In this photo taken Thursday, April 2, 2020 women queue alongside a testing clinic in Khayelitsha, Cape Town, South Africa. South Africa, one of the world's most unequal countries with a large population vulnerable to the new coronavirus, may have an advantage in the coronavirus outbreak, honed during years battling HIV and tuberculosis: the know-how and infrastructure to conduct mass testing. (AP Photo/Nardus Engelbrecht)

JOHANNESBURG– South Africa, one of the world’s most unequal countries with a large population vulnerable to the new coronavirus, may have an advantage in the outbreak, honed during years battling HIV and tuberculosis: the know-how and infrastructure to conduct mass testing.

Health experts stress that the best way to slow the spread of the virus is through extensive testing, the quick quarantine of people who are positive, and tracking who those people came into contact with.

“We have a simple message for all countries: test, test, test,” Tedros Adhanom Ghebreyesus, director-general of the World Health Organization and a former Ethiopian health minister, said recently.

South Africa has begun doing just that with mobile testing units and screening centers established in the country’s most densely populated township areas, where an estimated 25% of the country’s 57 million people live.

Clad in protective gear, medical workers operate a mobile testing unit in Johannesburg’s poor Yeoville area. In the windswept dunes of Cape Town’s Khayelitsha township, centers have been erected where residents are screened and those deemed at risk are tested.

The disease can be particularly dangerous for older people and those with existing health problems, such as those whose immune systems are weakened or who have lung issues. That means many in South Africa — with world’s largest number of people with HIV, more than 8 million, and one of the world’s highest levels of TB, which affects the lungs — are at high risk of getting more severe cases of the disease.

“Social distancing is almost impossible when a large family lives in a one-room shack. Frequent hand-washing is not practical when a hundred families share one tap,” said Denis Chopera, executive manager of the Sub-Saharan African Network for TB/HIV Research Excellence.