Background: Poliomyelitis is a vaccine-preventable disease, with oral poliomyelitis vaccines (OPVs) and injectable poliomyelitis vaccines. In the Democratic Republic of the Congo (DRC), circulating vaccine-derived polioviruses (VDPVs) persist due to intrinsic and extrinsic factors, including the quality of the cold chain, which may make the vaccines less effective. This study’s objective was to evaluate the cold chain’s quality of OPVs and its effect on the vaccine’s viability and potency at different levels in health systems in Kinshasa. Methods: A cross-sectional study was conducted in Kinshasa, collecting OPVs at different levels of the health pyramid. Vaccine viability was assessed by cell culture using a modified World Health Organization (WHO) protocol, and the viral titer was determined using the Karber formula. The vaccine titer was classified as “very good”, “good”, or “poor” according to the WHO standard’s viral titer. Results: A total of 53 vaccines were collected and analyzed, compressing 38 bivalent oral poliomyelitis (bOPV) vaccines and 15 novel oral poliomyelitis vaccines, type 2 (nOPV2). The viral titer ranged from log10^5.8 to log 10^7.3 and from log10^5.4 to log10^8.9 for the nOPV2 and the bOPV, respectively. Of these 53 vaccine samples, 10% of the bOPVs showed viral titers below the recommended WHO threshold (>10⁶ CCID₅₀/dose), 100% of the nOPV2 had viral titers within the WHO standards (>10⁵ CCID₅₀/dose), and a significant decline in the viral titer was observed for both types of vaccines (nOPV2 and bOPV) as the distribution progressed along the level of the health pyramid. Conclusions: This study demonstrated that the viral titer of OPV declined from central to peripheral areas in routine and campaign strategies in Kinshasa.

Background: During the COVID‐19 pandemic, international border restrictions, along with traveler screening and quarantine, were implemented to limit virus spread. This study analyzes the epidemiological and genomic profiles of SARS‐CoV‐2 infections imported into Kinshasa (DRC) during the restrictions period in 2021. Methods: As part of the national response to the pandemic, self‐reported demographic and clinical data were collected from travelers entering the DRC via N'djili‐Kinshasa International Airport. SARS‐CoV‐2 infection was diagnosed using RT‐PCR, and positive samples were subjected to whole genome sequencing (WGS) to determine variant types and viral lineages. The impact of the virus's genomic profile on the clinical presentation of travelers and on the COVID‐19 epidemiology in the DRC was then assessed. Results: Of 102,810 included travelers, 1037 (1.0%) tested positive for SARS‐CoV‐2 and reported significantly more nausea, diarrhea, and weight loss than uninfected travelers ( p < 0.001). SARS‐Cov‐2‐infected travelers were predominantly under 43 years old ( p < 0.001) and primarily from France (24.8%) and Belgium (19.5%). Of the 105 WGS analyzed, 86 (81.9%) were variants of concern (VOCs), 14 (13.3%) were variants under monitoring (VUM), and the main genomic lineages identified were Delta‐B.1.617.2 (24.8%), Alpha‐B.1.1.7 (10.5%), Delta‐AY.122 (7.6%), and B.1.620 (5.7%). The Delta‐VOC was the most prevalent among positive travelers (61/86) and appeared to cause more symptomatic infections than non‐Delta variants, although one‐third of positive travelers reported no symptoms. Conclusions: SARS‐CoV‐2 importation into Kinshasa (DRC) mirrored global variant circulation patterns at the study's time. This genomic landscape was consistent with in‐country clinical observations, emphasizing the importance of robust border surveillance and adaptive public health strategies during pandemics.

Background: Environmental surveillance (ES) of wastewater was introduced by the Global Polio Eradication Initiative (GPEI) to improve the sensitivity of acute flaccid paralysis (AFP) surveillance. In the Democratic Republic of the Congo (DRC), ES for poliovirus has been implemented since 2017. This study assessed its sensitivity and productivity. Methods: A retrospective descriptive study using ES for poliovirus data collected in the DRC between September 2017 and June 2025. Wastewater samples were analyzed at the National Institute for Biomedical Research (INRB), using a standardized algorithm that included concentration, cell culture, real-time reverse transcription polymerase chain reaction (rRT-PCR), and VP1 sequencing. Site sensitivity was assessed by productivity, defined as a viral isolation rate ≥ 50%. Results: A total of 2491 wastewater samples were collected. ES expanded from 6 sites in 3 provinces to 27 sites across 8 provinces. Overall site productivity was 33.9% (846/2491 cultures positive for enteroviruses), showing significant variability between sites and over time, which sometimes led to site closures. Non-polio enteroviruses were the most commonly isolated viruses. Among poliovirus isolates, Sabin-like strains (types 1, 2, and 3), novel oral poliovirus vaccine type 2 (nOPV2), and vaccine-derived poliovirus type 2 (VDPV2) were identified, with VDPV2 representing 13.1%. No wild poliovirus was detected. Conclusion: ES for poliovirus has expanded in the DRC, helping detect vaccine-derived poliovirus circulation and confirming the absence of wild poliovirus. Despite ongoing operational and logistical challenges causing fluctuations in site productivity, this study emphasizes the vital role of ES as a supplement to AFP surveillance.

In the context of a rapidly spreading pandemic, early detection of active infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) remains essential to break the chain of transmission and limit associated complications. In the Democratic Republic of the Congo (DRC), access to nucleic acid amplification tests (NAATs), such as RT-PCR, remains limited due to logistical, technical, and financial constraints. The introduction of rapid antigen diagnostic tests (RATs) represented a major advance in strengthening diagnosis. We conducted a descriptive cross-sectional study in Kinshasa to assess the operational and epidemiological contribution of RATs in detecting active SARS-CoV-2 infection. Two approved antigen tests (Panbio™ from Abbott and Standard Q™ from SD Biosensor), validated by the World Health Organization (WHO), the High Authority of Health (HAH) internationally and locally by the Institut National de Recherche Biomédicale (INRB). A total of 111,278 people suspected of infection were tested during the study period. Of these, 56,846 (51.1%) were diagnosed by RT-PCR, with a positivity rate of 30.2%, while 54,432 (48.9%) were tested by RATs, with a positivity rate of 16.8%. The male gender represented 59 780 (53,7%) and the female gender 51 498 (46,3%), with the estimated mean age at 36.9±15.9 years. The age group ≤ 21 years had the highest rate (19.1%), with a tendency for positivity to increase with age. Females had a slightly higher positivity rate than males (17.1% vs. 16.4%). All Health Zones in Kinshasa had deployed RATs, with the Barumbu Health Zone showing the highest positivity rate (37.8%). Fever (≥ 38°C) was the symptom most frequently associated with RATs positivity (16.5%). All other symptoms, including close contact with a confirmed case, showed a significant association with positivity, with the exception of cough and dyspnea. RATs played a key role in the detection of SARS-CoV-2 during the third and fourth epidemic waves, complementing RT-PCR. These results highlight the relevance of their use in resource-limited settings to improve rapid detection and guide response strategies to emerging or re-emerging respiratory epidemic threats.