Publications by authors named "Njouom Richard"

Article Synopsis
  • The study examined SARS-CoV-2 immunity in Cameroon from August 2021 to September 2022, assessing changes in antibody levels, mortality rates, and vaccination.
  • Seroprevalence surged from 11.2% to nearly 60% while COVID-19-related deaths dropped dramatically, indicating improved immunity without a corresponding rise in vaccinations.
  • The findings suggest that high vaccination rates may not be necessary for controlling outbreaks in Africa, urging policymakers to consider local research for better epidemic management strategies.
View Article and Find Full Text PDF

This study presents a retrospective assessment of the diagnostic performance of the newly developed hepatitis B core-related antigen rapid diagnostic test (HBcrAg-RDT) in detecting plasma samples with elevated hepatitis B virus (HBV) DNA levels (≥200,000 IU/ml) in Yaoundé, Cameroon. Samples were collected consecutively from treatment-naïve adults living with HBV between January 1, 2021, and June 30, 2023. Analyzing 146 samples from participants with a median age of 36 years, the HBcrAg-RDT exhibited a sensitivity of 97.

View Article and Find Full Text PDF

Rabies is a viral zoonosis that causes an estimated 60,000 human deaths each year, mainly in Africa and Asia. The etiological agent of rabies, the Rabies Lyssavirus or Rabies Virus (RABV) has been characterized in dog populations in Cameroon, in previous studies. However, the dynamics of RABV maintenance and propagation in dogs are still to be documented in Cameroon.

View Article and Find Full Text PDF
Article Synopsis
  • * A study conducted in six universities from June to October 2022 used antigen rapid diagnostic tests to identify SARS-CoV-2 cases and assess participants' knowledge and attitudes towards COVID-19.
  • * Out of 7,006 participants, only 0.8% tested positive for SARS-CoV-2, revealing gaps in COVID-19 precautions like mask-wearing and social distancing that could contribute to virus spread on campuses.
View Article and Find Full Text PDF

On August 14, 2024, following a regional declaration by the Africa Centres for Disease Control and Prevention, the World Health Organization declared mpox a Public Health Emergency of International Concern, marking the second such declaration in two years. A series of outbreaks involving the more virulent clade I virus (compared to clade II, which caused a global outbreak in 2022), has now spread in 13 African countries, exposing the inadequacies of the public health infrastructure in these settings. There was significant investment during the 2022 global outbreak, but these efforts failed to address vaccine access and treatment in the Global South.

View Article and Find Full Text PDF

During the COVID-19 pandemic, the need for making testing readily available was recognized as an important factor for individuals to help make informed decisions, including to isolate or seek care, and for policymakers to control transmission. Toward this end, FIND and the Access to COVID-19 Tools Accelerator funded 16 rapid operational research studies and one implementation project in Africa, the Caribbean, and Asia evaluating the utility, acceptability, and feasibility of different community-based SARS-CoV-2 testing approaches. Here, we discuss common factors and challenges encountered during study implementation.

View Article and Find Full Text PDF
Article Synopsis
  • The Central African Republic (CAR) is experiencing a significant HIV epidemic with diverse and unique strains, particularly atypical non-M HIV-1 strains.
  • In a study analyzing over 6,000 HIV-positive samples, researchers identified six rare atypical strains, including three HIV-1 group O and three HIV-2 strains, each linked to different years and areas.
  • The findings stress that while HIV-1/M remains the most prevalent type in CAR, the presence of rare strains highlights the necessity for updated surveillance and management practices to address the challenges posed by HIV's genetic diversity.
View Article and Find Full Text PDF

Background: Formal assessment of a surveillance system's features and its ability to achieve objectives is crucial for disease control and prevention. Since the implementation of the mpox surveillance system in Cameroon, no evaluation has been conducted.

Methods: In a cross-sectional study, we assessed the performance of the mpox surveillance system in accordance with the Centers for Disease Control and Prevention (CDC) and World Health Organization (WHO) guidelines.

View Article and Find Full Text PDF

While treatment options for hepatitis C virus (HCV) infection have expanded considerably over the past decade thanks to the development of pan-genotypic therapies, genotype testing remains a prerequisite for treatment in sub-Saharan African countries, including Cameroon, where multiple HCV genotypes and subtypes exist. The main objective of this study was to describe the trend in the distribution of HCV genotypes and subtypes from 2013 to 2023 in the Cameroonian population. Viral loads were determined using the Abbott real-time assay, and genotyping/subtyping was based on nested and semi-nested reverse transcription polymerase chain reaction (RT-PCR) amplification of the regions encoding the core and non-structural protein 5B (NS5B) regions, respectively, followed by sequencing and phylogenetic analysis.

View Article and Find Full Text PDF

Introduction: Community Advisory Boards (CABs) play an important role in developing and delivering patient-centered care. However, the impact of participation on CAB members has not been well studied, particularly on the global scale. In 2022, the Hepatitis B Foundation (HBF) convened the first global hepatitis B and hepatitis delta CAB with 23 members from 17 countries, representing six out of the seven World Health Organization (WHO) regions, and countries with the largest hepatitis B and hepatitis delta disease burden.

View Article and Find Full Text PDF
Article Synopsis
  • - High seroreactivities to Ebola (EBOV) and Sudan (SUDV) orthoebolavirus antigens were found in rural populations of Cameroon, particularly among Pygmies, despite no reported outbreaks.
  • - The study did not find a direct link between the risk of NHP (nonhuman primates) bites and seroreactivity, but indicated that exposure may vary among different ethnic groups.
  • - These findings suggest a possible silent circulation of orthoebolaviruses or other unknown filoviruses in forested regions, emphasizing the need for increased surveillance and research in these areas.
View Article and Find Full Text PDF
Article Synopsis
  • The epidemiology and ecology of Mycobacterium ulcerans (MU) infections are not well understood, especially regarding disease burden, host range, and transmission methods.
  • A review of 155 articles from various countries showed MU's presence in humans, animals, plants, and environmental samples, with prevalence rates varying widely.
  • Significant gaps exist in understanding the viability of MU in non-human reservoirs, prompting a need for further research on its transmission routes and host interactions.
View Article and Find Full Text PDF

Introduction: Global monitoring of severe acute respiratory syndrome related coronavirus 2 (SARS-CoV-2) genetic sequences and associated metadata is essential for coronavirus disease 2019 (COVID-19) response. Therefore, Sanger's partial genome sequencing technique was used to monitor the circulating variants of SARS-CoV-2 in Cameroon.

Methodology: Nasopharyngeal specimen was collected from persons suspected of SARS-CoV-2 following the national guidelines between January and December 2021.

View Article and Find Full Text PDF

Background: Respiratory syncytial virus (RSV) is one of the major pathogens frequently associated with severe respiratory tract infections in younger children and older adults globally. There is an unmet need with a lack of routine country-specific databases and/or RSV surveillance systems on RSV disease burden among adults in most low- and middle-income countries, including Cameroon. We aim to estimate the adult RSV burden needed to develop a framework for establishing an RSV surveillance database in Cameroon.

View Article and Find Full Text PDF
Article Synopsis
  • - The study examined the presence and genetic diversity of Human Parechoviruses (HPeVs) in 200 children under 15 with Acute Flaccid Paralysis (AFP) in Cameroon from 2018 to 2019.
  • - HPeV RNA was found in 11% of the stool samples, with specific genotypes (A1, A4, A5, A10, A14, A15, A17, and A18) identified through advanced genetic sequencing.
  • - Results indicated significant genetic variability among the HPeVs detected, suggesting multiple genotypes circulate in Cameroon without associated outbreaks.
View Article and Find Full Text PDF

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.

View Article and Find Full Text PDF

Background: The 2022 African Cup of Nations (AFCON) took place in Cameroon from January 9th to February 5th, 2022, including Garoua in the north. We aimed to measure the impact of this event on the local COVID-19 epidemic given the implementation of a preventive strategy based on a health pass.

Methods: All players, staff and fans involved in the AFCON event were screened with PCR tests.

View Article and Find Full Text PDF

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.

View Article and Find Full Text PDF

Objectives: Widespread testing and treatment are essential to eliminate hepatitis B virus (HBV) infection as a public health concern. However, in resource-limited countries, access to HBV PCR is limited. In this study, we developed a quantitative HBV PCR assay on open molecular platforms and evaluate its performance in diagnosing clinically significant HBV DNA thresholds as defined by the WHO (2000 IU/mL, 20 000 IU/mL, and 200 000 IU/mL).

View Article and Find Full Text PDF

Background: Sub-Saharan African countries have a high burden of viral hepatitis and poor access to screening and care. The aim of this study was to evaluate the feasibility and acceptability of using the plasma separation card (PSC) for viral hepatitis B and C screening among people living with HIV (PLHIV) in Cameroon and Uganda.

Methods: This is a cross-sectional study carried out between 05/2021 and 03/2023 including 192 PLHIV in Cameroon (n = 104) and Uganda (n = 88).

View Article and Find Full Text PDF

Background: Hepatitis E virus (HEV) is a major cause of enterotropic viral hepatitis, a major public health problem in many developing countries. In Central African Republic (CAR), HEV genotypes 1, 2, and 3 have been found to have an impact on human health. However, data on HEV in animal reservoirs are still lacking for CAR.

View Article and Find Full Text PDF

Introduction: Poliovirus (PV) and non-polio enteroviruses (NPEV) belong to the Picornaviridae family. They are found worldwide and are responsible for a wide range of diseases such as acute flaccid paralysis (AFP). This study aimed to evaluate the detection rate of PV and NPEV in stool samples from children under fifteen years of age presenting with AFP in Cameroon and their distribution over time.

View Article and Find Full Text PDF

Background: Febrile jaundice is a common indicator of certain infectious diseases, including hepatitis E. In Cameroon, the yellow fever virus is the only pathogen that is monitored in patients who present with this symptom. However, more than 90% of the samples received as part of this surveillance are negative for yellow fever.

View Article and Find Full Text PDF

Background: Healthcare workers (HWs) are at a high risk of exposure to emerging health threats. Following the first wave of the coronavirus disease 2019 pandemic in Cameroon, we explored the presence and persistence of naturally acquired antibodies against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and the factors associated with seropositivity in HWs.

Methods: Staff at two referral hospitals in Yaoundé or two Health District Hospitals in Obala and Mbalmayo were included in a 6-month prospective cohort analysis or cross-sectional survey, respectively.

View Article and Find Full Text PDF