Autism Spectrum Disorders in Tanzania: Awareness, Diagnosis, Risk Factors and Endophenotypes

Ruparelia, Kavita (2021). Autism Spectrum Disorders in Tanzania: Awareness, Diagnosis, Risk Factors and Endophenotypes. PhD thesis The Open University.

DOI: https://doi.org/10.21954/ou.ro.0001389f

Abstract

Autism Spectrum Disorder (ASD) is common worldwide, but little is known of the condition in sub-Saharan Africa (SSA). I set out to study the lived experiences, identification, risk factors and phenotypic expressions of ASD in Dar-es-Salaam, Tanzania.

I conducted a systematic review of the Broader Autism Phenotype (BAP) in biological parents of ASD probands. I conducted a qualitative study using 7 focus group discussions and 13 in-depth interviews to investigate the knowledge and lived experiences of 14 caregivers of children with ASD and 37 key community informants. I screened 284 children (108 had ASD, 60 had other neurodevelopmental disorders (NDD) and 116 were typically developing (TD)), and used these groups of children to validate the Social Communication Questionnaire (SCQ), and for determining risk factors for ASD. Psychometric properties were examined, and risk factors determined in multivariable models. I further assessed BAP traits of 267 parents (of 103 children with ASD, 57 children with NDD and 107 TD children) exploring the psychometric properties of the Autism Spectrum Quotient (AQ).

The systematic review identified social/communication deficits, rigid/aloof personality traits, and pragmatic language difficulties as useful socio-behavioural endophenotype traits. The qualitative study identified consistent emerging sub-themes: knowledge/awareness in the identification/presentation of ASD, its‘ perceived causes, and the challenges experienced by caregivers and community stakeholders. The Kiswahili SCQ showed between acceptable and excellent reliability (Cronbach‘s (α)=0.65-0.92) and supports a 2-factor model of combined social interaction and communication, and repetitive behaviours, recommended by DSM-5 criteria. Early-life malaria was associated with the greatest independent risk for ASD, being more common among the ASD (31%) than TD group (4%). The Kiswahili AQ had acceptable reliability (Cronbach‘s α=0.84) for all items. The BAP in parents of children with ASD (53%) was higher than for those with NDD (21%) or TD (16%), suggesting BAP are particularly characteristic of ASD.