsAg, 27.3% were positive for total anti-HBc, and 2.0% were positive either for HBsAg or total anti-HBc and were classified as chronically HBV-infected. Furthermore, 70.3% of the patients were classified as never having been infected. Male gender, age >40 years and Caucasian ethnicity were associated with an anti-HBc positive test.

CONCLUSIONS

The results showed an intermediate prevalence of HBsAg among the studied patients. Moreover, the associations between the anti-HBc marker and socio-demographic factors suggest a need for HBV immunization among these HIV-positive individuals, who are likely to have HIV/HBV coinfection.

Viral hepatitis and human immunodeficiency virus co-infections in Asia

Hepatitis B virus (HBV), hepatitis C virus (HCV), and human immunodeficiency virus (HIV) affect many people in Asian countries, although there are geographic differences. Both HBV and HIV (HBV/HIV) and HCV/HIV co-infections are highly prevalent in Asia. Hetero- and homosexual, injection drug use, and geographic area are strong predictors of HBV, HCV, and HIV serostatus. In HBV endemic regions, the prevalence and genotype distribution of HBV/HIV co-infection is almost comparable with that in the general population. In Japan, where HBV has low endemicity, the prevalence of HBV/HIV co-infection is approximately 10-fold higher than that in the general population, and HBV Ae is the most common subgenotype among HIV infected individuals. Highly active antiretroviral therapy (HAART) is an effective treatment for HIV/Acquired Immune Deficiency Syndrome. Lamivudine, a component of HAART, is an effective treatment for HBV, HIV, and HBV/HIV co-infection; however, cost, emerging drug resistance, antiretroviral-associated liver toxicity and liver-related morbidity due to HCV progression are particular concerns. HCV/HIV co-infection may accelerate the clinical progression of both HCV and HIV. The high prevalence of HBV/HIV and HCV/HIV co-infections in Asia underscores the need to improve prevention and control measures, as fewer evidence-based prevention strategies are available (compared with Western countries). In this review, the most recent publications on the prevalence of HBV/HIV and HCV/HIV co-infections and related issues, such as therapy and problems in Asia, are updated and summarized.

Hepatitis B virus infection in a cohort of HIV infected blood donors and AIDS patients in Sichuan, China

Background

Co-infections of HBV and HIV are frequent due to similar routes of transmission. In that transmission through blood is an important route for both HBV and HIV, evaluation of the prevalence of HBV in HIV infected blood donors may be important for transfusion safety. In addition, because the epidemiological characteristics of HBV in HIV infected patients and blood donors may differ from each other, understanding of it could be significant for therapy and prevention of HBV in HIV infected adults. However, data reported on these in Chinese people remains limited.

Methods

614 HIV confirmed positive samples were collected from blood donors and patients and were screened for HBsAg and HBV DNA. The samples screened reactive for HBsAg or positive for HBV DNA were tested for the other serological markers of HBV including anti-HBs, HBeAg, anti-HBe and anti-HBc. For the samples tested positive for HBV DNA, the S region of HBV was amplified by nested PCR and the HBV genotypes were determined.

Results

HBV coinfections were found in 12.9% (79/614) HIV infected individuals including 42/417(10.1%) blood donors and 37/197 (18.8%) AIDS patients. In the HBsAg positive individuals, 80.0% were HBeAg negative in which 10.0% were HBV DNA negative and 38.3% with HBV DNA lower than 2000 IU/ml. The average HBV DNA levels were lower in donors than in patients. In the HBV DNA positive populations, HBV genotypes B, A and C accounted for 48.1%, 22.8% and 8.86% respectively. Mutations related to the failure of HBsAg detection were found in 2 of the 4 HBsAg-/HBV DNA + subjects.

Conclusions

High prevalence of HBV in HIV infected individuals was found in this study. Hence, we recommend routine testing of HBV for patients newly diagnosed with HIV/AIDS in China. Some HIV-HBV co-infected patients remain undiagnosed if only conventional serological markers for HBV are used and it’s important to detect HBV DNA for HIV infected patients. HBV DNA levels were relatively low in HBeAg negative patients, thus this serologic marker may be useful in prioritizing patients on their need for HBV treatment in settings in which HBV DNA is not available.

Background paper to the revised recommendation for hepatitis B vaccination of persons at particular risk and for hepatitis B postexposure prophylaxis in Germany

The German Standing Committee on Vaccination (Ständige Impfkommission, STIKO) recommends vaccinating risk groups against hepatitis B and gives advice for postexposure prophylaxis. STIKO has recently revised this recommendation, focusing on: (i) classification of risk groups, (ii) duration of protection after primary immunization, and (iii) anti-HBs threshold that defines successful hepatitis B vaccination. Orientating literature reviews were performed for the first objective. Examples of population subgroups at increased risk were identified and classified into three indication groups. Systematic reviews on the duration of vaccine-induced protection identified one randomized controlled trial (RCT) and nine cohort studies. When applying the grading of recommendation, assessment, development, and evaluation (GRADE) methodology, evidence from RCTs was considered of very low quality regarding the question of whether hepatitis B can be prevented for 15 years after successful primary vaccination (anti-HBs ≥ 10 IU/l) with a vaccine efficacy of 96 % against chronic hepatitis, 89 % against HBsAg positivity, and 73 % against isolated anti-HBc positivity. However, seven cohort studies showed that no cases of clinical hepatitis B or HBsAg positivity occurred during a maximum follow-up period of 10 years in settings comparable to the situation in Germany when anti-HBs ≥ 10 IU/l was used to indicate vaccination success. Less than 1 % of vaccinated study participants had isolated anti-HBc positivity. GRADE assessment of two cohort studies revealed that evidence of very low quality exists that the use of anti-HBs ≥ 100 IU/l to measure vaccination success leads to a lower frequency of anti-HBc positivity during follow-up than the use of anti-HBs ≥ 10 IU/l. The recommendation was revised according to this evidence.

Occult hepatitis B virus coinfection in HIV-positive African migrants to the UK: a point prevalence study

Objectives

Occult (surface antigen-negative/DNA-positive) hepatitis B virus (HBV) infection is common in areas of the world where HBV is endemic. The main objectives of this study were to determine the prevalence of occult HBV infection in HIV-infected African migrants to the UK and to determine factors associated with occult coinfection.

Methods

This anonymized point-prevalence study identified Africans attending three HIV clinics, focussing on patients naïve to antiretroviral therapy (ART). Stored blood samples were tested for HBV DNA. Prevalence was calculated in the entire cohort, as well as in subpopulations. Risk factors for occult HBV coinfection were identified using logistic regression analysis.

Results

Among 335 HIV-positive African migrants, the prevalence of occult HBV coinfection was 4.5% [95% confidence interval (CI) 2.8–7.4%] overall, and 6.5% (95% CI 3.9–10.6%) and 0.8% (95% CI 0.2–4.6%) in ART-naïve and ART-experienced patients, respectively. Among ART-naïve anti-HBV core (anti-HBc)-positive patients, the prevalence was 16.4% (95% CI 8.3–25.6%). The strongest predictor of occult coinfection was anti-HBc positivity [odds ratio (OR) 7.4; 95% CI 2.0–27.6]. Median HBV DNA and ALT levels were 54 IU/mL [interquartile range (IQR) 33–513 IU/mL] and 22 U/L (IQR 13–27 U/L), respectively.

Conclusions

Occult HBV coinfection remains under-diagnosed in African HIV-infected patients in the UK. Given the range of HBV DNA levels observed, further studies are warranted to determine its clinical significance and to guide screening strategies and ART selection in these patients.

Hepatitis B and C co-infection in HIV/AIDS population in the state of Michigan

A retrospective cohort study was conducted from 1 January 2006 to 31 December 2009 in Michigan to estimate the prevalence of HIV and hepatitis co-infection and identify associated factors. The prevalence of co-infection was 4.1% [95% confidence interval (CI) 3.8-4.5]. Multivariable logistic regression analysis revealed a significant association between co-infection and being male and: of Black race [odds ratio (OR) 2.0, 95% CI 1.2-3.6] and of Other race (OR 3.5, 95% CI 1.7-7.0) compared to Hispanic race. A significant association was found between co-infection and risk categories of blood products (OR 11.1, 95% CI 6.2-20.2), injecting drug user (IDU) (OR 3.6, 95% CI 2.7-4.8) and men who have sex with men/IDU (OR 3.4, 95% CI 2.4-4.9) in addition to two interactions; one between sex and current HIV status and the other between current HIV status and age at HIV diagnosis. Our results document the changing epidemiology of HIV-hepatitis co-infection which can guide preventive measures and interventions to reduce the prevalence of hepatitis co-infection.

Response to antiretroviral therapy in occult hepatitis B and HIV co-infection in West Africa

This study evaluated the outcome of first-line antiretroviral therapy among 35 Ghanaians with occult HBV/HIV co-infection, comparing them over 2 years to 120 patients with HBsAg+ HBV/HIV co-infection and 230 patients without HBV co-infection. Increases in CD4 cell count and BMI were similar, whereas elevations of hepatic transaminases were more frequent in both the occult HBV and HBsAg+ patients. Occult HBV/HIV co-infection appears not to impact adversely on response to antiretroviral therapy in Ghana.

Comparison of HIV-1 viral load assay performance in immunological stable patients with low or undetectable viremia

The goal of antiretroviral therapy is reduction in morbidity and mortality via suppression of human immunodeficiency virus (HIV) viral load (VL) to undetectable levels. VL assay sensitivity has improved over time, but the reproducibility and clinical importance of VL results marginally higher than the limit of detection (LoD) are uncertain. We assessed the reproducibility and concordance of low VL results obtained with the Roche Cobas AmpliPrep/Cobas TaqMan HIV-1 version 2.0 (CAP-CTM) and the Abbott RealTime (m2000) HIV-1 assays, using longitudinal specimens from HIV-1-infected patients with low VL (<300 copies/ml) and stable CD4+ cell counts. Based on replicate testing of 3 specimens, coefficients of variation for log-transformed VL results were 5-8 % for m2000 and 9-10 % for CAP-CTM. The concordance between assays in specimens from patients with previously undetectable, detectable but not quantifiable VL, or variable (undetectable/detectable but not quantifiable VL) results over time was 90, 56, and 56 %, respectively. Correlation between results for specimens with quantifiable VL (initially 40-300 copies/ml) was moderate (R (2) = 0.48) with significantly higher results for CAP-CTM and a mean difference (CAP-CTM minus m2000) of 0.10 log(10) copies/ml. T-cell activation (CD8+/CD38+ percentage) in patients with low VL was initially higher than in patients with undetectable VL, and then decreased to equivalent levels over time. These results indicate that residual viremia at levels slightly above the LoD have no negative effect on T-cell activation.

Recent publications in medical microbiology and immunology: a retrospective

A look back is done to some clinical and basic research activities recently published in medical microbiology and immunology. The review covers clinical experiences and in vitro experiments to understand the emergency, pathogenicity, epidemic spread, and vaccine-based prevention of avian and swine-origin flu. Some new developments and concepts in diagnosis, (molecular) epidemiology, and therapy of AIDS, viral hepatitis C, and herpesvirus-associated diseases are outlined. Regulation of immune system has been discussed in a special issue 2010 including some aspects of CNS affections (measles). Mycobacterial infection and its prevention by modern recombinant vaccines have reached new interest, as well as new concepts of vaccination and prophylaxis against several other bacteria. Adaptation to host niches enables immune escape (example brucella) and determines virulence (example N. meningitidis). Chlamydia pneumoniae, previously considered to trigger atherosclerosis, is hypothetically associated to Alzheimer disease, while CMV, another putative trigger of atherosclerosis, gains evidence of oncomodulation in CNS tumor diseases. In terms of globalization, exotic virus infections are increasingly imported from southern countries.

Mutational patterns in the frameshift-regulating site of HIV-1 selected by protease inhibitors

Sustained suppression of viral replication in HIV-1 infected patients is especially hampered by the emergence of HIV-1 drug resistance. The mechanisms of drug resistance mainly involve mutations directly altering the interaction of viral enzymes and inhibitors. However, protease inhibitors do not only select for mutations in the protease but also for mutations in the precursor Gag and Pol proteins. In this study, we analysed the frameshift-regulating site of HIV-1 subtype B isolates, which also encodes for Gag and Pol proteins, classified as either treatment-naïve (TN) or protease inhibitor resistant (PI-R). HIV-1 Gag cleavage site mutations (G435E, K436N, I437V, L449F/V) especially correlated with protease inhibitor resistance mutations, but also Pol cleavage site mutations (D05G, D05S) could be assigned to specific protease resistance profiles. Additionally, two Gag non-cleavage site mutations (S440F, H441P) were observed more often in HIV-1 isolates carrying protease resistance mutations. However, in dual luciferase assays, the frameshift efficiencies of specific clones did not reveal any effect from these mutations. Nevertheless, two patterns of mutations modestly increased the frameshift rates in vitro, but were not specifically accumulating in PI-resistant HIV-1 isolates. In summary, HIV-1 Gag cleavage site mutations were dominantly selected in PI-resistant HIV-1 isolates but also Pol cleavage site mutations influenced resistance profiles in the protease. Additionally, Gag non-cleavage site mutations accumulated in PI-resistant HIV-1 isolates, but were not related to an increased frameshift efficiency.