Role of monkeys in the sylvatic cycle of
chikungunya virus in Senegal
Benjamin M. Althouse
, Mathilde Guerbois
, Derek A.T. Cummings
, Ousmane M. Diop
, Ousmane Faye
, Diawo Diallo
, Bakary Djilocalisse Sadio
, Abdourahmane Sow
, Oumar Faye
Amadou A. Sall
, Mawlouth Diallo
, Brenda Beneﬁt
, Evan Simons
, Douglas M. Watts
, Scott C. Weaver
Kathryn A. Hanley
Arboviruses spillover into humans either as a one-step jump from a reservoir host species
into humans or as a two-step jump from the reservoir to an ampliﬁcation host species and
thence to humans. Little is known about arbovirus transmission dynamics in reservoir and
ampliﬁcation hosts. Here we elucidate the role of monkeys in the sylvatic, enzootic cycle of
chikungunya virus (CHIKV) in the region around Kédougou, Senegal. Over 3 years, 737
monkeys were captured, aged using anthropometry and dentition, and tested for exposure to
CHIKV by detection of neutralizing antibodies. Infant monkeys were positive for CHIKV even
when the virus was not detected in a concurrent survey of mosquitoes and when population
immunity was too high for monkeys alone to support continuous transmission. We conclude
that monkeys in this region serve as ampliﬁcation hosts of CHIKV. Additional efforts are
needed to identify other hosts capable of supporting continuous circulation.
Institute for Disease Modeling, Bellevue, 98005 WA, USA.
Information School, University of Washington, Seattle, 98105 WA, USA.
Biology, New Mexico State University, Las Cruces, 88003 NM, USA.
Department of Microbiology and Immunology, University of Texas Medical Branch,
Galveston, 77555 TX, USA.
Emerging Pathogens Institute, University of Florida, Gainesville, 32608 FL, USA.
Institut Pasteur de Dakar, Dakar, Senegal.
Department of Anthropology, New Mexico State University, Las Cruces, 88003 NM, USA.
Ofﬁce of Research and Sponsored Projects, University of Texas
at El Paso, El Paso, 79968 TX, USA.
Center for Biodefense and Emerging Infectious Diseases and Department of Pathology, University of Texas Medical
Branch, Galveston, 77555 TX, USA.
Institute for Human Infections and Department of Microbiology and Immunology, University of Texas Medical Branch,
Galveston, 77555 TX, USA. These authors contributed equally: Benjamin M. Althouse, Mathilde Guerbois. Correspondence and requests for materials should
be addressed to B.M.A. (email: firstname.lastname@example.org)