Successful strategies implemented towards the elimination of canine rabies in the Western Hemisphere

Abstract

Almost all cases of human rabies result from dog bites, making the elimination of canine rabies a global priority. During recent decades, many countries in the Western Hemisphere have carried out large-scale dog vaccination campaigns, controlled their free-ranging dog populations and enforced legislation for responsible pet ownership. This article reviews progress in eliminating canine rabies from the Western Hemisphere. After briefly summarizing the history of control efforts and describing the approaches listed above, we note that programs in some countries have been hindered by societal attitudes and severe economic disparities, which underlines the need to discuss measures that will be required to complete the elimination of canine rabies throughout the region. We also note that there is a constant threat for dog-maintained epizootics to re-occur, so as long as dog-maintained rabies "hot spots" are still present, free-roaming dog populations remain large, herd immunity becomes low and dog-derived rabies lyssavirus (RABLV) variants continue to circulate in close proximity to rabies-naïve dog populations. The elimination of dog-maintained rabies will be only feasible if both dog-maintained and dog-derived RABLV lineages and variants are permanently eliminated. This may be possible by keeping dog herd immunity above 70% at all times, fostering sustained laboratory-based surveillance through reliable rabies diagnosis and RABLV genetic typing in dogs, domestic animals and wildlife, as well as continuing to educate the population on the risk of rabies transmission, prevention and responsible pet ownership. Complete elimination of canine rabies requires permanent funding, with governments and people committed to make it a reality. An accompanying article reviews the history and epidemiology of canine rabies in the Western Hemisphere, beginning with its introduction during the period of European colonization, and discusses how spillovers of viruses between dogs and various wild carnivores will affect future eradication efforts (Velasco-Villa et al., 2017).

Fig. 1

Distribution of dog-maintained rabies and its impact on rabies in humans transmitted from dogs in Latin America and the Caribbean. Solid red circles depict the total number of human rabies cases from 1993 to 2015; the size of each circle represents the number of cases according to the scale (lower left). Grayscale of countries represents the number of laboratory-confirmed rabid dogs carrying dog-maintained RABLV variants from 1993 to 2015. Scale for number of cases is depicted in the lower left. Countries with no cases or no data available are in white. Source, SIRVERA/SIEPI-PANAFTOSA/PAHO/WHO, http://new.paho.org/panaftosa. (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)

Fig. 2

Canine rabies elimination efforts in Latin America and the Caribbean. Geographic location of dog-maintained rabies foci, as confirmed by PAHO collaborating center laboratories in the period 2010–15.

Fig. 3

Laboratory-confirmed infections with dog-derived RABLV variants in humans and animals that were acquired from carnivore species other than dogs from 2005 to 15. Grayscale reflects the number of confirmed human cases in which dog-derived variants transmitted by cats and wild carnivore hosts were identified. (Cats are not reservoir hosts, but can be involved as secondary transmitters of rabies.) Countries that did not report cases during this time period (Chile, Argentina, Guatemala, Costa Rica, El Salvador and Panama) and those with no data available or that do not report to PAHO (Trinidad and Tobago, Guyana, Surinam, and French Guiana) are shown in white. Colored bars within countries depict the most frequently positive species and major transmitters to humans, with cats (red), foxes (blue), skunks (yellow), and mongoose (green). Source, SIRVERA/SIEPI-PANAFTOSA/PAHO/WHO, http://new.paho.org/panaftosa. (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)

Fig. 4

Distribution of rabies diagnostic laboratories in Latin America and the Caribbean, their capacity and their affiliation to a Ministry of Health or Ministry of Agriculture. Color-coded countries represent total human rabies cases reported, as a reflection of testing capacity. Countries with low numbers of cases are in blue, medium in pink, and high in red. Countries with no cases reported or no data available are shown in white. Laboratory diagnostic capacity is depicted as follows: green dots for countries performing the “gold standard” direct fluorescent antibody test (DFA), filled black squares for countries performing DFA and viral typing by monoclonal antibodies and/or sequencing techniques (typing), and gold stars for countries performing DFA, viral typing and antibody titration via rapid immune fluorescent foci inhibition test (RIFFT). Countries with two icons (dot and square) represent independent diagnostic capacities for laboratories of the Ministry of Health and the Ministry of Agriculture. The locations of the icons represent the actual geographic locations of the labs. (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)