This picture taken on October 29, 2013 shows pregnant teenager Ying (L), 16, standing with another pregnant woman (R) at the Association for the Promotion of the Status of Women (APSW) in Bangkok. AFP PHOTO / NICOLAS ASFOURI VIA GETTY IMAGES
Fortunately, Thailand had launched a programme that year to provide antiretroviral (ARV) treatment and counselling for pregnant women with HIV, and her son was born free of the virus.
A decade later, she had a second son - this time, armed with knowledge about how to monitor the amount of HIV in her blood - her viral load - and the CD4 cells protecting her from infection. She was confident that he would not get sick.
"With my first child, I was scared, but with my second, I was not scared at all because I knew what my viral load and CD4 levels were, and he wouldn't contract it," Anya said by telephone while at sea fishing in eastern Chanthaburi province.
The World Health Organization announced on Wednesday that Thailand has become the first Asian country to eliminate mother-to-child transmission of HIV and syphilis.
Elimination of transmission is defined as a reduction of transmission to such a low level that it no longer constitutes a public health problem.
Last year, Cuba was the world's first country to receive WHO validation for eliminating mother-to-child transmission of HIV.
But Thailand, which is home to about 450,000 people living with HIV, is "the first with a large HIV epidemic to ensure an AIDS-free generation," the WHO said in a statement.
"This is a remarkable achievement for a country where thousands of people live with HIV," Dr Poonam Khetrapal Singh, the head of WHO for Southeast Asia, said in a statement.
"Thailand has demonstrated to the world that HIV can be defeated," she added.
UNAIDS Executive Director Michel Sidibé called the achievement an important milestone in efforts to end the AIDS epidemic by 2030.
In the 1980s and 1990s, Thailand struggled with a huge HIV epidemic, with an estimated 143,000 new infections in 1991.
Over the decades, it has conducted awareness and condom use campaigns, and provided free antiretroviral (ARV) treatment for all Thais, cutting the estimated number of new infections to 8,100 in 2013.
Thailand's decision to provide all pregnant women – including undocumented migrant workers – free antenatal care, delivery and services for HIV and syphilis, pushed treatment coverage rates up, culminating in the validation of elimination of mother-to-child transmission, WHO said.
Mother-to-child transmission has dropped to 85 children infected with HIV in 2015, from about 1,000 children infected in 2000, it said.
According to Thai health authorities, the number of women newly infected with HIV fell to 1,900 in 2014, from 15,000 in 2000.
Untreated, women living with HIV have a 15 percent to 45 percent chance of transmitting the virus to their children during pregnancy, labour, delivery or breastfeeding, WHO said.
That risk drops to just over 1 percent if ARVs are given to mothers and children throughout the stages when infection can occur.
According to the Thai Ministry of Public Health, 98 percent of all pregnant women living with HIV have access to ARVs, and the rate of mother-to-child transmission of HIV has been reduced to less than 2 percent.
(Reporting by Alisa Tang, editing by Katie Nguyen. Please credit the Thomson Reuters Foundation, the charitable arm of Thomson Reuters, that covers humanitarian news, women’s rights, corruption and climate change. Visit news.trust.org to see more stories)