By Alfred Nyakinda

Participants at the 9th KEMRI scientific and health conference

The movement of animals along trade routes between counties has been linked to the spread of the parasite that causes cystic echinococcosis, a research reveals.

The disease which is caused by a tapeworm spreads through ingestion of the parasites’ eggs in contaminated food, water or soil, or through direct contact with the animal hosts.

According to the World Health Organization (WHO), cystic echinococcosis is found on every continent except Antarctica and prevalence levels among humans may reach five to ten percent in parts of South America, East Africa and Asia. The WHO adds that the disease presents a significant health burden in humans when cysts containing the tapeworm’s larvae develop in the liver, lungs, muscles and other body parts.

Symptoms range from abdominal pain, nausea and vomiting when the liver is affected, to chronic coughs and chest pains when the lungs are affected. Other general symptoms include anorexia, weight loss and weakness.

According to Titus Mutwiri, a medical microbiologist, the appearance of cystic echinococcosis in western Kenya, especially in areas that previously presented no evidence of the parasite’s cycle, occurred through livestock trade routes from north-western counties-Turkana and West Pokot-where it is endemic. These remarks were made during the 9th KEMRI Annual Scientific and Health (KASH) 2019 conference, held in Nairobi.

The study conducted on 12 slaughter houses in the western region of Kenya by Mutwiri and other researchers, revealed that out of 932 animals, 288kg of organs (135 lungs, 45 livers, 12 spleens, 1 kidney and 1 tongue) had cysts.

According to the study, poor slaughter condemnation and porous slaughterhouse enclosures where dogs frequent to scavenge for food can lead to the rise of cystic echinococcosis in western Kenya, where it was non-existent.

Mutwiri noted that cystic echinococcosis is a serious problem in sub-Saharan Africa, saying, “Effective control is prevented by sometimes lack of resources or knowledge about the epidemiology of the disease and the life cycle thereof”.

As carnivores such as dogs act as the primary hosts, carrying the mature tapeworm in their intestines, researchers conducted another study where they collected stool samples from free-roaming dogs around the slaughterhouses. Analysis of the collected samples showed evidence of tapeworm eggs in 9 dog samples, which await more sensitive analysis to determine the exact type.

Though the disease usually remains asymptomatic in humans for years as cysts grow to maturity, it can cause death if the cysts rupture, according to the Centers for Disease Control and Prevention (CDC). The CDC adds that surgery remains the most effective treatment for the disease.

The parasite is difficult to detect in animals as it causes no symptoms in livestock. It can however, be prevented through regular deworming of dogs and hygienic slaughterhouse practices.