(Bloomberg) — Malaysia has confirmed its first case of polio in almost three decades, sparking fears that the disease is spreading across the region after the Philippines declared an epidemic in September.

A test by the World Health Organization found that the virus, detected in a three-month-old boy from the eastern state of Sabah, is linked to the one found in the Philippines, according to Malaysia’s health ministry. The last polio case in Malaysia was in 1992. In 2000, the country had declared itself free of the crippling and potentially fatal disease.

The Philippines, which lies across a narrow sea from Sabah, declared an outbreak in September. The WHO has confirmed at least nine cases in the country this year.

Polio ceased to be a public health problem in industrialized nations during the 1950s and 1960s with the introduction of effective vaccines. Since a global initiative began in 1988, polio cases have decreased by more than 99%. But the virus can be imported into a polio-free country and spread rapidly among unimmunized populations.

Malaysia, following a similar move by the Philippines, is embarking on an aggressive immunization drive to prevent the virus from spreading further. The health ministry issued public notices and held seminars to encourage parents to vaccinate their children, calling it a “sign of true love” and citing an Islamic religious leader who said it’s a sin not to ensure children are protected from preventable diseases.

The strain detected in Sabah came from a weakened polio virus used in vaccines, which could infect those without immunity in unsanitary conditions, the ministry said. It found that 12% of children age 2 months through 15 years in the affected area weren’t vaccinated.

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