People should be careful when choosing and using mosquito repellents containing the chemical Deet (another name for N,N-diethyl-meta-toluamide) as it has side effects, a pharmacist group in Hong Kong has advised amid the Zika virus outbreak in Latin America. The Hong Kong Academy of Pharmacy reminded the public that different mosquito repellents could contain different ingredients, and the hours of protection they provide could vary. “Based on the threat of the Zika virus, there are many consumers looking for insect repellents. When they go to shop for insect repellents, usually they won’t pay attention to what is in the ingredients,” said academy president Iris Chang Yee-man. READ MORE: Zika virus alert – Hong Kong expert recommends strengthened monitoring of pregnant women over mosquito bites “Deet is one of the chemicals [that is] more of a concern,” she said. “When the ingredient is inhaled inside the body or seeps into the skin, then it could cause different side effects such as dizziness, disorientation and in severe cases seizures.” She added: “Deet really smells. It’s a highly toxic chemical. Mosquitoes are really afraid of it. So are people.” Chang said repellents with or without Deet should be equally effective, but people going to high-risk areas were advised to bring some repellents containing Deet, the concentration of which could vary. Chang added that consumers should consult doctors and pharmacists on what repellents they should use. If consumers also use sunscreen, Chang said, they should apply the sunscreen first before applying the repellent. When asked whether mosquitoes could develop resistance to Deet repellent, Chang said she was not aware of mosquitoes developing resistance to the chemical at the moment. READ MORE: The Zika virus explained – why the world is not taking chances with birth defect-linked disease spread by mosquitoes The Zika virus, which the World Health Organisation has declared a public health emergency of international concern, has affected 26 countries in Central and South America. The disease was now suspected by health authorities to have affected pregnant women the most and cause microcephaly for newborn babies. More than 4,000 babies in the region were born with the rare birth defect. The virus is spread by mosquitoes, and a case in the United States reported this week was understood to have been transmitted sexually. Meanwhile, with the flu season continuing in Hong Kong, Chang reminded the public to always keep their hands clean by washing them regularly with disinfectant soap.