As the global focus on water safety intensifies, a recent study led by Opeoluwa F. Iwaloye, a researcher specializing in Microbiology and Immunology, has uncovered alarming evidence of contamination in hand-dug wells used for drinking and domestic purposes in a rural community in Southwest Nigeria.
The study, which evaluated the water quality and identified the presence of antifungal-resistant and aflatoxigenic fungi, highlights serious public health concerns for residents relying on these water sources.
The research, which aimed to investigate the safety of hand-dug wells in the region, revealed a high risk of contamination in over half of the wells examined.
The findings suggest that not only are these water sources exposed to bacterial pathogens, but they also harbour a significant presence of fungi, including antifungal-resistant strains and aflatoxin-producing species, posing a multifaceted threat to the community’s health.
Iwaloye, in her research, stated, “Our analysis shows that these water sources, which serve as lifelines for many rural communities, are heavily contaminated, posing both immediate and long-term health risks. This calls for urgent interventions to improve water safety and address the spread of antifungal resistance.”
The study involved a thorough examination of 23 hand-dug wells. A sanitary survey checklist was employed to assess the contamination risk, while microbiological testing was used to detect bacterial and fungal pathogens. The results were startling: 56.52% of the wells scored high for risk of contamination, with high nitrate levels (73.9%) and the presence of coliform bacteria in all samples (100%).
Among the bacterial contaminants, Escherichia coli, a well-known indicator of faecal contamination, was found in 43.48% of the wells, underscoring the potential for waterborne diseases. Even more concerning, however, was the detection of fungi in 91.3% of the wells, many of which exhibited resistance to antifungal treatments.
In the fight against fungal infections, resistance is becoming a global concern, and Iwaloye’s study emphasizes its growing prevalence in rural Nigeria. Using the diffusion method for susceptibility testing, the team identified multidrug-resistant strains of filamentous fungi, including Aspergillus flavus, a fungus known for producing aflatoxins, toxic compounds linked to liver cancer.
“Antifungal resistance is a silent threat,” Iwaloye warned. “The fungi we isolated not only resist common treatments but also have the potential to produce aflatoxins, which are carcinogenic and can lead to serious health complications, especially when consumed over time.”
The antifungal resistance profiling revealed that several fungal strains isolated from the wells were resistant to multiple antifungal agents, making them difficult to treat if infections were to occur. Multidrug-resistant strains were further confirmed through DNA barcoding, providing a deeper understanding of the genetic makeup of these dangerous pathogens.
In addition to the risk of fungal infections, the study also highlighted the presence of aflatoxigenic Aspergillus flavus in the water samples. Aflatoxins, which are produced by this fungus, are among the most potent naturally occurring carcinogens. Long-term exposure to aflatoxins can lead to liver damage and increase the risk of liver cancer, especially in communities where contaminated water and food are consumed regularly.
“The presence of aflatoxigenic Aspergillus flavus in drinking water is a critical concern,” Iwaloye noted. “Our findings indicate that these fungi are not only present but capable of producing harmful toxins, further complicating the already severe issue of water safety in rural areas.”
To investigate the aflatoxigenic potential, fungal isolates were screened through culture methods, and the production of aflatoxins was confirmed using densitometric analysis. The combination of aflatoxigenic fungi and antifungal resistance presents a dual challenge for public health officials, as both the prevention and treatment of these infections become more difficult.
The study also uncovered a strong correlation between the presence of fungi and faecal contamination in the wells. Spearman’s rank correlation coefficient revealed a positive and significant relationship between total fungal counts and faecal coliform levels (r = 0.701; p = 0.016), indicating that these fungi might be linked to overall contamination in the water sources.
Iwaloye emphasized the importance of addressing these issues through improved water management practices and community awareness. “There is a critical need for better sanitation, regular monitoring of water sources, and education on the dangers of using contaminated water,” he said. “Without intervention, these communities face continued exposure to harmful pathogens and toxins.”
The findings have broader implications for water safety across Nigeria and other developing regions where hand-dug wells are a primary source of drinking water. The study calls for urgent government action to ensure that rural water supplies are safe and free from microbial contamination, including dangerous fungi.
