Information regarding hepatitis C virus genotypes and subtypes circulating in Pakistan and various risk factors for their transmission are not known well. The specific objective of this study was to find out the frequency of various HCV genotypes present in well-characterized Pakistani HCV isolates and their possible routes of contamination.
Method: A total of 3351 serum samples were tested by type-specific genotyping assay. Out of 3351 HCV RNA positive patients, 2039 were males and 1312 were females.
The 2165 genotyped patients belonged to Punjab region, 823 patients to North West Frontier Province, 239 to Sindh and 124 patients were from Balochistan.
Results: Out of the total 3351 tested serum samples, type-specific PCR fragments were observed in 3150 (94.00%) serum samples.
The distribution of genotypes of the 3150 typable samples as determined by this assay, was as follows: 280 (8.35%) patients were infected with HCV genotype 1a, 101 (3.01%) with genotype 1b, 5 (0.15%) with 1c, 252 (7.52%) with subtype 2a, 27 (0.80%) with subtype 2b, 3 (0.09%) were with type 2c, 1664 (49.05%) with subtype 3a, 592 (17.66%) with genotype 3b, 25 (0.75%) were with 3c, 50 (2%) with genotype 4, 6 (0.18%) with subtype 5a, 4 (0.12%) with subtype 6a and 161 (4.80%) patients were infected with mixed infection. Two hundred and one (6.00%) serum samples were found untypable by the present genotyping system.
More than 86% and 72% patients with genotypes 3a and 3b respectively had received multiple injections in past. For genotypes 1a and 1b the route of contamination was major/minor surgery along with unknown reasons.
Majority of the cases with type 2a, 2b and indeterminate genotypes were sporadic. Mixed infections were common in thalassaemic patients.
Conclusion: The most common HCV genotype in Pakistan is type 3a. Regional difference in genotypes was observed only in Balochistan province of Pakistan.
More than 70% of the cases were acquired in hospitals through reuse of needles/syringes and major/minor surgery that is very common in this country.
Author: Muhammad Idrees and Sheikh Riazuddin
Credits/Source: BMC Infectious Diseases 2008, 8:69
