RESUMO Dengue, Zika e Chikungunya são arbovírus emergentes e importante causa de doença febril aguda em áreas tropicais. Embora a dengue não represente uma doença nova, houve uma expansão geográfica ao longo do tempo, com o aparecimento de complicações neurológicas graves. A negligência desta situação permitiu a propagação do vetor (Aedes spp) em todo o mundo, que também é responsável pela transmissão de outras infecções pelos vírus Zika e Chikungunya. O grande número de casos infectados contribui para o aumento de manifestações neurológicas incluindo encefalite, mielite, meningite, síndrome de Guillain-Barré e má formações congênitas, como microcefalia. Nesta revisão narrativa, destaca-se o impacto da expansão geográfica do vetor no aparecimento de complicações neurológicas e a falta de testes laboratoriais de elevada acurácia para o diagnóstico da infecção neurológica. Estes aspectos representam desafio para a saúde pública mundial, considerando o grande número de indivíduos que moram ou viajam para áreas endêmicas.

ABSTRACT Dengue, Zika and Chikungunya are emerging arboviruses and important causes of acute febrile disease in tropical areas. Although dengue does not represent a new condition, a geographic expansion over time has occurred with the appearance of severe neurological complications. Neglect has allowed the propagation of the vector (Aedes spp), which is also responsible for the transmission of other infections such as Zika and Chikungunya throughout the world. The increased number of infected individuals has contributed to the rise of neurological manifestations including encephalitis, myelitis, meningitis, Guillain-Barré syndrome and congenital malformations such as microcephaly. In this narrative review, we characterize the impact of the geographic expansion of the vector on the appearance of neurological complications, and highlight the lack of highly accurate laboratory tests for nervous system infections. This represents a challenge for public health in the world, considering the high number of travelers and people living in endemic areas.

The aim of this study was to evaluate the efficacy of a polymerase chain reaction (PCR)-based method to detect Schistosoma mansoni DNA in stool samples from individuals living in a low-endemicity area in Brazil. Of the 125 initial stool samples, 80 were ELISA reactive and eggs were identified in 19 of the samples by parasitological examination. For the PCR evaluations, 56 stool samples were selected and divided into five groups. Groups I-IV were scored negative for S. mansoni eggs by parasitological examination. Groups I and II were ELISA reactive, whereas Groups III and IV were ELISA nonreactive. Groups II and III were positive for other intestinal parasites. PCR testing scored eight samples as positive from these four groups. Group V represented the S. mansoni -positive group and it included ELISA-reactive samples that were scored positive for S. mansoni by one or more parasitological examinations (6/19 were positive by Kato-Katz method, 9/17 by saline gradient and 10/13 by Helmintex®). PCR scored 13 of these 19 samples as positive for S. mansoni . We conclude that while none of these methods yielded 100% sensitivity, a combination of techniques should be effective for improving the detection of S. mansoni infection in low-endemicity areas.