Brazil changes guidelines to determine microcephaly

The Brazilian Health Ministry has changed guidelines that determine if newborns have microcephaly, or abnormally small heads that can indicate brain damage.

Health Minister Marcelo Castro said Wednesday that health professionals must now report suspected microcephaly cases when the head circumference of a male infant at birth measures 31.9 centimeters or less and a female's is 31.5 centimeters or less.

The previous criterion was 32 centimeters for both sexes.

This change could lower the number of reported microcephaly cases because an initial diagnosis is often based on head size.

The latest health ministry figures report 6,158 cases of microcephaly nationwide since the Zika virus outbreak started in October. Only 745 of those cases have been confirmed, 1,182 have been discarded and 4,231 are still being investigated.

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