Kinetics of SARS-CoV-2 infection biomarkers in a household transmission study.

SARS-CoV-2 is the causative agent of COVID-19. Timely and accurate diagnostic testing is vital to contain the spread of infection, reduce delays in treatment and care, and inform patient management. Optimal specimen type (e.g. nasal swabs or saliva), timing of sampling, viral marker assayed (RNA or antigen), and correlation with viral infectivity and COVID-19 symptoms severity remain incompletely defined. We conducted a field study to evaluate SARS-CoV-2 viral marker kinetics starting from very early times after infection. We measured RNA and antigen levels in nasal swabs and saliva, virus outgrowth in cell culture from nasal swabs, and antibody levels in blood in a cohort of 30 households. Nine household contacts (HHC) became infected with SARS-CoV-2 during the study. Viral RNA was detected in saliva specimens approximately 1-2 days before nasal swabs in six HHC. Detection of RNA was more sensitive than of antigen, but antigen detection was better correlated with culture positivity, a proxy for contagiousness. Anti-nucleocapsid antibodies peaked one to three weeks post-infection. Viral RNA and antigen levels were higher in specimens yielding replication competent virus in cell culture. This study provides important data that can inform how to optimally interpret SARS-CoV-2 diagnostic test results.

Differences in the Course of CD4 and CD8 Cells After Chemoradiotherapy in People Living with HIV with Anal Cancer.

Incidence of anal carcinoma (AC) in people living with HIV (PLWH) is increased compared to the general population. Adverse effects of chemoradiotherapy (CRT) on the immune system are associated with a significant detrimental prognosis on overall survival in patients receiving CRT for solid tumors. The aim of this study was to evaluate immunological factors, in particular the differences in recovery of CD4+ and CD8+ cell counts before and after CRT for AC in PLWH. Retrospective single-center chart review extraction to analyze immunological data collected from PLWH with AC; descriptive statistics were used. Thirty-six PLWH with histologically proven AC were included in the analysis. Absolute CD4 cell count 60 months after CRT was 67.2% of the value at the beginning of CRT, whereas the CD8 cell count reached 82.3%. These differences were statistically significant (p = .048), whereas CD4/CD8-ratio remained stable. The findings of the presented study regarding CD4+ and CD8+ cell recovery after CRT are congruent with results from prior studies in non-HIV infected patients. Although not reaching the level of prior CRT T cell numbers, the ability to generate CD8+ cells seems to be better recovered, while CD4+ regeneration is more impaired. These observations are best explained by faster recovery of CD8+ cells via thymic-independent pathways, which are not available for regeneration of CD4+ cells. Further studies with larger numbers of patients are required to analyze the specific CD4+ and CD8+ cell subsets.

Sexually transmitted diseases in people living with HIV after implementation of cost coverage of HIV pre-exposure prophylaxis by statutory health insurance in Germany.

OBJECTIVES: After pre-exposure prophylaxis (PrEP) was introduced, rates of sexually transmitted infections (STIs) increased among PrEP users. However, data on STI trends in people living with HIV since then are limited. Since September 2019, PrEP has been covered by statutory German health insurance (SHI) in vulnerable groups. This study aimed to determine whether this coverage of PrEP costs affected STI rates in people living with HIV (specifically, men who have sex with men). METHODS: All patients of the HIVCENTER Frankfurt diagnosed with at least one STI within the observation period were retrospectively enrolled in the study. STIs included infection with Treponema pallidum, Chlamydia trachomatis, Neisseria gonorrhoeae, and/or Trichomonas vaginalis. The observation period covered 1 year before and 1 year after the coverage of PrEP costs by German SHI. Data were collected from outpatient clinic records. RESULTS: In total, 143 patients were enrolled in the study. The observation period was September 2018 to August 2019 for group 1 (n = 73) and September 2019 to August 2020 for group 2 (n = 70). The most frequent STIs were syphilis and infections due to chlamydia, gonococci, and trichomonads, in descending order. Infections with T. pallidum occurred more often in group 2 than in group 1 (60.0% vs. 50.7%; p = 0.253) as did chlamydia (37.1% vs. 28.8%; p = 0.286). CONCLUSIONS: A tendency for an increased ratio of STIs in people living with HIV was observed after the introduction of PrEP coverage by German SHI. STIs should be discussed intensively with people living with HIV, since the communities of PrEP users and people living with HIV overlap, and changes in risk behaviour might influence both groups.

Genetic Predisposition and the Variable Course of Infectious Diseases.

BACKGROUND: Contact with a pathogen is followed by variable courses of infectious disease, which are only partly explicable by classical risk factors. The susceptibility to infection is variable, as is the course of disease after infection. In this review, we discuss the extent to which this variation is due to genetic factors of the affected individual (the host). METHODS: Selective review of the literature on host genetics in infectious disease, with special attention to the pathogens SARSCoV- 2, influenza viruses, Mycobacterium tuberculosis, and human immunodeficiency virus (HIV). RESULTS: Genetic variants of the host contribute to the pathogenesis of infectious diseases. For example, in HIV infection, a relatively common variant leading to a loss of function of the HIV co-receptor CCR5 affects the course of the disease, as do variants in genes of the major histocompatibility complex (MHC) region. Rare monogenic variants of the interferon immune response system contribute to severe disease courses in COVID-19 and influenza (type I interferon in these two cases) and in tuberculosis (type II interferon). An estimated 1.8% of life-threatening courses of COVID-19 in men under age 60 are caused by a deficiency of toll-like receptor 7. The scientific understanding of host genetic factors has already been beneficial to the development of effective drugs. In a small number of cases, genetic information has also been used for individual therapeutic decision-making and for the identification of persons at elevated risk. CONCLUSION: A comprehensive understanding of host genetics can improve the care of patients with infectious diseases. Until the present, the clinical utility of host genetics has been limited to rare cases; in the future, polygenic risk scores summarizing the relevant genetic variants in each patient will enable a wider benefit. To make this possible, multicenter studies are needed that will systematically integrate clinical and genetic data.