Microcephaly cases among newborns in Brazil 2010-2023

In 2023, the reported number of microcephaly cases among newborns in Brazil amounted to 318 children. This figure more than doubled in comparison to years prior to 2015, but was not nearly as high as during the highest point of the Zika epidemic, which took place in the country between 2015 and 2016. However, the figures reported might be impacted by the surge of the COVID-19 pandemic in 2020, when a great share of the resources were allocated to mitigate the spread of the new virus.

Microcephaly and the Zika virus

The dramatic rise in microcephaly cases in Brazil between 2015 and 2016 is believed to be connected with the spread of the Zika virus in South America. Microcephaly is a neurodevelopmental disorder that is usually defined as a head circumference that deviates from the mean standards for age and sex which commonly affects brain development. As of July 2017, Brazil had reported the highest number of microcephaly and/or CNS malformation cases potentially associated with Zika virus infection in the world, with 2,366 such cases.

Congentinal Zika virus syndrom in Brazil

The congenital Zika virus syndrome (CZS) is a series of birth defects including microcephaly that can be found in newborns when a women is infected with the Zika virus during pregnancy. In Brazil, the Northeast Region had the highest number of confirmed cases of congenital Zika virus syndrome (CZS) between 2015 and 2021, with a total of 1,410 children affected. During that period, the most affected state in the country was Pernambuco.