Objective: The exact mode of hepatitis C virus (HCV) transfer remains elusive in a vast majority of cases. We examined the possibility of non-conventional transmission of HCV by person-to-person contact.
Method: A questionnaire based, prospective study was conducted at Pakistan Institute of Medical Sciences (PIMS) from July-October, 2006. Patients with compensated chronic hepatitis B (CHB) &/or C (CHC) were registered for 6 month interferon (IFN) therapy. All candidates furnished information about age, gender and mode of transmission. The unanswered queries were interpreted as "missing data". After omission of cases with hepatitis B virus (HBV) infection alone, the remaining persons included in the present study were placed in: Group-A: Multifactorial transfer involving conventional (blood borne) and non-conventional modes; Group-B: Unifactorial transfer by non-conventional routes only; Group-C: No identifiable risk factor. Unlike conventional routes, the non-conventional modes represented likelihood of CHB &/or CHC by exposure to household contacts, to persons with hepatic cirrhosis and during traveling.
Results: Initially, 879 patients (mean age: 35.52 +/- 9.1 years) were registered. After exclusion of 25 subjects with HBV infection only, the remaining 854 were included. Of 854 cases, 830 (97.18%) were infected with HCV and 24 (2.81%) had co-infection with HBV & HCV. According to the mode(s) of transmission, Group-A: 515 (60.30%); Group-B: 136 (15.92%) and Group-C: 203 (23.77%) cases were identified. Dental treatment: 278 (32.55%) was the commonest conventional risk factor in Group-A. The non-conventional transfer of HCV in Group-A was mainly suggested by household contact: 222 (25.99%). Groups-A and -B combined, the sum of any non-conventional risk factor was comparable with and even higher than the leading haematogenous routes in Group-A. Groups-B and -C combined, HCV infection in 339 patients (39.69%) was apparently acquired by non-conventional modes, most probably by person-to-person interaction.
Conclusion: Non-conventional transmission of HCV is a genuine possibility which is currently underestimated.