A magnified image of the hepatitis C virus.
A new study, coinciding with World Hepatitis day, has estimated for the first time the number of children born globally with hepatitis C virus.
The research, led by researchers from the National Institute for Health Research Health Protection Research Unit in Evaluation and Behavioural Science (NIHR HPRU EBS) at the University of Bristol, estimated that each year around 74,000 children globally are born with hepatitis C virus (HCV), with around 23,000 of these children estimated to still have HCV infection at age five.
Pakistan and Nigeria were the countries shown to have the highest levels of cases, followed by China, Russia, and India, which in total were found to make up around half of all vertically transmitted infections.
The study, published in the journal Lancet Gastroenterology and Hepatology, produced estimates for each country which is a first, as previously such figures were only available for Pakistan, Egypt, and the USA using data from more than 10 years ago.
Lead author Dr Adam Trickey, Senior Research Fellow at the University of Bristol Medical School, said: "Our study findings highlight not only the scale of transmission, but also the great need for more testing. Without this testing the virus, which can be cured in most cases, is left untreated in young children who contract the virus from birth.
"These statistics are important for policymakers and healthcare planners as they uncover a major source of new HCV infections that has so far been understudied. There are also implications for service delivery, as pregnancy is often a time where it is possible for healthcare providers to engage with people who they might not usually be in contact with, offering a chance to screen them for HCV and connect them to care if necessary."
The World Health Organization estimates that across the world there are some 50 million people living with HCV, a bloodborne virus, and that around 240,000 people died of hepatitis C-related liver disease in 2022.
Dr Trickey added: "This is despite highly effective treatments for HCV being available in many countries since 2014. These treatments involve a course of pills that need to be taken for around three months, with effective cure rates of more than 90%."
This new study combined estimates of the number of women aged 15-49 with HCV in each country, with new estimates of the probability of transmission of HCV to the child whilst the mother is pregnant, which is around 7% per birth. The researchers also accounted for new estimates of the proportion of children born with HCV who will naturally clear the virus before they reach five-years-old, which is high at around two-thirds.
Hepatitis C is generally concentrated among marginalised populations, for example people who inject drugs or those exposed to unsterile medical procedures. In 2022 the World Health Organization reported that only around a third (36%) of people with HCV were aware of their infection. This is partially because HCV can have few or no symptoms for many years and then eventually result in severe liver-related issues such as cirrhosis and cancers of the liver. More testing is therefore needed in most populations to identify who has hepatitis C.
American and European HCV guidelines now recommend screening for all pregnant women. However, screening among pregnant women is uncommon in most settings, including where it is recommended.
Recommendations for treatment of HCV in children vary, but guidelines mostly indicate children can be treated from the age of three years onwards.
Dr Trickey added: "Most guidelines do not advise for pregnant women with HCV to be treated because of a lack of evidence of the safety of these treatments, although a clinical trial is currently investigating this – preliminary results indicate high cure rates and few major side effects.
"Given the availability of effective medicine, and further progress in this field, it's vital that testing and diagnosis rates improve so more people can be treated and cured."
Paper
'Estimating the annual number of hepatitis C virus infections through vertical transmission at country, regional, and global levels: a data synthesis study' by Adam Trickey, Adelina Artenie, Jordan Feld, and Peter Vickerman in The Lancet Gastroenterology and Hepatology
