Molecular characterization of hepatitis B virus among chronic hepatitis B patients from Pointe Noire, Republic of Congo

Brunel Monic Angounda; Gildas Hoffman Ngouloubi; Amélia Bokilo Dzia; Luc Magloire Anicet Boumba; Warda Baha; Donatien Moukassa; Gabriel Ahombo; Moulay Mustapha Ennaji; Jean-Rosaire Ibara

doi:10.1186/s13027-016-0088-3

Molecular characterization of hepatitis B virus among chronic hepatitis B patients from Pointe Noire, Republic of Congo

Infect Agent Cancer. 2016 Sep 15:11:51. doi: 10.1186/s13027-016-0088-3. eCollection 2016.

Authors

Brunel Monic Angounda^{1

2

3}, Gildas Hoffman Ngouloubi⁴, Amélia Bokilo Dzia^{1

5}, Luc Magloire Anicet Boumba^{3

5

6}, Warda Baha³, Donatien Moukassa^{5

6}, Gabriel Ahombo², Moulay Mustapha Ennaji^#³, Jean-Rosaire Ibara^#⁵

Affiliations

¹ Laboratory of screening of the transmitted infectious diseases, National Blood Transfusion Centre, Brazzaville, Republic of Congo.
² Cellular and Molecular Biology Laboratory, Faculty of Science and Technology, University Marien NGOUABI, Brazzaville, Congo.
³ Laboratory of Virology, Microbiology, Quality and Biotechnologies/Eco-toxicology and biodiversity, Virology Team, Cancerology, Quality and Medical Biotechnology, Faculty of Science and Techniques Mohammedia University Hassan II of Casablanca, BP: 146, Mohammedia, 20650 Morocco.
⁴ Gastroenterology, Adolphe Sice Hospital, Pointe Noire, Republic of Congo.
⁵ Faculty of Health Sciences, University Marien NGOUABI, Brazzaville, Congo.
⁶ General Laondjili Hospital, Pointe-Noire, Congo.

^# Contributed equally.

Abstract

Background: Chronic Hepatitis B infection is a major health problem in Republic of Congo therefore molecular analysis of HBV strains is important to detect the patients at high risk of disease progression.

Methods: Serum samples were obtained from 111 chronic HBV patients in Pointe Noire. HBsAg, HBeAg and HBeAb were detected. A fragment of the preS1 region of HBV was amplified and sequenced to determine genotypes, subgenotypes and to identify mutations.

Results: Of the 111 samples analyzed, 35 patients were asymptomatic carriers (ASC), 24 with a chronic active hepatitis (CAH), 33 with liver cirrhosis (LC) and 19 have a hepatocellular carcinoma (HCC). The mean age were 45 ± 13 year, 88 (79.3 %) were male and 23 (20.7 %) female. The prevalence of HBeAg was 15.3 % and 73 % of subjects were anti-HBe positive. The mean serum level of alanine aminotransferase transaminase (ALT) and aspartate transaminase (AST) was 25.1 ± 9 IU/L and 28.6 ± 10 IU/L respectively. Eighty two samples out of 111 (73.9 %) were genotyped by the analyzing of the S region of HBV, 58 (70.7 %) cases belonged to HBV genotype E and 24 (29.3 %) were genotype A with three subgenotypes; A3 (66.7 %), A4 (20.8 %) and A6 (12.5 %). Prevalence of genotype A was relatively high in CAH (33.3 %) and HCC (31.6 %) patients in comparison with other groups. The most prevalent amino acids substitutions were R38K found in 14 (17.1 %) sequences, following by H44L in 11 (13.4 %), K13E in 8 (9.8 %), N29K in 8 (9.8 %), A35E in 8 (9.8 %), V80I in 7 (8.5 %) and in 6 (7.3 %) sequences for S90T. Different substitutions located in the hepatocyte binding site were higher among patients with LC and HCC (p < 0.05).

Conclusions: This study have shown that HBV genotype E and A were the most frequent strains circulating in Republic of Congo patients. HBV pres1 substitutions found in this study were associated with severe clinical forms of liver diseases. This data have shown the importance of implementing an effective program to fight HBV infection.

Keywords: Chronic; Genotypes; Hepatitis B Virus; Phylogenetics.