Identifying, and testing, patients at risk of hepatitis C (HCV) infection by GPs mainly focuses on people who inject drugs (PWID) but migrants from medium- or high-prevalence countries are often overlooked, a UK study has found.

Six GP practices in Bristol, serving a total population of 73,814 patients, took part in the study. Three had a high prevalence of PWID and three a low prevalence.

The researchers used routinely collected information in the practices’ clinical database systems to identify patients at risk of HCV infection, and the proportion of these patients who had not been tested. Additional qualitative information on GPs’ views on testing was obtained through semi-structured face-to-face interviews with 17 of the participating GPs.

A total of 3,765 patients were identified as being at risk of HCV infection (5% of the study population). A large majority of these had no record of an HCV test (81%), while 8% had tested positive and 11% negative.

Overall, PWID were more likely to have been tested than those whose risk status came from their country of birth; 47% of the former group had a record of an HCV test compared with 7% of the latter.

Practices where more than two GPs had undergone RCGP training on HCV infection were more likely to test.

In the interviews, GPs reported that their experience of HCV infection had been predominantly with PWID, and the majority stated that they did not consider country of origin to be a prompt for HCV testing.

Although all the GPs stated that they usually tested PWID, testing ranged from 29% to 62%, median 42.5%.

Most GPs did not routinely question patients about HCV risk, and admitted they did not always remember to consider testing. Other barriers to testing cited included the chaotic lifestyle of PWID, and difficulty raising the issue and extracting information from computerised records.

The study demonstrated that routine information in primary care clinical databases can be used to identify many patients at risk of HCV infection, but that the large majority of those with risk factors in the study population had not been tested. It also showed that GPs may not routinely ask about HCV risk factors, and that they may be relatively unaware of country of birth as a risk factor.

It is estimated that around 150,000 people in England have chronic HCV infection, and of these more than half are unaware of the diagnosis.

There have been major advances in recent years in the treatment of HCV infection, with clearing of the virus

(a sustained viral response) a realistic goal for most. Although those with HCV infection may be asymptomatic for a number of years, they are at long-term risk of developing cirrhosis and hepatocellular carcinoma, and of transmitting the virus to others.

NICE has published guidance on ways to promote and offer testing to people at increased risk of HCV.1

Computer prompts and GP education on which patients to test are warranted, the study authors conclude. They also suggest that ensuring that country of origin and drug use are included on the new patient questionnaire might also aid case finding for HCV.

HCV case finding needs to be proactive, with risk factors identified from routine information in the clinical database, or disclosed through active questioning. Training for GPs needs to emphasise testing patients from countries with higher HCV risk, and to encourage GPs to ask questions about risk factors.

Dr Jez Thompson