Guillain-Barré syndrome associated with ZIKV infection in Cúcuta is characterized by a high frequency of cranial nerve involvement, autonomic dysfunction and requirement of mechanical ventilation indicating an aggressive and severe course. AIDP is the most frequent electrophysiological subtype. Demyelination is prevalent distally but this pattern is not specific for ZIKV infection.

Stick insects (Phasmatodea) are among the least studied insect groups in Brazil. Although in recent years there has been an increase in the number of published studies on taxonomy and morphology of Brazilian stick insects, they remain very little-known concerning biological and bionomic aspects. From five females of Cladoxerus cryphaleus (Phasmatidae: Cladomorphinae) collected in the Iguaçu National Park, Paraná, Brazil, a captive colony of parthenogenetic females was started, based on which data on longevity, fertility, and viability of eggs of this species were recorded for the first time. After imaginal molting, the 21 females studied had an average longevity of 103.7 days. Each female produced on average 125.3 eggs, which had a hatching rate of 34.2%. In addition, we recorded a C. cryphaleus male nymph being parasitized by a biting midge of the subgenus Forcipomyia (Microhelea) (Diptera: Ceratopogonidae). The male, in pre-imaginal instar and already parasitized, was collected in the municipality of Petrópolis, Rio de Janeiro.

Despite the severe morbidity caused by Zika fever, its specific treatment is still a challenge for public health. Several research groups have investigated the drug repurposing of chloroquine. However, the highly toxic side effect induced by chloroquine paves the way for the improvement of this drug for use in Zika fever clinics. Our aim is to evaluate the anti-Zika virus (ZIKV) effect of hybrid compounds derived from chloroquine and sulfadoxine antimalarial drugs. The antiviral activity of hybrid compounds (C-Sd1 to C-Sd7) was assessed in an in-vitro model of human cervical and Vero cell lines infected with a Brazilian (BR) ZIKV strain. First, we evaluated the cytotoxic effect on cultures treated with up to 200 µM of C-Sds and observed CC50 values that ranged from 112.0 ± 1.8 to >200 µM in cervical cells and 43.2 ± 0.4 to 143.0 ± 1.3 µM in Vero cells. Then, the cultures were ZIKV-infected and treated with up to 25 µM of C-Sds for 48 h. The treatment of cervical cells with C-Sds at 12 µM induced a reduction of 79.8% ± 4.2% to 90.7% ± 1.5% of ZIKV–envelope glycoprotein expression in infected cells as compared to 36.8% ± 2.9% of infection in vehicle control. The viral load was also investigated and revealed a reduction of 2- to 3-logs of ZIKV genome copies/mL in culture supernatants compared to 6.7 ± 0.7 × 108 copies/mL in vehicle control. The dose–response curve by plaque-forming reduction (PFR) in cervical cells revealed a potent dose-dependent activity of C-Sds in inhibiting ZIKV replication, with PFR above 50% and 90% at 6 and 12 µM, respectively, while 25 µM inhibited 100% of viral progeny. The treatment of Vero cells at 12 µM led to 100% PFR, confirming the C-Sds activity in another cell type. Regarding effective concentration in cervical cells, the EC50 values ranged from 3.2 ± 0.1 to 5.0 ± 0.2 µM, and the EC90 values ranged from 7.2 ± 0.1 to 11.6 ± 0.1 µM, with selectivity index above 40 for most C-Sds, showing a good therapeutic window. Here, our aim is to investigate the anti-ZIKV activity of new hybrid compounds that show highly potent efficacy as inhibitors of ZIKV in-vitro infection. However, further studies will be needed to investigate whether these new chemical structures can lead to the improvement of chloroquine antiviral activity.

The order Phasmatodea includes insects known as stick insects. In Brazil, few taxonomic, ecological or evolutionary studies have been published in recent years, the reason is related to the few number of researchers dedicated to this particular group. Cladomorphus phyllinus Gray is one of the largest Brazilian insects and perhaps one of the most studied species of Phasmatodea in the country. It is considered as a phytophagous, generalist, and feeds mainly on guava leaves (Psidium guajava), powder-puff (Calliandra sp.) or Angico (Piptania sp.). Females of this species reproduce in a sexual and asexual manner, by the production of diploid daughters from unfertilized eggs (thelytokous parthenogenesis). The absence of records on the reproductive capacity of virgin parthenogenetic females of C. phyllinus led us to record the longevity, fertility, and eggs viability of ten specimens. The results obtained were compared to those found in the scientific literature for mated females of the same species. The fertility and eggs viability were observed to be much lower for the parthenogenetic females when compared to the mated females; however, the longevity for virgin females was longer than that recorded in the literature for mated females.

Zika virus (ZIKV) infection during pregnancy is associated with a congenital syndrome. Although the virus can be detected in human placental tissue and sexual transmission has been verified, it is not clear how the virus reaches the fetus. Despite the emerging severity caused by ZIKV infection, no specific prophylactic and/or therapeutic treatment is available. The aim of the present study was to evaluate the effectiveness antiviral of nitazoxanide (NTZ) in two important congenital transmission targets: (i) a primary culture of human placental chorionic cells, and (ii) human cervical epithelial cells (C33-A) infected with Brazilian ZIKV strain. Initially, NTZ activity was screened in ZIKV infected Vero cells under different treatment regimens with non-toxic drug concentrations for 48 h. Antiviral effect was found only when the treatment was carried out after the viral inoculum. A strong effect against the dengue virus serotype 2 (DENV-2) was also observed suggesting the possibility of treating other Flaviviruses. Additionally, it was shown that the treatment did not reduce the production of infectious viruses in insect cells (C6/36) infected with ZIKV, indicating that the activity of this drug is also related to host factors. Importantly, we demonstrated that NTZ treatment in chorionic and cervical cells caused a reduction of infected cells in a dose-dependent manner and decreased viral loads in up to 2 logs. Pre-clinical in vitro testing evidenced excellent therapeutic response of infected chorionic and cervical cells and point to future NTZ activity investigation in ZIKV congenital transmission models with the perspective of possible repurposing of NTZ to treat Zika fever, especially in pregnant women.