The largest population study of hepatitis C in Africa has found three new strains of the virus circulating in the general population.
The discovery suggests certain antiviral drugs used in the West may be less effective against these strains, and local clinical trials of patients are urgently needed to assess optimal treatment strategies in the region.
The discovery of the new strains could inform hepatitis C treatment and vaccine development worldwide, and assist the World Health Organisation's aim of eliminating hepatitis C globally by 2030.
Hepatitis C is caused by a virus, transmitted mainly by sharing contaminated needles and exposure to infected blood, with infection causing liver cirrhosis (scarring) and liver cancer. Globally, an estimated 71 million people have chronic hepatitis C infection, with 10 million living in Africa. Nearly 400,000 people die from hepatitis C infection each year.
Most drugs that are effective against multiple strains of the hepatitis C virus (HCV), are tailored towards strains found in high-income countries such as the US and the UK, and research on HCV in Africa and other low-income regions has been extremely limited.
That coupled with limited access to diagnosis and treatment, has a huge impact on the elimination of hepatitis C. Researchers carefully screened the blood of more than 7,000 people in Uganda, and found undiagnosed HCV in 20 patients.
Using molecular methods, they sequenced the HCV genomes from the infected patients and genes from two blood samples from people born in the Democratic Republic of Congo.
From this sequencing, they discovered three completely new strains of the hepatitis C virus, in addition to some strains seen in the West.
“We discovered new strains that had never been seen before. Further research is needed as some antiviral drugs are effective against specific strains of hepatitis C virus and may not work as well in these populations,” said first author George Mgomella, from the Wellcome Sanger Institute and the University of Cambridge.
The researchers discovered that current screening methods using antibody detection were inaccurate in Uganda and that detection of the virus itself would likely be a superior method for diagnosing the infection in high-risk populations.
Moreover, many of the strains found in Uganda, carried mutations in genes known to be associated with resistance to some commonly used antiviral drugs, proving that careful approaches are needed to diagnose and treat HCV effectively in Africa.
“It is important that there is a concerted effort to characterise hepatitis C strains in Africa at a population level in order to assist countries select optimal treatments for national procurement. This would also inform vaccine design to catalyse the elimination of hepatitis C by 2030,” added senior author Emma Thomson, from Glasgow University in the UK.
The researchers called for investments in further studies and clinical trials in Africa to help understand the clear differences in the viral strains in the region, in the journey towards elimination by 2030.
The findings were published in the journal Hepatology. – Science Daily