RIO DE JANEIRO (Reuters) - Brazil's health ministry on Wednesday reported 4,443 suspected and confirmed cases of microcephaly, up from 4,314 the previous week, as the South American country wrestles with an outbreak of Zika virus and its suspected link to the rare birth defect.

Of the total reported Wednesday, Brazil said 508 cases of microcephaly have been confirmed, while 3,935 are still being investigated.

The ministry said last week said that 41 of the confirmed cases of microcephaly had shown links to a Zika infection. It did not update that figure on Wednesday.

Microcephaly is a condition marked by abnormally small head size that can result in developmental problems. Brazil is investigating a surge in the number of cases across the country in conjunction with the outbreak of Zika, but have not proven that the virus can cause microcephaly.

Zika has now spread to more than 30 countries and has led the World Health Organization to declare a global health emergency.

(Reporting by Paulo Prada; Editing by Frances Kerry)