Zika virus (ZIKV) emerged in Brazil in 2015, which was followed by an increase of Guillain–Barre Syndrome (GBS) cases. We report the epidemiological, clinical, and laboratory findings of the first six neurological cases associated with ZIKV in Brazil seen in a reference neurology hospital in Pernambuco, Brazil. In all cases, ZIKV was detected in serum and/or cerebrospinal fluid (CSF) samples. In this case series, four cases were defined as GBS, one as acute disseminated encephalomyelitis (ADEM) and the other as encephalitis. ZIKV was detected in all cases by RT-PCR and virus isolation was successful in two patients. The time between ZIKV acute symptoms and the development of neurological manifestations varied from 3 to 13 days and ZIKV was detected between 15 and 34 days after the initial symptoms. Our results highlight the need to include ZIKV as a differential diagnosis for neurological syndromes in countries with circulation of this arbovirus. Because the viremia in these patients appears to persist longer, direct diagnostic techniques such as RT-PCR and viral isolation should be considered even if it is after the acute phase of viral infection.

Hydroxychloroquine (HCQ) has been used for the treatment of novel coronavirus disease (COVID-19) cases. However, evidence of efficacy remains limited, and adverse events can be associated with its use. Here, we report a case of a patient with severe COVID-19 who, after being administered HCQ, exhibited a 10-fold increase in serum levels of transaminases, followed by a rapid decrease after HCQ was withdrawn. Considering the significantly increased use of HCQ during the COVID-19 pandemic, this case alerts us to the potential for HCQ to be associated with hepatotoxicity and the need to monitor liver function during HCQ therapy.

Keywords: Aedes; Arboviruses; Flavivirus; Flaviviridae Infections.

Since the detection of the Chikungunya virus in America in 2013, two million cases of the disease have been notified worldwide. Severe cases and deaths related to Chikungunya have been reported in India and Reunion Island, estimated at 1 death per 1,000 inhabitants. Joint involvement in the acute and chronic phase is the main clinical manifestation associated with Chikungunya. The severity of the infection may be directly attributable to viral action or indirectly, owing to decompensation of preexisting comorbidities. In Brazil, the virus was identified in 2014, and recently, there has been a significant increase in the number of deaths caused by the Chikungunya virus infection, especially in Pernambuco. However, the numbers of fatalities are probably underreported, since for many cases, the diagnosis of Chikungunya infection may not be considered, for deaths by indirect causes. An increase in the mortality rate within months of epidemic occurrence, compared to previous years has also been reported and may be associated with Chikungunya virus infection. An in-depth investigation of reported mortality in Brazil is necessary, to measure the actual impact of the deaths, thereby, allowing the identification of possible causes. This will alert professionals about the risks, and hence, enable creation of protocols that target reducing mortality.

Zika virusis an arbovirus of the Flaviviridae family with two major strains, an Asian and an African strain. The main vectors involved in the transmission of Zika virus are the Aedes aegypti and Aedes albopictus mosquitoes. Despite its identification, discovered in 1947 in the Zika forest in Uganda, only isolated and sporadic occurrences of human infection were reported within a largely asymptomatic proportion of individuals. The first reported outbreak occurred in 2007 in the Yap Island, which belongs to the Federated States of Micronesia in the Pacific Ocean, and in French Polynesia, where high attack rates occurred and the first cases of associated Guillain-Barré syndrome were reported. From November 2014 to early 2015, the Northeast states of Brazil reported the first outbreaks of Zika virus infection, with laboratory confirmation of Zika virus circulation in April 2015. In the second quarter of 2015, the association between Zika virus infection and neurological symptoms was confirmed in adults. Moreover, in October 2015 a novel suspicion was raised based on clinical and epidemiological observations: that an association between Zika virus infection and neonatal microcephaly may exist. A year after the first reports on Zika virus in Brazil, many hypotheses and much evidence on the patterns of involvement of the disease and its complications have been produced, both in this country and others; other hypotheses still need to be clarified. This review is a synthesis of a new chapter in the history of medicine; it outlines the main results produced.