Self-testing kits for hepatitis C are being made available from the NHS in England from Saturday.
The move comes as a government health official says that "tens of thousands of people" in England are living with the infection without realising.
The free, confidential service is designed to reach people who may not access other services or do not feel able to approach their GP.
The potentially fatal condition has symptoms which can go unnoticed for years, but can lead to liver disease and cancer. It tends to affect current or past drug users and people who have had contact with infected blood.
NHS national medical director Professor Sir Stephen Powis said: “As we celebrate 75 years of the NHS, I’m delighted we are on track to eliminate hepatitis C as a public health threat by 2030, which may rank among the most significant NHS successes in history, alongside the mass vaccination of polio and diphtheria, organ transplants and driving down smoking rates.
“As patient numbers get smaller and each remaining case becomes harder to find and cure, it’s vital we offer easy-to-access self-test kits — especially for those who have been exposed to the virus but may be reluctant to come forward.”
The tests, which can be ordered online, involve a sample of blood from a finger prick which is sent for analysis.
People returning a positive test will be contacted and the NHS website says it can usually be cured by taking a course of tablets.
Dr Monica Desai, head of hepatitis at the UK Health Security Agency, said: “Hepatitis C can cause severe liver disease and be fatal without the right treatment.
“Tens of thousands of people in England are living with the infection without realising, as it can be symptomless or cause very non-specific symptoms like tiredness in the initial stages.”
She continued: “The quicker you get diagnosed, the quicker you can start life-saving treatments.
“The virus is passed on through blood, so if you have ever injected drugs – even just once or years ago – please take up the offer of a hepatitis C test either through this new portal or through your GP. You should also get tested if you have had contact with the blood of someone who has the infection.”