A British woman who developed 38 parasites in her brain believes she contracted the infection during a two-month trip to India in 2007, according to reports by UK-based media outlets. Lowri Denman, 42, was diagnosed with neurocysticercosis, a rare parasitic disease caused by the pork tapeworm, Taenia solium. The condition affects the brain and nervous system and is a leading preventable cause of epilepsy worldwide. Denman is among only a handful of people diagnosed with the disease in the UK each year, according to a report by the BBC.
Denman first realised something was wrong in 2011, four years after returning from India, when she discovered a metre-long tapeworm after using the toilet, reported the BBC. An MRI scan later revealed 38 parasitic cysts in her brain. She subsequently underwent years of treatment and now has to take lifelong medication to control epilepsy caused by the infection.
But was her trip to India really responsible for the infection? According to the World Health Organisation (WHO), people develop neurocysticercosis after ingesting microscopic Taenia solium eggs through contaminated food or water, usually because of poor sanitation or hygiene.
Eating raw or undercooked pork infected with the parasite can cause an intestinal tapeworm infection, although that alone does not directly lead to neurocysticercosis. Denman told the BBC she deliberately avoided animal products during her stay in India. However, Dr Brendan Healy, a consultant in infectious diseases and microbiology, believes she most likely acquired the infection in India after inadvertently consuming pork contaminated with tapeworm eggs. Here are three facts about the disease — and one important question.
FACT ONE: NOT JUST PORK, TAPEWORM INFESTATION CAN HAPPEN FROM OTHER SOURCES AS WELL
Denman’s doctor told the BBC that she picked up the tapeworm infection after “inadvertently eating pork that contained microscopic tapeworm eggs”.
Although Taenia solium is commonly known as the pork tapeworm, tapeworm infections are not exclusive to pork. Different species of tapeworm are associated with different foods.
Eating raw or undercooked pork can transmit Taenia solium, while undercooked beef can carry Taenia saginata (beef tapeworm), and raw or undercooked freshwater fish can transmit fish tapeworms such as Diphyllobothrium species.
However, only Taenia solium is capable of causing neurocysticercosis, the condition in which tapeworm larvae invade the brain and central nervous system.
According to the World Health Organization (WHO) and the US Centers for Disease Control and Prevention (CDC), neurocysticercosis occurs when a person ingests microscopic tapeworm eggs shed in the faeces of someone carrying an adult pork tapeworm. These eggs can contaminate a wide range of foods, not just pork, including raw vegetables, fruits and other ready-to-eat foods handled by an infected person with poor hand hygiene.
The contaminated food can include fruits, vegetables and other ready-to-eat items—not just pork. In contrast, eating infected pork, beef or fish typically results in an intestinal tapeworm infection rather than larvae spreading to the brain.
FACT TWO: TAPEWORM INFESTATION CAN ALSO OCCUR FROM INGESTING CONTAMINATED WATER
Alongside contaminated food, ingesting contaminated water is a major route for tapeworm transmission. Specifically, people can develop neurocysticercosis after swallowing the microscopic eggs of the pork tapeworm (Taenia solium) found in facally contaminated drinking water. These eggs can also contaminate food and surfaces in areas with inadequate hygiene or poor sanitation.
According to the WHO, these eggs are shed in the faeces of an individual carrying an adult tapeworm. In regions with substandard sanitation and sewage systems, the eggs easily breach the water supply. Once a person ingests the contaminated water or food, the eggs hatch in the intestine. The resulting larvae then migrate through the bloodstream to the brain, muscles, and other tissues, where they form cysts.
It is crucial to distinguish this from a standard intestinal tapeworm infection: while the intestinal version is linked to eating undercooked pork, neurocysticercosis results specifically from swallowing the parasite’s eggs via facally contaminated food or water.
Neurocysticercosis can also be contacted from swimming if a person accidentally swallows water while in unmanaged natural bodies of water or rivers in endemic regions with poor sanitation. However, it is virtually impossible to contract the infection from a properly chlorinated and filtered swimming pool.
FACT THREE: NEUROCYSTICEROCIS IS RARE IN THE UK, COMMON IN INDIA
Neurocysticercosis is exceptionally rare in the UK, owing to strict food safety standards, regulated pig farming, effective meat inspection, and modern sanitation systems. A study by the Hospital for Tropical Diseases, London, identified just 26 active cases between 2001 and 2015, an average of fewer than two cases a year.
Of those, 65.4% occurred in immigrants, while the remaining 34.6% were UK-born travellers who had visited endemic regions across South and Central America, sub-Saharan Africa, and South and Southeast Asia.
India, however, remains one of the countries where the disease is endemic. According to the World Health Organisation (WHO), neurocysticercosis is widespread across parts of Asia, sub-Saharan Africa and Latin America, particularly in areas with inadequate sanitation and where the parasite can circulate between humans and pigs. The disease is recognised as one of the leading preventable causes of epilepsy in endemic regions.
Unlike the UK, India does not maintain nationwide surveillance data for neurocysticercosis because it is not a nationally notifiable disease. However, a community-based study in Vellore district, Tamil Nadu, published in the Indian Journal of Medical Research, found that neurocysticercosis accounted for 28–34% of active epilepsy cases in the study population.
Based on those findings, researchers estimated a national prevalence of around one case per 1,000 people, suggesting that more than one million Indians may be living with the disease, although the true burden is likely to vary across regions and remains difficult to quantify.
QUESTION: HOW CAN BRITISH WOMAN BE SO SURE SHE GOT PORK TAPEWORM FROM INDIA VISIT?
The short answer is, we cannot be completely certain that Lowri Denman contracted neurocysticercosis from visiting India. There is no laboratory test that can pinpoint the country or exact location where a person came into contact with pork tapeworm.
Instead, doctors rely on a patient’s travel history, the prevalence of the disease in different regions, and the likely period of exposure to make an informed clinical assessment.
In Denman’s case, her two-month stay in India in 2007 is considered the most likely source because India is endemic for neurocysticercosis, whereas the disease is exceptionally rare in the UK.
She also developed an intestinal tapeworm before brain scans revealed parasitic cysts, suggesting she had been infected years earlier. The long gap between exposure and diagnosis is not unusual, as the parasite’s cysts can remain dormant for months or even years before triggering symptoms such as seizures.
However, it is impossible to rule out every other potential source of infection. Because people contract neurocysticercosis by ingesting microscopic tapeworm eggs through contaminated food or water, the exposure could theoretically have occurred anywhere the parasite was present.
Dr Brendan Healy’s conclusion that Denman most likely acquired the infection in India is therefore based on probability rather than definitive proof, taking into account her travel history and the epidemiology of the disease, rather than evidence that identifies the exact place of infection.
– Ends
