Occurrence, clinical manifestation and the epidemiological implications of naturally occurring canine trypanosomosis in western Kenya

Abstract

<span>Domestic dogs were screened for <em>Trypanosoma brucei</em> infection using the haematocrit centrifugation technique as part of routine active surveillance exercises in the Busia and Teso districts of Kenya. The purpose was to assess the role of dogs as sentinels for the occurrence of human sleeping sickness. Out of 200 dogs screened, five were found to be infected at the various test sites. These five succumbed to the disease within four weeks, and exhibited a distinct and pronounced corneal opacity before death. Blood from two naturally infected dogs were tested for the presence of the serum resistance associated (SRA) gene and one tested positive, confirming it as human infective (<em>T. brucei rhodesiense</em>) prevalence (0.5 %). It is considered that the occurrence of this clinical sign could be used as an early warning prediction of future outbreaks. This type of prediction could form an integral part of an indigenous technical knowledge set in areas lying at the edges of the tsetse (<em>Glossina</em>) belts where <em>T. brucei</em> is the main trypanosome species that affects dogs. The occurrence of corneal opacity in dogs could indicate a rise in the levels of <em>T. brucei</em> a proportion of which could be human infective <em>T. b. rhodesiense</em> circulating in the population early enough before disease outbreak occurs. It is thought that during sleeping sickness epidemics the domestic dog will be the first casualty rapidly succumbing to disease long before it is noticed in man. Prompt prediction of disease outbreaks would thus enable early interventions that would reduce the morbidity, mortality and the general economic losses associated with sleeping sickness to be instituted.</span&gt

Epidemiological study of canine Trypanosomosis in an urban area of Ivory coast

“…The results of the entomological survey during the three periods are summarized in table I. Glossina palpalis palpalis was the only captured species. They were present in high densities, mainly in the traps situated on the east side of the BIMa near the forest, but very few around the kennel and the horses (< 0.2 fly/trap/day Matete, 2003). Infections with T. brucei appear to be the most pathogenic (Nwosu & Ikeme, 1992;Matete, 2003).…”

“…They were present in high densities, mainly in the traps situated on the east side of the BIMa near the forest, but very few around the kennel and the horses (< 0.2 fly/trap/day Matete, 2003). Infections with T. brucei appear to be the most pathogenic (Nwosu & Ikeme, 1992;Matete, 2003). T. congolense infection in dogs may occur in an acute, chronic or subclinical form (Losos & Ikede, 1972 ;Sayer et al, 1979;Davoust et al, 2006a).…”

Disease: A Hitherto Unexplored Constraint on the Spread of Dogs (Canis lupus familiaris) in Pre-Columbian South America

“…All save leishmaniasis present severe disease challenges to dogs in Africa today. In some cases-for example, trypanosomiasis caused by infection with Trypanosoma brucei brucei (Matete 2003;Morrison et al 1980)-fatality rates as high as 100% continue to be recorded. Significantly, however, some dogs of African (rather than European) origin show partial tolerance to several of these conditions, while endemic wild canid species-black-backed jackals (C. mesomelas), side-striped jackals (C. adustus), and African hunting dogs (Lycaon pictus)-generally show no overt clinical signs of infection (e.g.…”

Determination of the prevalence of African trypanosome species in indigenous dogs of Mambwe district, eastern Zambia, by loop-mediated isothermal amplification

“…Specifically, dogs are affected by Trypanosoma congolense , Trypanosoma evansi and Trypanosoma brucei subspecies [8-10], causing canine African trypanosomosis (CAT). In exotic breeds of dogs, T. brucei subspecies tend to cause acute CAT [5] while infections caused by T. congolense appear to be more chronic [5,9,11].…”

“…Although such dogs get infected with trypanosomes, they either exhibit subclinical signs or may not exhibit any overt clinical signs of the disease at all. Consequently, such dogs may also act as sources of infection to other domesticated animals and, more importantly, those with the human-infective T. brucei rhodesiense and T. brucei gambiense may serve as a source of infection for humans [5,8,11-13]. …”