Portal de Periódicos da CAPES

Vector control versus case isolation for chikungunya

2011; Elsevier BV; Volume: 15; Issue: 12 Linguagem: Inglês

10.1016/j.ijid.2011.09.004

1878-3511

Émilie Javelle, Isabelle Leparc-Goffart, Frédéric Pagès, Fabrice Simon,

Viral Infections and Vectors

The recently published review on chikungunya virus in Asia (Chikungunya in Southeast Asia: understanding the emergence and finding solutions; Pulmanausahakul et al.1Pulmanausahakul R. Roytrakul S. Auewarakul P. Smith D.R. Chikungunya in Southeast Asia: understanding the emergence and finding solutions.Int J Infect Dis. 2011 Jul 18; ([Epub ahead of print])PubMed Google Scholar) reports the current phylogenetic and pathological aspects of the explosive and ongoing re-emergence of this virus across continents. As explained by Pulmanausahakul et al., as long as a chikungunya vaccine remains a prospect, the prevention of large-scale outbreaks will continue to rely on vector control programs.1Pulmanausahakul R. Roytrakul S. Auewarakul P. Smith D.R. Chikungunya in Southeast Asia: understanding the emergence and finding solutions.Int J Infect Dis. 2011 Jul 18; ([Epub ahead of print])PubMed Google Scholar In this context, measures to contain the spread of the virus should be taken, with the widespread provision of bednets to suspected viremic cases in order to protect them against mosquito bites as quickly as possible. Considering that the Aedes spp mosquito is commonly diurnal, it is imperative that any clinical case of chikungunya be isolated under a bednet all day long, whether in the medical setting or at home. This strategy appears relevant and achievable with regard to several mosquito-borne viral diseases, including chikungunya; the case can be made as follows: (1) The fairly high viral load of chikungunya virus in the blood during the first days of infection, as is the case for dengue virus,2Laurent P. Le Roux K. Grivard P. Bertil G. Naze F. Picard M. et al.Development of a sensitive real-time reverse transcriptase PCR assay with an internal control to detect and quantify chikungunya virus.Clin Chem. 2007; 53: 1408-1414Crossref PubMed Scopus (105) Google Scholar increases the risk of a mosquito being contaminated after only a single bite. (2) Considering the lessons from Singapore,1Pulmanausahakul R. Roytrakul S. Auewarakul P. Smith D.R. Chikungunya in Southeast Asia: understanding the emergence and finding solutions.Int J Infect Dis. 2011 Jul 18; ([Epub ahead of print])PubMed Google Scholar no appropriate identification of the main vector species is required for this strategy to be effective. (3) The mandatory isolation of suspected cases under bednets in the early 20th century helped to control yellow fever in epidemic areas such as Havana.3Le Dantec A. Précis de pathologie exotique.2nd ed. Octave Doin, Paris1911Google Scholar (4) Reinforcement of nets (insecticide-impregnated curtains, doors and windows screened with insecticide treated nets) in an integrated vector control approach against dengue transmission was proved to limit mosquito bites more efficiently than environmental management alone.4Erlanger T.E. Keiser J. Utzinger J. Effect of dengue vector control interventions on entomological parameters in developing countries: a systematic review and meta-analysis.Med Vet Entomol. 2008; 22: 203-221Crossref PubMed Scopus (132) Google Scholar Furthermore, a cluster-randomized trial in Haiti revealed that insecticide-treated bednets have a long lasting effect on reducing the dengue vector populations.5Lenhart A. Orelus N. Maskill R. Alexander N. Streit T. McCall P.J. Insecticide-treated bednets to control dengue vectors: preliminary evidence from a controlled trial in Haiti.Trop Med Int Health. 2008; 13: 56-67Crossref PubMed Scopus (100) Google Scholar (5) Finally, the World Health Organization recommends the use of bednets to protect primarily those who are sick, but also those who rest during the day in order to limit the spread of the virus.6World Health Organization WHO Regional Office for South-East Asia. Fact sheet on dengue fever and dengue haemorrhagic fever. Online 2011; 10:10. Last update 2006; 04:08.Google Scholar This complementary action would probably not increase resistance to insecticides significantly.7Gratz N.G. Jany W.C. What role for insecticides in vector control programs?.Am J Trop Med Hyg. 1994; 50: 11-20PubMed Google Scholar The cost-effectiveness of the application of this strategy should be evaluated in tropical and temperate risk areas already equipped with long-lasting impregnated bednets as a priority. Conflict of interest: No conflict of interest to declare.