Clusters of acute exanthematous illness in Brazil have been linked since 2014 to the Zika virus, but research also suggests the concurrent transmission of dengue and chikungunya by the same vectors, a new report reveals.
Zika virus is an emerging mosquito-borne flavivirus that causes a denguelike illness characterized by exanthema, low-grade fever, conjunctivitis, and arthralgia. In a letter to the journal Emerging Infectious Diseases published online, Dr. Cristiane W. Cardoso of the Municipality of Health in Salvador, Brazil, and her coauthors describe the challenges Brazilian public health authorities faced in clinically differentiating Zika virus infections from dengue and chikungunya viruses, also circulating in Brazil from February 2015 to June 2015 (Emerg Infect Dis. 2015 Dec. doi: 10.3201/eid2112.151167).
All three viruses are etiologic agents of acute exanthematous illness, which suggests that the three Aedes mosquito−transmitted viruses were co-circulating in the state of Salvador. The research highlights the challenge in clinically differentiating the infections during outbreaks. The researchers were not able to determine the specific incidence of each virus but write that the low frequency of fever and arthralgia, which are indicators of dengue and chikungunya, point to Zika virus as the probable cause of several reported cases in 2015.
Dr. Cardoso says the spread of Zika virus represents a challenge for public health systems because of the risk for concurrent transmission of dengue and chikungunya by the same vectors – Aedes aegypti and Aedes albopictus mosquitoes – which are abundant throughout tropical and subtropical regions. The authors also suggest that an increase in reports of Guillain-Barré syndrome during the outbreak deserves further investigation to determine whether the syndrome is associated with Zika infection.
To read the entire letter, click here.
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