A red ribbon the symbol for AIDS. (Nikki Kahn)

The 23 children, aged between five and 10, were being treated at the government run Junagadh Civil Hospital for the blood disorder thalassaemia, the Associated Press reports. This inherited disease requires regular blood transfusions, which are free at this hospital. The AP notes the children all come from poor families.

There are discrepancies in reports about where the transfusions took place and the origins of the blood. State government spokesman Jai Narayan Vyas said the transfusions were given at more than one hospital. Patients’s families said only one hospital gave the transfusions.

The Times of India reports that the patients’s families acquire the blood personally from blood banks. Junagadh doctors said blood banks test for diseases including HIV, but if the donor is in the “window period,” the time between infection and production of antibodies, the test can give a false positive.

This is not the first time thalassaemic children in India have been infected with HIV through blood transfusions. In July 2010, at least 56 children tested positive for HIV after being treated at another government run hospital, the Times of India reports.

Last year, the Indian Red Cross Society asked the state health department to start Nucleic Acid Test Centers, the Indian Express reports. These centers, which have not come about, would give people in poorer areas access to testing that shortens the window period.

There are 2.31 million people with HIV and AIDS in India, according to Avert.org. About 3.5 percent of the cases are seen in children.