Misdiagnosis, climate change to blame for pathogens' resistance to drugs

Antimicrobial resistance is among the top 10 global public health concerns threatening humanity, according to the World Health Organization (WHO). [iStockphoto]

Not many months ago, Prof Rita Oladele, a medical doctor, researcher and lecturer took a call from a colleague from one of the hospitals she’s affiliated with, asking her to come and see a young man who had been on all kinds of treatments but just kept sinking deeper into ill health.

The man had been prescribed antibiotics, but they weren’t working. As expected, the attending doctors, believing the man presented with tuberculosis symptoms, kept administering even more potent antibiotics.

The illness persisted. The man could no longer lie down due to the sensation of drowning, and the clock was ticking fast. He sat up day and night, connected to all kinds of fluid aspiration and drainage pipes.

Prof Oladele promptly assessed him and recommended a culture test, which showed a serious case of fungal infestation in the man’s lungs.

She quickly administered medication for the fungus and sure enough, he made a dramatic recovery. Although he later died of pulmonary embolism, caused by the prolonged immobility, Prof Oladele took away a key message to share with the world.

At this year’s microbiology conference held last month in Nairobi courtesy of Aga Khan University Hospital, Prof Oladele pointed out a growing concern where patients are exposed to antimicrobial resistance (AMR) due to misdiagnosis.

“Clinicians do not routinely suspect or look for fungal infections when they are developing a diagnosis. That being the case, they do not request that laboratories isolate them in the samples they send. There is a shortage of laboratories able to test for the presence of fungal pathogens in samples. Proper diagnostics is at the centre of Antimicrobial stewardship (AMS),” she said.

AMR is among the top 10 global public health concerns threatening humanity, according to the World Health Organization (WHO).

Unfortunately, the highest rates of antimicrobial resistance (AMR), where pathogens survive in the presence of a drug that once annihilated them, are in sub-Saharan Africa.

According to the global research on antimicrobial resistance report, deaths caused directly by AMR are approximately 24 in 100,000 in sub-Saharan Africa as of 2019. Lancet recently ran a study which indicated that deaths caused by drug-resistant germs have surpassed deaths by AIDS and malaria.

Climate change emerged as another key trigger for AMR. “There’s proof that invasive fungal infections have been on the rise, worsened by the climate crisis, so there’s a growing need for better diagnostics if we are to curb AMR,” said Oladele.

According to Dr Paul Yonga, a consultant infectologist and clinical epidemiologist, one of the lesser-known consequences of climate change is the heightened prevalence and spread of bacterial, viral, parasitic, fungal and vector-borne diseases in humans, animals and plants, as well as the ability of the pathogens to evolve and resist to medicines.

“Rising sea levels reduce water quality, leading to waterborne diseases, including diarrhoeal diseases, a leading cause of mortality in Africa,” he said. “Increasing levels of air pollution are associated with increased risk of antibiotic resistance. Warmer temperatures are a breeding gift to pathogens.”

He added that high disease rates lead to increased use of antibiotics, and that poses the threat of developing resistance to these pathogens.

“Over 30 per cent of antibiotics prescribed to people are unnecessary,” he said. “When a virus or fungus is the cause of disease, antibiotics don’t help, and they end up causing harm.”