Exclusive: Brazil says Zika virus outbreak worse than believed

A health worker carries out fumigation as part of preventive measures against the Zika virus and other mosquito-borne diseases at the cemetery of Carabayllo on the outskirts of Lima, Peru February 1, 2016. REUTERS/Mariana Bazo

By Anthony Boadle and Lisandra Paraguassu

BRASILIA (Reuters) – Brazil’s top health official said on Monday that the Zika virus outbreak is proving to be worse than believed because most cases show no symptoms, but improved testing should allow the country to get a better grip on the burgeoning public health crisis.

A health worker carries out fumigation as part of preventive measures against the Zika virus and other mosquito-borne diseases at the cemetery of Carabayllo on the outskirts of Lima, Peru February 1, 2016. REUTERS/Mariana Bazo
A health worker carries out fumigation as part of preventive measures against the Zika virus and other mosquito-borne diseases at the cemetery of Carabayllo on the outskirts of Lima, Peru February 1, 2016. REUTERS/Mariana Bazo

Health Minister Marcelo Castro told Reuters that Brazil will start mandatory reporting of cases by local governments next week when most states will have labs equipped to test for Zika, the mosquito-borne virus that has quickly spread through Latin America. The virus has no vaccine or cure at present.

On Monday, the World Health Organization declared the Zika outbreak to be a global emergency, a decision that should help fast-track international action and research priorities.

In Brazil, believed to be the country hit hardest by Zika, the outbreak has sparked fear especially among pregnant women after local experts linked the virus to thousands of cases of microcephaly, or abnormally small heads and underdeveloped brains, in newborns.

“Eighty percent of the people infected by Zika do not develop significant symptoms. A large number of people have the virus with no symptoms, so the situation is more serious that we can imagine,” Castro said in an interview.

“Our big hope is finding a vaccine,” he added.

The Zika emergency comes at a particularly bad time for President Dilma Rousseff’s unpopular government, adding a new burden to a public health system hit by budget cuts in the midst of a severe recession. It has also cast a shadow on Brazil’s hosting of the Olympic Games in Rio de Janeiro in August.

The Brazilian government suspects the virus was brought to Brazil during the 2014 soccer World Cup by a visitor from Africa or Oceania where Zika is endemic. An estimated 1.5 million Brazilians have caught Zika, a virus first detected in Africa in the 1947 and unknown in the Americas until it appeared in May in the poverty-stricken northeastern region of Brazil.

The Pan-American health Organization said the virus has since spread to 24 countries and territories in the hemisphere.