New Delhi, Aug 27: When doctors at the M.D. Anderson Cancer Centre concluded that Leander Paes was not suffering from a tumour but from a parasitic infection called neurocysticercosis, the tennis star’s family and his army of fans heaved a sigh of relief. So did the public at large, though perhaps for a different reason: they believed that the infection, which attacks the central nervous system, is mainly transmitted through consumption of pork, not a staple in India.

They were wrong, and there’s reason to be careful. The infection — which can prove fatal — can just as easily be transmitted through improperly washed vegetables and, say neurological experts, is becoming increasingly common in India.

‘‘We have seen it in strictly vegetarian communities like the Jains and even among Muslims, who don’t eat pork’’, says Dr C.S. Agarwal, Senior Consultant of Neurology at New Delhi’s Sir Ganga Ram Hospital. Though little empirical data is available on the prevalence of neurocysticercosis, as it isn’t a notifiable disease, doctors at major institutes of neurosciences say they see at least two or three new cases every day.

‘‘The detection of cases has increased substantially since use MRIs and CT Scans became more common. The numbers could be more if properly investigated’’, said Dr V.S. Mehta, professor and head of neurosurgery at AIIMS. Neurocysticercosis is spread by tissue-invading larval forms of the pork tapeworm taenia solium. The human being plays primary host to the worm, which lodges itself in the intestines while the eggs are passed out in the faeces. When a pig eats the faeces (a common habit), the eggs become larvae that are lodged in the soft tissues of the pig. When the pig’s meat is consumed as pork, the larvae flows into the bloodstream and travels up to the head and spinal regions.

‘‘As the human body reacts to any foreign substance, a cyst is formed around the larva in the brain, spinal cord or in eye tissues. The brain reacts by producing an inflammation around the area, which is the danger,’’ Dr Mehta added.
It’s roughly the same with vegetables, when human faeces is used as, or mixed with, manure. Most vulnerable are tight-leafed vegetables such as cabbage, where the manure may not be dislodged by casual cleaning. These vegetables, when eaten raw, pass on the worm.

The common factor in both is, of course, hygiene — or lack of it. ‘‘Even most of the doctors don’t know that pork is not the main reason of infection in the country In India, the infection spreads mostly through unwashed hands, unhygienic or contaiminated vegetables,’’ said Dr A.K. Banerji, Director of Neurosurgery at Vimhans and former head of the department at AIIMS.

‘‘The state that has the least prevalence is Kerala. The reason is simple: it has a very good sanitation system,’’ he adds.

According to him, children are at a higher risk of contracting the disease. ‘‘We should ensure that raw food isn’t sold near the schools,’’ Dr Banerji warns.

The gravity of the infection depends on the number of cysts and their location — the brain is the most dangerous. The more cysts that are present, the less the body’s immune system will act to destroy the organism, allowing the cysts to live for upto five years undetected. Neurological symptoms arise when the encysted worm dies and the human mounts an associated inflammatory response.

The symptoms can be epilepsy or fits, recurrent headaches and vomiting and blurring of vision. ‘‘In rare cases it can lead to paralytic illness, blindness or even death,’’ said Dr Agarwal.
However, the cyst can be treated medically, though the use of albendazole and praziquantel. ‘‘However, these drugs shouldn’t be administered without medical supervision; they can induce severe reactions, including death, if the worm is still alive in the brain’’, said Dr Mehta.