With limited data available from Central Africa, the aim of our study was to evaluate the anti-SARS-CoV-2 Ab prevalence in indigenous residents of Bomassa, a village located in the Sangha region in the Republic of Congo. Plasma and oropharyngeal swab samples were collected from 304 healthy adult individuals, randomly recruited in May 2021 before vaccine introduction in the area. In addition, 82 plasma samples from the same area in 2019 were included as controls for the investigation of cross-reactivity against other coronaviruses. The SARS-CoV-2 virus was detected by qRT-PCR and sequenced using next-generation sequencing. ELISA was used for detecting IgG, IgM, and neutralizing Ab against SARS-CoV-2 antigens. Around 4.9% (15/304) of the participants were SARS-CoV-2 positive, with B.1.631 being the only variant identified. Of 109 individuals harboring anti-SARS-CoV-2 IgG and/or IgM Ab, 45.9% (50/109) had anti-SARS-CoV-2 neutralizing Ab. Of the control samples collected before the pandemic, 3.7% (3/82) were positive for IgG, but negative for neutralizing Ab. Seroprevalence against SARS-CoV-2 occurred in 25% of the indigenous population sample, with almost 50% of these seropositive participants possessing neutralizing antibodies. These findings suggest that the spread of SARS-CoV-2 has been underestimated in the Republic of Congo.

Background: Evaluating progress towards WHO End Tuberculosis Strategy goals is crucial for high burden countries like the Republic of Congo. This study analysed trends in tuberculosis (TB) incidence, treatment, care quality and operational research activities from 2016 to 2023 to assess the country’s control efforts. Methods: An 8-year retrospective study of TB incidence/mortality trends was performed using a Joint Point Analysis V.5.2.0. We extracted annual national and WHO TB programme data for the period under review. Results: From 2016 to 2023, the TB incidence rate decreased by 2.6% (annual percentage change (APC)=−0.33, 95% CI− 0.5 to −0.005; p<0.05). The proportion of bacteriologically confirmed cases significantly increased (APC=4.2, 95% CI 0.9 to 7.7; p<0.001), while treatment coverage rose by 22% (APC=2.81, 95% CI 1.1 to 4.5; p<0.05). The proportion of notified patients with TB tested for HIV significantly increased (APC=25, 95% CI 2.6 to 52.63; p<0.05), but the rate of patients with TB testing HIV positive decreased significantly (APC=−13.9, 95% CI −23.9 to −2.6; p<0.05). The proportion of unsuccessful treatment outcomes showed a non-significant decline, with an APC of 4.90% (95% CI −11.7% to 2.3%; p=0.1), while TB-related deaths increased non-significantly, with an APC of 3.76% (95% CI −1.3% to 9.2%; p=0.12). Patients with TB/HIV on ART increased by 51% (APC=6.4, 95% CI −23.9 to −2.6; p<0.05). No operational research activity has been carried out throughout the review period. Conclusion: The observed progress was insufficient, as the Republic of Congo failed to meet the 20% TB incidence reduction target for 2020 and is unlikely to achieve the 50% reduction goal for 2025. More investment in case detection, diagnosis, treatment quality and the implementation of operational research activities is needed to achieve global goals.

Tuberculosis (TB) treatment outcome is one of the key indicators to evaluate the performance of TB control programs. This study aims to assess TB treatment outcomes and their related associated factors in patients treated at the Antituberculosis Center of Brazzaville, Republic of Congo. A prospective cohort study was conducted at the Antituberculosis Center of Brazzaville from July 2022 to August 2023, involving 305 patients with pulmonary TB diagnosed with the GenXpert MTB/RIF assay. These patients were closely monitored using acid-fast bacillus microscopy while receiving treatment based on whether they were drug-sensitive (DS) or drug-resistant. Sputum samples from patients who were DS were analyzed at 2, 5, and 6 months, whereas patients who were multi-drug–resistant (MDR) underwent a monthly sputum analysis for 9 months. The overall successful treatment rate was 80.3%, with 70.8% of patients cured and 9.5% completing treatment. Conversely, 19.7% experienced unsuccessful outcomes, including 13.4% loss to follow-up, 3.6% deaths, and 1.6% treatment failures. The treatment success in individuals co-infected with HIV was 46.7% (seven of 15), whereas it was 42% (eight in 19) in patients who were MDR. HIV-negative status (adjusted odds ratio = 5.11; 95% confidence interval: 1.73-13.44) and DS-TB (adjusted odds ratio = 8.29; 95% confidence interval: 3.17-21.04) were associated with increased success of treatment outcome. The overall TB treatment success rate was below the World Health Organization End TB Strategy threshold, with a high proportion of patients lost to follow-up and a low treatment success in patients with TB/HIV and those who were MDR. The findings highlight the need to enhance supervision, improve directly observed treatment short course monitoring, and develop strategies to minimize patients lost to follow-up.

National Tuberculosis Reference Laboratories (NTRLs) are central to tuberculosis (TB) control programs. Between 2018 and 2024, the Republic of Congo, a country of 6 million inhabitants, achieved a transformative strengthening of its TB diagnostic system, coordinated by the NTRL. Strategic investments, supported mainly by international partners, enabled a substantial decentralization of services, expanding the diagnostic network from 38 to 113 diagnostic and testing centers and increasing GeneXpert sites from 3 to 31. The expansion of the diagnostic network and specimen referral system was associated with a reduced structural gap in diagnostic coverage by extending access to GeneXpert testing to a larger number of peripheral and previously underserved centers. Critically, the establishment of a BSL-3 laboratory and the deployment of advanced assays like Xpert MTB/XDR ended the reliance on overseas testing by introducing in-country capacity for multidrug-resistant and pre-extensively drug-resistant TB detection. These systemic improvements were associated with significant positive outcomes, including an annual molecular testing surging from 11,609 in 2022 to over 27,000 in 2024 and bacteriological confirmation rates rising from 34 to 73%. This comprehensive laboratory systems strengthening, which also facilitated cross-programmatic initiatives like HIV and Mpox testing integration, underscores how sustained investment in infrastructure, logistics, and quality management is fundamental to improving case detection, surveillance, and progress toward the WHO End TB Strategy milestones.

Liver function abnormalities during tuberculosis (TB) treatment can indicate anti-TB drug-induced liver injury (ATLI), a serious adverse event. Therefore, this study aims to evaluate transaminase levels in a cohort of patients with TB undergoing treatment. It also assesses the prevalence and severity of ATLI. We conducted a cross-sectional study of 235 patients with TB during the intensive phase (2 months) of treatment to assess liver function. Serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were measured, and hepatotoxicity was graded according to the World Health Organization/common terminology criteria for adverse events criteria. HIV was screened according to the national algorithm, and hepatitis B was assessed serologically. Median ALT and AST levels varied by age, sex, and HIV status. Males had higher ALT (19.2 vs 15.3 IU/l; P = 0.009) and AST (28.1 vs 24.0 IU/l; P = 0.009) levels than females. Levels increased with age (P <0.05) and were higher in patients positive for HIV (ALT 25 vs 17.7 IU/l, AST 33 vs 27 IU/l; P <0.05). No differences were observed according to hepatitis B status. Overall, 53 (22.6%) patients had elevated transaminases, mostly mild (92.5%), whereas 7.5% experienced ATLI. Hepatotoxicity was common at 2 months of TB treatment and was associated with male sex, older age, and HIV co-infection. These findings highlight the importance of regular liver function monitoring in these patient groups during treatment.

Tuberculosis (TB) remains a major public health challenge, particularly in sub-Saharan Africa, where the emergence of drug-resistant MTB undermines current control efforts. This study aimed to characterize genetic mutations associated with resistance to first- and second-line injectable drugs in MTB isolates from pulmonary TB patients in the Republic of Congo. A total of 45 culture-positive MTB isolates collected between 2018 and 2019 were analyzed using targeted next-generation sequencing on the MinION device. Resistance-associated genes, including rpoB, katG, embB, gyrA, and rrs, were examined. Overall, 22/45 isolates (48%) harbored at least one mutation associated with drug resistance. Among resistant isolates, rifampicin resistance was detected in 15 of 22 (68.2%), predominantly associated with mutations in the rpoB rifampicin resistance–determining region, including p.Ser531Leu, p.Asp516Val, and p.His526Tyr.Ethambutol resistance was observed in 11 of 22 isolates (50.0%) and was mainly associated with the embB p.Met306Val mutation. Isoniazid resistance was detected in 9 of 22 isolates (40.9%), primarily associated with the KatG p.Ser315Thr mutation. Fluoroquinolone resistance was identified in 2 of 22 isolates (9.1%), mainly associated with gyrA p.Ala90Val and p.Asp94Gly mutations. Resistance to second-line injectable drugs was detected in 1 of 22 isolates (4.5%) and was associated with the rrs p.Ala1401Gly mutation. These findings underscore the need to enhance molecular surveillance and strengthen treatment protocols for drug-resistant TB in the Republic of Congo to effectively combat this evolving health crisis.