The Detection of Influenza Virus Before and During the COVID-19 Pandemic in Cameroon.

BACKGROUND: Influenza and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are both respiratory viruses with similar clinical manifestations and modes of transmission. This study describes influenza data before and during the coronavirus disease pandemic (COVID-19) in Cameroon and SARS-CoV-2 data during the pandemic period. METHODS: The study ran from 2017 to 2022, and data were divided into two periods: before (2017-2019) and during (2020-2022) the COVID-19 pandemic. Nasopharyngeal samples collected from persons with respiratory illness were tested for influenza using the Centers for Disease Control and Prevention (CDC) typing and subtyping assays. During the COVID-19 pandemic, the respiratory specimens were simultaneously tested for SARS-CoV-2 using the DaAn gene protocol or the Abbott real-time SARS-CoV-2 assay. The WHO average curve method was used to compare influenza virus seasonality before and during the pandemic. RESULTS: A total of 6246 samples were tested. Influenza virus detection rates were significantly higher in the pre-pandemic period compared to the pandemic period (30.8% vs. 15.5%; p < 0.001). Meanwhile, the SARS-CoV-2 detection rate was 2.5%. A change in the seasonality of influenza viruses was observed from a bi-annual peak before the pandemic to no clear seasonal pattern during the pandemic. The age groups 2-4 and 5-14 years were significantly associated with higher influenza positivity rates in both pre-pandemic and pandemic periods. For SARS-CoV-2, all age groups above 15 years were the most affected population. CONCLUSION: The COVID-19 pandemic had a significant impact on the seasonal influenza by changing the seasonality of the virus and reducing its detection rates.

Genetic Diversity of Human Respiratory Syncytial Virus during COVID-19 Pandemic in Yaoundé, Cameroon, 2020-2021.

Worldwide, human respiratory syncytial virus (HRSV) is a major cause of severe infections of the lower respiratory system, affecting individuals of all ages. This study investigated the genetic variability of HRSV during the COVID-19 outbreak in Yaoundé; nasopharyngeal samples positive for HRSV were collected from different age groups between July 2020 and October 2021. A semi-nested RT-PCR was performed on the second hypervariable region of the G gene of detected HRSV, followed by sequencing and phylogenetic assessment. Throughout the study, 40 (37.7%) of the 106 HRSV-positive samples successfully underwent G-gene amplification. HRSV A and HRSV B co-circulated at rates of 47.5% and 52.5%, respectively. HRSV A clustered in the GA2.3.5 genetic lineage (ON1) and HRSV B clustered in the GB5.0.5a genetic lineage (BA9). Differences in circulating genotypes were observed between pre- and post-pandemic years for HRSV A. Predictions revealed potential N-glycosylation sites at positions 237-318 of HRSV A and positions 228-232-294 of HRSV B. This study reports the molecular epidemiology of HRSV in Cameroon during the COVID-19 pandemic. It describes the exclusive co-circulation of two genetic lineages. These findings highlight the importance of implementing comprehensive molecular surveillance to prevent the unexpected emergence of other diseases.

Viral co-infection with human respiratory syncytial virus in suspected acute and severe respiratory tract infections during COVID-19 pandemic in Yaoundé, Cameroon, 2020-2021.

BACKGROUND: Acute lower respiratory tract infections (ALRIs) are one one of the leading causes of morbidity and mortality among people of all ages worldwide, particularly in low- and middle-income countries (LMICs). The purpose of this study was to determine epidemiological characteristics of respiratory viruses in acute respiratory infection (ARI) patients during the COVID-19 pandemic in Yaoundé, Cameroon. METHODS: Patients were monitored for respiratory symptoms as part of the surveillance of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and other respiratory viral infections. Patients of all ages with respiratory symptoms less than 5 days were considered. Sociodemographic and clinical data as well as nasopharyngeal samples was collected from patients. Nasopharyngeal samples were tested for SARS-CoV-2, influenza, and respiratory syncytial virus (RSV) using real-time reverse-transcription polymerase chain reaction methods. Virus distribution and demographic data were analyzed with R version 2.15.1. RESULTS: From July 2020 to October 2021, 1120 patients were included. The overall viral detection rate was 32.5%, including 9.5% for RSV, 12.6% for influenza virus and 12.8% for SARS-CoV-2. Co-infections were detected in 6.9% of positive cases. While RSV and influenza virus showed seasonal trends, SARS-CoV-2 was detected throughout the study period. CONCLUSION: We found that during COVID-19 pandemic, respiratory viruses play an important role in etiology of influenza-like illness in Cameroon, and this observation was true for patients of all ages.

Detection of Influenza C Virus Infection among Hospitalized Patients, Cameroon.

We report 3 cases of influenza C virus in children hospitalized with severe acute respiratory infection in Cameroon. Two of these case-patients had grave clinical manifestations, but all 3 recovered. The lack of specific antiviral drugs for influenza C virus highlights the need to identify and describe cases involving this virus.

First documented evidence of dengue and malaria co-infection in children attending two health centers in Yaoundé, Cameroon.

To date, only a few cases of malaria and dengue co-infections have been reported around the world. We describe for the first time in Cameroon, concurrent infections among children (2 to 10 years) in two health centers of Yaoundé. The two dengue strains isolated in Cameroon clustered with the Asian II genotype. Although acute concurrent infections were benign, special attention should be given to malaria and dengue co-infection in order to prevent possible severe cases.

High seroprevalence of hepatitis E among pigs suggests an animal reservoir in Cameroon.

INTRODUCTION: Hepatitis E virus (HEV) is one of the most prevalent cause of acute hepatitis in humans worldwide. The risk of HEV transmission is not limited only to spread from human to human but the infection can also spread from animals to humans, especially from the domestic pigs. Despite mounting evidence regarding the zoonotic potential of porcine HEV infection, there are limited data on its prevalence in pigs in the sub-Sahara Africa region. Therefore, the present study aimed to determine the seroprevalence of HEV antibodies among pigs in two Cameroonian regions. METHODOLOGY: A total of 162 sera were collected from slaughtered-age pigs from January to March 2012. To determine whether pigs might represent a HEV reservoir in the Northern and Western region in Cameroon, anti-HEV IgG and IgM were tested by ELISA using commercials available kits. RESULTS: Overall, 70 of the 162 samples (43.2%, 95% CI: 35.5% - 51.2%) were positive for at least one of the serological markers of HEV infection (IgM and / or IgG).We observed a significant seroprevalence of HEV antibodies between the northern and western regions (60% (42/70) and 40% (28/70), p = 0.01796) respectively. CONCLUSION: Overall, this study reports a high seroprevalence of Hepatitis E virus antibodies in slaughter pigs in Cameroon. Our findings suggest that pigs might be a cause of zoonotic HEV transmission in Cameroon. Therefore, further studies are warranted to establish the dynamics of zoonotic HEV and characterize the different genotypes circulating in humans and pigs.

Sero-epidemiology of human immunodeficiency virus, hepatitis B virus and hepatitis C virus: a cross-sectional survey in a rural setting of the West region of Cameroon.

INTRODUCTION: Human immunodeficiency Virus (HIV), hepatitis B virus (HBV), and hepatitis C virus (HCV) are the three most common chronic viral infections worldwide, specifically in sub-Saharan Africa (SSA). This study aimed to determine the sero-epidemiology of HIV, HBV and HCV infections in a rural setting of the West region of Cameroon, a SSA country. METHODS: We conducted a cross-sectional study from August 2 to 5, 2014 in the three health districts of the Menoua Division, West region of Cameroon. Sixteen villages were randomly selected. Participants were currently living in the Division at the time of the survey, and enrolled after they had provided a signed consent form. HIV screening used the "determine test" followed by Hexagon HIV for positive cases to the first assay. HBV and HCV were detected using DIASpot HBsAg and DIASpot HCV-Ab, respectively. RESULTS: On the whole, 612 subjects consented to take part in this study, of whom 71.1% were females. Mean age of the study population was 45.3 ± 17.9 years. The seroprevalences of HIV, HBV and HCV infections were 1.0% (6/582), 4.5% (20/443) and 6.3% (23/365), respectively. The 41-50 years age group was the most represented among HIV-positive subjects. HBV prevalence was higher in the 21-30 years age group (13.4%), followed by the 51-60 years age group (7.8%), with a significant difference of prevalences among age groups (p = 0.002). All HCV-positive cases were above 40 years of age with a higher prevalence in the > 70 years age group (33.3%) followed by the 61-70 years age group (14.5%); there was a significant difference between the age groups (p = 0.001). CONCLUSION: The seroprevalences of HIV, HBV and HCV infections in the Menoua Division of the West region of Cameroon were 1.0%, 4.5% and 6.3%, respectively. Preventive measures against these health threats need to be reinforced in this setting.