Journal Article > ResearchFull Text
Medical Research Archives. 24 January 2025; Volume 13 (Issue 1); 1-12.; DOI:10.18103/mra.v13i1.6155
Otshudiema J, Essomba R, Diagne M, Bitoungui V, Ebogo Y, et al.
Medical Research Archives. 24 January 2025; Volume 13 (Issue 1); 1-12.; DOI:10.18103/mra.v13i1.6155
BACKGROUND
Two sub variants (BA.4 and BA.5) of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Omicron variant are concerning as they are spreading rapidly worldwide; however, no published data concerning these variants are available in Cameroon. We report the early detection of these new sub variants that are associated with the onset of the fifth wave of coronavirus 2019 (COVID-19) in Cameroon.
METHODS
Positive samples were selected for next-generation sequencing (NGS). BA.4 and BA.5 complete genome sequences underwent sequence data analysis, epidemiology analysis of COVID-19’s resurgence and wave, recombination and pairwise matrix analysis, and phylogenetic analysis. We selected the first nine SARS-CoV-2 Omicron BA.4 and BA.5 sub variants detected in Cameroon using local whole genome sequencing for the NGS analysis.
RESULTS
During the fifth wave of resurgence of COVID-19 cases in Cameroon, it was found that the Northwest and Littoral regions were the most affected areas, while the Center and Littoral regions recorded the highest number of new deaths. The study identified evidence of recombination between the BA.2 sub variant and BA.4 and BA.5 Cameroonian strains. This result highlights the dynamic nature of SARS-CoV-2 evolution. The BA.5 strain (entitled hCoV-19/Cameroon/23850/2022) showed the highest sequence similarity to the first reported genome of the Omicron strain with 497 mutations. Phylogenetic analysis revealed that these nine Omicron sub variants were grouped into a distinct and highly distant cluster separate from the first Omicron variant detected in Botswana and were intermixed with sequences from other countries (the United States, Denmark, Scotland, and England), thus implying multiple introductions of the BA.4 and BA.5 sub variants in Cameroon.
CONCLUSIONS
Omicron BA.4 and BA.5 sub-lineages are associated with the onset of the fifth wave of COVID-19 in Cameroon. In addition to providing early warning of COVID-19 resurgence, continuous local genome sequencing of emerging variants is essential for detecting variants of concern, thereby guiding the country's response. This study emphasizes the value of real-time surveillance.
Conference Material > Poster
Eyong J, Fai KN, Nikolay B, Gignoux EM, Nsaibirini R, et al.
Epicentre Scientific Day 2024. 23 May 2024
Français
Journal Article > ResearchFull Text
Sci Rep. 8 December 2023; Volume 13 (Issue 1); 21654.; DOI:10.1038/s41598-023-48773-3
Fokam J, Essomba RG, Njouom R, Okomo MCA, Eyangoh S, et al.
Sci Rep. 8 December 2023; Volume 13 (Issue 1); 21654.; DOI:10.1038/s41598-023-48773-3
While the SARS-CoV-2 dynamic has been described globally, there is a lack of data from Sub-Saharan Africa. We herein report the dynamics of SARS-CoV-2 lineages from March 2020 to March 2022 in Cameroon. Of the 760 whole-genome sequences successfully generated by the national genomic surveillance network, 74% were viral sub-lineages of origin and non-variants of concern, 15% Delta, 6% Omicron, 3% Alpha and 2% Beta variants. The pandemic was driven by SARS-CoV-2 lineages of origin in wave 1 (16 weeks, 2.3% CFR), the Alpha and Beta variants in wave 2 (21 weeks, 1.6% CFR), Delta variants in wave 3 (11 weeks, 2.0% CFR), and omicron variants in wave 4 (8 weeks, 0.73% CFR), with a declining trend over time (p = 0.01208). Even though SARS-CoV-2 heterogeneity did not seemingly contribute to the breadth of transmission, the viral lineages of origin and especially the Delta variants appeared as drivers of COVID-19 severity in Cameroon.
Journal Article > ResearchFull Text
Sci Afr. 4 October 2023; Online ahead of print; e01925.; DOI:10.1016/j.sciaf.2023.e01925
Eyong J, Fai KN, Nikolay B, Gignoux EM, Nsaibirini R, et al.
Sci Afr. 4 October 2023; Online ahead of print; e01925.; DOI:10.1016/j.sciaf.2023.e01925
BACKGROUND
Although the first year of the COVID-19 pandemic in Africa did not produce the expected catastrophe, the true impact of COVID-19 in the Cameroonian population was unclear. We therefore assessed the seroprevalence of anti-SARS-CoV-2 antibodies and retrospective mortality in a representative sample of the general population in the 10 administrative regions of Cameroon more than one year after the first confirmed cases of COVID-19 in these regions. We aimed to assess the extent of SARS-COV-2 infection and to detect potential increases in the crude mortality rate (CMR) during the SARS-COV-2 pandemic phase.
METHODS
We assessed retrospective mortality and seroprevalence of anti-SARS-CoV-2 antibodies in the 10 capital cities of Cameroon using representative samples of the general population. The study included nested anti-SARS-CoV-2 antibody prevalence surveys and retrospective mortality surveys and was conducted between 27 July 2021 and 31 August 2021. To further analyse crude mortality rates by age group and COVID wave, pre-pandemic and pandemic periods were stratified. Both laboratory-based assays (ELFA) and rapid diagnostic tests (RDT) were used to measure anti-SARS-CoV-2 seroprevalence.
RESULTS
The crude mortality rate (CMR) increased from 0.06 deaths per 10 000 persons per day (pre-pandemic) to 0.17 deaths per 10 000 persons per day (pandemic). The increase in CMR was more pronounced in people aged 20-35 years (pre-pandemic 0.02 deaths per 10 000 persons per day; pandemic 0.06 deaths per 10 000 persons per day). The estimated seroprevalence among unvaccinated persons was 9.5% (RDT) and 15.4% (laboratory-based).
CONCLUSION
The seroprevalence results showed that cases were significantly underdetected by the national surveillance systems.
Although the first year of the COVID-19 pandemic in Africa did not produce the expected catastrophe, the true impact of COVID-19 in the Cameroonian population was unclear. We therefore assessed the seroprevalence of anti-SARS-CoV-2 antibodies and retrospective mortality in a representative sample of the general population in the 10 administrative regions of Cameroon more than one year after the first confirmed cases of COVID-19 in these regions. We aimed to assess the extent of SARS-COV-2 infection and to detect potential increases in the crude mortality rate (CMR) during the SARS-COV-2 pandemic phase.
METHODS
We assessed retrospective mortality and seroprevalence of anti-SARS-CoV-2 antibodies in the 10 capital cities of Cameroon using representative samples of the general population. The study included nested anti-SARS-CoV-2 antibody prevalence surveys and retrospective mortality surveys and was conducted between 27 July 2021 and 31 August 2021. To further analyse crude mortality rates by age group and COVID wave, pre-pandemic and pandemic periods were stratified. Both laboratory-based assays (ELFA) and rapid diagnostic tests (RDT) were used to measure anti-SARS-CoV-2 seroprevalence.
RESULTS
The crude mortality rate (CMR) increased from 0.06 deaths per 10 000 persons per day (pre-pandemic) to 0.17 deaths per 10 000 persons per day (pandemic). The increase in CMR was more pronounced in people aged 20-35 years (pre-pandemic 0.02 deaths per 10 000 persons per day; pandemic 0.06 deaths per 10 000 persons per day). The estimated seroprevalence among unvaccinated persons was 9.5% (RDT) and 15.4% (laboratory-based).
CONCLUSION
The seroprevalence results showed that cases were significantly underdetected by the national surveillance systems.
Journal Article > ResearchFull Text
Sci Afr. 1 July 2021; Volume 12; e00802.; DOI:10.1016/j.sciaf.2021.e00802
Fai KN, Corine TM, Bebell LM, Mbroingong AB, Nguimbis EBPT, et al.
Sci Afr. 1 July 2021; Volume 12; e00802.; DOI:10.1016/j.sciaf.2021.e00802
Official case counts suggest Africa has not seen the expected burden of COVID-19 as predicted by international health agencies, and the proportion of asymptomatic patients, disease severity, and mortality burden differ significantly in Africa from what has been observed elsewhere. Testing for SARS-CoV-2 was extremely limited early in the pandemic and likely led to under-reporting of cases leaving important gaps in our understanding of transmission and disease characteristics in the African context. SARS-CoV-2 antibody prevalence and serologic response data could help quantify the burden of COVID-19 disease in Africa to address this knowledge gap and guide future outbreak response, adapted to the local context. However, such data are widely lacking in Africa. We conducted a cross-sectional seroprevalence survey among 1,192 individuals seeking COVID-19 screening and testing in central Cameroon using the Innovita antibody-based rapid diagnostic. Overall immunoglobulin prevalence was 32%, IgM prevalence was 20%, and IgG prevalence was 24%. IgM positivity gradually increased, peaking around symptom day 20. IgG positivity was similar, gradually increasing over the first 10 days of symptoms, then increasing rapidly to 30 days and beyond. These findings highlight the importance of diagnostic testing and asymptomatic SARS-CoV-2 transmission in Cameroon, which likely resulted in artificially low case counts. Rapid antibody tests are a useful diagnostic modality for seroprevalence surveys and infection diagnosis starting 5-7 days after symptom onset. These results represent the first step towards better understanding the SARS-CoV-2 immunological response in African populations.
Journal Article > ResearchFull Text
PLoS Negl Trop Dis. 19 December 2007; Volume 1 (Issue 3); DOI:10.1371/journal.pntd.0000101
Pouillot R, Matias G, Wondje CM, Portaels F, Valin N, et al.
PLoS Negl Trop Dis. 19 December 2007; Volume 1 (Issue 3); DOI:10.1371/journal.pntd.0000101
BACKGROUND: Buruli ulcer is an infectious disease involving the skin, caused by Mycobacterium ulcerans. This disease is associated with areas where the water is slow-flowing or stagnant. However, the exact mechanism of transmission of the bacillus and the development of the disease through human activities is unknown. METHODOLOGY/PRINCIPAL FINDINGS: A case-control study to identify Buruli ulcer risk factors in Cameroon compared case-patients with community-matched controls on one hand and family-matched controls on the other hand. Risk factors identified by the community-matched study (including 163 pairs) were: having a low level of education, swamp wading, wearing short, lower-body clothing while farming, living near a cocoa plantation or woods, using adhesive bandages when hurt, and using mosquito coils. Protective factors were: using bed nets, washing clothes, and using leaves as traditional treatment or rubbing alcohol when hurt. The family-matched study (including 118 pairs) corroborated the significance of education level, use of bed nets, and treatment with leaves. CONCLUSIONS/SIGNIFICANCE: Covering limbs during farming activities is confirmed as a protective factor guarding against Buruli ulcer disease, but newly identified factors including wound treatment and use of bed nets may provide new insight into the unknown mode of transmission of M. ulcerans or the development of the disease.
Journal Article > ResearchFull Text
PLoS Negl Trop Dis. 23 June 2009; Volume 3 (Issue 6); DOI:10.1371/journal.pntd.0000466
Porten K, Sailor K, Comte E, Njikap A, Sobry A, et al.
PLoS Negl Trop Dis. 23 June 2009; Volume 3 (Issue 6); DOI:10.1371/journal.pntd.0000466
BACKGROUND: Buruli ulcer (BU) is a chronic, indolent necrotizing disease of the skin and underlying tissues caused by Mycobacterium ulcerans, which may result in functional incapacity. In 2002, Médecins Sans Frontières (MSF) opened a BU programme in Akonolinga Hospital, Cameroon, offering antibiotic treatment, surgery and general medical care. Six hundred patients have been treated in the project to date. However, due to the nature of the disease and its stigmatization, determining the exact prevalence and burden of disease is difficult and current estimates may not reflect the magnitude of the problem. The objectives of this survey were to estimate the prevalence of BU in the health district of Akonolinga, describe the geographic extension of the highly endemic area within the health district, and determine the programme coverage and its geographical distribution. METHODOLOGY/PRINCIPAL FINDINGS: We conducted a cross-sectional population survey using centric systematic area sampling (CSAS). A 15x15 km grid (quadrats of 225 km(2)) was overlaid on a map of Akonolinga district with its position chosen to maximize the area covered by the survey. Quadrats were selected if more than 50% of the quadrat was inside of the health district. The chiefdom located closest to the centre of each quadrat was selected and Buruli cases were identified using an active case finding strategy (the sensitivity of the strategy was estimated by capture-recapture). WHO-case definitions were used for nodules, plaque, ulcer, oedema and sequelae. Out of a total population of 103,000 inhabitants, 26,679 were surveyed within the twenty quadrats. Sensitivity of the case finding strategy was estimated to be 84% (95%CI 54-97%). The overall prevalence was 0.47% (n = 105) for all cases including sequelae and 0.25% (n = 56) for active stages of the disease. Five quadrats had a high prevalence of >0.6% to 0.9%, 5 a prevalence >0.3% to 0.6% and 10 quadrats <0.3%. The quadrats with the high prevalence were situated along the rivers Nyong and Mfoumou. Overall coverage of the project was 18% (12-27%) for all cases and 16% (9-18%) for active cases, but was limited to the quadrats neighbouring Akonolinga Hospital. CONCLUSIONS/SIGNIFICANCE: Prevalence was highest in the area neighbouring the Nyong River. Coverage was limited to the area close to the hospital and efforts have to be made to increase access to care in the high prevalence areas. Use of the CSAS method was particularly useful for project planning and to identify priority areas of intervention. An added benefit of the method is that the survey procedure incorporated an awareness campaign, providing information about the disease and treatment to the population.
Journal Article > CommentaryFull Text
Lancet Infect Dis. 12 April 2021; Volume 21 (Issue 9); 1194-1195.; DOI:10.1016/S1473-3099(21)00197-3
Boum Y II, Eyangoh S, Okomo MC
Lancet Infect Dis. 12 April 2021; Volume 21 (Issue 9); 1194-1195.; DOI:10.1016/S1473-3099(21)00197-3
Journal Article > ResearchFull Text
Microbiol Resour Announc. 11 March 2021; Volume 10 (Issue 10); e00093-21.; DOI:10.1128/MRA.00093-21
Njouom R, Sadeuh-Mba SA, Tchatcheung J, Diagne MM, Dia N, et al.
Microbiol Resour Announc. 11 March 2021; Volume 10 (Issue 10); e00093-21.; DOI:10.1128/MRA.00093-21
We describe the coding-complete genome sequence of a severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) strain obtained in Cameroon from a 58-year-old French patient who arrived from France on 24 February 2020. Phylogenetic analysis showed that this virus, named hCoV-19/Cameroon/1958-CMR-YAO/2020, belongs to lineage B.1.5 and is closely related to an isolate from France.
Journal Article > Pre-PrintFull Text
Res Sq. 2 February 2021; DOI:10.21203/rs.3.rs-156679/v1
Buri D, Njuwa FK, Matchim L, Akendji B, Eteki L, et al.
Res Sq. 2 February 2021; DOI:10.21203/rs.3.rs-156679/v1
BACKGROUND
Infection with SARS-CoV-2 can lead to a detectable serological immune response even though extent of its protection is still not yet well known. We report long duration and resurgence of SARS-CoV-2 in patients with COVID-19.
METHODS
We included a cohort of 99 participants from our non-blinded non-randomized evaluation of COVID-19 tests in Cameroon. Demographic and clinical information was collected from participants including self-reported age, race, ethnicity, and gender. Qualitative data was described as proportions while quantitative data was described with means and accompanying ranges.
RESULTS
Duration of PCR for SARS-CoV-2 positivity was found to range from 4 – 81 days, with mean duration of 32.8 days in patients with PCR-positive. We also identified 4 participants who also had SARS-CoV-2 resurgence within a three-month period.
CONCLUSION
These observations raise questions on clinical decision to release COVID-19 cases from isolation after 14 days.
Infection with SARS-CoV-2 can lead to a detectable serological immune response even though extent of its protection is still not yet well known. We report long duration and resurgence of SARS-CoV-2 in patients with COVID-19.
METHODS
We included a cohort of 99 participants from our non-blinded non-randomized evaluation of COVID-19 tests in Cameroon. Demographic and clinical information was collected from participants including self-reported age, race, ethnicity, and gender. Qualitative data was described as proportions while quantitative data was described with means and accompanying ranges.
RESULTS
Duration of PCR for SARS-CoV-2 positivity was found to range from 4 – 81 days, with mean duration of 32.8 days in patients with PCR-positive. We also identified 4 participants who also had SARS-CoV-2 resurgence within a three-month period.
CONCLUSION
These observations raise questions on clinical decision to release COVID-19 cases from isolation after 14 days.