Detecting spatial clusters of Taenia solium infections in a rural block in South India

• Published in: Transactions of the Royal Society of Tropical Medicine and Hygiene Vol. 104; no. 9; pp. 601 - 612
• Main Authors: Raghava, M. Venkata, Prabhakaran, V., Jayaraman, T., Muliyil, J., Oommen, A., Dorny, P., Vercruysse, J., Rajshekhar, V.
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01-09-2010; Royal Society of Tropical Medicine and Hygiene; Oxford University Press
• Subjects: Adolescent; Adult; Animals; Antibodies, Helminth - isolation & purification; Biological and medical sciences; Child; Child, Preschool; clusters; Cysticercosis; Diseases caused by cestodes; epilepsy; Female; General aspects; geographic information systems; Headache. Facial pains. Syncopes. Epilepsia. Intracranial hypertension. Brain oedema. Cerebral palsy; Helminthic diseases; Humans; India; Infectious diseases; Male; Meat - parasitology; Medical sciences; Middle Aged; Nervous system (semeiology, syndromes); Neurocysticercosis - epidemiology; Neurocysticercosis - immunology; Neurology; Parasitic diseases; Rural Health - standards; Space-Time Clustering; Swine - parasitology; Taenia; Taenia solium; Taenia solium - immunology; Taenia solium - isolation & purification; taeniasis; Taeniasis - epidemiology; Taeniasis - immunology; Young Adult; Asia; India; India, Vellore; epilepsy; geographic information systems; Cysticercosis; taeniasis; clusters; Nervous system diseases; Rural environment; Epilepsy; Teniasis; Parasitosis; Helminthiasis; Cestode disease; Cerebral disorder; Infection; Central nervous system disease; Digestive diseases; Tropical medicine
• ISSN: 0035-9203; 1878-3503
• DOI: 10.1016/j.trstmh.2010.06.002

Neurocysticercosis (NCC) is a major cause of seizures/epilepsy in countries endemic for the disease. The objectives of this study were to spatially map the burden of active epilepsy (AE), NCC, taeniasis, seroprevalence for cysticercal antibodies and positivity to circulating cysticercal antigens in Kaniyambadi block (approximately 100 villages comprising 100 000 population) of Vellore district and to detect spatial clusters of AE, NCC, taeniasis and seroprevalence. Using geographic information system (GIS) techniques, all 21 study villages with over 8000 houses (population of 38 105) were mapped. Clustering of different indices of
Taenia solium infection was determined using a spatial scan statistic (SaTScan). There was a primary spatial cluster of AE with a log likelihood ratio (LLR) of 10.8 and relative risk (RR) of 22.4; however, no significant clustering for NCC was detected. Five significant spatial clusters of seropositivity for cysticercal antibodies, two clusters of seropositivity for cysticercal antigens and one for taeniasis were detected (LLR of 8.35 and RR of 36.67). Our study has demonstrated the use of GIS methods in mapping and identifying ‘hot spots’ of various indices of
T. solium infection in humans. This spatial analysis has identified pockets with high transmission rates so that preventive measures could be focused on an intensive scale.