CAPE TOWN – Drug-resistant pathogens have been found in the Kuwaiti sea, soil and rivers in South Africa, Nigerian poultry, Ugandan pigs and numerous other sites, according to scientists at the eighth global One Health congress held in Cape Town over the past four days.

This evidence was presented on the eve of Thursday’s United Nations High-Level Meeting on Antimicrobial Resistance (AMR), where global leaders are due to adopt a political declaration aimed at addressing the alarming possibility that drug resistance will render many antibiotics useless in coming years – leaving humans vulnerable to death from common germs.

Around three-quarters of antibiotics are used on animals and AMR can only be addressed if urgent changes are made to agricultural practices, particularly in low and middle-income countries (LMICs), focusing on the overuse of antibiotics, and the management of wastewater.

This underscores the importance of a One Health response, which means developing an integrated approach to human, animal and environmental health.

Sewage is a major source of AMR

Sewage is a major source of AMR, yet farmers in many countries use untreated wastewater to irrigate their crops. This spreads pathogens to vegetables and the animals and humans that eat them.

Lack of sanitation is also driving AMR. Researcher Mary Chibwe painted an alarming picture of a South African river teeming with pathogens in the places where people lived alongside it in shacks. With no sanitation, everything ends up in the water – including human and animal faeces, used nappies, trash and unfinished medicine, said Chibwe.

“Industrial effluents are also contributing to AMR, through the discharge of heavy metals, residues and other pollutants,” she added.

Chibwe’s research found 87,5% of water samples were positive for Campylobacter, a bacteria that causes diarrhoea, in parts of the Swartkops River where there was high human activity. (The river flows near the biggest city in South Africa’s Eastern Cape province.)

Some 81% of these samples contained Campylobacter multi-drug resistant gene B, and 62,5% were resistant to tetracycline.

China’s Chendi Zhu reported on a study in Guangxi region, home to half a million people. Samples of E-coli were collected from slaughterhouses, local markets, households, farms and hospitals.

“The overall rate of multi-drug resistance was an alarmingly high 87,3%,” he reported. “The high multi-drug resistance rate highlights the critical need for integrated surveillance and intervention strategies that encompass human, animal and environmental health.”

Other studies and posters showed antibiotic-resistant Salmonella in poultry being sold in Ghana and Nigeria, drug-resistant pathogens in pigs in Uganda, and many other alarming examples of how widespread AMR is.

Wild animals are not exempt

Even wild animals are not exempt from AMR. Ghana’s Winnifred Offih-Kyei reported on research on the carcasses of 60 wild animals at a bushmeat market in the Ashanti region. Some 522 bacteria were isolated, and there was an almost total resistance (97%) to Ampicillin, with high resistance to Cefotaxime (84.6%) and Tetracycline (78.2%).

“Wildlife are important reservoirs of AMR,” said  Offih-Kyei. “The continuous consumption of bushmeat may heighten AMR and limit the effective treatment of bacterial infections in both humans and animals.”

Around 60% of emerging infectious diseases come from animals, while three-quarters of the 30 new human pathogens detected in the last 30 years originated in animals, according to the World Health Organization (WHO).

Yewande Alimi, head of One Health and AMR at the Africa Centres for Disease Control and Prevention, told the congress that outbreaks of zoonotic diseases on the continent have jumped from 63% to about 85% in the past decade.

“We are faced with a multi-faceted crises dealing with several other health issues, economic issues, and this is why the One Health approach is important,” said Alimi.

Managing animal, human and environmental health has become more and more important. Thus in 2022, the FAO, WHO, UN Environmental Program (UNEP) and the World Organization of Animal Health (WOAH) formalised their leadership of One Health, now known as the Quadripartite.

Thanawat Tiensen, the Food and Agricultural Organization (FAO)’s Director of Animal Production and Health, described AMR as “a silent pandemic with devastating effect on food production, ecosystems and economies”. 

“FAO is leading the fight against AMR with a 10-year global initiative to reduce the need for antimicrobials on farms for a sustainable agri-food system transformation,” said Tiensen.

In addition, FAO’s international AMR antimicrobial resistance monitoring system called InFARM, helps countries to collect and analyze AMR surveillance and monitoring data, primarily from livestock, fisheries and agriculture, he added.

Strengthening countries’ One Health efforts

The WHO’s Maria Van Kerkhove, interim Director of Epidemic and Pandemic Preparedness and Prevention, told the congress on Monday that the WHO has identified 18 pathogens that have the potential to cause epidemics and pandemics. These include mpox, dengue, Heniparviruses and Nipah.

The WHO is building a dashboard to map the emergence and spillover potential of these pathogens, which will eventually include diagnostic resources, available healthcare systems services and reporting capacity.

“Our aim is partly efficacy. Working with governments to say: ‘You do know the risks that are there, but how do you consider the following based on the changes that we’re seeing in terms of climate, in terms of urbanization, in terms of displaced people, so that governments can anticipate and be ready.”

There is also a global arbovirus initiative focusing on dengue, chikungunya, yellow fever and Zika and a global focus on respiratory threats, added Van Kerkhove. 

“We would like a world that is on alert. We don’t want every individual on alert. We need governments to be on alert and across different sectors, looking at different legal aspects, looking at financial aspects. So that, where we can prevent, we do and when we can’t, that we mitigate as much as we can. 

“These spillovers that we see happening, which will continue to happen, don’t amplify. And all of this is based on a foundation of science, trust, transparency and collaboration,” she concluded.