• Study population:
• Village with high proportion of pig-keeping households (HH) and suspected high rate of
porcine cysticercosis, Busibwabo sub-location, Busia County, Kenya (Figure 1)
• Sampling:
• Three-stage door-to-door community based survey (Figure 2)
• Pigs: Assessment of individual characteristics, lingual exam (Figure 3)
• Exam not performed on pigs that were pregnant, lactating, or under 3 months of age
• Humans:
• Stage 1:
• Humans: Assessment of household characteristics, individual survey and epilepsy
screening questionnaire
• Stage 2:
• Screen positive for epilepsy: Neurologist evaluation to confirm epilepsy diagnosis
and blood test for cysticercal antigen (Ag)
• Screen negative for epilepsy: A random sample of 2% of individuals who were
negative on epilepsy screening questions had blood test for cysticercal Ag
• Stage 3:
• Confirmed Lifetime Epilepsy ≥5 yrs old: Computed Tomography (CT) brain
• CT done in Children <5yrs if focal neurological deficit or positive cysticercal Ag
• 2% sample of screen negative and positive cysticercal Ag: CT brain
• Procedures:
• Epilepsy Screening: 9-question epilepsy screening questionnaire was adapted from a
widely used instrument and translated into the predominant local languages12
• Lifetime Epilepsy: ILAE 1993 criteria.13
• Porcine Cysticercosis: Presence of one or more palpable lingual cysts
• Human Cysticercosis: Blood was tested for circulating cysticercal antigen using the
apDia Cysticercosis Antigen ELISA, a commercially available enzyme immunoassay for
qualitative determination of viable metacestodes (cysticerci) of Taenia spp. Cut-off
values were calculated according to kit instructions.
• Human Neurocysticercosis: Contrast-enhanced Computed Tomography (CT) of the brain
was performed using standard protocols and read by a radiologist blinded to the
serostatus and presence or absence of epilepsy
• Analysis: Fishers exact tests were used to compare proportions.
Methods Conclusions
Prevalence of Epilepsy, Human and Porcine
Cysticercosis in Western Kenya
1. Meyer, A., et al., Global disparities in the epilepsy treatment gap: a systematic review. Bull
World Health Organ, 2010. 88: 260-266.
2. Leonardi, M. and T. Ustun, The global burden of epilepsy. Epilepsia, 2002. 43(sup6):21-25.
3. Del Brutto, O.H., Neurocysticercosis: A Review. The Scientific World Journal, 2012.
4. Ndimubanzi, P., et al., A Systematic Review of the Frequency of Neurocysticercosis with a
Focus on People with Epilepsy. PLoS Negl Trop Dis, 2010. 4(11): e870.
5. Ngugi, A., et al., Estimation of the burden of active and life-time epilepsy: A meta-analytic
approach. Epilepsia, 2010. 51(5): 883-890.
6. Carabin, H., et al., Clinical manifestations associated with neurocysticercosis: A systematic
review. PLoS Negl Trop Dis, 2011. 5(5): e1152.
7. Mafojane, N., et al., The current status of neurocysticercosis in Eastern and Southern
Africa. Acta Tropica, 2003. 87:25-33.
8. Balogou, A., et al., Cysticercose et épilepsie au nord du Togo dans le Tone. Rev Neurol
(Paris), 2000. 156(3):270-273.
9. Blocher, J., et al., A Cross-Sectionnal Study of People with Epilepsy and
Neurocysticercosis in Tanzania: Clinical Characteristics and Diagnostic Approaches. PLoS
Negl Trop Dis, 2011. 5(6): e1185.
10. Dongmo, L., et al., Cysticercose et épilepsie: étude cas-témoins dans la Vallée du Mbam,
Cameroun. Bull Soc Pathol Exot, 2004. 97(2): 105-8.
11. Nsengiyumva, G., et al., Cysticercosis as a major risk factor for epilepys in Burundi, East
Africa. Epilepsia, 2003. 44(7): 950-5.
12. Placencia, M, Shorvon, SD, Paredes, V, Bimos, C, Sander JWAS, Suarez, J, Cascante,
SM. Epileptic Seizures in an Andean Region of Ecuador. Brain (1992), 115, 771-782.
13. Commission on Epidemiology and Prognosis ILAE. Guidelines for Epidemiologic Studies
on Epilepsy. Epilepsia 1993;34:592-6.
Results
Introduction
References
• Epilepsy affects 50 million people worldwide, of
whom 80% live in resource-limited settings where
there are high treatment gaps1,2
• Neurocysticercosis (NCC) is the leading cause of
acquired epilepsy worldwide3,4
• In Latin American regions with endemic NCC, epilepsy
prevalence is 2-3x higher than global rates4-6
• Human cysticercosis is strongly associated with
keeping free-ranging pigs and lack of latrines7
• Most studies from African settings derive only from
clinic-based settings7-11
Objectives
• To estimate the prevalence of epilepsy and NCC-
associated epilepsy in humans in a region with
suspected high porcine cysticercosis in Western
Kenya
• To estimate the prevalence of human and porcine
cysticercosis
• Age- and gender- adjusted human epilepsy
prevalence is 3-7 times higher than global
estimates of 5-10 per 1000 population5
• Human cysticercosis prevalence was moderate
• Surprisingly, there were no cases of NCC-associated
epilepsy
• Prevalence of porcine cysticercosis is comparable
to other areas of East/Southern Africa but lower
than Latin America
• Limitations include:
• apDia Ag ELISA only detects viable cysticerci and is
more sensitive in extra-parenchymal disease
• small absolute number of people with epilepsy
• porcine lingual exam has limited sensitivity
• Additional research to identify potential protective
factors explaining the low prevalence of human
cysticercosis despite high rates in pigs is essential
Meyer, AC1, Sokhi, D,2 Ngugi, A,3 Solomon, T, 4 Févre, E 2,4
1Yale University, 2 International Livestock Research Institute, 3Aga Khan University East Africa,
4University of Liverpool
Acknowledgements
• Chiefs, Assistant Chiefs and the communities in Busibwabo sub-location
• Ministry of Agriculture, Livestock and Fisheries, Ministries of Medical Services and Public
Health, County Government of Busia, Kenya
• Leadership and staff, Ministry of Health facilities near Busibwabo sub-location
• Dr. Prabhakar Reddi, Dr. Sam Oula, Aga Khan Hospital Kisumu
• EPICC Study staff
• Fogarty International Center, NIH (K01TW008764- Meyer)
• Global Health Equity Scholars Program, Yale University (Meyer)
• CGIAR Research Program on Agriculture for Nutrition and Health (A4NH) led by IFPRI (Fevre)
• International League Against Epilepsy, UK Chapter (Sokhi)
• Association of British Neurologists (Sokhi)
• Epilepsy Research UK (Sokhi)
Kenya
Lake
Victoria
Busibwabo
Sub-location
Busia
Figure 1. Map of Study Area.
Prevalence
per 1000
population [95% CI]
Lifetime Epilepsy
Crude 26.2 [15.4-41.7]
Crude Female 21.7 [9.4-42.3]
Crude Male 32.1 [14.8-60.1]
Age-Adjusted 30.4 [12.1-48.8]
Age-Sex-Adjusted 36.0 [13.1-58.9]
Cysticercosis
Human
Epilepsy 0 [0, 195.0]*
Without Epilepsy 83.3 [2.1, 384.8]
Porcine 84.5 [31.6, 174.9]
* One sided 97.5% confidence interval
Table 1. Prevalence of Epilepsy and Cysticercosis.
Humans
• Mean 4.5 people per HH [Range:1-20]
• 57% were female (368/648)
• 60% were children <18 yrs (392/648)
• Among adults:
• 72% had a primary school education or
less (185/256)
• 75% were farmers (193/256)
• 73% always used latrine (474/648)
• 27% had a worm in their faeces in the last
one year (158/579)
• 2% had taken de-worming medication in
the last month (14/648)
• Epilepsy
• 37 people screened positive for epilepsy
• of whom 16 were confirmed after
neurology review
• One additional individual with epilepsy
was identified by her mother
• Crude and adjusted epilepsy prevalence
is presented in Table 1.
• Cysticercosis prevalence is presented in
Table 1
• No neurocysticercosis was identified.
Pigs
• 28% of HH kept pigs (41/145)
• Mean of 1.8 pigs per HH [Range:1-7]
• Median age was 4 months [IQR: 2-6]
• 69% of pigs were always tethered in both
wet and dry seasons (50/72)
• No associations were observed between
porcine cysticercosis and:
• allowing pigs to range freely in wet
(p=0.66) or dry (p=0.67) seasons
• presence of a latrine (p=0.32) or all
closed latrines (p=0.34) in the HH
• Having an ill pig in the HH in last 12
mos (p=0.10)
• We evaluated 145 households, containing 648 humans and 72 pigs between 2/25-6/3/15
Figure 3.
Lingual
examination for
cysticercosis.
154 Households
810 Humans
5 HH did not consent
4 HH missed after 2 visits
660
humans present
on study day
654 consented
648 participated
37
pos screen
12
neg screen
random sample
2.6% (17/648)
epilepsy
0% (0/10) +apDia
0% (0/15) CT+NCC
8.3%(1/12) +apDia
0% (0/1) CT+NCC
145 HH participated
72 pigs
evaluated
8.4% (6/71)
cysts on
lingual exam
Stage 1
Stage 2
Stage 3
Figure 2. Recruitment and Study Flow.
+apDia: apDia Cysticercosis Antigen ELISA above cut-off value; CT+NCC: Contrast-enhanced
Computed Tomography of the Brain consistent with diagnosis of neurocysticercosis; HH:
Household.
LB-5329