Hepatitis C enhanced surveillance: results from a southeastern Sydney pilot program

Hepatitis C virus (HCV) is a potentially serious bloodborne virus, which persists in the majority of those infected. Long-term sequelae include liver cirrhosis, liver cancer and premature death. Early identification of newly acquired infection is important for protection of public health. Routine surveillance based on laboratory notification of HCV infection is not sufficient to differentiate between newly acquired and chronic infections. Enhanced surveillance systems have been trialled globally in a number of settings. This pilot program aimed to increase identification of newly acquired HCV cases in southeastern Sydney residents and to ascertain the likely mode of transmission.

All HCV notifications in southeastern Sydney residents with specimen dates from 1 July to 31 December 2012 were included in a pilot program. Demographic data, Australian Indigenous identification and previous laboratory results were collected from electronic medical records, where available. Enhanced surveillance forms were sent to referring doctors to seek information about clinical symptoms and previous hepatitis C pathology. Data were collated to assess, according to Australian national case definitions, whether cases were newly acquired or not, or were unable to be determined on the available information.

There were 104 notifications of HCV infection during the surveillance period. Forms were sent to 100 requesting doctors, with 72 forms returned. Six newly acquired cases were identified, a rate of 8%, compared with 1-3% classified by routine surveillance. Twenty cases (28%) were not newly acquired and the status of 46 (64%) was unable to be determined. Of the six newly acquired cases, sexual transmission was deemed to be the likely route of exposure for four cases, and injecting drug use for the remaining two.

Enhanced surveillance increased the rate of identification of newly acquired infections. However, the process was labour-intensive and the status of most cases was unable to be determined. Since identification of newly acquired cases has an important public health benefit in understanding factors in disease transmission, other approaches should be examined.