Epidemiological role of indigenous dogs in the transmission of animal and human African trypanosomiasis in Zambia: a case study of dogs from Mambwe District

Abstract

In Zambia, African trypanosomiasis (AT) is endemic in tsetse-infested Mambwe district. Although cases are common in livestock, they are rarely reported in dogs. However, recent studies have detected trypanosomes in Zambian dogs. As a follow-up, the current research was designed to investigate what communities know about tsetse flies and AT and the role that dogs might play as trypanosome hosts. Data from the knowledge, attitudes, and practices survey and focus group discussions revealed that tsetse flies were present and respondents correctly identified and associated tsetse flies with the transmission of AT.

This study also followed a cohort of 162 indigenous dogs for a period of six months. Nearly 20% of dogs were lost to follow-up, with the main causes being ill-health, predation, and euthanasia. Various African trypanosome species were detected by microscopy, serology, and PCR.

Nzi traps captured a total of 3895 tsetse flies; molecular analyses found 70% of tsetse flies trypanosome positive. Blood meal analysis of 217 tsetse flies found DNA linked to humans (64.1%), wildlife (31.8%), cattle (2.3%), and dogs (1.8%).

In conclusion, the results suggest that dogs acquire and maintain trypanosomes long enough for them to be potential reservoirs in the epidemiology of AT in Mambwe district. Therefore, the policy on treatment, prevention, and control of AT in Zambia needs to include dogs as important hosts.