RIO DE JANEIRO, Jan. 31 (Xinhua) -- Brazilian Health authorities suspect that the death of a 43-year-old woman in Sao Paulo was due to side effects of yellow fever vaccine.

    Marizete Alves de Abreu died on Thursday in a hospital in southeastern Brazil, 15 days after taking the vaccine. She had decided to get immunized, despite the fact that national health authorities were asking the population to take the vaccine only if they were planning to travel to yellow fever endangered areas.

    According to the Ministry of Health, De Abreu was one of the 43cases detected of patients who suffered from side effects of the vaccine, and the only one who has died so far. Last week, the government informed that at least 30 of those cases were of patients who had taken the shot unnecessarily.

    The ministry also recommended that people who had immunological problems should try to avoid taking the vaccine. Physicians revealed that De Abreu had a pre-existing disease, a type of lupus,which affected her defense system.

    Up to the present, 20 cases of yellow fever have been confirmedin Brazil. Ten patients died as a result and the other 10 are undergoing proper treatment. All the patients were reported to have been infected in the midwest of the country, especially in rural areas of the states of Goias and Mato Grosso.