TZ scientists explain why mosquito net treatment safe

Dar es Salaam. Senior scientists at the National Institute for Medical Research (Nimr) in Tanzania yesterday allayed public fears following reports of a study by a Kenyan researcher who claimed that the common Insecticide Treated Nets (ITNs)—also used here—are unsafe.

News broke in Kenya last week, saying a top researcher at the Kenya Medical Research Institute (Kemri) had found a high risk of cancer and asthma to children in man-made versions of insecticides commonly used for treating bed nets.

The researcher, Dr Festus Tolo from Kemri, raised the concern in his study, with an observation that the nets, which are treated using synthetic substances—pyrethroids–were also harmful to the environment because they do not break down easily.

“All mosquito bed nets distributed to households in East African countries are treated using synthetic insecticides, which are not safe,’’ Dr Tolo was quoted by Daily Nation in Kenya as saying on Friday.

He is advocating a naturally occurring form of insecticides produced from another substance known as pyrethrin which is said to be less harmful. He said that the study was a long overdue since some countries have banned the use of synthetic treated nets.

“We are looking for a way of coming up with a natural extract form…to make safe insecticides and even use them in making indoor residual sprays which are harmless,” said the don who also heads the Natural Product Research and Drug Development Programme at Kemri.

As news of his study spread across East Africa, there was widespread panic—given the fact that there was an estimated 25 million people using the ITNs in 22 of the 25 malaria endemic regions in the country. However, the authorities appeared not to be jolted into action, not until the director general of Nimr, Prof Yunus Mgaya, told The Citizen that consultations were still ongoing with researchers at his organisation on how to handle the fast-spreading reports.

Later during the day, he issued a text to The Citizen, quoting a senior scientist at Nimr who argued that there was no solid justification and rationale to convince the scientific community that the man-made substances used for treating bed nets were unsafe.

“Currently, synthetic pyrethroids are the only available insecticides for treating bed nets. Several randomized community trials … by renowned scientists, including Nimr have proved that there were no obvious side effects [caused by the synthetic insecticides] apart from some irritations,’’ said a quote issued by Prof Mgaya.

“Dr Tolo wants to mislead the world with a wrong statement. I presume the statement is his own and not that of Kemri. People should not worry about it as pyrethroids are the only available tools to fight against malaria using bed nets,’’ said the quote.

Back in Kenya, Kemri has also refuted claims made by Dr Tolo but the institute has admitted that pyrethroids are generally known to be harmful, although it said the levels of concentrations, used in manufacturing bed nets were “completely safe.”