Prof Armanda Bastos has always cared for animal welfare, but it was probably her first field trip to the Kruger National Park as a veterinary researcher that inspired her most to dedicate her professional life to animal disease control research.
As part of a research team, Prof Bastos was involved in the encephalomyocarditis (EMC) virus vaccine trial in African elephants in the Kruger National park. While this virus has one of the smallest genomes, it can cause mortalities in elephants in a matter of days. The virus results in sex-biased mortalities, affecting adult elephant bulls that are in their prime and are dominating breeding and should be ensuring the viability of the population by passing on their “good” genes.
“When I saw for myself the effect that this tiny virus had on an elephant heart and realised that in the 1993/4 outbreak it had wiped out 63 elephants, the majority (83%) of which were males, I was both in awe and determined to unravel the drivers behind ‘virus escape’ and transmission between hosts so that spill overs could be prevented, or at the very least, to limit the impact,” says Prof Bastos.
Since then, she has spent most of her career discovering the diversity of pathogens that exist in wildlife reservoirs (pathogens naturally live in a number of wildlife species), understanding what their threats are and how to deal with them. “Understanding disease ecology is key to formulating intervention and control strategies that limit the impact of infectious diseases,” she explains.
Her research is focused on generating baseline data to assist with the development of improved diagnostic tests and the selection of vaccine strains that will be most effective against the strains circulating in the field. This contributes to animal disease detection and control.
Understanding disease ecology and having baseline data are key to minimising human-wildlife conflict, arising from the perception that wildlife species host numerous economically and life-threatening diseases. “These perceptions reduce wildlife’s perceived value and render all control measures aimed at ensuring food security justifiable,” warns Prof Bastos. “I strongly believe that if we understand the drivers and risks of disease transmission, that it should be possible to develop control strategies that balance the sustainability needs of our own species with those of others,” she says.
Prof Bastos has worked extensively on foot and mouth disease – which threatens the cattle industry – and African swine fever – which threatens the pork industry. These diseases have severe economic implications due to their global trade bans and therefore strict control zones are in place in South Africa. However, many of these control zones were put in place decades ago when comprehensive surveys were last done. A need for re-evaluation and monitoring of the African swine fever control zone was highlighted by successive studies in which no evidence of the virus could be found in ticks from the Mkuze Game Reserve in KwaZulu-Natal, nor in Swaziland (which is bordered by African swine fever- positive regions).
This highlights some of the benefits of research on animal diseases and wildlife reservoirs – by conducting such assessments a more accurate reflection is gained and areas in need of comprehensive reassessment can be prioritised. If it can be shown conclusively that there aren’t any risks, then it begs the question whether these controls should be kept in place. Recognition of a disease-free status would mean that farmers adjacent to disease-free wildlife areas might be able to upscale their production and improve their living standards.
Prof Bastos’ work has relevance therefore, not only on a conservation level, but also on a food security and economic level and it highlights the importance of striving for a One Health approach, which is an integrative effort to attain optimal health for humans, animals and the environment. At the end of the day, they are all inextricably connected to each other.