Rhabdomyolysis, acute kidney injury, and mortality in Ebola virus disease: retrospective analysis of cases from Eastern Democratic Republic of the Congo, 2019.

BACKGROUND: Skeletal muscle injury in Ebola virus disease (EVD) has been reported, but its association with morbidity and mortality remains poorly defined. METHODS: Retrospective study of patients admitted to two EVD Treatment Units, over an eight-month period in 2019, during a large EVD epidemic in the Democratic Republic of the Congo. RESULTS: 333 patients (median age 30 years, 58% female) had at least one creatine kinase (CK) measurement (total 2,229 CK measurements, median 5 (IQR 1-11) per patient). 271 patients (81%) had an elevated CK (>380U/L), 202 (61%) had rhabdomyolysis (CK>1,000 IU/L), and 45 (14%) had severe rhabdomyolysis (≥5,000U/L). Among survivors, the maximum CK level was median 1,600 (IQR 550 to 3,400), peaking 3.4 days after admission (IQR 2.3 to 5.5) and decreasing thereafter. Among fatal cases, the CK rose monotonically until death, with maximum CK level of median 2,900 U/L (IQR 1,500 to 4,900). Rhabdomyolysis at admission was an independent predictor of AKI (aOR 2.2 [95%CI 1.2-3.8], p=0.0065) and mortality (aHR 1.7 [95%CI 1.03-2.9], p=0.037). CONCLUSIONS: Rhabdomyolysis is associated with AKI and mortality in EVD patients. These findings may inform clinical practice by identifying lab monitoring priorities and highlighting the importance of fluid management.

U.S. Preparedness and Response to Increasing Clade I Mpox Cases in the Democratic Republic of the Congo - United States, 2024.

Clade I monkeypox virus (MPXV), which can cause severe illness in more people than clade II MPXVs, is endemic in the Democratic Republic of the Congo (DRC), but the country has experienced an increase in suspected cases during 2023-2024. In light of the 2022 global outbreak of clade II mpox, the increase in suspected clade I cases in DRC raises concerns that the virus could spread to other countries and underscores the importance of coordinated, urgent global action to support DRC's efforts to contain the virus. To date, no cases of clade I mpox have been detected outside of countries in Central Africa where the virus is endemic. CDC and other partners are working to support DRC's response. In addition, CDC is enhancing U.S. preparedness by raising awareness, strengthening surveillance, expanding diagnostic testing capacity for clade I MPXV, ensuring appropriate specimen handling and waste management, emphasizing the importance of appropriate medical treatment, and communicating guidance on the recommended contact tracing, containment, behavior modification, and vaccination strategies.

Co-Circulating Monkeypox and Swinepox Viruses, Democratic Republic of the Congo, 2022.

In September 2022, deaths of pigs manifesting pox-like lesions caused by swinepox virus were reported in Tshuapa Province, Democratic Republic of the Congo. Two human mpox cases were found concurrently in the surrounding community. Specific diagnostics and robust sequencing are needed to characterize multiple poxviruses and prevent potential poxvirus transmission.

Lower Limb Paralysis Associated with Chikungunya in Kinshasa, the Democratic Republic of the Congo: Survey Report.

Polio-associated paralysis is one of the diseases under national surveillance in the Democratic Republic of the Congo (DRC). Although it has become relatively rare due to control measures, non-polio paralysis cases are still reported and constitute a real problem, especially for etiological diagnosis, which is necessary for better management and response. From September 2022 to April 2023, we investigated acute flaccid paralysis (AFP) cases in Kinshasa following an alert from the Provincial Division of Health. All suspected cases and their close contacts were investigated and sampled. Among the 57 sampled patients, 21 (36.8%) were suspects, and 36 (63.2%) were contacts. We performed several etiological tests available in the laboratory, targeting viruses, including Poliovirus, Influenza virus, SARS-CoV-2, Enterovirus, and arboviruses. No virus material was detected, but the serological test (ELISA) detected antibodies against Chikungunya Virus, i.e., 47.4% (27/57) for IgM and 22.8% (13/57) for IgG. Among suspected cases, we detected 33.3% (7/21) with anti-Chikungunya IgM and 14.3% (3/21) of anti-Chikungunya IgG. These results highlight the importance of enhancing the epidemiological surveillance of Chikungunya.

Impact of Ebola epidemics on the daily operation of existing systems in Eastern Democratic Republic of the Congo: a brief review.

AIMS: to provide insights into the recent Ebola virus disease (EVD) outbreaks on different aspects of daily life in the Democratic Republic of the Congo and propose possible solutions. METHODS: We collected information regarding the effects of EVD outbreaks on existing systems in the eastern part of the Democratic Republic of the Congo (DRC). We searched the PubMed database using the terms "impact effect Ebola outbreak system", "Management Ebola Poor Resources Settings", "Health Economic Challenges Ebola" and "Economic impact Ebola systems." Only studies focusing on epidemiology, diagnostics, sequencing, vaccination, therapeutics, ecology, work force, governance, healthcare provision and health system, and social, political, and economic aspects were considered. The search included the electronic archives of EVD outbreak reports from government and partners. RESULTS: EVD outbreaks negatively impacts the functions of countries. The disruption in activities is proportional to the magnitude of the epidemic and slows down the transport of goods, decreases the region's tourist appeal, and increases 'brain drain'. Most low- and medium-income countries, such as the DRC, do not have a long-term holistic emergency plan for unexpected situations or sufficient resources to adequately implement countermeasures against EVD outbreaks. Although the DRC has acquired sufficient expertise in diagnostics, genomic sequencing, administration of vaccines and therapeutics, clinical trials, and research activities, deployment, operation, and maintenance of these expertise and associated tools remains a concern. LIMITATIONS: Despite the data search extension, additional reports addressing issues related to social aspects of EVD outbreaks in DRC were not retrieved. CONCLUSION: National leadership has not yet taken the lead in strategic, operational, or financial aspects. Therefore, national leaders should double their efforts and awareness to encourage local fundraising, sufficient budget al.location, infrastructure construction, equipment provision, and staff training, to effectively support a holistic approach in response to outbreaks, providing effective results, and all types of research activities.

2020 Ebola virus disease outbreak in Équateur Province, Democratic Republic of the Congo: a retrospective genomic characterisation.

BACKGROUND: The Democratic Republic of the Congo has had 15 Ebola virus disease (EVD) outbreaks, from 1976 to 2023. On June 1, 2020, the Democratic Republic of the Congo declared an outbreak of EVD in the western Équateur Province (11th outbreak), proximal to the 2018 Tumba and Bikoro outbreak and concurrent with an outbreak in the eastern Nord Kivu Province. In this Article, we assessed whether the 11th outbreak was genetically related to previous or concurrent EVD outbreaks and connected available epidemiological and genetic data to identify sources of possible zoonotic spillover, uncover additional unreported cases of nosocomial transmission, and provide a deeper investigation into the 11th outbreak. METHODS: We analysed epidemiological factors from the 11th EVD outbreak to identify patient characteristics, epidemiological links, and transmission modes to explore virus spread through space, time, and age groups in the Équateur Province, Democratic Republic of the Congo. Trained field investigators and health professionals recorded data on suspected, probable, and confirmed cases, including demographic characteristics, possible exposures, symptom onset and signs and symptoms, and potentially exposed contacts. We used blood samples from individuals who were live suspected cases and oral swabs from individuals who were deceased to diagnose EVD. We applied whole-genome sequencing of 87 available Ebola virus genomes (from 130 individuals with EVD between May 19 and Sept 16, 2020), phylogenetic divergence versus time, and Bayesian reconstruction of phylogenetic trees to calculate viral substitution rates and study viral evolution. We linked the available epidemiological and genetic datasets to conduct a genomic and epidemiological study of the 11th EVD outbreak. FINDINGS: Between May 19 and Sept 16, 2020, 130 EVD (119 confirmed and 11 probable) cases were reported across 13 Équateur Province health zones. The individual identified as the index case reported frequent consumption of bat meat, suggesting the outbreak started due to zoonotic spillover. Sequencing revealed two circulating Ebola virus variants associated with this outbreak-a Mbandaka variant associated with the majority (97%) of cases and a Tumba-like variant with similarity to the ninth EVD outbreak in 2018. The Tumba-like variant exhibited a reduced substitution rate, suggesting transmission from a previous survivor of EVD. INTERPRETATION: Integrating genetic and epidemiological data allowed for investigative fact-checking and verified patient-reported sources of possible zoonotic spillover. These results demonstrate that rapid genetic sequencing combined with epidemiological data can inform responders of the mechanisms of viral spread, uncover novel transmission modes, and provide a deeper understanding of the outbreak, which is ultimately needed for infection prevention and control during outbreaks. FUNDING: WHO and US Centers for Disease Control and Prevention.

Effect of anti-Ebola virus monoclonal antibodies on endogenous antibody production in survivors of Ebola virus disease in the Democratic Republic of the Congo: an observational cohort study.

BACKGROUND: The use of specific anti-Ebola virus therapy, especially monoclonal antibodies, has improved survival in patients with Ebola virus disease. We aimed to assess the effect of monoclonal antibodies on anti-Ebola virus antibody responses in survivors of the 2018-20 Ebola outbreak in the Democratic Republic of the Congo. METHODS: In this observational prospective cohort study, participants were enrolled at three Ebola survivor clinics in Beni, Mangina, and Butembo (Democratic Republic of the Congo). Eligible children and adults notified as survivors of Ebola virus disease (ie, who had confirmed Ebola virus disease [RT-PCR positive in blood sample] and were subsequently declared recovered from the virus [RT-PCR negative in blood sample] with a certificate of recovery from Ebola virus disease issued by an Ebola treatment centre) during the 2018-20 Ebola virus disease outbreak were invited to participate in the study. Participants were recruited on discharge from Ebola treatment centres and followed up for 12-18 months depending on recruitment date. Routine follow-up assessments were done at 1, 3, 6, and 12-18 months after inclusion. We collected sociodemographic (age, sex, visit site), clinical (anti-Ebola virus drugs), and laboratory data (RT-PCR and Ct values). The primary outcome was the antibody concentrations against Ebola virus glycoprotein, nucleoprotein, and 40-kDa viral protein antigens over time assessed in all participants. Antibody concentrations were measured by the multiplex immunoassay, and the association between anti-Ebola virus antibody levels and the relevant exposures, such as anti-Ebola virus disease drugs (ansuvimab, REGN-EB3, ZMapp, or remdesivir), was assessed using both linear and logistic mixed regression models. This study is registered at ClinicalTrials.gov, NCT04409405. FINDINGS: Between April 16, 2020, and Oct 18, 2021, 1168 survivors were invited to participate in the Les Vainqueurs d'Ebola cohort study. 787 survivors were included in the study, of whom 358 had data available for antibody responses. 85 (24%) of 358 were seronegative for at least two Ebola virus antigens on discharge from the Ebola treatment centre. The antibody response over time fluctuated but a continuous decrease in an overall linear evolution was observed. Quantitative modelling showed a decrease in nucleoprotein, glycoprotein, and VP-40 antibody concentrations over time (p<0·0001) with the fastest decrease observed for glycoprotein. The probability of being seropositive for at least two antigens after 36 months was 53·6% (95% CI 51·6-55·6) for participants who received ansuvimab, 73·5% (71·5-75·5) for participants who received REGN-EB3, 76·8% (74·8-78·8) for participants who received remdesivir, and 78·5% (76·5-80·5) for participants who received ZMapp. INTERPRETATION: Almost a quarter of survivors were seronegative on discharge from the Ebola treatment centre and antibody concentrations decreased rapidly over time. These results indicate that monoclonal antibodies might negatively affect the production of anti-Ebola virus antibodies in survivors of Ebola virus disease which could increase the risk of reinfection or reactivation. FUNDING: The French National Agency for AIDS Research-Emergent Infectious Diseases-The French National Institute of Health and Medical Research, the French National Research Institute for Development, and the European and Developing Countries Clinical Trials Partnership. TRANSLATION: For the French translation of the abstract see Supplementary Materials section.

Clade I-Associated Mpox Cases Associated with Sexual Contact, the Democratic Republic of the Congo.

We report a cluster of clade I monkeypox virus infections linked to sexual contact in the Democratic Republic of the Congo. Case investigations resulted in 5 reverse transcription PCR-confirmed infections; genome sequencing suggest they belonged to the same transmission chain. This finding demonstrates that mpox transmission through sexual contact extends beyond clade IIb.

A premature newborn born to an adolescent girl with acute Ebola virus disease and malaria survives in a resource-limited setting in an Ebola treatment unit in DR Congo: "A case report".

Key Clinical Message: In the acute phase of Ebola virus disease (EVD) premature neonatal survival is extremely rare. High mortality is related to prematurity, neonatal complications of Ebola, and precarious conditions of neonatal care in underresourced ETUs. This is a case of preterm neonatal survival in the setting of acute maternal EVD infection. Abstract: This case describes rare preterm newborn survival in the setting of an Ebola treatment unit in Eastern DRC. The neonate was born vaginally to an acutely ill 17-year-old mother who was vaccinated against Ebola virus after being identified as a contact of her father, who was a confirmed case and who did not survive his infection. This woman was admitted to an Ebola treatment unit at 32 weeks of gestation and given monoclonal antibody treatment. She gave birth vaginally, succumbing to postpartum hemorrhage 14 h after delivery. This child survived despite compounding vulnerabilities of preterm birth and maternal Ebola infection. Despite a negative test for EVD, the neonate was given a single dose of monoclonal antibody therapy in the first days of life. We believe maternal vaccination and neonatal monoclonal antibody treatment contributed to the child's survival. The circumstances surrounding neonatal survival in this extremely resource-limited context must be analyzed and disseminated in order to increase rates of neonatal and maternal survival in future outbreaks. Maternal and neonatal health are critical aspects of outbreak response that have been understudied and underreported leaving clinicians severely underresourced to provide life-saving care in outbreak settings. Pregnancy and childbirth do not stop in times of disease outbreak, adequate equipment and trained staff required for quality neonatal care must be considered in future outbreak responses.

Cost-effectiveness of incorporating Ebola prediction score tools and rapid diagnostic tests into a screening algorithm: A decision analytic model.

BACKGROUND: No distinctive clinical signs of Ebola virus disease (EVD) have prompted the development of rapid screening tools or called for a new approach to screening suspected Ebola cases. New screening approaches require evidence of clinical benefit and economic efficiency. As of now, no evidence or defined algorithm exists. OBJECTIVE: To evaluate, from a healthcare perspective, the efficiency of incorporating Ebola prediction scores and rapid diagnostic tests into the EVD screening algorithm during an outbreak. METHODS: We collected data on rapid diagnostic tests (RDTs) and prediction scores' accuracy measurements, e.g., sensitivity and specificity, and the cost of case management and RDT screening in EVD suspect cases. The overall cost of healthcare services (PPE, procedure time, and standard-of-care (SOC) costs) per suspected patient and diagnostic confirmation of EVD were calculated. We also collected the EVD prevalence among suspects from the literature. We created an analytical decision model to assess the efficiency of eight screening strategies: 1) Screening suspect cases with the WHO case definition for Ebola suspects, 2) Screening suspect cases with the ECPS at -3 points of cut-off, 3) Screening suspect cases with the ECPS as a joint test, 4) Screening suspect cases with the ECPS as a conditional test, 5) Screening suspect cases with the WHO case definition, then QuickNavi™-Ebola RDT, 6) Screening suspect cases with the ECPS at -3 points of cut-off and QuickNavi™-Ebola RDT, 7) Screening suspect cases with the ECPS as a conditional test and QuickNavi™-Ebola RDT, and 8) Screening suspect cases with the ECPS as a joint test and QuickNavi™-Ebola RDT. We performed a cost-effectiveness analysis to identify an algorithm that minimizes the cost per patient correctly classified. We performed a one-way and probabilistic sensitivity analysis to test the robustness of our findings. RESULTS: Our analysis found dual ECPS as a conditional test with the QuickNavi™-Ebola RDT algorithm to be the most cost-effective screening algorithm for EVD, with an effectiveness of 0.86. The cost-effectiveness ratio was 106.7 USD per patient correctly classified. The following algorithms, the ECPS as a conditional test with an effectiveness of 0.80 and an efficiency of 111.5 USD per patient correctly classified and the ECPS as a joint test with the QuickNavi™-Ebola RDT algorithm with an effectiveness of 0.81 and a cost-effectiveness ratio of 131.5 USD per patient correctly classified. These findings were sensitive to variations in the prevalence of EVD in suspected population and the sensitivity of the QuickNavi™-Ebola RDT. CONCLUSIONS: Findings from this study showed that prediction scores and RDT could improve Ebola screening. The use of the ECPS as a conditional test algorithm and the dual ECPS as a conditional test and then the QuickNavi™-Ebola RDT algorithm are the best screening choices because they are more efficient and lower the number of confirmation tests and overall care costs during an EBOV epidemic.

Exploring host-virus interaction to improve immunotherapy against Ebola virus.

Recent immunological advances have led to the development of FDA-approved immunotherapies against Ebola virus (EBOV). However, patients with high viral loads have not seen as large a benefit as mild cases. Here we discuss areas of investigation that may lead to adjunctive immune therapy for patients with severe EBOV disease.

Extensive Survey and Analysis of Factors Associated with Presence of Antibodies to Orthoebolaviruses in Bats from West and Central Africa.

The seroprevalence to orthoebolaviruses was studied in 9594 bats (5972 frugivorous and 3622 insectivorous) from Cameroon, the Democratic Republic of Congo (DRC) and Guinea, with a Luminex-based serological assay including recombinant antigens of four orthoebolavirus species. Seroprevalence is expressed as a range according to different cut-off calculations. Between 6.1% and 18.9% bat samples reacted with at least one orthoebolavirus antigen; the highest reactivity was seen with Glycoprotein (GP) antigens. Seroprevalence varied per species and was higher in frugivorous than insectivorous bats; 9.1-27.5% versus 1.3-4.6%, respectively. Seroprevalence in male (13.5%) and female (14.4%) bats was only slightly different and was higher in adults (14.9%) versus juveniles (9.4%) (p < 0.001). Moreover, seroprevalence was highest in subadults (45.4%) when compared to mature adults (19.2%), (p < 0.001). Our data suggest orthoebolavirus circulation is highest in young bats. More long-term studies are needed to identify birthing pulses for the different bat species in diverse geographic regions and to increase the chances of detecting viral RNA in order to document the genetic diversity of filoviruses in bats and their pathogenic potential for humans. Frugivorous bats seem more likely to be reservoirs of orthoebolaviruses, but the role of insectivorous bats has also to be further examined.

Congenital Mpox Syndrome (Clade I) in Stillborn Fetus after Placental Infection and Intrauterine Transmission, Democratic Republic of the Congo, 2008.

We report the autopsy pathology findings of a 21-week stillborn fetus with congenital mpox syndrome that occurred in the Democratic Republic of the Congo in 2008. The fetus acquired mpox from the mother after intrauterine transplacental monkeypox virus transmission. We confirmed monkeypox virus infection in the mother, fetus, and placenta by using a monkeypox virus-specific quantitative PCR. Subtyping of the virus was not performed, but the mother and fetus were almost certainly infected with the clade I variant that was endemic in the Democratic Republic of the Congo at the time. Risk for intrauterine infection appears to differ between virus clades, but clinicians should be aware of potential for intrauterine monkeypox virus transmission among pregnant persons during ongoing and future mpox outbreaks.

Sensitive poliovirus detection using nested PCR and nanopore sequencing: a prospective validation study.

Timely detection of outbreaks is needed for poliovirus eradication, but gold standard detection in the Democratic Republic of the Congo takes 30 days (median). Direct molecular detection and nanopore sequencing (DDNS) of poliovirus in stool samples is a promising fast method. Here we report prospective testing of stool samples from suspected polio cases, and their contacts, in the Democratic Republic of the Congo between 10 August 2021 and 4 February 2022. DDNS detected polioviruses in 62/2,339 (2.7%) of samples, while gold standard combination of cell culture, quantitative PCR and Sanger sequencing detected polioviruses in 51/2,339 (2.2%) of the same samples. DDNS provided case confirmation in 7 days (median) in routine surveillance conditions. DDNS enabled confirmation of three serotype 2 circulating vaccine-derived poliovirus outbreaks 23 days (mean) earlier (range 6-30 days) than the gold standard method. The mean sequence similarity between sequences obtained by the two methods was 99.98%. Our data confirm the feasibility of implementing DDNS in a national poliovirus laboratory.

The Human Mpox Global Outbreak: Available Control Tools and the Opportunity to Break a Cycle of Neglect in Endemic Countries.

The 2022 global outbreak of human Mpox (formerly monkeypox) virus (MPXV) infection outside of the usual endemic zones in Africa challenged our understanding of the virus's natural history, transmission dynamics, and risk factors. This outbreak has highlighted the need for diagnostics, vaccines, therapeutics, and implementation research, all of which require more substantial investments in equitable collaborative partnerships. Global multidisciplinary networks need to tackle MPXV and other neglected emerging and reemerging zoonotic pathogens to address them locally and prevent or quickly control their worldwide spread. Political endorsement from individual countries and financial commitments to maintain control efforts will be essential for long-term sustainability.

Emergence of mpox in the post-smallpox era-a narrative review on mpox epidemiology.

BACKGROUND: The 2022 mpox outbreak drew global attention to this neglected pathogen. While most of the world was taken by surprise, some countries have seen this pathogen emerge and become endemic several decades prior to this epidemic. OBJECTIVES: This narrative review provides an overview of mpox epidemiology since its discovery through the 2022 global outbreak. SOURCES: We searched PubMed for relevant literature about mpox epidemiology and transmission through 28 February 2023. CONTENT: The emergence of human mpox is intertwined with the eradication of smallpox and the cessation of the global smallpox vaccination campaign. The first human clade I and II monkeypox virus (MPXV) infections were reported as zoonoses in Central and West Africa, respectively, around 1970 with sporadic infections reported throughout the rest of the decade. Over the next five decades, Clade I MPXV was more common and caused outbreaks of increasing size and frequency, mainly in the Democratic Republic of the Congo. Clade II MPXV was rarely observed, until its re-emergence and ongoing transmission in Nigeria, since 2017. Both clades showed a shift from zoonotic to human-to-human transmission, with potential transmission through sexual contact being observed in Nigeria. In 2022, clade II MPXV caused a large human outbreak which to date has caused over 86,000 cases in 110 countries, with strong evidence of transmission during sexual contact. By February 2023, the global epidemic has waned in most countries, but endemic regions continue to suffer from mpox. IMPLICATIONS: The changing epidemiology of mpox demonstrates how neglected zoonosis turned into a global health threat within a few decades. Thus, mpox pathophysiology and transmission dynamics need to be further investigated, and preventive and therapeutic interventions need to be evaluated. Outbreak response systems need to be strengthened and sustained in endemic regions to reduce the global threat of mpox.

Use of Mpox Multiplex Serology in the Identification of Cases and Outbreak Investigations in the Democratic Republic of the Congo (DRC).

Human Mpox cases are increasingly reported in Africa, with the highest burden in the Democratic Republic of Congo (DRC). While case reporting on a clinical basis can overestimate infection rates, laboratory confirmation by PCR can underestimate them, especially on suboptimal samples like blood, commonly used in DRC. Here we used a Luminex-based assay to evaluate whether antibody testing can be complementary to confirm cases and to identify human transmission chains during outbreak investigations. We used left-over blood samples from 463 patients, collected during 174 outbreaks between 2013 and 2022, with corresponding Mpox and VZV PCR results. In total, 157 (33.9%) samples were orthopox-PCR positive and classified as Mpox+; 124 (26.8%) had antibodies to at least one of the three Mpox peptides. The proportion of antibody positive samples was significantly higher in Mpox positive samples (36.9%) versus negative (21.6%) (p < 0.001). By combining PCR and serology, 66 additional patients were identified, leading to an Mpox infection rate of 48.2% (223/463) versus 33.9% when only PCR positivity is considered. Mpox infections were as such identified in 14 additional health zones and 23 additional outbreaks (111/174 (63.8%) versus 88/174 (50.6%)). Our findings highlight the urgent need of rapid on-site diagnostics to circumvent Mpox spread.

Seroprevalence of SARS-CoV-2 antibodies and retrospective mortality in two African settings: Lubumbashi, Democratic Republic of the Congo and Abidjan, Côte d'Ivoire.

Although seroprevalence studies have demonstrated the wide circulation of SARS-COV-2 in African countries, the impact on population health in these settings is still poorly understood. Using representative samples of the general population, we evaluated retrospective mortality and seroprevalence of anti-SARS-CoV-2 antibodies in Lubumbashi and Abidjan. The studies included retrospective mortality surveys and nested anti-SARS-CoV-2 antibody prevalence surveys. In Lubumbashi the study took place during April-May 2021 and in Abidjan the survey was implemented in two phases: July-August 2021 and October-November 2021. Crude mortality rates were stratified between pre-pandemic and pandemic periods and further investigated by age group and COVID waves. Anti-SARS-CoV-2 seroprevalence was quantified by rapid diagnostic testing (RDT) and laboratory-based testing (ELISA in Lubumbashi and ECLIA in Abidjan). In Lubumbashi, the crude mortality rate (CMR) increased from 0.08 deaths per 10 000 persons per day (pre-pandemic) to 0.20 deaths per 10 000 persons per day (pandemic period). Increases were particularly pronounced among <5 years old. In Abidjan, no overall increase was observed during the pandemic period (pre-pandemic: 0.05 deaths per 10 000 persons per day; pandemic: 0.07 deaths per 10 000 persons per day). However, an increase was observed during the third wave (0.11 deaths per 10 000 persons per day). The estimated seroprevalence in Lubumbashi was 15.7% (RDT) and 43.2% (laboratory-based). In Abidjan, the estimated seroprevalence was 17.4% (RDT) and 72.9% (laboratory-based) during the first phase of the survey and 38.8% (RDT) and 82.2% (laboratory-based) during the second phase of the survey. Although circulation of SARS-CoV-2 seems to have been extensive in both settings, the public health impact varied. The increases, particularly among the youngest age group, suggest indirect impacts of COVID and the pandemic on population health. The seroprevalence results confirmed substantial underdetection of cases through the national surveillance systems.