Murine Model of Neuroschistosomiasis Mansoni: Clinical, Histological and
Magnetic Resonance Imaging Studies
Thiago Andre Alves Fidelis
1,2
*, Patricia Parreiras
2
, Fernanda Tovar-Moll
3
, Fernanda Meireles
3
, Geraldo Brasileiro Filho
4
, Paulo Marcos Zech Coelho
2
and Jose
Roberto Lambertucci
1
1
Division of Infectology and Tropical Medicine, Department of Internal Medicine, School of Medicine, Universidade Federal de Minas Gerais, Belo Horizonte, Minas
Gerais, Brazil
2
Schistosomiasis Laboratory, Rene Rachou Research Center, Oswaldo Cruz Foundation (Fiocruz), Belo Horizonte, Minas Gerais, Brazil
3
CENABIO/Universidade Federal do Rio de Janeiro, Brazil
4
Department of Pathology, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
*Corresponding author: Thiago Andre Alves Fidelis, Physical Therapist, Universidade Federal de Minas Gerais, Infectious diseases, Alfredo Balena avenue 190, Belo
Horizonte, Minas Gerais 30130-100, Brazil, Tel: +55 31 994208520; Fax: +55 31 994208520; E-mail: tfidelis1@gmail.com
Received date: June 01, 2018; Accepted date: August 17, 2018; Published date: August 24, 2018
Copyright: © 2018 Fidelis TAA, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted
use, distribution, and reproduction in any medium, provided the original author and source are credited.
Abstract
The schistosomiasis mansoni infection is responsible for 3.6% of the worldwide estimated causes of death and
the central nervous system can be affected. In humans, the eggs of this helminth have been found in the
leptomeninges, cerebral cortex, basal ganglia, choroid plexus, cerebellum and spinal cord. Neurological
manifestations, histhology and magnetic resonance imaging of neuroschistosomiasis mansoni in humans serve as
our chief reference points for the examination of the experimental infections in murine model. In this study,
experimental infection of S. mansoni cercariae in mice aims to demonstrate the presence of granulomas in the brain
and correlate to the clinical, histologic, and magnetic resonance findings. Twenty five Swiss-webster mice were
infected subcutaneously, and followed for 160 days post-infection. Another group of twenty five mice were not
infected and kept as controls. Images were obtained in the different planes by magnetic resonance. Histological
samples were stained by Hematoxilin and Eosin (HE) to examine S. mansoni eggs, granulomas and inflammatory
lesions. The results showed neurological manifestations as head and chest tilt (to the left or right side), hemiparesis,
ataxia, body contortion, loss of balance and spinning, induced by granulomas in several regions of the central
nervous system, and vascular changes associated with haemorrages. The MRI indicated multiple irregular nodules
dispersed associated with oedema. These findings indicate that the murine model subcutaneously infected by S.
mansoni cercarie may be used for studying mechanisms leading to human neuroschistosomiasis.
Keywords: Schistosomiasis; Schistosomiasis mansoni;
Neuroschistosomiasis murine model; Encephalitis; Neuroinfection
Introduction
Te World Health Organization estimates that between 200 and 300
million people worldwide are infected with Schistosoma spp. and that
800 million people in the world are at risk of infection. In Brazil,
approximately 2.5 million people are infected with Schistosoma
mansoni and 30 million are exposed to infection [1,2].
Central Nervous System (CNS) involvement in schistosomiasis can
occur during acute primary infections, but as the disease becomes
chronic, neurological complications can occur as the newly forming of
granulomas are smaller, shrunken and fbrotic [2,3].
In the year of 1944, 800 people from Asia continent were attended at
Moore General Hospital (North Caroline-United States of America)
and approximately 2% (160 people) developed cerebral complications
attributed to schistosomiasis japonica [4-8]. In Zimbabwe, Gelfand
(1950) found S. haematobium eggs in the digested brains of 56% (28
people) of 50 patients with S. haematobium infection of the bladder.
Alves (1958) found that in 28% of 150 unselected autopsy cases S.
haematobium eggs were detected in the brain [9-11]. It is estimated
that the incidence of neurological complications varies between 0.3%
and 4% of schistosomiasis mansoni [2]. Te incidence of encephalic
demage caused by S. mansoni in humans is unknown.
Neurological manifestations of schistosomiasis are caused by an
increase in intracranial pressure, and the focal signs are triggered by
the tumor masses produced by granulomas, ofen in the productive
phase with slight fbrosis, which suggested the chronic phase of
infection. Te initial signs and symptoms include headache, focal or
generalized seizures, ataxia, nystagmus, nausea and vomiting,
intracranial hypertension and various neurological defcits [2].
For many years, we have observed evidence of brain disease
(hemiplegia, spinning and urinary retention) in mice infected with S.
mansoni, but these mice were considered to have other diseases, such
as labyrinthitis or cerebral infection [2].
Tus, neuromotor manifestations presented by infected animals
should characterize neurological damage caused by S. mansoni eggs in
the murine model. Terefore, the relationship between histological
fndings and the neurological signs of encephalic involvement, such as
hemiparesia, spinning, head tilt, chest tilt, ataxia, and loss of balance
could be established in this study.
Aloe et al. described eggs, both with and without granuloma
formation, in CD-1 mice infected with 60 S. mansoni cercariae (Puerto
Rican strain). However, the mice did not present the signs of brain
disease. Additionally, Silva et al. observed very few eggs in the brains of
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ISSN: 2379-1764
Advanced Techniques in Biology &
Medicine
Fidelis et al., Adv Tech Biol Med 2018, 6:3
DOI: 10.4172/2379-1764.1000 263
Research Article Open Access
Adv Tech Biol Med, an open access journal
ISSN:2379-1764
Volume 6 • Issue 3 • 1000263