Toxoplasmosis and cytomegalovirus infection and their role in Egyptian autistic children

Zeinab R Hassan; Kareman M Zekry; Elham Adel Heikal; Hanan F Ibrahim; Seham K Khirala; Samar M Abd El-Hamid; Doaa R Amin; Nora Seliem; Gehad N Abd El-Aal; Mohammad M Alkherkhisy; Salwa A Abd Elhamid; Emad A Mahgoub; Mahmoud E N Hefny; Ghada H El Nady; Mohamed S Badr

doi:10.1007/s00436-023-07818-2

Toxoplasmosis and cytomegalovirus infection and their role in Egyptian autistic children

Parasitol Res. 2023 May;122(5):1177-1187. doi: 10.1007/s00436-023-07818-2. Epub 2023 Mar 14.

Authors

Affiliations

¹ Department of Parasitology, Faculty of Medicine for girls, Al-Azhar University, Cairo, Egypt. zenabramadan.medg@azhar.edu.eg.
² Department of Parasitology, Faculty of Medicine for girls, Al-Azhar University, Cairo, Egypt.
³ Department of Medical Microbiology and Immunology, Faculty of Medicine for girls and boys, Al-Azhar University, Cairo, Egypt.
⁴ Department of Clinical Pathology, Al-Zahraa University Hospital,Faculty of Medicine for girls, Al-Azhar University, Cairo, Egypt.
⁵ Department of Biochemistry, Faculty of Medicine for girls, Al-Azhar University, Cairo, Egypt.
⁶ Department of Pediatric, Faculty of Medicine for girls, Al-Azhar University, Cairo, Egypt.
⁷ Department of Pediatric, Faculty of Medicine, Ain Shams University, Cairo, Egypt.
⁸ Department of Psychology, Faculty of Art, Cairo University, Cairo, Egypt.
⁹ Department of Psychological Sciences, Faculty of Education for Early Childhood, Cairo University, Cairo, Egypt.
¹⁰ Medical Genetic Center, Department of Medical Genetics, Faculty of Medicine, Ain Shams University, Cairo, Egypt.
¹¹ Medical Research Centre, Department of Molecular Biology, Faculty of Medicine, Ain Shams University, Cairo, Egypt.

Abstract

Autism is a neurodevelopmental disorder with a significantly increased incidence rate across the world over the past few years. Toxoplasmosis and cytomegalovirus (CMV) infection are globally prevalent and have been associated with diverse neurological and psychiatric disorders. A few studies have demonstrated the role of toxoplasmosis and CMV as potential etiological factors for autism. Accordingly, this study was performed to estimate the relationship between toxoplasmosis and CMV infection in children with autism as well as to assess their impact on the Childhood Autism Rating Scale (CARS) score. A total of 45 autistic children (6 girls, 39 boys) and 45 (21 girls, 24 boys) healthy control children were enrolled in our study. Their blood samples were collected and tested for the presence of Toxoplasma and CMV (IgG and IgM) antibodies and DNA by ELISA and real-time PCR (RT-PCR), respectively. Toxoplasmosis was detected in 11 (24.4%) autistic children through the ELISA [10 (22.2%) IgG + /IgM - and 1 (2.2%) IgG + /IgM +]; however, RT-PCR assay recorded only 1 positive case (2.2%), while it was detected in 10 (22.2%) control children through ELISA [9 (20%) IgG + /IgM - and 1 (2.2%) IgG + /IgM +] and 1 (2.2%) by RT-PCR. On the other hand, CMV infection was detected in all autistic children with 44 (97.8%) testing positive by ELISA [24 (53.3%) IgG + /IgM - , 18 (40%) IgG + /IgM + and 2 (4.4%) IgG - /IgM +] and 25 (55.6%) testing positive by RT-PCR assay. In addition, ELISA assay recorded 43 (95.6%) [19 (42.2%) IgG + /IgM + and 22 (48.9%) IgG + /IgM - and 2 (4.4%) IgG-/IgM +] and RT-PCR recorded 21 (46.7%) positive samples in control children with CMV. No significant difference was noted between autistic and control children for the overall prevalence of Toxoplasma or/and CMV infection. Similarly, the CARS score indicated a non-significant difference with Toxoplasma or/and CMV infection. Our data does not show an association between autism and toxoplasmosis or/and CMV infection. Nevertheless, considering that autistic children are at a high risk of contracting these infections, further studies with a larger sample size are recommended.

Keywords: Autism; CARS; CMV; ELISA; Prevalence; RT-PCR; Toxoplasmosis.

MeSH terms

Autistic Disorder* / epidemiology
Child
Cytomegalovirus Infections* / complications
Cytomegalovirus Infections* / epidemiology
Egypt / epidemiology
Enzyme-Linked Immunosorbent Assay
Female
Humans
Immunoglobulin G
Immunoglobulin M
Male
Toxoplasma* / genetics
Toxoplasmosis* / complications
Toxoplasmosis* / diagnosis
Toxoplasmosis* / epidemiology

Substances

Immunoglobulin M
Immunoglobulin G