I thought that I already know a lot about the impact of microbial invasion into our beings as I documented throughout the articles on this site, that she came in recently with her father to see me and find out the reason for her mental slowness and learning disability. She is 24 years old, immigrated from Haiti 8 years ago with her family. Her birth and early couple of years of life were normal like other children in their poor rural Haiti, until when 3 years old, worms were coming out of her nose and she started to have seizure. She was taken to hospital each time after the seizures but no diagnosis or final treatment were provided. Later on the worms and seizures both stopped, but she was left with delays in her full speech function and then in school learning disability. She was slow in comprehension and after all special education classes in her new country, since formal graduation from high school, she has not been able to be hired for any job due to her neuro-developmental delay.
The worms were Taenia solium or the pork tapeworm that is passed on to humans as definite hosts, through infested pigs as the intermediate hosts, by eating uncooked or undercooked pork. The infection that is generally considered harmless and asymptomatic could cause the systematic cysts forming disease of cysticercosis and when invades the central nervous system, neurocysticercosis, a major cause of epilepsy in children and adults. The infestation is most common in central and south America, Africa, India, Pakistan, Southeast Asia. In 1990 and 1991, four unrelated members of an orthodox Jewish community who do not consume pork by religion, in New York city developed recurrent seizures and brain lesions, which were found to have been caused by T. solium. All of the families had housekeepers from Latin American countries who were suspected to be source of the infections.
Neurocysticercosis or the formation of cysts in the brain as seen in the above MRI, while it is the the most common parasitic disease of the human nervous system in the under-developed regions of the world, in the developed world is known as the “hidden epidemic” or “neglected parasitic infection” of the brain. In India and many other southeast Asian countries, solitary cysticercus granuloma is considered the most frequent type of neurocysticercosis, that has been reported in the developed countries, mostly in the immigrant populations. Calcification of the lesion and perilesional gliosis may be responsible for frequent seizure recurrences. Neurocysticercosis is common in infants and toddlers, with seizures as the primary manifestation of the disease. Despite the frequency of Neurocysticercosis in the under-developed world and being the leading cause of acquired epilepsy in these regions, it is still under-diagnosed! Raccurt and colleagues from France conducted a serological retrospective survey to detect any such hidden infestation in Haiti in 2007. From a total of 216 serum samples, obtained from healthy adults, the frequency of antibodies in serum samples of the study population was 2.8%, which confirmed an endemic situation of cysticercosis in humans in Haiti.
While the manifestations and complications of a disease such as systemic cysticercosis and neurocysticercosis are at the best recognized in short-term, the long-term impact of microbial invasions, including Taenia Solium like other offending agents is coming to the attention of some researchers. Pathogenetic mechanisms explaining possible oncogenic effects of cysticerci include: (a) parasite-induced modulation of the host immune response that may be associated with loss of regulatory mechanisms implicated in the immunological surveillance against cancer; (b) transfer of genetic material from the parasite to the host, causing DNA damage and malignant transformation of host cells, and (c) chronic inflammation with liberation of nitric oxide and inhibition of tumor suppressor genes. Additionally, the complex interaction between the immune state of the host with variable cytokine release and the presence of inflammatory cells releasing nitric oxide that cause DNA damage and impair tumor suppressive mechanisms needs to be considered.
The simple case of the pork tapeworm or taenia solium in my patient and many unprivileged children in the under-developed world that haunts them even after immigration to the developed world, like my patient must be eye opening to the extent of microbial invasion into our beings! Taenia Solium is not a virus, but a parasite and a large worm, 1-2 cm in their intermediate human host, but can reach a normal adult size of 2-3 meters with a maximum length of 8 meters. While we as scientists thought that the smaller microbial agent, the more serious damage and impact on our beings, but a large, visible worm, coming out of the nose of my patient could be destructive not in short-term but for long. The long-lasting damage seems not be limited to epilepsy and other neurological ailments including blindness, but in longer-terms in the individual and perhaps in his or her next generations, leading to cancers. Once again we learn that the microbial offending agents seem not to leave our bodies after their first impact, but remain in one form or another to continue with their damages! To them, this is a symbiotic life, to us that is a devastating and the end of life!
Dr.Mostafa Showraki, MD, FRCPC Lecturer, University of Toronto,School of Medicine,Author: “ADHD:Revisited” Book “adhdrevisited.com”/”medicinerevisited.com”
1.Zimmer, C.(2012) Hidden epidemic:Tapeworms living inside people’s brains. Discover magazine.
- White, A. C. (1997). “Neurocysticercosis: A Major Cause of Neurological Disease Worldwide”. Clinical Infectious Diseases 24 (2): 101–13; quiz 114–5.
- Hotez, P.J. (2014) Neglected parasitic infections and poverty in the United States. PLoS Neglected Tropical Diseases 8 (9): e3012.
- Del Brutto OH. Neurocysticercosis in infants and toddlers: report of seven cases and review of published patients. Pediatr Neurol. 2013 Jun;48(6):432-5.
- Raccurt CP, Agnamey P, Boncy J, Henrys JH, Totet A. Seroprevalence of human Taenia solium cysticercosis in Haiti. J Helminthol. 2009 Jun;83(2):113-6.
- Garg RK, Malhotra HS. Solitary cysticercus granuloma. Expert Rev Anti Infect Ther. 2012 May;10(5):597-612.
- Del Brutto OH. Neurocysticercosis: a review. ScientificWorldJournal. 2012; 2012:159821.
- Del Brutto OH, Dolezal M, Castillo PR, García HH. Neurocysticercosis and oncogenesis. Arch Med Res. 2000 Mar-Apr;31(2):151-5.
- Herrera LA, Ramirez T, Rodríguez U, Corona T, Sotelo J, Lorenzo M, Ramos F, Verdorfer I, Gebhart E, Ostrosky-Wegman P. Possible association between Taenia solium cysticercosis and cancer: increased frequency of DNA damage in peripheral lymphocytes from neurocysticercosis patients. Trans R Soc Trop Med Hyg. 2000 Jan-Feb; 94(1):61-5.
- Trejo V, Talamas O, Granados G, Castro L, Rabiela MT, Sotelo J, Gorodezky C. What is the significance of the presence of MHC molecules on the surface of parasites in human neurocysticercosis? J Immunogenet. 1989 Dec; 16(6):427-36.
- Azad R, Gupta RK, Kumar S, Pandey CM, Prasad KN, Husain N, Husain M. Is neurocysticercosis a risk factor in coexistent intracranial disease? An MRI based study. J Neurol Neurosurg Psychiatry. 2003 Mar; 74(3):359-61.