Prevalence of hepatitis B and hepatitis C in a UK genitourinary medicine clinic

Introduction

Individuals attending genitourinary medicine (GUM) clinics may be at increased risk of hepatitis B (HBV) and C (HCV), however testing for viral hepatitis is usually limited to those with HIV infection and those with risk factors. The 2008 British Association for Sexual Health and HIV hepatitis guideline advised targeting testing of HBV to ‘men who have sex with men (MSM), sex workers (of either sex), injecting drug users (IDU), HIV-positive patients, sexual assault victims, people from countries where hepatitis B is common (outside of Western Europe, North America and Australasia), needlestick victims and sexual partners of positive or high-risk patients’ and to consider testing for HCV, ‘in all IDUs, especially if equipment has been shared, in haemophiliacs or other patients who received blood or blood products pre1990 and in people sustaining a needlestick injury if the donor HCV status is positive or unknown. Other groups to be considered for testing are sexual partners of HCV-positive individuals, MSM, all HIV-positive patients, female sex workers, tattoo recipients, alcoholics and exprisoners.’ ¹ These recommendations remained virtually unchanged in the 2015 guideline. ² Recommended screening assays are anti-HBc or HBsAg and anti-HCV antibody.

However, in our service it has been practice to test for HBsAg in all patients and for HCV Ab/Ag (antibody/antigen), and HCV RNA if HCV Ab/Ag positive, in all those with risk factors including all MSM. HBsAg and HCV RNA are detectable in those with current infection while HCV Ab/Ag is detectable in those who have been exposed, whether currently or only previously infected. The HBV screening policy was initiated around 2000 on the basis of HBV being a sexually-transmitted virus. HCV, although predominantly transmitted percutaneously, has also been recognised to be transmitted sexually between MSM. ³ Our clinic provides GUM and HIV services but not yet contraception. In common with all GUM clinics in the UK, the clinic is open-access (in that access is not limited by residence) but it is located in and primarily serves Mid Essex. This is a mixed area including rural and urban areas and has close links with London. The proportion of residents born outside the EU is lower than the average for the UK (3.7% vs. 9.0%). ⁴

Methods

Demographic information was obtained from routinely collected clinic data submitted in statutory (GUMCAD) returns of GUM attendees and combined with an electronic database of laboratory test results. We do not have an electronic patient record and our clinic database does not include all relevant risk factors. Checking all the paper records of all attendees for risk factors is impractical; however, the paper records of those with positive test results were examined.

For HIV-positive patients receiving HIV care at the clinic, results were included if they attended at least once for non-HIV-related care in 2014.

The clinic notes of those patients who tested positive were examined for any record of risk factors that may have indicated a need for testing if testing were targeted.

All analyses were performed using Stata (StataCorp LP, College Station, Texas).

Results

During 2014 a total of 7331 individuals were seen in our service. Of these 1310 did not have a test for HBsAg, generally because no blood tests were done, or because they opted for a finger-prick sample rather than a venous sample, in which case no hepatitis testing is performed. In patients with more than one test for HBsAg, all results were the same (733 with all negative results, three with all positive). Of patients with HIV, 86 had at least one attendance for non-HIV care; the others were excluded. This left 6020 patients who are included in this report.

Just over half the patients (3182; 52.9%) were female. Sexual orientation was recorded for 6001 with 0.5% (17 of 3181) of female and 11.5% (325 of 2820) of male patients being recorded as having same-sex partners. The ages of the patients ranged from 13 to 80 years with a median of 26 and interquartile range of 22 to 35. Patients were born in 93 different countries with the majority (5424; 90.1%) having been born in the UK. Of the remainder, 217 (3.6%) were born in Europe, 212 (3.5%) in sub-Saharan Africa and 94 (1.6%) in Asia.

HCV Ab/Ag results

HCV Ab/Ag testing was performed in 1153, all of whom had also been tested for HBsAg. HCV Ab/Ag was positive in 12 (1.0%), nine of whom were born in the UK with the other three being born in the Republic of Ireland, Thailand and Zimbabwe. Eight were male, two of whom had male sexual partners, and four were female. Four were HIV-positive, including one female from Thailand, one male heterosexual from Zimbabwe and two MSM from the UK. None were co-infected with HBV.

Similarly to the patients with detectable HBsAg, all those with a positive result for HCV Ab/Ag had indications to test for HCV: eight of 12 gave a history of IDU and one of a partner with previous IDU; the other three were all HIV-positive. Of the 12, two were men who gave a history of sex with men.

All 12 patients with a positive HCV Ab/Ag test result had subsequent testing for HCV RNA with five testing positive and seven testing negative. Thus 0.4% of all those tested for HCV had a positive HCV RNA result.

All serology results are shown in Table 1.

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Table 1.

Hepatitis serology test results.

	HBsAg			HCV Ab/Ag
	N	Positive	%	N	Positive	%
All	6020	13	0.2	1153	12	1.0
Female	3182	5	0.2	405	4	1.0
Male, heterosexual	2495	7	0.3	437	6	1.4
Male, MSM	325	1	0.3	294	2	0.7
Male, not recorded	18	0	0.0	7	0	0.0

MSM: men who have sex with men; HCV: hepatitis C.

Discussion

Outside of routine antenatal screening, the majority of hepatitis B testing in the UK is conducted in general practice (30%) and in GUM services (24%). ⁵ With the increasing recognition of the importance of diagnosing viral hepatitis, it is essential that GUM services have evidence-based testing guidelines, particularly at times of shrinking public health budgets.

Our clinic policy is unusual in that we aim to test HBsAg in all patients and HCV Ab/Ag in all MSM in addition to those with risk factors. Thus our data are a useful measure of HBsAg in unselected GUM attendees and of HCV Ab/Ag in MSM. However, our results should be used with caution as they are unlikely to be representative of other areas of the country.

Our results are broadly in line with previous estimates. We found 0.2% of our GUM patients tested positive for HBsAg. This is clearly lower than the 2.6% prevalence in London GUM patients but, as noted, those patients were selected on the basis of risk. It is closer to the 0.5% of women who tested positive in antenatal clinics included in the sentinel surveillance program and, similarly to those testing positive in that program, the majority of those with HBsAg were born abroad. Our prevalence may be lower because our clinic population has less foreign-born patients. Hepatitis C Ab/Ag tests were positive for 1.0% in our service, with 0.4% testing positive for HCV RNA, identical to the PHE estimate of current HCV infection in UK adults. Our HCV prevalence estimate is biased since we tested only in those with risk factors, including testing all MSM. We found two MSM with positive tests for HCV Ab/Ag, but both were HIV-positive and thus we found no HCV in HIV-negative MSM.

Thus, our results suggest that the BASHH advice on hepatitis testing is appropriate for our service and we have not picked up additional cases through widening the indications for testing. However, in antenatal services opt-out testing for viral hepatitis and for HIV were introduced some years ago since targeted testing meant that some patients with infection were being missed. In practice, if testing is not universal, some patients for whom a test is indicated may in fact not receive it. Also, some studies have found that most patients diagnosed with viral hepatitis do not give a history of risk factors and such history may only be given after a diagnosis is made. ¹¹ Despite these concerns, we now plan to change clinic policy in line with the national guideline. ² In the future, it would be useful to examine clinics which follow the BASHH guidance and perform tests for viral hepatitis on samples sent for HIV and/or syphilis to see how many, if any, of those with infection fail to be identified.