Background: Dengue infection is caused by a flavivirus, with 4 virus serotypes (types 1 to 4). The serotypes 2 and 3 represent the principal agents related to nervous system involvement. Neurologic involvement occurs in 4%–5% of dengue infection cases. The major mechanisms of the disease may be related to direct viral infection or postinfectious autoimmune process. The detection of intrathecal synthesis of specific antibodies has been used to support neurologic diagnosis as a proof of local reaction. It may be quantitatively calculated by the specific antibody index.

Dengue is an important global public health problem. The World Health Organization estimates that 2/5 of entire world population are in risk of dengue infection. Almost 50 millions cases occur annually, with at least 20 thousand deaths. The etiological agent of this acute febrile disease is a single-strand positive-sense RNA virus of Flavivirus genus. It is an arboviral disease transmitted by Aedes sp. mosquitoes (Aedes aegypti and A. albopictus). Most infected individuals present asymptomatic infection, but some may develop clinical signs. Therefore, a wide spectrum of illness can be observed, ranging from unapparent, mild disease, called dengue fever, to a severe and occasionally fatal dengue hemorrhagic fever/dengue shock syndrome. Currently, neurological manifestations related to dengue infections are increasingly been observed and appears as a challenge for medical practice. In this study the neurological complications of dengue infection will be reviewed, focusing a better understanding of the disease for the clinical practice.

• Breastfeeding as a potential route of Zika virus (ZIKV) transmission needs to be proved. • Breastfed children of ZIKV-infected mothers showed no ZIKV infection. • The presence of replicative particles in milk is insufficient to infect breastfed children. • Breastfeeding might be a less efficient route of ZIKV transmission.

BACKGROUND: Dengue infection may cause neurological manifestations such as encephalitis, myelitis, mononeuropathies, acute disseminated encephalomyelitis, and Guillain Barré syndrome (GBS). In endemic regions, the infection course can be oligosymptomatic making difficult the diagnosis of the neurological picture associated with dengue infection. OBJECTIVE: To report dengue infection and GBS association, even in oligosymptomatic cases of this infection. METHOD: During the dengue epidemic in Rio de Janeiro city we looked for GBS cases, testing IgM antibodies for dengue and dengue polymerase chain reaction (PCR) in the cerebrospinal fluid (CSF) and serum. RESULTS: We report seven cases (46.6%), presenting dengue positive IgM in serum but with poor or without clinical symptoms of the previous infection. Two of them had also positive IgM antibodies in CSF. CONCLUSION: These data show that search for dengue infection should be a routine in GBS cases living in endemic areas.