Story highlights Thailand has effectively eliminated cases of mothers passing on HIV to their newborns

The country is the first in the Asia-Pacific region to achieve the landmark

(CNN) The World Health Organization has congratulated Thailand as the first country in the Asia-Pacific region to eliminate mother-to-child transmission of HIV and syphilis.

It is also the first with a "large HIV epidemic" to eradicate mother-to-child transmission of the diseases. In 2014, an estimated 450,000 people were living with HIV in Thailand.

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The disease is passed from mother to child either in the womb or during labor, delivery or breastfeeding, and if untreated, there is a 15-45% chance of the baby inheriting HIV from its mother.

If treatment -- in the form of antiretroviral medicine -- is given during the crucial stages, that chance is reduced to 1%.

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