Brazil's dengue epidemic in the state and city of Rio do Janeiro added another 10.635 cases last week and totaled 110 deaths since the beginning of the year according to the latest report from the city's sanitary authorities.
The city's Health Secretariat said in a release that another 124 deaths are been investigated to confirm if they were caused by the viral disease transmitted by mosquitoes.
Since January the number of dengue cases reported in Rio totals 155.985, which is almost half the national total for the Brazilian population of 180 million. Of those, 84.131 are concentrated in the famous city of Rio do Janeiro followed by the world famous seaside resort of Angra dos Reis with 10.652 cases.
However sanitary authorities also pointed out that the peak of cases was last March with 63.196 cases and has since steadily decreased with 40.364 in March and 12.256 so far in May.
The incidence of the epidemics is significantly diminishing, as had been anticipated by sanitary authorities, because of the fall and lower temperatures which are not favorable for the reproduction of the Aedes aegypti mosquito.
Besides, last March the Brazilian Armed Forces were ordered into the city with camp hospitals to help with the mounting number of cases which had overwhelmed the precarious municipal hospital system.
According to the US Center for Disease Control and Prevention, dengue and dengue hemorrhagic fever are caused by one of four closely related, but antigenically distinct, virus serotypes (DEN-1, DEN-2, DEN-3, and DEN-4), of the genus Flavivirus.
DF and DHF are primarily diseases of tropical and sub tropical areas, and the four different dengue serotypes are maintained in a cycle that involves humans and the Aedes mosquito.
However, Aedes aegypti, a domestic, day-biting mosquito that prefers to feed on humans, is the most common Aedes species. Infections produce a spectrum of clinical illness ranging from a nonspecific viral syndrome to severe and fatal hemorrhagic disease.
Important risk factors for DHF include the strain of the infecting virus, as well as the affected person's age, and especially the prior dengue infection history of the patient.