Detection of hepatitis A virus genotype IB variants in clams from Maputo Bay, Mozambique.

• Clams provide an important source of food and income for the population of Maputo, Mozambique, where conditions of poor water supply and inadequate sanitation favor endemic infection with hepatitis A virus (HAV). To determine the role of bivalves in an endemic area, clams gathered from Maputo Bay were bought from market and examined for HAV. Four batches, total 150 clams, were sampled over the year. RNA extracted from individual digestive glands was assayed by nested RT-PCR and sequencing of HAV 5' noncoding region (5' NCR). Specific HAV signals were detected in one batch, 23 of 34 clams (67%) testing positive. Phylogenetic analyses of VP3/VP1, VP1/P2A, and 5' NCR determined clustering of clam strains as genotype I, subtype B. In addition to identifying HAV IB strains with predicted conserved amino acid sequence, IB variants exhibiting novel amino acid substitutions at the VP1/P2A junction were detected. HAV strains from clams showed 93%-99% homology with wild-type IB strains from South African outbreaks and from a panel of HAV IgM positive Swedish patients. DNA from enteric human adenovirus 40/41 was found in a limited number of clams from two batches, 6/34 (17%) and 4/35 (11%). Detection of HAV subgenotype IB in bivalves provided indirect evidence of the strains circulating in a densely populated coastal region where HAV is presumed to be hyperendemic. The results suggest that clams may be an important source of HAV in Maputo region, and indicate the need for further molecular study of strains circulating in the indigenous population.

Nyckelord

5' Untranslated Regions

Adenoviruses

Human

genetics

isolation & purification

Amino Acid Sequence

Animals

Base Sequence

Bivalvia

virology

Food Microbiology

Genotype

Hepatitis A virus

classification

genetics

isolation & purification

Humans

Molecular Sequence Data

Mozambique

Mytilus edulis

virology

Phylogeny

RNA

Viral

genetics

isolation & purification

Reverse Transcriptase Polymerase Chain Reaction

Sensitivity and Specificity

Sequence Homology

Amino Acid

Variation (Genetics)

Viral Structural Proteins

genetics

Publikations- och innehållstyp

ref (ämneskategori)

art (ämneskategori)