Bacterial infection that triggers deadly blood poisoning killing off African elephants

By Stephen Beech via SWNS

A bacterial infection that triggers deadly blood poisoning is killing off African elephants, reveals new research.

Conservationists warned it is a new threat to the iconic endangered species whose numbers are dwindling by eight percent a year, mainly due to poaching, with just an estimated 350,000 remaining in the wild.

A probe was launched following the mysterious deaths of several African savanna elephants in Zimbabwe in 2000.

Now, following a complex investigation involving researchers in the UK and Africa, scientists say a bacterium, closely associated with deadly septicemia, could have caused the deaths of six elephants in Zimbabwe - and possibly more in neighboring countries.

Scientists from the Victoria Falls Wildlife Trust, the Animal and Plant Health Agency (APHA) UK, the University of Surrey and laboratories in South Africa were involved in the probe into the death of 35 elephants mostly between August and September 2020 in North-Western Zimbabwe.

It followed the similar deaths of around 350 elephants in neighboring Botswana in May and June 2020, which triggered international concern.

Conservationists described the findings, published in the journal Nature Communications, as "very worrying" since elephants are already on the International Union for Conservation of Nature's "red list" of endangered species.

Lead investigator Dr. Chris Foggin, a wildlife veterinarian at the Victoria Falls Wildlife Trust, said: “Investigating this mortality in the wildlife areas in north-west Zimbabwe proved challenging. Identifying and then reaching the carcasses in time to obtain useful samples is one problem we often face in this type of work.

“However, we also didn’t know what disease we may be dealing with, although we initially suspected that it could be anthrax, which is known to occur in the area; or possibly some other disease that might pose a risk to human health.

"We therefore had to be cautious when undertaking the post-mortem examinations on elephant which, in itself, is a difficult task with such a big animal, especially working in field conditions.”

He said a number of post-mortems were conducted and poaching was quickly ruled out, mainly because all the dead elephant had their tusks intact.

Toxicology analyses, including immediate testing for cyanide which is sometimes used to kill elephants in Zimbabwe, as well as more sophisticated analyses done in the UK, found no traces of poisons in the carcasses or at a waterhole close to where many of them were found.

Further examination by vets and scientists identified a septicaemic infection caused by a by a little known bacteria provisionally named Bisgaard taxon 45, in six elephants.

The breakthrough was confirmed by bacterial isolation and genetic analysis.

Only a limited amount of samples were suitable to carry out such examinations.

Pasteurella bacteria have previously been implicated in sudden deaths of wild animals such as antelope, but a role in elephant deaths was not suspected prior to the study.

Professor Falko Steinbach, of the APHA, said: “The identification of this bacterium is a significant step forward in learning more about why these elephants died.

“Transmission of the bacteria is possible, especially given the highly sociable nature of elephants and the link between this infection and the stress associated with extreme weather events such as drought, which may make outbreaks more likely."

He added: “Further research is needed to learn more about the bacteria and its long-term implications for the African elephant population and other wildlife.”

Dr. Arnoud van Vliet, Senior Lecturer in Veterinary Microbiology at the University of Surrey, said: “The international composition of our research team highlights the opportunities arising for conservation investigations into the disease and death of free-ranging animals.

"Bisgaard taxon 45 has never before been associated with bacterial septicemia and it adds to the growing list of disease-related threats to elephant conservation.”