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

Matthew John Valentine,Amy Beierschmitt,Christa Ann Gallagher,Chengming Wang,Tatiana Corey,Brenda Ciraola,Bernard Tenebray,Xavier De Lamballerie,Matthew Thomas Aliota,Michel Vandenplas,Isabelle Leparc-Goffart,Silvia Marchi,Kerry Mcauliffe Dore,Patrick John Kelly,Courtney Cuin Murdock

doi:10.1186/s13071-020-04419-1

Abstract

BackgroundDengue, 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.MethodsWe 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.ResultsAll 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.ConclusionSylvatic cycles involving AGMs and DENV, CHIKV and ZIKV do not currently exist on St. Kitts.

Highlights

Dengue, chikungunya and Zika viruses (DENV, Chikungunya virus (CHIKV) and ZIKV) are transmitted in sylvatic transmission cycles between non-human primates and forest mosquitoes in Africa and Asia
While foraging for food and water, which can be over large areas depending on availability that varies with season, it would be anticipated that African green monkey (AGM) should come into contact with, and potentially host a wide variety of mosquitoes we know of no data on the species involved
Serology of AGMs The 268 sera tested with an in-house ELISA in France and with commercial ELISA test kits for antibodies to Dengue virus (DENV) and CHIKV all gave negative results

Summary

Introduction

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. Valentine et al Parasites Vectors (2020) 13:540 mosquitoes maintain the viruses in sylvatic (NHP-mosquito-NHP) transmission cycles which continue to this day [3, 7,8,9] It remains an outstanding question whether sylvatic cycles of these arboviruses are present elsewhere in the world where there are similar non-human primate vertebrate hosts and mosquitoes [8, 10,11,12].

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