These health education efforts may have reduced the risk of HCV transmission by needle sticks in all three communities. an average of 1.3 years. None Sofosbuvir impurity A of the 25 incident cases were jaundiced or had symptoms of hepatitis but elevated serum alanine aminotransferase levels confirmed hepatitis in nine. Our data suggest that asymptomatic HCV infections frequently occurred during the perinatal period but often cleared and that educating medical personnel on safe practices possibly reduced HCV transmission. = CD40LG 373, 10.9%), anti-HCV only (= 166, 4.9%) or HCV-RNA only (= 11, 0.3%) were excluded, as well as those with incomplete follow-up data (= 688). The 2171 subjects in the cohort were seen during their second or third trimester of pregnancy and asked to return two months post-partum and yearly thereafter until their child was five years old; 365 women had a second pregnancy and 23 had a third pregnancy during follow up. For the first pregnancy, 2073 women were seen at the two-month visit; 1330, 919, 630, 427 and 303 attended the one-, two-, three-, four- and five-year visits, respectively. For the second Sofosbuvir impurity A pregnancy, 278 attended the two-month visit, while 193, 124, 53, 31 and five attended one-, two-, three-, four- and five-year follow up. Fifteen, eight and one woman attended the two-month visit and one- and two-year visits following their third pregnancy, respectively. This provided a total of 4814 person-years (PY) of follow up. The women answered a detailed questionnaire at enrolment about socio-demographic characteristics, as well as behavioural and environmental risk factors for acquiring HCV infection. Additional data were gathered at the first post-partum visit about the delivery process and outcome. An 810ml blood sample was drawn from the women at the time of enrolment and during each follow-up visit. 2.2. Laboratory testing and criteria Sera were initially tested for anti-HCV with a second-generation enzyme immunoassay (EIA; Abbott, Wiesbaden, Delkenheim, Germany). During the project this Sofosbuvir impurity A kit was replaced by a third-generation assay from the same manufacturer and all seroconverting paired samples were retested on the same plate with the third-generation assay. Testing for HCV-RNA was performed on Sofosbuvir impurity A sera using RT-PCR without RNA extraction, as previously described (Abdel-Hamid et al., 1997). Sera that were anti-HCV positive and HCV-RNA negative were retested following RNA extraction using QIAamp Viral RNA kit (Qiagen, Santa Clara, CA, USA). Serum alanine aminotransferase (ALT) was tested using standard laboratory methods. The upper limit of normal for the procedure used was 40 IU/l. Incident HCV cases were defined as individuals who seroconverted from negative to positive for anti-HCV and/or HCV-RNA. Anti-HCV seroconversion in the absence of HCV-RNA conversion was further confirmed by repeat testing the last negative and first positive samples of the same woman in duplicate on the same plate. 2.3. Statistical analysis Incidence rates were calculated by dividing the total number of HCV infections by the number of PY of follow up. For incident cases, follow-up duration was calculated by measuring the time between study enrolment and the suspected time of infection (assumed to be midway between the last negative and first positive HCV result); otherwise duration of follow up was calculated from study enrolment until the last collected blood sample. To calculate separate incidence rates in the perinatal and non-perinatal periods, the person-time of follow up that occurred between the time of enrolment during pregnancy and the first postnatal visit was considered to be follow up during the perinatal period; follow up after that was considered to be after the perinatal period. However, if a woman’s first postnatal visit occurred more than six months after delivery we modified that approach. In that case, if the woman was HCV negative at the first postnatal visit, the first six months after delivery was assigned to the perinatal period and the remaining time was assigned to the non-perinatal period. If the woman’s first.
