|Year : 2014 | Volume
| Issue : 1 | Page : 21-24
Risk factors for neurocysticercosis: A study from Northwest India
Mohit Girotra1, Chanchal Gera2, Rtika Ryfka Abraham1, Paramdeep Kaur1, Rajat Gauba1, Yashpal Singh1, Jeyaraj Durai Pandian1
1 Department of Neurology, Christian Medical College, Ludhiana, Punjab, India
2 Department of Medicine, Christian Medical College, Ludhiana, Punjab, India
|Date of Web Publication||11-Feb-2014|
Jeyaraj Durai Pandian
Department of Neurology, Head of Research, Betty Cowan Research and Innovation Centre, Christian Medical College, Ludhiana 141 008, Punjab
Source of Support: None, Conflict of Interest: None
Background: Neurocysticercosis (NCC) is a common cause of epilepsy in the low- and middle-income countries. The risk factors for NCC vary from region to region. Aims: To study the risk factors NCC among patients with NCC and compare with age-and gender-matched controls without NCC. Setting and Design: Hospital-based case-control study. Materials and Methods: A total of 214 subjects were studied (109 NCC patients and 105 age- and gender-matched controls without NCC). The participants were selected from neurology and medical wards of a tertiary referral hospital in Northwest India. They were interviewed by trained medical interns using a questionnaire. Results: Patients with NCC were more likely to dispose garbage close to water source (P = 0.01), eat nonvegetarian food (P < 0.001), and often eat in restaurants (P < 0.001). Pigs were seen more in and around the NCC patient's houses than the control subjects residential areas (P = 0.001). A total of 15% of the NCC subjects lived close to slaughter houses, while only 2.7% of the control group stayed near a slaughter house (P = 0.002). Conclusions: Unhygienic practices, nonvegetarian food, and eating in restaurants were the risk factors for NCC in this study. There is an opportunity for prevention of NCC using public education.
Keywords: India, neurocysticercosis, risk factors
|How to cite this article:|
Girotra M, Gera C, Abraham RR, Kaur P, Gauba R, Singh Y, Pandian JD. Risk factors for neurocysticercosis: A study from Northwest India. CHRISMED J Health Res 2014;1:21-4
|How to cite this URL:|
Girotra M, Gera C, Abraham RR, Kaur P, Gauba R, Singh Y, Pandian JD. Risk factors for neurocysticercosis: A study from Northwest India. CHRISMED J Health Res [serial online] 2014 [cited 2019 Jun 17];1:21-4. Available from: http://www.cjhr.org/text.asp?2014/1/1/21/126781
| Introduction|| |
Neurocysticercosis (NCC) is a major public health problem in India, Latin America, Southeast Asian countries, and also in developed world. , More than two-thirds of people with epilepsy in the world reside in the developing world, where epilepsy continues to be a highly stigmatizing condition. ,,,,
NCC presents commonly with epilepsy and raised intracranial hypertension. , It accounts for 50% patients presenting with partial seizures in some parts of India. , Single-enhancing computed tomography lesions (SECTL) are the commonest radiological abnormality in patients with new-onset partial seizures in the endemic regions in India.  Epilepsy caused by NCC consequently represents an enormous expenditure for the developing world. 
The risk factors for NCC in India are different from the Latin American countries. In a large serological study of 1881 NCC patients from Delhi, 34% were vegetarians.  In another study, 65% of the patients had never consumed nonvegetarian food items in their lifetime.  The plausible explanation for the occurrence of NCC among vegetarians is by ingestion of food or water contaminated with human feces or by autoinfection. 
The control measures recommended to combat this disease include improvements in hygiene, sanitation, control of pig slaughter, mass tenicidal chemotherapy, and health education.  In India, there is no paucity of literature on clinical manifestations, diagnosis, and prognosis of NCC in adults and children. However, there is only limited information available in regards to different risk factors of NCC from Indian subcontinent.
Our objectives were to study the risk factors of NCC and compare with patients without NCC.
| Materials and Methods|| |
This hospital-based study was conducted at a tertiary referral hospital in northwest India.
All consecutive patients aged ≥16 years with NCC, who were admitted in the department of neurology between January 2005 and January 2006, were eligible for inclusion. Only patients with new onset NCC presenting with neurological symptoms for the first time were included. The diagnosis of NCC (definitive or probable NCC based on the absolute, major, minor and epidemiologic criteria) or SECTL (seizures without raised intracranial pressure or focal deficits and absence of systemic illness; solitary enhancing lesion in the computed tomography (CT) of ≤ 2 cm without midline shift) was made according to the published criteria. ,
The questionnaire was adapted from previous studies, which were modified by authors to suit local socioeconomic practices. , The first section of the questionnaire gathered demographic information about the patient along with their religion, education, and income. The second section concerned the attitudes and practices of the subjects. The target information included the source of water they drink (municipal water, hand pump [superficial ground water], tullu pump [deep ground water], river and pond, water storage (open bucket, over head tanks, and pots), water purifying media (boiling, filter, and Aquaguard), their food habits, personal and environmental hygiene, and professional or residential proximity to animals like pigs or cows. We also questioned them about actual symptomatology they encountered in their illness and also noted down their CT/magnetic resonance imaging (MRI) findings along with the type of treatment they received.
The survey instrument was pretested using a sample of 20 subjects (10 cases and 10 controls). A few necessary changes were made in the questionnaire based on the pretesting.
Trained medical interns interviewed the subjects using a structured, pretested open-ended questionnaire. Questions were asked during a one to one interview in local vernacular language (i.e. Punjabi or Hindi) and the interviewer intervened only to clarify a question, when needed. Effort was made to interview the NCC patients before the diagnosis was discussed with them.
The controls were consecutive patients admitted to medical/neurology wards without CT/MRI lesions consistent with those of NCC. These patients underwent imaging for other neurological symptoms (e.g., stroke, headache, vertigo, etc.). The same questionnaire was used to interview the control subjects.
Statistical analyses was done using SPSS version 16. Fisher's exact test and Chi-square test was used to compare the different variables between the NCC and the control group. The means of the continuous variables were compared between the two groups using t-test. A P < 0.05 was considered significant.
| Results|| |
A total of 214 individuals (109 cases and 105 controls) were interviewed using the questionnaire.
The two groups were matched for age and gender (NCC group, age 28.3 ± 12.9 years and control group, 29.8 ± 12.8 years, P = 0.50; gender: NCC group, men 63 and control group, men 58, P = 0.40). Other demographic data are shown in [Table 1].
|Table 1: Demographic characteristics in neurocysticercosis and control group|
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Water source and drinking habits
Majority of the respondents used municipal water in both the groups (NCC-78%, Control-79%, [Table 2]). Open buckets (P = 0.001) and overhead tanks (P = 0.001) were commonly used for storage of drinking water in the control group, while pots (P < 0.001) were used in NCC group [Table 2]. Majority of the respondents did not use any purifying media in the study [Table 2].
|Table 2: Comparison of water sources and drinking water habits between neurocysticercosis and control groups|
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Environment and garbage disposal practices
Majority in both the groups lived in brick houses (NCC-97.2%, control group-98%, [Table 3]). Most of the individuals (86.6%) in control group dumped garbage at a distance of >100 feet from water source as compared to 64.2% of NCC patients (P < 0.001), while NCC patients dumped garbage between 50 and 100 feet from the water source (P = 0.001) [Table 3]. Pigs were seen more in and around the NCC patient's houses than the control subjects residential areas (P = 0.001). A total of 15% of the NCC subjects lived close to slaughter houses, while only 2.7% of the control group stayed near a slaughter house (P = 0.002).
|Table 3: Comparison of environmental factors in neurocysticercosis and control groups|
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NCC patients ate more frequently in hotels (once a week or >4 times a month) as compared with control group (P < 0.001) [Table 4].
Nonvegetarians were more among the NCC group than the control group (P < 0.001) [Table 4]. More number of NCC patients ate pork (P < 0.001), chicken (P < 0.001), and goat meat (P < 0.001) than the control group [Table 4].
|Table 4: Comparison of responses regarding eating habits in neurocysticercosis and control groups|
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| Discussion|| |
We explored the risk factors of NCC in this study. Patients with NCC used water from unsafe drinking sources, disposed garbage close to water source, and were predominantly nonvegetarians who ate very frequently outside the house. There were more slaughter houses and pigs around the houses of NCC patients than the control group.
NCC group used pots more frequently, while control group used open buckets and overhead tanks for storing drinking water. In India, safe drinking water is a major problem sometimes people store in unhygienic environment, for example, pots. Water source was not a significant risk factor for NCC in other studies from China,  Peru,  Bolivia,  Mexico,  and India. 
The NCC patients disposed garbage close to the house and water source in this study. Garbage disposal close to the house was not a risk factor in a study from India.  In a rural village of Mexico, 14.5% of the 3065 inhabitants reported that they indiscriminately disposed of feces in the environment around their houses. 
Another interesting observation in this study was the presence of slaughter houses and pigs in close proximity to the NCC patient's houses. A total of 50% of the patient group and 55% of control group subjects in a study from Bolivia had pigs roaming around their houses.  Raising and free roaming of pigs were important risk factors in the Peruvian  and the Chinese studies. 
Only 34% of the NCC patients ate pork in our study. In a rural village of Mexico, 95% of the families ate pork and 77% served it at least once a week; however, 4% said they sometimes ate uncooked pork.  Pork for consumption in the Mexican study was obtained from pigs raised in the households, butcher's shops, and from illegal slaughterhouses.  In a study from North India, 26% patients ate pork and NCC was associated with consumption of pork more than once a week. 
Interestingly, NCC patients more often (once a week or >4 times in a month) ate outside the house (e.g., restaurants and fast foods) than the control subjects. The rapid economic growth in India and the improvement in the lifestyle of the people expose them to changing food habits seen in developed countries. This reflects unhygienic environment in restaurants and fast food locations.
This study has limitations. First, it is a hospital-based study which has its own selection bias unlike population-based studies. Second, we did not make field visits to confirm about the various environmental risk factors such as type of house, garbage disposal, and personal hygiene of the subjects and family members. Despite its limitations, this is the first Asian study to explore the awareness and attitudes toward NCC among the patients.
In conclusion, this study has shown unhygienic practices, nonvegetarian diet, and eating outside in restaurants as the risk factors for NCC. There is an opportunity to prevent NCC through public educational programs.
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[Table 1], [Table 2], [Table 3], [Table 4]