Ali* is a person living with HIV and receives care at treatment at the Guru Teg Bahadur Hospital in Delhi. The hospital recently referred him to the liver department at GB Pant Hospital after he tested positive for hepatitis C antibodies. Patients with positive hepatitis C antibody tests need to immediately undergo to confirmatory testing and treatment.

After standing in line from 4 am and finally meeting the doctor at the GB Pant Hospital’s gastroenterology department, Ali was disappointed. He needed another confirmatory viral load test before he could be treated with hepatitis C medicines, which are direct acting antivirals and available for free to patients at the hospital.

The hospital, which specialises in liver disease, receives a high burden of hepatitis patients from across Delhi and Western Uttar Pradesh but does not have the facility for viral load testing. Ali was handed a voucher to get the confirmatory test done at a private laboratory. But he just cannot afford the Rs 2,000 test. His hepatitis C is advanced. He is easily fatigued and unable to do the long hours of work that expected of him as a driver in Delhi. He can barely pay for his meals, let alone expensive diagnostics in the private sector.

Situations like this occur daily in India. Due to lack of access to confirmatory viral load testing many hepatitis C patients do not receive the drugs they need to cure the disease and save their lives.

But this could change. Last month the WHO launched the Essential Diagnostics List or EDL, forty years after it first published the Essential Medicines List. The EDL covers 113 essential tests of which 58 are basic tests such as haemoglobin, blood glucose measurement, and 55 tests are for “priority diseases” like HIV, tuberculosis, malaria, hepatitis B and C, human papillomavirus and syphilis. It also recommended where these tests should be placed in the health system – primary care, district hospital, tertiary care, national or regional reference laboratories.

Similar to the WHO Essential Medicines List, the Essential Diagnostics List is intended to serve as a reference for countries to update or develop their own list of essential diagnostics.

This is good news for public health, which has often been stunted by the lack of tools to screen, diagnose and monitor communicable and non-communicable diseases, fevers, infections and resistance. It could also fundamentally change the way people think about access to treatment. While most view availability and affordability of medicines as part of their entitlement and right to health, availability of essential screening tools, tests and diagnostics is often viewed as a facility that patients and their families have to pay for.

“An accurate diagnosis is the first step to getting effective treatment,” said Dr Tedros Adhanom Ghebreyesus, director-general of the World Health Organisation, when the list was published in May. “No one should suffer or die because of a lack of diagnostic services, or because the right tests were not available.”

Health and patient groups can now work towards advocacy that encourages the public healthcare system to provide access to essential diagnostics free of cost, address supply chain issues and make them affordable in the private sector, where price regulation is the need of the hour. Viral load tests, for example, can go as high as $100 in the private sector and the public sector often sees stock out of viral load kits and reagents.

Treatment providers, health groups and treatment activists will no doubt push to have other essential diagnostics included in future editions. Guidance on essential diagnostics for cancers would be useful to improve detection and quality of treatment for patients and a complementary list for essential devices such as coronary stents could boost access and availability in the public healthcare system.

WHO plans to expand the list over the next few years, as it incorporates other important areas including antibiotic resistance, neglected diseases and additional noncommunicable diseases.

*Name changed

Leena Menghaney is a lawyer specialising in public health and access to treatment and is currently working for Medecins Sans Frontieres – Access Campaign in India.