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. 2019;8(1):186-196.
doi: 10.1080/22221751.2018.1564631.

Evidence of exposure and human seroconversion during an outbreak of avian influenza A(H5N1) among poultry in Cameroon

Chavely Gwladys Monamele  1 , Phalla Y  2 , Erik Albert Karlsson  2 , Marie-Astrid Vernet  1 , Abel Wade  3 , Marie-Claire Assoumou Okomo  4 , Aristide Stéphane Abah Abah  5 , Sokhoun Yann  2 , Georges Alain Mballa Etoundi  5 , Njankouo Ripa Mohamadou  1 , Jean-Marc Feussom  3 , Sreyviseth Horm  2 , Paul Francis Horwood  2   6 , Sowath Ly  7 , Richard Njouom  1 , Philippe Dussart  2
Affiliations

Evidence of exposure and human seroconversion during an outbreak of avian influenza A(H5N1) among poultry in Cameroon

Chavely Gwladys Monamele et al. Emerg Microbes Infect. 2019.

Abstract

From May 2016 to March 2017, 22 poultry outbreaks of avian influenza A(H5N1) were reported in Cameroon, mainly in poultry farms and live bird markets. No human cases were reported. In this study, we sought to describe the 2016 A(H5N1) outbreak strain and to investigate the risk of infection in exposed individuals. We find that highly pathogenic influenza subtype A(H5N1), clade 2.3.2.1c from Cameroon is closely related phylogenetically and antigenically to strains isolated in central and western Africa at the time. No molecular markers of increased human transmissibility were noted; however, seroconversion was detected in two poultry workers (1.5% of total screened). Therefore, the continued outbreaks of avian influenza in poultry and the risk of zoonotic human infection highlight the crucial need for continued and vigilant influenza surveillance and research in Africa, especially in areas of high poultry trade, such as Cameroon.

Keywords: Africa; Avian influenza; Cameroon; H5N1; Zoonoses; outbreak; surveillance.

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Figures

Figure 1.
Figure 1.
Map of poultry and human sampling sites in Cameroon. Sites where sampling took place for avian influenza prevalence and exposure are indicated on the map of Cameroon in central Africa. Blue squares represent poultry sampling locations. Red stars indicate human sampling locations.
Figure 2.
Figure 2.
Phylogenetic analysis of the A(H5N1) haemagglutinin (HA) genes from representative viruses from Cameroon (A). The phylogenetic tree was generated using the maximum-likelihood method. Bootstrap values (n = 500) > 70 are shown. Scale bars indicate substitutions per site. Sequences from representative Cameroonian strains included in the study are indicated in bold and italic. Other control strains are indicated in bold. Representative Cameroonian isolates used in the study for antigenic analysis are indicated with black stars while control strains are indicated with black circles. Amino acid differences determined in representative strains as compared to other clade 2.3.2.1c HA genes are indicated in red on the model (B). Positions are stated under H5 numbering.
Figure 3.
Figure 3.
Phylogenetic analysis of the A(H5N1) neuraminidase (NA) genes from representative viruses from Cameroon. The phylogenetic tree was generated using the maximum-likelihood method. Bootstrap values (n = 500) > 70 are shown. Scale bars indicate substitutions per site. Sequences from representative Cameroonian strains included in the study are indicated in bold and italic. Other control strains are indicated in bold. Representative Cameroonian isolates used for antigenic analysis are indicated with black stars while control strains are indicated with black circles.
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