Dengue viruses in Brazil, 1986-2006

Abstract

A total of 4,243,049 dengue cases have been reported in Brazil between 1981 and 2006, including 5,817 cases of dengue hemorrhagic fever/dengue shock syndrome (DHF/DSS) and a total of 338 fatal cases. Although all Brazilian regions have been affected, the Northeast and Southeast regions have registered the highest number of notifications. DENV-1 and DENV-4 were isolated for the first time in the Amazon region of Brazil in 1981 and 1982. The disease became a nationwide public health problem following outbreaks of DENV-1 and DENV-2 in the state of Rio de Janeiro in 1986 and 1990, respectively. The introduction of DENV-3 in 2000, also in the state of Rio de Janeiro, led to a severe epidemic with 288 245 reported dengue cases, including 91 deaths. Virus strains that were typed during the 2002 epidemic show that DENV-3 has displaced other dengue virus serotypes and entered new areas, a finding that warrants closer evaluation. Unusual clinical symptoms, including central nervous system involvement, have been observed in dengue patients in at least three regions of the country.

Potential impact of a presumed increase in the biting activity of dengue-virus-infected Aedes aegypti (Diptera: Culicidae) females on virus transmission dynamics

“…The absolute number of infections was greater, and most strikingly, the annual pattern of epidemics changed, with more severe biennial epidemics being observed. This pattern of biennial epidemics more closely resembles the observed multi-annual cycle of dengue epidemics in endemic countries, including the pattern observed in Brazil (Nogueira et al 2007, Nogueira & Eppinghaus 2011. In agreement, other studies have shown the importance of the parameters related to the vector-host interaction, including the biting rate, in determining the seasonal and multi-annual cycle of dengue (Hay et al 2000, Bartley et al 2002.…”

Temporal analysis of the relationship between dengue and meteorological variables in the city of Rio de Janeiro, Brazil, 2001-2009

“…These numbers may underestimate true incidence 34,35 . Another limitation was the lack of reliable information in each time period on the specific incidence rates for each serotype (among the circulating serotypes) 36 . Some authors claim that the entry of a new serotype into a non-immune population entails a risk of explosive epidemics, even while the succession of serotypes can result in epidemics with more severe cases 10,18,37 .…”

Dengue: twenty-five years since reemergence in Brazil

“…In Southeast Asia dengue is predominantly a childhood disease, whereas in Brazil as of 2006, the incidence of dengue fever, dengue hemorrhagic fever, and even clinically unapparent dengue virus infection was much higher in adults 6,7,8 . Still, in the epidemic that exploded in the summer of 2008 in Rio de Janeiro, Brazil's second largest city, there was a sudden rise in the incidence among individuals younger than 15 years, both for dengue fever and dengue hemorrhagic fever 9 .…”