According to the WHO, the two most successful vector control methods are insecticide-treated nets (ITNs) and indoor residual spraying (IRS) (“WHO | Global report on insecticide resistance in malaria vectors: 2010–2016,” n.d.). UNICEF is the world’s top buyer of long-lasting insecticidal nets (LLINs) which require no further treatment during the net’s lifespan (“Mosquito nets | Supplies and Logistics | UNICEF,” n.d.). A study done by the WHO determined that the presence of a mosquito net at all – regardless of whether or not it had been treated with insecticides – significantly lowered infection rates. Something to note, however, is that treated nets have the ability to kill mosquitos as well as keep them out, thus increasing their efficacy (“WHO | Five-year WHO investigation shows that LLINs remain a highly effective tool in the malaria fight,” n.d.). Current vector-prevention practices being implemented in Yemen by the WHO fail to include ITNs or LLINs, with prevention and control focusing on surveillance and early warning systems (“WHO EMRO | WHO develops national strategy for dengue prevention and control | Yemen-news | Yemen,” n.d.).
Sources:
Mosquito nets | Supplies and Logistics | UNICEF. (n.d.). Retrieved April 8, 2019, from https://www.unicef.org/supply/index_39977.html
WHO | Five-year WHO investigation shows that LLINs remain a highly effective tool in the malaria fight. (n.d.). Retrieved April 8, 2019, from https://www.who.int/malaria/news/2016/llins-effective-tool-malaria-fight/en/
WHO | Global report on insecticide resistance in malaria vectors: 2010–2016. (n.d.). Retrieved April 8, 2019, from https://www.who.int/malaria/publications/atoz/9789241514057/en/
WHO EMRO | WHO develops national strategy for dengue prevention and control | Yemen-news | Yemen. (n.d.). Retrieved April 9, 2019, from http://www.emro.who.int/yem/yemen-news/who-develops-national-strategy-for-dengue-prevention-and-control.html