Screening for sexually transmitted infections in people co-infected
with HIV and hepatitis C during or shortly after
completing direct-acting antiviral treatment to cure hepatitis C may predict
which patients are at higher risk of hepatitis C reinfection, a study carried
out in San Diego reports.
The study found that people who became reinfected after being cured were significantly more likely to test positive on a gonorrhoea-chlamydia screen during treatment or in the 12 weeks after completing treatment.
Reinfection with hepatitis C after being cured of the virus
by direct-acting antiviral treatment is more common in gay and bisexual men
with HIV than in people who inject drugs. Studies in Europe and North America
have reported high rates of reinfection:
- A multicentre
study in western European cities found that one in four gay and bisexual
men with HIV cured of hepatitis C became reinfected within three years. This
study found big variations between cities.
- A multicentre
study in Germany found that one in seven gay and bisexual men with HIV
cured of hepatitis C became reinfected after a median of one year.
- A US study found a reinfection rate of four
cases per 100 person-years of follow-up in New York City in gay and bisexual
men with HIV after being cured.
Reinfection appears to be predominantly due to sexual transmission,
not sharing of injecting equipment.
Predicting who might be at higher risk of reinfection and
offering education, harm reduction measures and support to reduce the risk of
reinfection is essential for achieving elimination of hepatitis C among gay and
bisexual men with HIV.
To investigate the rate of reinfection among people with HIV
in San Diego, researchers at the University of California San Diego carried out
a prospective study among all people with HIV cured of hepatitis C between 2014
and 2019.
The study enrolled 200 people with HIV, 85% male, 56% gay or
bisexual men and 23% non-White. A total of 59% of participants had a history of
injecting drug use, including approximately one-third of gay or bisexual men.
During treatment, participants were screened for sexually
transmitted infections and underwent urine drug screens at each clinical visit.
Screening also took place 12 weeks after completion of treatment. Participants
were tested for hepatitis C virus during the follow-up period. Study
investigators did not collect information about sharing of injecting equipment,
condom use or chemsex.
Reinfection was defined as detectable hepatitis C virus
after a sustained virologic response to treatment.
During a median follow-up period of 1.38 years, eight out of
200 people were reinfected with hepatitis C (2.44 cases per 100 person-years of
follow-up). Five cases occurred in gay and bisexual men, two in gay or bisexual
men who inject drugs and one in a heterosexual injecting drug user. No
reinfections occurred in women, even though 83% had a history of injecting drug
use. Although the difference in reinfection rate between exposure groups was
not statistically significant, there was a trend towards a higher reinfection
rate in gay and bisexual men and in people aged 30-39 years.
Reinfection was not associated with a positive urine drug
screen during direct-acting antiviral treatment but was associated with a
positive gonorrhoea-chlamydia screen. Twenty-five per cent of people with a positive
gonorrhoea-chlamydia result prior to achieving a sustained virologic response
were reinfected, compared to 3% of those without a positive screen (p = 0.04).
Due to the small number of reinfections, it was not possible
to determine whether a positive gonorrhoea-chlamydia screen at a specific site
(rectal, pharyngeal or urine) was more strongly associated with reinfection, although
no reinfections occurred in people who only tested positive on a urine or
throat screen.
The study investigators say that STI testing may help to
identify those at risk of reinfection, but they acknowledge that counselling
appears to have limited effectiveness in influencing behaviours that increase
the risk of hepatitis C reinfection. However, positive STI screening results might be used as a prompt for intensified counselling before the completion of treatment, potentially improving the effectiveness of counselling.