The relationship between humans and animals goes way back. It can be cryptic, yet basic. While humans consider animals as agreeable in many ways, asking no questions nor passing judgments, the tie between the two sides can be multiplex of independence, dependence or interdependence.
This is what makes nature universal, and it happens with plants as well.
However, these ties come with their fair share of risks and dangers.
One of the perils stemming from this compounded relationship is diseases that can be transmitted from animal to man – either through eating meat that is contaminated or even a single bite from the infected animal.
According to Dr Maurice Karani Murungi, a veterinarian and epidemiologist, when affected animals are treated with antibiotics, residues can remain in their meat if not well managed. When humans consume this, they ingest the antibiotics.
“Over time, this exposure can contribute to the development of antibiotic resistance, as it may not be sufficient to kill bacteria found in humans completely, but would be enough to encourage bacteria to adapt and become resistant. This means that when humans become ill and use antibiotics to treat infections, they become less effective,” he says.
In Africa, the possibility of being sick or dying from diseases that are resistant to drugs has been spiking in recent years, posing a headache to health experts and systems.
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According to the World Health Organization (WHO), Antimicrobial Resistance (AMR), will lead to 10 million deaths by the year 2050, with Africa accounting for 4.5 million of these deaths unless deliberate steps are taken to combat what is now emerging to be a silent killer pandemic.
Data shows that in Kenya there were 8,500 deaths attributable to AMR and 37,300 deaths associated with AMR. Farmers play an important role in preventing AMR, by ensuring that their animals are well-treated and properly fed.
Muthoni Muchiri is a dairy farmer in Ruiru. She says the raw materials they use to formulate the dairy meal are maize gem, maize bran, polland, rice polish and sunflower.
They also buy their feeds from trusted suppliers who have to show a certificate proving that their products have been tested and approved.
“If it's a new supplier, you bring a sample of your product and before we offload the product, we take it to a private laboratory where we test (for) aflatoxin levels,” she says.
For silage, Muthoni says they ensure they harvest mature maize stalks, compact them well when storing in silos, and ensure silos are well sealed to prevent air.
She also adds that once they open a silo, they take samples for mycotoxins test before consumption.
Mycotoxins are naturally occurring toxins produced by certain moulds (fungi) and can be found in food.
Muthoni explains that they run several tests including an organoleptic test to check the appearance, taste and smell of food products.
They also run an alcohol test to check for mastitis, a lactometer test to check the density of milk, and a microbial strip test to check for any animal drugs in milk.
Thanks to research, experts have come up with different ways of managing the situation, including the 'One Health' approach.
According to Dr Victor Yamo, The Executive Director of Global One Health Advocacy, the approach recognises that the health of humans, domestic and wild animals, plants, and the wider environment, including ecosystems, are closely linked and interdependent.
It is an integrated, unifying approach that aims to sustainably balance and optimise the health of people, animals and ecosystems at the community, sub-national, national, regional and global levels.
“The One Health approach is particularly important in the management of Antimicrobial Resistance because irresponsible and excessive use of antimicrobials in humans and animals has led to an upsurge of resistant organisms," says Dr Yamo.
"The organisms quickly spread through our healthcare facilities, farms, animals, food and the environment (soil and water), leading to severe illnesses, challenging treatment of certain infections in humans and animals and even death in some instances,” he adds.
He dittoes the importance of interventions for containment of AMR to achieve sustainable and long-lasting results.
He also insists that this must be multisectoral and multidisciplinary, involving collaboration across human, animal and environmental health sectors which essentially is the One Health approach.
Dr Maurice Murungi says drugs become ineffective in animals like how they become ineffective in humans—through the development of resistance.
There have been tall tales about some farmers using antibiotics to ‘accelerate’ the growth of their animals. Research has also revealed that poultry is the most prone animal where these types of illicit experiments are applied.
“When antibiotics are used excessively or inappropriately in veterinary medicine, such as for non-therapeutic purposes like growth promotion, bacteria can develop resistance. These resistant bacteria can survive despite the use of drugs, making infections harder to treat over time,” he warns.
He adds that animals treated with antibiotics are required to undergo a withdrawal period before they can be slaughtered for human consumption.
“This withdrawal time is necessary to ensure that any antibiotic residues degrade and are cleared from the animal's system, making the meat safe for human consumption," he says.
"The duration of the withdrawal period varies depending on the antibiotic used and the species of the animal, and it is usually labelled on each antibiotic container,” he adds.
Dr Karani adds that meat from animals treated with antibiotics can be separated through rigorous record-keeping and tracking systems from the farm to the processing plant.
“This involves documenting all treatments given to each animal, including the type of antibiotic, the dosage, and the treatment dates. Testing can also be conducted on meat products to detect the presence of antibiotic residues, ensuring compliance with food safety regulations and standards,” he says.
Dr Wambulwa Benard, an Infectious Disease Pharmacist and Clinical Research Scientist, says drug-resistant infections are very difficult to treat.
The resistant organisms that are transmitted to humans will cause infections in humans that are difficult to treat and mostly cause infections that lead to long hospitalisation.
He, however, says the prevention of the spread of resistant microorganisms requires a One Health approach while acknowledging that combating AMR is integral to achieving the Sustainable Development Goals (SDGs).
“To adequately address AMR, it is therefore necessary to take a One Health approach, with integrated actions across all sectors," he says.
The specific interventions include prescriber education, delayed prescription of antibiotics, limiting antibiotic use without prescription, restrictions on counterfeit and substandard antimicrobials, and separating prescription from dispensing.
Others are mass public information campaigns, improving health literacy, observing proper hand hygiene and environmental cleaning, screening and isolating infected patients, and addressing vaccine hesitancy.
Dr Wambulwa also cautions that multi-drug resistant organisms can spread from one patient to another.
“This is a common problem in hospital settings where these organisms are passed to other patients, caregivers and healthcare workers, and are very difficult to treat," he says.
These Healthcare-Associated Infections include Hospital Acquired Pneumonia, Ventilator Acquired Pneumonia, Surgical Site Infections, Catheter-Associated Urinary Tract Infections, and Drug-Resistant Tuberculosis.
He however adds that this can be overcome by proper compliance to hand hygiene practices and safe food handling, rational antimicrobial use, patient isolation where necessary, source control of the infection, proper handling of hospital linen, cleaning using correct detergents, and proper disinfection and sterilisation of hospital instruments.
The African Union Landmark Report launched at Africa Centre for Disease Control (CDC) headquarters in August 2024 states that currently, millions in Africa lack access to essential antibiotics and that only 1.3 per cent of microbiology labs in 14 member states can test for key AMR pathogens.
Africa CDC Deputy Director General, Dr Raji Tajudeen, said the silent threat should not be ignored since it disproportionately impacts the most vulnerable populations.
WHO estimates that AMR would lead to 10 million deaths by the year 2050 if nothing is done to combat the silent pandemic.
The GRAM Study in 2019 revealed that 4.95 million people who died in 2019 suffered from drug-resistant infections globally.
AMR directly caused 1.27 million of those deaths, and 1 in 5 of those deaths occurred among children under five years of age.
In Kenya, there were 8,500 deaths attributable to AMR and 37,300 deaths associated with AMR. Fighting AMR entails substantial healthcare costs and it has serious damage to countries’ economies and GDP.
Patients infected with resistant bugs stay longer in hospitals, leading to increased healthcare costs and posing a danger of transmitting the resistant bugs to other patients, caregivers and healthcare workers.
Animal products such as meat, milk and eggs from animals undergoing treatment should not be consumed because such products contain levels of the medicine being used to treat the animal beyond the acceptable residue limit, which can be harmful to the consumer, but also contributes to antimicrobial resistance.
Experts agree that producers should observe the recommended withdrawal period for such products.
The withdrawal period is defined as the minimum period between the last administration of a veterinary medicinal product to an animal and the consumption of products from the animal.
The period varies depending on the active compound in the medicine and can be a short as one day to as long as a month.
Hence, producers must consult competent, registered and licensed veterinary personnel when treating animals to be advised on the appropriate medicine with the shortest withdrawal period to use.