Mosquitoes have become resistant to some insecticides, resulting in a surge in malaria cases in Rwanda, World Health Organization (WHO) official said Friday.

Olushayo Olu, the WHO country representative in Rwanda made the remarks at a one-day malaria symposium in Kigali.

Olushayo said the plasmodium, the germ that causes malaria, has also become resistant to some drugs.

He called on experts to analyze the malaria situation in the country, reflect on what has been done so far and find out the challenges.

Rwanda had in the past succeeded in rolling back malaria.

Between 2005 and 2012, the country had seen large scale successes registered, with malaria cases reduced by 86 percent and mortality down by 74 percent during the period, according to officials.

However, cases surged last year to 2 million, up from around 500,000 in 2012.

Agnes Binagwaho, Rwanda's minister of Health noted that malaria is a threat. "It is not only a health threat. It is an economic threat too," she said.

Brigadier General Dr. Emmanuel Ndahiro, the commandant of Rwanda Military Hospital said the hospital had set out to act as a center of excellence in the fight against the disease.

Corine Karema, head of Malaria Division in Rwanda's ministry of Health said research is going on in an etymology laboratory at Rwanda Biomedical Center on insecticide resistance by mosquitoes.

Rwanda last year distributed 903,150 treated mosquito nets in seven malaria prone districts and carried out residual spraying in three other malaria prone districts, according to figures from the ministry.