RT Journal Article SR Electronic T1 Monkey in the middle: monkeys serve as amplification hosts but not reservoir hosts of sylvatic chikungunya virus JF bioRxiv FD Cold Spring Harbor Laboratory SP 079046 DO 10.1101/079046 A1 Benjamin M. Althouse A1 Mathilde Guerbois A1 Derek A. T. Cummings A1 Ousmane M. Diop A1 Ousmane Faye A1 Abdourahmane Faye A1 Diawo Diallo A1 Bakary Djilocalisse Sadio A1 Abdourahmane Sow A1 Oumar Faye A1 Amadou A. Sall A1 Mawlouth Diallo A1 Brenda Benefit A1 Evan Simons A1 Douglas M. Watts A1 Scott C. Weaver A1 Kathryn A. Hanley YR 2016 UL http://biorxiv.org/content/early/2016/10/03/079046.abstract AB Background Novel pathogens can emerge into humans via one-step transmission from a reservoir host, an animal species in which the pathogen is maintained, or a two-step process in which the pathogen is transmitted from the reservoir host into a different amplification host species and thence to humans. Here we use serosurveillance and mathematical modeling to discover whether monkeys serve as reservoir or amplification hosts for mosquito-borne chikungunya virus (CHIKV). CHIKV invaded the Americas in 2013, and our study provides key data for predicting whether and where CHIKV will establish enzootic transmission among animal hosts in the New World.Results Over three years we captured 219 African green monkeys, 78 patas monkeys, and 440 Guinea baboons, the three monkey species near Kédougou, Senegal. Monkey age was determined by anthropometry and dentition, and exposure of each animal to CHIKV was determined via detection of neutralizing antibodies. Age and exposure were used to estimate age-specific CHIKV seroprevalence, force of infection (FoI), and basic reproductive number (R0) in each species. CHIKV FoI were extremely high, ranging from 0.13 (95% CI, 0.07–0.22) in patas in 2012 to 1.12 (95% CI, 0.81–2.28) in African greens in 2011. R0 ranged from 1.5 (95% CI, 1.3–1.9) in patas in 2012, to 6.6 (95% CI, 5.1–10.4) in baboons in 2011.Conclusions These findings demonstrate that monkeys in this region are constantly exposed to CHIKV transmission, even when population seropositivity, and therefore immunity, was too high for monkeys themselves to support continuous CHIKV transmission. We therefore conclude that monkeys in this system serve as amplification rather than reservoir hosts of CHIKV.Considering the potential for CHIKV to spill back in to monkeys in the Americas and elsewhere, improved understanding of its sylvatic cycle is essential to understanding and perhaps controlling the spread of this virus.