Pork sold in Nairobi, neigbouring towns has harmful parasites

What you need to know:

  • The study further details that despite the risk of infection in Nairobi, the demand for pork in the country is on the rise.
  • They estimate that Kenyans consume about 400 tons of pork per year or about 0.4 kilograms per person

About one million people living in and around Nairobi are at risk of contracting a parasite from unprocessed pork slaughtered in Kiambu County.

This is according to a study conducted by scientists from the International Livestock Research Institute (ILRI) in collaboration with the University of Nairobi's Department of Public Health Pharmacology and Toxicology and the University of Liverpool's Institute of Infection, Veterinary and Ecological Sciences.

The results, published in the journal MDPI, show that for every 100 pigs sampled by the researchers, about 34 of them had the harmful parasite called Toxoplasma gondii.

Sometimes written as T. gondii, the study shows that this parasite is a public health risk with likely dire consequences, especially for people with weakened immune systems and pregnant mothers.

"This study has shown that slaughtered pigs have evidence of infection with T. gondii and that small farm size and increased live weight are important risk factors," the study says.

The researchers explain that since pigs are intermediate hosts for the parasite if Nairobi residents eat either raw or undercooked pork, they are likely to be infected.

Read: White is just as dangerous as red meat

However, the study shows that when people with stronger immune systems are infected with the parasite, they are less likely to be severely affected by the infections.

"However, people with weakened immune systems will have serious health complications. These individuals include people with HIV and AIDS, cancer patients, diabetics, pregnant women, the elderly and the very young," the study explains.

The Centers for Disease Control and Prevention (CDC) explains that most people may not be aware of an infection because its impact on humans generally comes without symptoms. 

"Some people who have toxoplasmosis may feel like they have the "flu" with swollen lymph glands or muscle aches and pains that can last for a month or more," explains the CDC.

Some of the possible health complications that the parasite results in; include encephalitis (inflammation of the brain), ocular (eye) abnormalities, mental disorders and secondary respiratory infections. 

The study shows that the infection of the parasite shows different ways of getting into the pig and consequently into humans who consume raw or undercooked pork.

The pig's environment, water and feed are susceptible candidates for infection.

"Exposure to the parasite is likely to increase with the length of time animals are reared in the farm environment, where they are likely to come into contact with infective oocysts," they explain.

"The decreasing prevalence in farms with more than 100 animals may suggest that biosecurity and hygiene practices can be improved in these farms, but there is a need for further research on the exposure of pigs to T. gondii at the farm level in Kenya to gain insights into the contextual risk factors and design appropriate mitigation strategies," the study shows.

The study explains that farms that have larger herd sizes but ensure proper hygiene, rodent control systems, and adequate supply of clean water with uncontaminated feed have better outcomes.

"Further investigation of on-farm practices that predispose pigs to T. gondii infection, such as the presence of cats and appropriate biosecurity practices, is suggested in order to provide context-appropriate recommendations to farmers," they explain.

The study further details that despite the risk of infection in Nairobi, the demand for pork in the country is on the rise. They estimate that Kenyans consume about 400 tons of pork per year or about 0.4 kilograms per person.

"The increasing demand for pork suggests that despite overtime, there may be an increased risk of exposure to T. gondii through pork consumption if mitigation measures are not put in place," the study said.

Read: Study reveals meat sold in Kenya is contaminated with superbugs

"Mitigation measures are needed in this value chain, including improved on-farm biosecurity and public health education for consumers, especially those in high-risk categories," they added.

Another study, published in the journal Cell, shows that about 3 in 10 people in the world are affected by this parasite.

They explain that in pregnant mothers, the impact of the parasite should a mother become infected is determined by the age of the unborn baby.

"While the likelihood of mother-to-child transmission is highest in the third trimester, the severity of congenital disease is inversely related to gestational age. In the first trimester, infections generally result in the most severe clinical symptoms in newborns, including spontaneous abortion or stillbirth," the Cell study explains.

The study also explains that once someone is infected, there is a likelihood that there will be a long-term effect, especially behavioural, on such people.

The study shows that they are susceptible to conditions such as Alzheimer's disease, bipolar disorder, epilepsy and schizophrenia.