Isolation of Rickettsia rickettsii in Rocky Mountain Spotted Fever Outbreak, Panama

One health approach to Rickettsia spp.: Brazilian indigenous individuals, their dogs and ticks, and healthcare professionals

Although Indigenous populations have historically overlapped the occurrence of vector-borne pathogens, no One Health approach study has investigated Rickettsia spp. in indigenous communities worldwide. Accordingly, the aim of this study was to investigate anti-Rickettsia spp. antibodies in indigenous individuals, their dogs and healthcare professionals, and Rickettsia spp. infection in ticks from ten indigenous communities of southern and southeastern Brazil. In overall, 66/771 (8.6 %) indigenous individuals, 9/99 (9.1 %) healthcare professionals and 116/386 (30.1 %) dogs were seropositive for at least one out four Rickettsia species tested by immunofluorescence assay (IFA). Out of 603 ticks collected from dogs in indigenous communities, 9/190 (4.7 %) tested positive to fragment of Rickettsia gltA gene by real-time PCR. The homologous antigenic reactions in dogs were significantly more frequent for R. bellii when compared to R. parkeri and R. amblyommatis and may be associated with the high diversity of hard and soft ticks in Americas, and R. bellii capacity of inhibiting another pathogenic rickettsia. Tick bite history increased the seropositivity (odds ratio = 9.29; p = 0.019) in healthcare professionals. This difference may be consequence of higher capacity to recognize tick bites by healthcare professionals, which highlighted the necessity of health care education for indigenous individuals for prevention and early recognition of tick-borne diseases in indigenous communities. In addition, the One Health approach herein has provided a holistic understanding of Rickettsia spp. infection in such communities and correspondent healthcare personal.

Clinical manifestations of Rickettsia rickettsii in a familial outbreak in Panama

We report an isolated outbreak of Rickettsia rickettsii in the Ngäbe-Buglé indigenous region, located 750 m (tropical wet) above sea level, in a jungle and mountainous area of Western Panama. Seven members of a family were infected simultaneously, resulting in four deaths. Family outbreaks have been previously described and are responsible for 4-8% of the cases described [1-4]. The simultaneous onset of symptoms in the affected population group is extremely unusual [1,5], but it should not dissuade the clinician from considering the possibility of Rickettsia rickettsii infection.

Ticks infesting humans in Central America: A review of their relevance in public health

Ticks are blood-sucking arthropods that parasitize most groups of terrestrial or semiaquatic vertebrates. Humans are accidental hosts to the ticks; however, in humans the ticks can cause damages varying from simple irritation to severe allergies, toxicosis, paralysis, and the transmission of pathogens, some of which can be fatal. Central America represents a narrow isthmus between North and South America and is considered a biodiversity hotspot. The importance of tick-borne diseases in this region is manifested by fatal outbreaks caused by Rickettsia rickettsii, severe and mild cases of other rickettsioses, ehrlichiosis, and tick-borne relapsing fevers, in addition to cases paralysis and strong allergic reactions. Even so, this information is scarce in most countries of this region, and there are no epidemiological data. In this article we present a review of the ticks that parasitize humans in Central America, covering data from the 19th Century to the present day. Of nearly 80 tick species reported in Central America, 28 species are reported on humans. This list includes species that thrive within homes, grazing areas and, to a lesser extent, in wild environments, both in lowland and high mountain forests. The most important genus in this region is Amblyomma, followed by Rhipicephalus and Ornithodoros, and to a lesser extent Haemaphysalis, Ixodes and Dermacentor. These data provide information on the tick species most commonly associated with humans in Central America, and highlight the potential for tick-borne diseases in wild, rural and urban regions.

Ticks and Tick-Borne Diseases in Central America and the Caribbean: A One Health Perspective

Ticks have complex life cycles which involve blood-feeding stages found on wild and domestic animals, with humans as accidental hosts. At each blood-feeding stage, ticks can transmit and/or acquire pathogens from their hosts. Therefore, the circulation of tick-borne pathogens (TBPs), especially the zoonotic ones, should be studied in a multi-layered manner, including all components of the chain of infections, following the 'One Health' tenets. The implementation of such an approach requires coordination among major stakeholders (such as veterinarians, physicians, acarologists, and researchers) for the identification of exposure and infection risks and application of effective prevention measures. In this review, we summarize our current knowledge on the epidemiology of tick-borne diseases in Central America and the Caribbean and the challenges associated with the implementation of 'One Health' surveillance and control programs in the region.