Swine flu outbreak in Brazil has claimed lives of 46 people in less than two months. The country hardest hit by Zika virus is facing H1N1 virus outbreak with the Olympics it is hosting just months away.
The death toll is 10 times the figure for all of 2015, the Health Ministry said.
In Rio de Janeiro, which will host the Games from August 5-21, a first fatality was reported on March 31 by health care authorities.
A large majority -- 260 cases, 38 of them fatal -- were reported in the Sao Paulo region, the economic and financial engine of the now struggling South American powerhouse.
People have been waiting in line for more than three hours outside some hospitals to get vaccinated.
In Brazil, the H1N1 virus has normally appeared in recent years between May and July when temperatures are cooler.
But this year it has caught health authorities by surprise as it began in February.
It is not clear why, but many doctors say it stems from Brazilians who traveled to the northern hemisphere in the first months of the year.
A major H1N1 outbreak sparked a World Health Organization pandemic alert in June 2009, after the virus emerged from Mexico and the United States.
The epidemic killed around 18,500 people in 214 countries. The alert was lifted in August 2010.
Since late 2015 Brazil has been at the epicenter of the Zika virus crisis. The virus has been blamed for birth defects in babies born to women infected with the virus, which is carried by mosquitoes.