Cysticercosis al. 1998). Cysticerci (larval cysts) can develop in

Cysticercosis
is a parasitic zoonoses caused by the metacestodes of Taenia solium, a two-host zoonotic cestode. It is of much economic
and public health importance causing morbidity and mortality in many developing
countries of South-East Asia, Africa and Latin America (Giri & Parija, 2012;
Rajshekhar et al, 2003; Ito et al, 2004) where pigs are raised for
consumption under traditional husbandry practices. It has been designated as a
“biological marker” of the social and economic development of a community
(Carpio et al. 1998).

Cysticerci
(larval cysts) can develop in any organ in the body. Cystercerci in the central
nervous system (brain or spinal cord) causes the most serious form of infection
known as neurocysticercosis (NCC). It is considered to be the most common
parasitic infection of the human nervous system and the most frequent
preventable cause of epilepsy in the developing world (Román et al.,
2000; Del Brutto et al., 2001). The clinical manifestations of NCC vary
with seizures being the most common presentation of symptomatic NCC, affecting
from 69% to 96% of cases (Del Brutto et
al.,1992; Bern et al., 1999; Carpio and Hauser, 2002; Garcia et
al, 2005) which is the main cause of late onset epilepsy in endemic areas
(Flisser et al., 1998). In addition
to seizures and epilepsy, NCC can manifest with severe chronic headaches,
blindness, hydrocephalus, meningitis, symptoms due to space-occupying CNS
lesions, dementia and even death (Townes et al., 2004; Sorvillo et al., 2007). People who neither raise
pigs nor consume pork are also at risk of cysticercosis if they ingest T.
solium eggs after coming into direct or indirect contact with tapeworm
carriers. Vegetarians in India have been found to be at high risk of infection
from tapeworm infected food preparers (Rajshekar et al., 2003).

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The
disease is prevalent in virtually all states of the country, although the
prevalence rates vary significantly between different states (Rajshekhar and
Chandy, 2000). The
single cyst infection (47.7% – 53.4%), is the most common in Indian
subcontinent (Prasad et al., 2008). In most cases, NCC diagnosis is based on neuroimaging studies i.e.
Computed Tomography (CT) and Magnetic Resonance Imaging (MRI). MRI is
considered the best neuro-imaging tool for the detection of degenerating and
innocuous (viable) cysticerci, while CT is the best for calcified lesions
(Garcia et al., 2003). These
techniques are also not accessible for the poor people of endemic area because
of very high cost. Therefore the development of immunodiagnostic tests that
detects specific antibodies in the serum or CSF is the need of urgency (Ito et al., 2003).

ELISA
has been used widely by for the detection of antibodies in the serum with
variable sensitivities and specificity in diagnosis of NCC in definitive cases
(Shukla et al., 2008). Western blot
with lentil lectin purified glycoprotein (LLGPs) or the enzyme-linked
immunoelectro transfer blot (EITB) has been the “gold standard” serodiagnostic
assay and was originally reported to have sensitivity of 98% and specificity of
100% (Tsang et al., 1989).
Immunodiagnostic techniques depend largely on a good, potent and purified
antigen prepared from the Taenia solium
metacestodes like low molecular mass antigens (Atluri et al., 2009), excretory/secretory, somatic antigens (Sahu et al., 2009), crude soluble extract
(Atluri et al., 2009), total saline
extract (Oliveira et al., 2007),
vesicular fluid (Arruda et al.,
2005), membrane and scolex extracts (Arruda et
al., 2005). For many parasitic diseases like malaria, amoebiasis etc.
excretory secretory (ES) antigens have been found to perform much better than
the crude somatic antigens. There are a few studies on use of ES antigens for
developing antibody ELISA. An advantage of using ES antigens instead of somatic
antigens for detection of antibodies against T. solium cysticerci is
that it is possible to determine whether the parasite larva is living, dead or
degenerated (Molinari et al., 2002).

Neurocysticercosis
remains a serious neglected problem in marginalized communities in many areas
of India mainly due to poverty, ignorance, lack of suitable diagnostic &
management capacity and inappropriate prevention and control strategies. The
costs for performing neuroimaging techniques are very high, mainly for the
public health system. For routine laboratory tests, the best choice for a NCC
screening could be the use of immunoassays that combines accuracy, sensitivity,
and reasonability (Ito, 2002? Flisser et
al., 2006). The present study utilizes three different antigenic
preparations (Sccolex antigen, excretory secretory antigen and membrane body
antigen) from Cysticercus cellulosae
in the serodiagnosis of NCC in epileptic patients by indiect IgG-ELISA and
EITB. Simultaneously, for the first time, an attempt has been made for the
detection of NCC by PCR from blood samples of the same patients targeting LSU
rRNA gene of Taenia solium.

Materials and methods

Collection of samples

The
present study was conducted in the Department of Veterinary Public Health,
Nagpur Veterinary College, Nagpur, Maharashtra, India. A total of 26 epileptic
patients who visited Get Well Hospital and Research Institute, Nagpur for
treatment during the period from January 2016 to July 2016, suspected to be NCC
clinically and/or radiologically with history of seizures, within the age range
of 6-53 years were included in the study after obtaining consent from them.
Blood and sera samples were collected along with their CT scan/ MRI findings
(as observed by the neurologist). Parallel 10 samples from healthy volunteers
having no neurological symptoms were included in the study as negative controls
in order to calculate the cut-off O.D. value. The sera were subjected to screening
of anti-cysticercus antibodies by in-house developed ELISA employing three
different antigens prepared from Cysticercus
cellulosae followed by determination of immunodominant proteins by EITB
employing the same antigens. The blood samples were subjected to DNA isolation
for molecular identification.