Pyrazinamide is important in tuberculosis treatment, as it is bactericidal to semidormant mycobacteria not killed by other antituberculosis drugs. Pyrazinamide is also one of the cornerstone drugs retained in the treatment of multidrug-resistant tuberculosis (MDR-TB). However, due to technical difficulties, routine drug susceptibility testing of Mycobacterium tuberculosis for pyrazinamide is, in many laboratories, not performed. The objective of our study was to generate information on pyrazinamide susceptibility among South African MDR and susceptible M. tuberculosis isolates from pulmonary tuberculosis patients. Seventy-one MDR and 59 fully susceptible M. tuberculosis isolates collected during the national surveillance study (

Consistently, QFT demonstrates increased risk of incident TB with rising IFN-γ concentrations, indicating that IFN-γ levels may be used to guide targeted treatment of LTBI.

Background During the coronavirus disease 2019 (COVID-19) pandemic, many countries experienced infection in healthcare workers (HCW) due to overburdened healthcare systems. However, whether infected HCW acquire protective immunity against SARS-CoV-2 is unclear. Here, we characterized SARS-CoV-2-specific antibody responses in Norwegian HCW in a prospective cohort study. Methods We enrolled 607 HCW pre- and post-the first COVID-19-pandemic wave. Exposure history, COVID-19-like symptoms and serum samples were collected. SARS-CoV-2-specific antibodies were characterized by spike-protein IgG/IgM/IgA enzyme-linked immunosorbent and live-virus neutralization assays. Results Spike-specific IgG, IgM, and IgA antibodies increased after the first pandemic wave in HCW with COVID-19-patient exposure, but not in HCW without patient exposure. Thirty-two HCW (5.3%) had spike-specific antibodies (11 seroconverted with ≥4-fold increase, 21 were seropositive at baseline). Neutralizing antibodies were found in 11 HCW that seroconverted, of whom 4 (36.4%) were asymptomatic. Ninety-seven HCW were tested by reverse-transcriptase-polymerase chain reaction (RT-PCR) during follow-up, 8 were positive (7 seroconverted and 1 had undetectable antibodies). Conclusions We found increases in SARS-CoV-2-neutralizing antibodies in infected HCW, especially after COVID-19-patient exposure. Our data show a low number of SARS-CoV-2-seropositive HCW in a low prevalence setting, however, the proportion of seropositivity was higher than RT-PCR positivity, highlighting the importance of antibody testing.

This study provides the first molecular characterization of isoniazid- and rifampicin-resistant M. tuberculosis isolates from Myanmar and gives information on the molecular basis for rifampicin and isoniazid drug resistance in M. tuberculosis. The study generates useful information for the development of potential rapid molecular drug susceptibility tests.