ISLAMABAD (AP) - A group of Pakistani doctors blames a recent outbreak of HIV among children in a southern city on poor healthcare practices such as using dirty needles and contaminated blood, according to a statement released on Friday (Dec 20).

The doctors are also urging Pakistan's government to do more to understand how the virus went from high-risk groups such as drug users and sex workers to the general population.

They also warned that there isn't enough medication in the city of Ratodero, in southern Sindh province, where 591 children need medical treatment.

The outbreak is extremely worrying, said the doctors, calling it "one of the worst" in Pakistan. They studied medical data of 31,239 people in Ratodero, where the HIV outbreak took place and who agreed to the study.

Out of that group, 930 were positive for HIV, with 604 of them being younger than five years of age and 763 younger than 16 years, according to the study published the international Lancet Infectious Disease Journal.

By the end of July, when the study was being completed, only one in three children had started antiretroviral treatment "due to an inadequate supply of drugs and a lack of trained staff", the statement said.

The study said 50 of the children examined are showing signs of "severe immunodeficiency" but did not specify if they have full-blown AIDS.

"The results, which are the first scientific report on the outbreak, appear to confirm observations... that HIV was mostly transmitted to children as a result of healthcare providers using contaminated needles and blood products," said the statement.

"Pakistan has experienced a series of HIV outbreaks over the past two decades, but we've never before seen these many young children infected or so many health facilities involved," said Dr Fatima Mir from Aga Khan University in Karachi, the Sindh provincial capital, one of the authors of the study quoted in the statement.

About 70 per cent of Pakistan's 220 million people use the private healthcare sector, which is mostly unregulated and rarely monitored for cleanliness and safety.

Among many Pakistanis, popular belief holds that intravenous or intramuscular injections are more effective than medicine taken by mouth, which has increased the use of syringes across the country - and the likelihood of dirty needles being used.

In the immediate aftermath of the HIV outbreak in Ratodero, the government did act quickly, closing three blood banks as well as 300 clinics run by untrained medical staff, the statement said.