BRASILIA (Reuters) - Recent laboratory analyses identified Zika virus infections in three people who died in Brazil last year, the health ministry said on Thursday, although authorities could not confirm that Zika alone was responsible for their deaths.
Brazilian Health Minister Marcelo Castro confirmed the findings at a press conference, while announcing that a new partnership with scientists at the University of Texas could lead to laboratory development of a vaccine within a year. He cautioned that full-fledged availability of a vaccine against the mosquito-borne virus would take longer.
The developments are the latest in an ongoing struggle with Zika in Brazil, which is at the center of an outbreak that has spread to more than 30 countries and has prompted the World Health Organization to declare a global emergency over possible links between the virus and birth defects.
The ministry said Brazilian researchers found the virus in the body of a 20-year-old woman in the northeastern state of Rio Grande do Norte, who died last April from respiratory problems. Two other patients last year also died from complications while they were infected with the virus.
Castro said the deaths possibly illustrated “comorbidity” caused by the virus and complications it may have caused in the patients. The woman’s respiratory problems were likely “associated with the infection,” he said.
Only one in five people infected with Zika experience illness and even then they are normally mild symptoms. The virus is still poorly understood by scientists.
The government believes that as many as 1.5 million Brazilians may have been infected by Zika so far. Scientists are investigating a potential link between infections of pregnant women and more than 4,000 suspected cases in Brazil of microcephaly, a condition marked by abnormally small head size that can result in developmental problems.
Though laboratory tests have showed traces of Zika in patients affected by the believed complications, no proof yet exists to show it causes the birth deformations or any reported deaths.
Researchers in Brazil and elsewhere are pushing ahead with efforts to better diagnose and prevent Zika infections.
Castro and Pedro Vasconcelos, a doctor at the Evandro Chagas Institute of Infectious Diseases, announced the vaccine partnership with the U.S. researchers as Brazil pledged $1.9 million to the effort over the next five years.
Castro said development of a vaccine could come as quickly as within one year, but said that another two years would likely be needed for any large-scale rollout of a successful vaccine.
The timeline is similar to that suggested by researchers elsewhere, many of whom say clinical availability of any Zika vaccine is still at least three years away. Researchers note that a vaccine for dengue, a similar virus that so far affects many more people than Zika, is still not widely available, despite successful models.
Castro said the ministry hopes to distribute tests soon that could be used to speed up diagnoses of patients with active symptoms of Zika, dengue and Chikungunya, another related viral infection.
At present, doctors have relied mostly on costly genetic tests to find traces of the virus in some patients, but those tests, known as PCR, are not widely available and are limited to when a patient is actively showing symptoms.
Though the new test is also limited to when patients have symptoms of the illnesses, it can be used at more facilities and could provide some diagnoses in a matter of hours, the ministry said.
Reporting by Silvio Cascione and Maria Carolina Marcello; Writing by Paulo Prada; Editing by Frances Kerry