Publications by authors named "Martial Yonga"
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.
Article Synopsis
- Nigeria and Cameroon reported their first mpox cases in over 30 years starting in 2017 and 2018, with Nigeria's outbreak recognized as a human epidemic.
- The study focused on understanding the zoonotic transmission dynamics of the mpox virus across the Nigeria-Cameroon border, revealing ongoing cases driven by a new Clade IIb.1 lineage and highlighting significant cross-border viral spread.
- The findings indicate that southern Nigeria is likely the origin of the mpox epidemic, with evidence of a zoonotic precursor lineage present in local animal populations for over 45 years, emphasizing the persistent risk of MPXV emergence in both countries.
During 1979-2022, Cameroon recorded 32 laboratory-confirmed mpox cases among 137 suspected mpox cases identified by the national surveillance network. The highest positivity rate occurred in 2022, indicating potential mpox re-emergence in Cameroon. Both clade I (n = 12) and clade II (n = 18) monkeypox virus (MPXV) were reported, a unique feature of mpox in Cameroon.
View Article and Find Full Text PDFBackground: The re-emergence of yellow fever poses a serious public health risk to unimmunized communities in the tropical regions of Africa and South America and unvaccinated travelers visiting these regions. This risk is further accentuated by the likely spread of the virus to areas with potential for yellow fever transmission such as in Asia, Europe, and North America. To mitigate this risk, surveillance of yellow fever is pivotal.
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- The study sequenced part of the E1 envelope protein gene from two chikungunya virus (CHIKV) samples collected during the 2020 outbreak in Chad.
- Phylogenetic analysis indicated that the viruses were part of the East/Central/South African genotype and did not have specific mutations known for enhancing adaptability and transmission.
- The findings provide important genetic information that can help monitor the evolution of the virus in future outbreaks in the region.
A monkeypox virus was detected from a human clinical case in 2018 in Cameroon; a country where no human cases were reported since 1989. The virus exhibited close genetic relatedness with another monkeypox virus isolated in Nigeria during the 2017-2018 outbreak. Although our molecular findings argue in favor of an extension of the monkeypox outbreak from Nigeria into Cameroon, the possibility that the monkeypox virus detected could be indigenous to Cameroon cannot be ruled out.
View Article and Find Full Text PDFBackground: Measles virus (MeV) is monotypic, but genetic variation in the hemagglutinin H and nucleoprotein N genes can be analyzed by molecular epidemiologic techniques and used to study virus transmission patterns. The World Health Organization currently recognizes 8 clades (A-H) within which are 24 genotypes of MeV and one provisional genotype, d11. Genotype B3 is clearly the endemic genotype in most of African continent where it is widely distributed.
View Article and Find Full Text PDFThere was an outbreak of cholera in Cameroon during 2004 and 2005; the epidemic began in Douala in January 2004 and spread throughout the south of the country. The World Health Organization (WHO) reported 8005 cases in 2004 and 2847 cases in 2005. Five hundred eighty-nine stool samples were received in the Pasteur Centre of Cameroon and 352 were microbiologically confirmed to be positive for Vibrio cholerae O1.
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