Testing for chronic hepatitis B infection was very low in
people living with HIV in Cameroon, a country with a high burden of hepatitis
B, and suppression of hepatitis B virus was suboptimal in people with HIV on
antiretroviral therapy, Cameroonian and French researchers report in BMC
Hepatitis B is a common co-infection in people living with
HIV. The World Health Organization estimates that approximately 7% of people
living with HIV have co-infection with hepatitis B and three-quarters of them live
in sub-Saharan Africa. The prevalence of hepatitis B co-infection in people
living with HIV is especially high in west and central Africa (around 12%).
World Health Organization guidelines recommend that people who
test positive for hepatitis B antibodies should be tested for hepatitis B
surface antigen to check for chronic infection and should receive antiretroviral
treatment with a regimen that contains tenofovir disoproxil fumarate (TDF), which is also active
against hepatitis B virus.
To investigate management of hepatitis B co-infection,
Cameroonian and French researchers carried out a cross-sectional study at 19 HIV
clinics in central Cameroon in 2014 (the EVOLCAM study). The study sites
included clinics in the country’s two largest cities, Yaoundé and
The research team wanted to find out what proportion of patients
at these clinics had been tested for hepatitis B surface antigen and how many
were receiving appropriate treatment in accordance with national guidelines,
and what proportion had suppressed hepatitis B virus.
The study recruited adults presenting at HIV clinics who had
been on antiretroviral treatment for more than six months. Study participants underwent
medical examination, blood tests and were interviewed regarding risk factors for
hepatitis B infection and sociodemographic characteristics.
The study recruited 1718 participants who had been on
antiretroviral treatment for a median of 3.4 years. Just under three-quarters
(74%) were women and 75% had a viral load below 300 copies/ml (undetectable). Nine
per cent (159 patients) were hepatitis B surface antigen positive and of these,
15% had been diagnosed hepatitis B surface antigen positive prior to the study.
Seventeen per cent of all participants had been tested for
hepatitis B surface antigen prior to the study. Almost half of these
participants had not been tested for hepatitis B surface antigen before starting
antiretroviral therapy and in these people the median interval between
starting treatment and being tested for hepatitis B surface antigen was 42
Women were less likely to be tested than men (adjusted odds
ratio 0.64, 95% CI 0.46-0.89, p = 0.010) and testing was more likely to have taken
place in people who started treatment after 2010 (aOR 1.66, 95% CI 1.23-2.27,
p < 0.001), in those with secondary or higher education (aOR 1.38, 95% CI
1.02-1.90, p = 0.042) and in those with a higher ALT level (aOR 1.26 per 10
IU/L, 95% CI 1.15-1.39, p < 0.001).
There were also big differences in testing between clinics.
Whereas 72.5% of participants had already been tested at one clinic, fewer than
10% of participants had been tested at nine study sites and only two study
sites had tested more than half of participants for hepatitis B surface antigen
prior to the study. The investigators are unable to explain this finding.
Looking at treatment, the researchers found that 30 out of
34 people diagnosed with chronic hepatitis B prior to the study were receiving
tenofovir-containing regimens. Overall, 61% of people recruited to the study
received tenofovir and either emtricitabine or lamivudine (also active against
hepatitis B), 35.2% a combination containing emtricitabine or lamivudine and
1.9% a combination containing tenofovir alone.
Despite the high frequency of treatment with drugs active
against hepatitis B, hepatitis B viral load suppression was suboptimal; 72%
had a viral load below 10 IU/ml and viral suppression was more likely in participants
who also had a fully suppressed HIV viral load (aOR 3.46, 95% CI 1.48-8.09,
p = 0.004) and in participants who were receiving HIV treatment at a secondary
treatment centre, largely located in district hospitals (aOR2.79, 95% CI
1.24-6.27, p = 0.013).
Patients with unsuppressed hepatitis B viral load had been
on antiretroviral treatment for a median of four years but multivariate analysis
did not identify any antiretroviral treatment factors, including drugs in the
regimen or adherence, associated with viral suppression.
Participants with higher ALT levels were less likely to have
suppressed hepatitis B viral load (aOR 0.86 per 10 IU/ml increase in ALT, 95% CI
0.75-0.97, p = 0.019). These people were at particular risk of liver disease progression,
the study investigators point out.
“The decision of some AIDS programmes (including Cameroon’s since 2016)
not to test for hepatitis B virus because TDF + 3TC [lamivudine] (or
FTC) [emtricitabine] is included in standard regimens should be
reviewed,” the study investigators conclude.