Brazil's first national census estimate of autism prevalence: Implications for surveillance and policy in the Global South.
Brazil’s census gives you the first solid national rate—1.2 %—and a loud signal that adults and rural areas are being missed.
01Research in Context
What this study did
Brazil asked every household a simple question in its 2022 census: 'Does this person have autism?'
About 2.4 million people answered yes. That is 1.2 % of the nation.
The count covers all ages, every state, rich and poor areas alike.
What they found
Young boys showed the highest rates. Adult identification was low.
Northern and rural states had fewer self-reports than big cities.
The 1.2 % figure is four times higher than Brazil’s only earlier local estimate.
How this fits with other research
Keintz et al. (2011) found just 0.27 % PDD in one Brazilian town. The new census shows that small study missed most cases.
Pillay et al. (2021) saw only 0.08 % ASD in South African schools. Brazil’s census now proves under-counting is a wider Global-South problem.
Morales Hidalgo et al. (2021) caught 1.53 % ASD in Spanish schools. Both papers agree: official lists leave many autistic people invisible.
Why it matters
You now have hard numbers to show funders why adult and rural services are needed. Use the 1.2 % figure when you write grants or train health workers. Push for screening in under-reported regions; the people are there even if clinics have not found them yet.
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02At a glance
03Original abstract
Autism prevalence data remain scarce in low- and middle-income countries. In 2022, Brazil incorporated, for the first time, a specific question on prior medical diagnosis of autism in its national census. Results from the preliminary publication of the 2022 Census sample, released in 2025, indicated that 1.2% of the population, approximately 2.42 million individuals, reported a diagnosis of autism. Among boys aged 5 to 9 years, prevalence reached 2.6%, declining to 1.6% among adolescents and 0.3% among adults aged 30 years or older. Although based on self-reported diagnosis, these data provide the first nationwide population estimate of autism in Brazil. Comparisons with U.S. figures from the Autism and Developmental Disabilities Monitoring Network should be interpreted cautiously given methodological differences. The observed age gradient suggests potential historical under-identification in older cohorts. Regional variation further highlights differences in diagnostic patterns across the country. The inclusion of autism in Brazil's national census represents an important step toward strengthening surveillance, research, and policy planning in low- and middle-income settings.Lay AbstractIn 2022, Brazil included, for the first time, a specific question on medical diagnosis of autism in its national census, as mandated by federal law. Results from the 2025 preliminary publication of the Census sample showed that 1.2% of the population reported a prior medical diagnosis of autism, totaling about 2.42 million people. Among boys aged 5 to 9 years, prevalence reached 2.6%, while rates were lower among adolescents and adults. This age pattern may reflect historical differences in access to diagnosis. Regional variation was also observed across states. Including autism in Brazil's national census represents a major step forward for epidemiological monitoring and policy planning in Latin America.
Autism : the international journal of research and practice, 2026 · doi:10.1177/13623613261428537