This study involved 384 patients treated with HD and was screened for anti HCV and tested for HCV RNA and HCV genotypes during January 2010-April 2010. The mean age of the patients was 40.9 ± 5.54 years (age rang15-75 years). 244 were male (mean age 40.4 ± 8.4) and 140 were female (age range 41.7 ± 10.07), 340 patients were married (mean age 42.7 ± 8.03) and 48 were unmarried (mean age 28 ± 4). The mean duration of HD was 6.7 years (range 1-12 years). Change of dialysis centre was noted in twelve patients. Of the total, 112 (29.2%) patients were anti HCV positive; 48 were females (42.85%) and 64 were males (57.14%). HCV RNA was detected in 90 (80.4%) anti HCV positive patients and in 16 (5.9%) anti HCV negative patients. None positive patients had exposure to known HCV-positive persons.
Risk assessment for HCV infection
The frequency distribution of genotypes in relation to age revealed that genotype 3a was most common in nearly all age groups while 3b and 2a were comparatively less frequent. Age group with > 46 years were more affected with mixed genotype while untypable genotype were more common in age group < 45 years. Genotype 3 (a and b) were common in female as compare to male while genotype 1a, untypable and mixed were more common in male as compared to female. Genotype 1b and 4a were found only in male. Prevalence of genotype subtypes within age groups (χ2 = 22.076, p = 0.004) were found significant while gender (χ2 = 42.48, p = 0.0113) and marital status (χ2 = 62.803, p = 0.247) of the patients were not statistically significant.
Mixed genotype was more prevalent in HD patients with history of blood transfusion and barber shops. Mixed and untypable genotype was found significantly more often in HD patients with history of mean number of 2.28 blood transfusions and genotype 3a, 3b and mixed genotype were found more commonly in patients with mean number of 4.61 blood transfusions. IDUs were found with untypable and mixed genotypes only. In patients infected through barber shops, genotype 3a and 2a were more prevalent, followed by 3b and 1a genotypes. The most prevalent risk factor for untypable genotype was found to be dental treatment and barber shop.
Regarding the duration on HD, 42% patients were being dialyzed during 1997-2009 and 58% from 2004-2009 with most prevalent genotypes 3a, 3b and 2a, and untypable and mixed genotypes, respectively.
Discussion
The HCV infection continues to be a major disease burden on the world. For example, the prevalence of HCV antibodies among dialysis patients has been reported to range from: 8 to 36% in North America, 39% in South America, 1 to 54% in Europe, 17 to 51% in Asia1.2 to 10% in New Zealand and Australia. The first description of HCV in Pakistan was recorded in 1992 and about 6%, i.e. at least ten million persons are carriers among a population of 140 million, showed there is no proper review of HCV and it is becoming a Herculean challenge. With the current disease burden, Pakistan has left behind the surrounding countries like India, Nepal, Myanmar, Iran and Afghanistan. HCV gained importance particularly as major complication in multiple transfused patients during the last decades especially in the countries where HCV is more prevalent in general population and amongst the blood donors. This was the first study conducted in patients treated with HD in Pakistan to determine the distribution of HCV genotypes and their interrelation with risk factors. Even though considerable progress has been attained during the last years, HCV prevalence rate among HD patients does not seem to have changed considerably.