Costa Rica counts some COVID-19 cases without tests

Costa Rica has adopted a less strict method of counting people infected with the new coronavirus, suddenly adding thousands of new cases to the country's COVID-19 totals.

The new “nexus” criteria adopted this month count people who show symptoms of the disease and who had direct contact with someone who tested positive, even if they were not tested themselves.

That has added more than 3,000 cases to the country's reported total of 36,307 COVID-19 infections as of Wednesday. There were 386 reported deaths.

Those newly counted under the change are also required to quarantine at home for 14 days.

Health Minister Daniel Salas himself entered quarantine on Tuesday after his father tested positive for COVID-19, though Salas hasn't reported suffering symptoms.

When he announced the new policy, Salas said the change isn't due to a lack of tests: “It’s about practicality and finding the greatest effectiveness in what we’re doing with the resources that we have."

It prompted some grumbling from sectors pushing for a faster reopening of the economy and some concerns that raising that increased infection numbers would deter tourists, but Juan José Romero, an epidemiologist at Costa Rica National University, said the change makes sense considering the contagiousness of COVID-19.

Counting those highly likely to be positive without a test avoids the delay of waiting for test results and potentially keeps infectious people from continuing activities outside the home, Romero said. It also doesn’t bar anyone from getting a test if their symptoms worsen and they need medical care.

Argentina’s government made a similar move this month and began adding the cases of people with symptoms and direct contact with a positive case to their count. The government reported a total of more than 370,000 COVID-19 infections Thursday, but does not provide a break out of test positive cases versus nexus cases.

Carla Vizzotti, the national government’s health access secretary, said the goal was to respond more quickly to infections. But Buenos Aires’ regional government announced it would not change to that protocol because it has the capacity to do the testing.

Some U.S. states also track “probable cases” based on clinical and epidemiological information without testing.

U.S. health officials came under fire Thursday for a change this week to testing guidance from the Centers for Disease Control and Prevention that critics say could lead to undercounting infections.

The CDC now says it’s not necessary to test people who have been in close contact with infected people if they don't feel sick. Previously it had recommended the opposite. Studies indicate that infected people can be highly contagious a day or two before feeling symptoms.

Costa Rica's Romero rejected the suggestion that counting positives by nexus would inflate the number of infections. Many people infected with the virus never report symptoms, or only light ones, and don't seek medical care. Romero said the real number of infected people is probably three times as high as the official count. The new change goes a little way toward capturing that.