Spatio-temporal dynamics of rabies and habitat suitability of the common marmoset Callithrix jacchus in Brazil

Abstract

Rabies transmitted by wildlife is now the main source of human rabies in the Americas. The common marmoset, Callithrix jacchus, is considered a reservoir of rabies causing sporadic and unpredictable human deaths in Brazil, but the extent of the spillover risk to humans remains unknown. In this study, we described the spatiotemporal dynamics of rabies affecting C. jacchus reported to Brazil’s Ministry of Health passive surveillance system between 2008 and 2020, and combined ecological niche modelling with C. jacchus occurrence data to predict its suitable habitat. Our results show that 67 outbreaks (91 cases) of rabies affecting C. jacchus were reported by 41 municipalities between January 2008 and October 2020, with a mean of 5 outbreaks/year [range: 1–14]. The maximum number of outbreaks and municipalities reporting cases occurred in 2018, coinciding with higher surveillance of primate deaths due to Yellow Fever. A mean of 3 [1–9] new municipalities reported outbreaks yearly, suggesting potential spatial expansions of the C. jacchus variant in northeastern Brazil and emerging rabies spillover from vampire bat Desmodus rotundus to C. jacchus in the north and south. Outbreaks were concentrated in the states of Ceará (72%) and Pernambuco (16%) up to 2012, but are now reported in Piauí since 2013, in Bahia since 2017 (D. rotundus’ antigenic variant, AgV3) and in Rio de Janeiro since 2019 (AgV3). Besides confirming suitable habitat for this primate in the northeast and the east coast of Brazil, our Maximum Entropy model also predicted suitable habitat on the north and the west states of the country but predicted low habitat suitability among inland municipalities of the Caatinga biome reporting rabies. Our findings revealed new areas reporting rabies infecting C. jacchus, highlighting the need to implement strategies limiting spillover to humans and to better understand the drivers of C. jacchus rabies dynamics.

Rabies virus variants from bats closely related to variants found in marmosets (Callithrix jacchus), a neglected source of human rabies infection in Brazil

“…11,12 In recent years, wild mammals, especially bats and marmosets (C. jacchus), have become prominent players in the rabies transmission chain in Brazil. 4,13 C. jacchus, a small diurnal primate (New World monkey) is native to the Atlantic Forest that extends along the Northeastern coast of Brazil. It is commonly captured and kept as a domestic pet in the State of Ceará and is widely dispersed in tourist regions throughout Brazil.…”

“…Another mammal, the white-tufted marmoset (Callithrix jacchus), considered the only primate reservoir of rabies, has also been associated with sporadic and unpredictable human deaths (10.63%) in Brazil. 4,5 However, epidemiological and evolutionary insights about the marmoset-associated RABV variant in a distinct animal host group and spillover events into the human population remains little explored. Here, we describe evolutionarily distinct bat variants of RABV amongst those classically reported in bats; they are phylogenetically close to those found in C. jacchus and associated with human deaths in Brazil.…”

“…Another mammal, the white‐tufted marmoset ( Callithrix jacchus ), considered the only primate reservoir of rabies, has also been associated with sporadic and unpredictable human deaths (10.63%) in Brazil 4,5 . However, epidemiological and evolutionary insights about the marmoset‐associated RABV variant in a distinct animal host group and spillover events into the human population remains little explored.…”

Infectious diseases of neotropical primates

“…In this case the sequenced viral DNA showed characteristic of hematophagous bats Desmodus rotundus RABV strain (AgV3), similar to the one detected in the cases from Bahia. C. jacchus antigenic RABV strain was also identified in 20 reported cases from the Brazilian Northeast (19). Capuchins (Sapajus sp.…”

“…In Brazil RABV has been controlled by preventive vaccination programs focusing on domestic animals. However, currently, wild animals, especially vampire (19,58,88,107,136). Interestingly, outbreaks of RABV were initially concentrated in the states of Ceará and Pernambuco (up to 2012) but now extended to other states, such as Piauí (since 2013), Bahia (2017), and Rio de Janeiro (2019) (19).…”