The epidemic of coronavirus disease 2019 (COVID-19), caused by a novel Betacoronavirus named severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) became a public health emergency worldwide. Few reports indicate that owned pets from households with at least one human resident that was diagnosed with COVID-19 can be infected by SARS-CoV-2. However, the exposure to SARS-CoV-2 of pets from households with no COVID-19 cases or stray animals remains less assessed. Using real-time reverse transcriptase polymerase chain reaction (RT-PCR) and plaque reduction neutralization test (PRNT90), we investigated the infection and previous exposure of dogs and cats to SARS-CoV-2 during the ongoing COVID-19 epidemic in Rio de Janeiro, Brazil. From June to August 2020, 96 animals were sampled, including 49 cats (40 owned and 9 stray) and 47 dogs (42 owned and 5 stray). Regarding owned pets, 75.6% (62/82) belonged to households with no COVID-19 cases. Samples included serum, and rectal and oropharyngeal swabs. All swabs were negative for SARS-CoV-2 RNA, but serum samples of a stray cat and a stray dog presented neutralizing antibodies for SARS-CoV-2, with PRNT90 titer of 80 and 40, respectively. Serological data presented here suggest that not only owned pets from households with COVID19 cases, but also stray animals are being exposed to SARS-CoV-2 during the COVID-19 pandemic.

BACKGROUND Zika has emerged as a new public health threat after the explosive epidemic in Brazil in 2015. It is an arbovirus transmitted mainly by Aedes aegypti mosquitoes. The knowledge of physiological, behavioural and biological features in virus-infected vectors may help the understanding of arbovirus transmission dynamics and elucidate their influence in vector capacity.OBJECTIVES We aimed to investigate the effects of Zika virus (ZIKV) infection in the behaviour of Ae. aegypti females by analysing the locomotor activity, egg production and viability.METHODOLOGY Ae. aegypti females were orally infected with ZIKV through an artificial feeder to access egg production, egg viability and locomotor activity. For egg production and viability assays, females were kept in cages containing an artificial site for oviposition and eggs were counted. Locomotor activity assays were performed in activity monitors and an average of 5th, 6th and 7th days after infective feeding was calculated.FINDINGS No significant difference in the number of eggs laid per females neither in their viability were found between ZIKV infected and non-infected females, regardless the tested pair of mosquito population and virus strain and the gonotrophic cycles. Locomotor activity assays were performed regardless of the locomotor activity in ZIKV infected females was observed, in both LD and DD conditions.MAIN CONCLUSIONS The lower locomotor activity may reduce the mobility of the mosquitoes and may explain case clustering within households reported during Zika outbreaks such as in Rio de Janeiro 2015. Nevertheless, the mosquitoes infected with ZIKV are still able to disseminate and to transmit the disease, especially in places where there are many oviposition sites.

chikungunya and Zika are arboviruses transmitted by the mosquito Aedes aegypti. Mosquito fecundity and egg viability are important parameters of vectorial capacity. Here we aim to understand, comparatively, the effects of Chikungunya virus (CHIKV) and Zika virus (ZIKV) infections on the fecundity and fertility of young and old Aedes aegypti females. Using artificial infection blood feeding experiments we observed that both cHiKV and ZiKV do not alter the number of eggs laid when compared to uninfected females, although the egg fertility significantly decreases in both young and old CHIKV-infected females. There is an upward trend of null females (infertile females) from 2.1% in young to 6.8% in old ZIKV-infected females. Together, our data revealed that CHIKV and ZIKV affects differently Ae. aegypti physiology, that may be related to different viral spread in nature. Chikungunya virus (CHIKV), a member of the Togaviridae family, Alphavirus genus, was first isolated in 1952 in Tanzania 1. Emerging and reemerging outbreaks have occurred since its discovery in several regions in Africa, Asia, Indian Ocean islands and Mediterranean areas in Europe 2,3. In Brazil, the first Chikungunya autochthonous cases occurred in 2014 4. The virus spread throughout the country 5 , being in co-circulation with dengue (DENV) and Zika (ZIKV) viruses during this period 6. Zika, a virus belongs to Flaviviridae family, Flavivirus genus, was first isolated in 1947 7. For 60 years, only sporadic Zika cases were reported in humans, however in 2007 an outbreak occurred in Yap Island, Micronesia 8. Subsequently, ZIKV expanded throughout the Pacific islands and reached the Americas in 2015, turning into an epidemic in Brazil. It is currently considered a new public health threat 9-11. Both arboviruses (Zika and Chikungunya) are transmitted by the bite of mosquitoes of genus Aedes 7,12,13. Among them, the Aedes aegypti is the main vector in the urban transmission cycle 14-16. This domestic and anthropophilic species is anautogenous (the females need blood supply for eggs maturation) 17. After one or more blood feedings, egg maturation occurs in about 3 or 4 days. Each period between blood feeding and egg laying is called gonotrophic cycle (GC) 17-19. An Ae. aegypti female is able to lay approximately 100 eggs per GC 20. The ingestion of more than one blood meal by mosquito females within a single gonotrophic cycle is called gonotrophic discordance and can occur in Aedes aegypti mosquitoes. This feature is involved in vectorial capacity and is very important for the transmission of viruses 21-23. Comparatively, the biology of the egg phase is less explored than other in the mosquito life cycle. The Ae. aegypti eggs can survive for long periods in dry conditions at the end of their embryonic development 17,19,24-26. This important feature is related to ecological issues such as dormancy, that enables the embryo to survive