Laboratory tests have confirmed that tainted drugs killed at least 13 women and sickened many others at a government-operated camp in India. The drugs were given to the women after doctors performed an operation to prevent them from having children.The incident raises questions about the custom of performing such operations at health camps.Amar Agrawal is the health minister in the Indian state of Chhattisgarh. He says the antibiotic drug ciprocin was given to women who had the sterilization treatments earlier this month. He says the drug contained zinc phosphide – a chemical commonly used in rat poison.Many of the patients felt sick to the stomach. They started vomiting and reported severe pain after they went home and took the medicine. In the following days, at least 13 women died and many others became extremely sick.The state government has taken legal action against the local drug company that supplied the antibiotic used at the camp. The owner and his son were arrested on fraud charges.D.G Shah is secretary general of the Indian Pharmaceutical Association. He says the tragedy calls attention to the need for increased government regulation of small companies. He says such businesses sometimes do not adhere to good manufacturing practices -- what he called GMT."They supply to one district or at the most one state or three, four states. They are not national players. And they are governed by the state drug commissioner. Though on paper they say everybody is complying, they do not comply and as it has been reported in this case, in spite of poor GMT standards, the state drug commissioner had not taken adequate action for closure of this unit. The only positive side of this incident we see is that it might act as a wake-up call."The tragedy has also turned attention to the custom of performing mass sterilizations at government-run camps. The Indian government supports use of such operations as a way to control population growth. India is home to 1.25 billion people. It is the second most populous country in the world.At the camps, doctors operate on large numbers of patients, although the government denies there is any use of force. Women are offered a monetary incentive of about $10 to have their fallopian tubes removed. The operation is called a tubectomy.Voluntary groups have raised concerns about India's sterilization program. They say Indian women are not given enough information about other methods of contraception, or birth control, by state health workers. They add that the workers are often under pressure to line up women to have tubectomies.Other questions have also been raised about the conditions in which the sterilizations are performed. Nibedita Phukan is with the Center for Health and Social Justice, a group based in New Delhi."These camps, they never adhere to those guidelines, actually. We have seen lot of camps, Rajasthan, Bihar, Madhya Pradesh, UP (Uttar Pradesh). If you go through the guidelines, you cannot operate any women after 4 o'clock and per day not more than 35 women. Everything has been violated in the mass sterilization camps."About four and a half million women were sterilized in India in the year that ended in March 2013. Observers say the latest tragedy will put the government under pressure to reconsider population control methods.I'm Marsha James.