First molecular characterization of the hepatitis E virus in humans in Cameroon: Confirmation of the HEV outbreak in Touboro, North‐Cameroon

Abstract

Hepatitis E virus (HEV) is a major causative agent of acute viral hepatitis in many regions of the world including Africa. In Cameroon, there is no published molecular study on HEV in humans. However, based on serological assays, the first outbreak of HEV was detected in North‐Cameroon. The objective of this study was to determine the molecular characterization of HEV that circulated during this period. A retrospective study design was used to select serum samples among those collected during the outbreak period. immunoglobulin M positive samples available in sufficient volumes to amplify HEV RNA were selected. RNA was extracted and then amplified by a real‐time reverse transcription polymerase chain reaction (real time RT‐PCR) assay, followed by a nested reverse transcription polymerase chain reaction (nested RT‐PCR) assay for sequencing and phylogenetic analysis. Overall, 24 samples were selected and HEV RNA was amplified by real‐time RT‐PCR in 20 samples. Amongst these, 12 samples were positive for HEV RNA by nested RT‐PCR and yielded good sequencing products. Phylogenetic analysis showed that 10 samples clustered with HEV genotype 1 (subtype 1e) and two samples clustered with HEV genotype 3 (subtype 3f). This study fills the gap of knowledge on the molecular epidemiology of HEV in Cameroon and confirms the first report of the hepatitis E outbreak in North‐Cameroon.

Hepatitis E outbreak in the health district of Bocaranga-Koui, Central African Republic, 2018–2019

“…Molecular analysis of HEV strains, obtained from infected patients, revealed that genotype 1e was the source of contamination during this epidemic. These results from our phylogenetic analysis are consistent with previous findings regarding the subtypes circulating in the CAR [ 22 , 31 ] and neighboring countries [ 32 , 33 ], and with waterborne transmission usually associated with HEV genotypes 1 and 2. Our genotypes 1e strains formed a cluster which were close to those found in the country during the 2008–2009 outbreak and in neighboring countries [ 22 , 32 , 34 ].…”

“…These results from our phylogenetic analysis are consistent with previous findings regarding the subtypes circulating in the CAR [ 22 , 31 ] and neighboring countries [ 32 , 33 ], and with waterborne transmission usually associated with HEV genotypes 1 and 2. Our genotypes 1e strains formed a cluster which were close to those found in the country during the 2008–2009 outbreak and in neighboring countries [ 22 , 32 , 34 ]. Our results show that HEV evolves very little and has circulated endemically in this area for almost 15 years.…”

“…Although we found HEV in water samples from just one well, it is likely that HEV transmission during this epidemic may have resulted from well water consumption and then amplified by direct human-to-human transmission, as previously demonstrated [ 35 ]. Fecal contamination of tap water as the source of the hepatitis E epidemic has been reported in various studies in regions where HEV is endemic [ 22 , 24 , 32 , 36 ]. The cessation of the epidemic after the distribution of non-food item (NFI) kits, the treatment of water points in the district, and awareness-raising on good hygiene and sanitation practices all support the hypothesis that fecal contamination of water was the source of this epidemic.…”

Hepatitis E virus infections among patients with acute febrile jaundice in two regions of Cameroon: First molecular characterization of hepatitis E virus genotype 4

“…Our study reports for the second time the detection and characterization of HEV RNA in humans in Cameroon. HEV RNA was first detected and characterized in 2020 in a retrospective study that confirmed serological data from the first HEV outbreak which occurred in 2013 [ 11 ]. Two HEV genotypes circulating during this outbreak were identified, namely genotypes 1 (subtype 1e) and 3 (subtype 3f).…”

“…Interestingly, the disease was initially suspected by local health authorities to be a yellow fever (YF) outbreak due to the predominance of jaundice. However, laboratory analysis ruled out yellow fever and identified HEV in 90% of cases, with genotypes 1, 2 and 3 present [ 10 , 11 ]. Since this outbreak, no other HEV outbreak has been reported in the country and little is known about the prevalence and genetic diversity of the HEV among symptomatic patients in Cameroon.…”