Exploring the effect of human and animal population growth on vector-borne disease transmission with an agent-based model of Rhodesian human African trypanosomiasis in eastern province, Zambia

Abstract

This paper presents the development of an agent-based model (ABM) to investigate Trypanosoma brucei rhodesiense human African trypanosomiasis (rHAT) disease transmission. The ABM model, fitted at a fine spatial scale, was used to explore the impact of a growing host population on the spread of disease along a 75 km transect in the Luangwa Valley, Zambia. The model was used to gain a greater understanding of how increases in human and domestic animal population could impact the contact network between vector and host, the subsequent transmission patterns, and disease incidence outcomes in the region. Modelled incidence rates showed increases in rHAT transmission in both humans and cattle. The primary demographic attribution of infection switched dramatically from young children of both sexes attending school, to adult women performing activities with shorter but more frequent trips, such as water and firewood collection, with men more protected due to the presence of cattle in their routines. The interpretation of model output provides a plausible insight into both population development and disease transmission in the near future in the region and such techniques could aid well-targeted mitigation strategies in the future.

Advancing protected area effectiveness assessments by disentangling social‐ecological interactions: A case study from the Luangwa Valley, Zambia

“…Finally, the prevalence of zoonotic diseases such as sleeping sickness (Human African Trypanosomiasis and African Animal Trypanosomiasis, henceforth HAT and AAT; Alderton et al, 2018; Leach et al, 2017), anthrax (Lehmann et al 2017), foot‐and‐mouth disease, and malaria (Lewis et al, 2011) impacts the compatibility of wildlife conservation and agro‐pastoralist land uses in the study area. With hot and dry climatic conditions ideal for the tsetse fly, North Luangwa is a hotspot of HAT and AAT (Anderson et al, 2015; Nakamura et al, 2019).…”

“…This is why attempts to control HAT historically conflicted with conservation objectives (Anderson et al, 2015). Recent intensification of farming practices, including the increased number of livestock in North Luangwa amplifies the risk of HAT and AAT epidemics (Alderton et al, 2018, Leach et al, 2017). Anderson et al (2015) predicted that “ecological changes associated with this diversion from traditional land‐use patterns will be contributing to reductions in biodiversity, ecosystem functioning and […] ecosystem services” (p. 3).…”

Insights into the Control and Management of Human and Bovine African Trypanosomiasis in Zambia between 2009 and 2019—A Review

“…Despite reported cases of HAT from tourists after visiting tsetse-infested areas [7,8], there are currently no deliberate interventions in place to protect international travellers from tsetse flies and HAT. In Zambia, most tsetse interventions have been focused in areas with potential for livestock production, with little synchronisation with human intervention programmes [30,31] Currently, African trypanosomiasis control in humans relies on early diagnosis and treatment. However, challenges in HAT diagnosis in rural settings of Zambia has hindered progress to the control of the disease.…”

Epidemiology of Trypanosomiasis in Wildlife—Implications for Humans at the Wildlife Interface in Africa

“…In the Luangwa Valley, Zambia, considerable efforts are made to keep domestic animals away from the national park, for biosecurity of livestock keepers, the national parks, and game conservancies ( 128 ). In Zambia, HAT infections have been associated with young children attending school and older women demonstrating in the homestead ( 129 , 130 ).…”