The number of reported malaria cases in Ethiopia has risen sharply amid fears it could get worse during the "malaria transmission season" which runs from June to October, the UN Office for the Coordination of Humanitarian Affairs (OCHA) said.
"A total of 77 kebeles [administrative zones] were affected by malaria epidemics in May and June, with 18,911 cases and 42 reported deaths," OCHA said in a humanitarian update on Monday.
It warned that the current amount of drugs and insecticide treated nets being imported into the country would be inadequate if there was an epidemic.
The highest number of cases, OCHA said, had been reported to the Ethiopian federal ministry of health from several regions including Tigray in the north, Amhara and Afar in northcentral, Oromiya, Somali in the east and Benshangul-Gumuz in the west.
Data from Tigray, for example, showed 20,000 cases with 21 deaths in June compared to 2,000 cases for the same period in 2004.
Malaria is the third biggest killer in Ethiopia claiming at least 100,000 people a year, according to the country's health ministry. A child is killed every 30 seconds by the disease throughout the African continent.
All forms of malaria are deadly, but the parasite species plasmodium falcifarum, which causes cerebral malaria, is the most lethal, according to the World Health Organization. Cerebral malaria - one of four types of malaria - could kill a person in three to four days if left untreated.
Most of Ethiopia's 70 million people live in rural areas where health services are poor or non-existent. Many of them are highly exposed to malaria.