No evidence for sylvatic cycles of chikungunya, dengue and Zika viruses in African green monkeys (Chlorocebus aethiops sabaeus) on St. Kitts, West Indies

Abstract

Background Dengue, chikungunya and Zika viruses (DENV, CHIKV and ZIKV) are transmitted in sylvatic transmission cycles between non-human primates and forest (sylvan) mosquitoes in Africa and Asia. It remains unclear if sylvatic cycles exist or could establish themselves elsewhere and contribute to the epidemiology of these diseases. The Caribbean island of St. Kitts has a large African green monkey (AGM) (Chlorocebus aethiops sabaeus) population and is therefore ideally suited to investigate sylvatic cycles. Methods We tested 858 AGM sera by ELISA and PRNT for virus-specific antibodies and collected and identified 9704 potential arbovirus vector mosquitoes. Mosquitoes were homogenized in 513 pools for testing by viral isolation in cell culture and by multiplex RT-qPCR after RNA extraction to detect the presence of DENV, CHIKV and ZIKVs. DNA was extracted from 122 visibly blood-fed individual mosquitoes and a polymorphic region of the hydroxymethylbilane synthase gene (HMBS) was amplified by PCR to determine if mosquitoes had fed on AGMs or humans. Results All of the AGMs were negative for DENV, CHIKV or ZIKV antibodies. However, one AGM did have evidence of an undifferentiated Flavivirus infection. Similarly, DENV, CHIKV and ZIKV were not detected in any of the mosquito pools by PCR or culture. AGMs were not the source of any of the mosquito blood meals. Conclusion Sylvatic cycles involving AGMs and DENV, CHIKV and ZIKV do not currently exist on St. Kitts.

Lack of serological and molecular evidences of Zika virus circulation in non-human primates in three states from Brazil

“… 17 , 18 Despite the preference for human host, other available mammals may serve as a blood smear for these antropophilic mosquito, including non-human primates. 19 , 20 …”

“…to feed in neotropical primates, as observed in previous studies with African Green monkeys. 19 In addition, the absence of ZIKV infection in free-ranging animals that possibly will have contact with sylvatic vectors may indicate the potential absence of primatophilic competent vectors in an enzootic cycle. 25 Although we have not sampled mosquitoes, the refractory infection and low competence viral were observed in an experimental study with five wild neotropical mosquito species including Haemagogus leucocelaenu , 26 considered one of the primary sylvatic YFV vectors in Brazil.…”

Praemonitus praemunitus: can we forecast and prepare for future viral disease outbreaks?

“…Factors affecting the origination and spread of the outbreak . While the broader epidemiology of MARV is unknown, at this point, non-human primates have not proven susceptible to the disease, unlike the Ebola virus (Valentine et al 2020). The majority of human outbreaks occurred due to spillover events in caves and mines.…”

Trade-offs shaping transmission of sylvatic dengue and Zika viruses in monkey hosts

“…Soon after, YFV established urban transmission in the Americas and spilled back into a sylvatic cycle maintained in neotropical primates and mosquitoes that plagues South America to present day 3 , 4 . The four serotypes of dengue virus (DENV-1-4) underwent a similar journey, albeit their ancestral sylvatic cycles occur in Asia, but compelling evidence of a sylvatic cycle of DENV in the Americas has never been detected despite being actively sought 5 – 7 . Thus, when ZIKV was detected in the Americas in 2015, there was great concern, but equally great uncertainty, about its potential to establish a neotropical sylvatic cycle 8 – 10 .…”