A STUDY OF HEPATITIS C VIRUS AND ITS MOLECULAR EPIDEMIOLOGY IN THE LOCAL POPULATION OF THE FAISALABAD REGION

Hepatitis C virus (HVC) is a major health problem worldwide and almost more than 39% population of the world is infected with HCV. HCV is present in the blood at extremely low level (Li et al., 1995) and the routine serological tests are not so sensitive to detect HCV in the samples tested. Thus the detection of HCV more accurately is done by molecular methods and PCR based detection in this regard is important, as it is more sensitive and specific. Present study was taken in order to find the incidence/prevalence of HCV infection and its genotypes in the local population of this area and also to find if any relationship existed between HCV infections and clinically diagnosed diabetic mellitus type-II cases. For this purpose, 2000 sample at random, from suspected HCV patients having some common symptoms of hepatitis were recruited for this study from various localities of Faisalabad region such as Jhang, Gojra, Toba Tek Singh, Jaranwala and Chiniot, along with 300 samples from general population, 100 samples from the Diabetics, 60 samples from non-Diabetics as control and 97 samples from HCV patients taking combined (interferon + ribazole) therapy. The results indicated that among the suspected HCV cases, 90.6% subjects were found to be anti-HCV Elisa positive. When these samples were retested through RT-PCR, 87.25% samples were found to be HCV-RNA positive, indicating a difference 3.35% between these two tests. The samples that were Elisa positive but PCR negative may be an indication of past infection or resolved cases still Elisa Positive. It was further found that HCV infection was more prevalent in the persons of age groups of 31 years to 50 years which are more prone to risk factors involved in its transmission. In case of subjects who were on combined therapy (interferon + Ribazol) for at least 3 months to 1 year, out 97 samples, 94 (95.87%) were found still anti-HCV positive while only 19.58% subjects wee found RT-PCR positive, indicating importance and superiority of molecular testing over serological methods especially, in therapy cases, for monitoring response rate of the medicine. In case of general population, out of 300 subjects tested, 20.6% were anti-HCV positive while 28% were RT-PCR positive, indicating higher prevalence of HCV infection in general population of the area. In general population samples, higher number of RT-PCR positive samples were found than diagnosed by anti-HCV testing, indicating new or very recent cases of infection, which were not yet seroconverted. It is also an alarming and dangerous situation, required urgent attention as more cases from general population are getting fresh HCV infection. One hundred diabetic subjects were also tested along with 60 non-diabetics and anti-HCV negative as control. Here again higher prevalence of HCV was found in diabetics as compared to the control group, indicating positive relation between HCV infection and diabetes mellitus type-II disease. Alanine aminotransferase (ALT), a marker of liver injury/damage was also checked for all the categories of the subjects tested. Generally good relation between RT-PCR positive subjects with higher ALT level was noted, although in certain case, important contradictions or discrepancies were noted where ALT level were higher, evening the absence of HCV-RNA or vice versa. HCV genotypes are considered important in its management or treatment. So HCV genotypes were also determined in some (n=120) of the HCV-RNA positive subjects by dot blot hybridization in suspected cases only while through PCR-RFLP analysis in 580 suspected cases, 84 HCV-RNA positive subjects from general population and 97 subjects on combined therapy before the initiation of therapy. It was noted that HCV genotype-3 was the most prevalent genotype in the area. It is a sign of some relief as considered that it is more responsive or sensitive against the anti-viral therapy. Response rate of the therapy against HCV genotypes was also checked. Although the results in this regard are very preliminary and no final conclusion can be drawn from the data and needed more follow-up studies for longer period but generally good response rate of the therapy in all the three HCV genotypes (type-1, type-2 and type-3) along with significant number of un-typed samples was noted. HCV genotype-3 seemed to be relatively more responsive to the therapy than other types prevalent in the area. So it may be concluded from the study that the area seemed to be very hot area as far as HCV incidence/prevalence is considered and its increasing infection to the general population is alarming. It requires urgent attention of the concerned authorities to take preventive measures. RT-PCR is very important for early diagnosis of HCV infection as well as for monitoring antiviral therapy response. HCV genotype-3 is the most prevalent type found in the area and relatively higher anti-viral response with combined therapy was noted in subjects infected with this type. Lastly relatively more incidence of HCV infection was noted in clinically known cases of diabetic mellitus-II than control.