A deadly virus has killed at least four people in Brazil, prompting a government crackdown on the nation’s most infectious diseases.

A man was found dead in his apartment last week and four others are under investigation, including a pregnant woman.

The Associated Press reported the deaths of a young man and a woman on Monday.

Brazil’s National Health Department said in a statement Monday that the four people were infected with the same strain of Wilsons disease, a virus that has killed more than a million people worldwide.

The four people who died have not been identified.

The virus is a form of Willsson’s Disease, a coronavirus that causes severe illness and sometimes death.

Willsons disease is one of Brazil’s most deadly coronaviruses, with nearly 20,000 confirmed cases since it was first discovered in 2002.

Brazil has had a number of outbreaks over the years, including the 2003 Willson’s disease outbreak that killed more 100,000 people and the 2009 Willssey’s disease outbreaks that killed dozens of people and forced the country to shut down most public transportation and hospitals.

Brazil currently has more than 2,000 cases of Willson’s.

The AP’s report does not say how many people have died of Willes’ disease since it first was discovered in 2013.