Miraa and muguka sold in most parts of Nairobi County are contaminated with disease-causing germs, a survey released last Friday shows.
A team from the Jomo Kenya University of Agriculture and Technology and the Kenya Medical Research Institute that collected and tested the stimulants said they pose a health risk to users.
The researchers have recommended that just like food outlets, khat and muguka vendors should observe strict hygiene standards.
The vendors should also possess medical certificates that are renewed after every three months. They should also have access to proper sanitation, including treated tap water and not water sourced from vendors.
“The county government should construct standard shops with good hygienic conditions for khat vendors and restrict sales to these shops,” the study states.
The researchers presented their findings last week at the annual JKUAT scientific conference held at the university's main Juja campus. The two-day conference attracted a huge number of local and foreign scientists and exhibitors.
The study also appears in the current issue of the International Academic Journal of Health, Medicine and Nursing.
The researchers collected leaf samples from 155 vendors in Eastleigh, Kawangware, Kibra, Mathare and Dandora. After the samples were tested, leaves from 24 sites spread across the five sub-counties were found to be contaminated.
“The main contaminants were G. lamblia and E. hystolitica with a wide spread across Nairobi County,” says the study.
These two contaminants, the authors say, can contribute to diarrhoeal disease outbreak in the city. G. lamblia causes giardiasis, an infection in the small intestines, that can lead to severe dehydration and inability to digest milk sugar. E. hystolitica causes amoebiasis, also called amoebic dysentery. Symptoms include abdominal pain, diarrhoea, or bloody diarrhoea.
In parts of Nairobi, the presence of amoeba parasites has been estimated at 19 per cent with a high incidence among water vendors.
Sites likely to have contaminated leaves were usually in areas with uncollected garbage and where the stimulants were poorly stored, such as on the ground and uncovered.
Other risk areas were near open and public toilets, communal taps and where water was supplied from street vendors.
“Since khat is usually chewed without cleaning and sold in the open, where it is exposed to dust, it can expose humans to a variety of pathogens ranging from bacteria, amoeba to intestinal parasites,” says the report.
Over 70 per cent of the vending sites, the researchers say, had undisposed waste, including human and animal faeces "although the vendors appeared not to be moved by any of this".
And while the study mainly focused on khat and hygiene, the scientists also warn of other serious consequences posed by chewing miraa and muguka. “Prolonged khat use can cause lethargy, mild depression, nightmares and slight tremors. It can precipitate a negative impact on liver function, permanent tooth darkening, susceptibility to ulcers and diminished sex drive," the study says.