An invasion of black flies in the Nabdam district of the Upper East region is having a toll on farming activities.

Farmers have had to stay away from their farms to avoid the irritating bites of the flies.

When the flies bite, it causes severe itching, disfigures the skin and visual impairment, including permanent blindness.

Some of the farmers who spoke to Joy News said it has become increasingly difficult to do anything on their farms or even at home.

One farmer said the farmers cannot even come out of their rooms. The only way they are able to stay out is to wear clothes that cover them completely.

They called on the Health Ministry, Non-Governmental Organisations and other philanthropists to come to their aid.

Environmental health officers for the Nabdam district, Isaac Yen said the only solution is for the area to be sprayed with chemicals.

However, the district cannot afford the chemicals because they are too expensive.

He said the situation is terrible and even though they want to believe what they have been told that the flies no longer cause onchocerciasis, they do not want to take any chances.

He said the best way to get rid of the flies is to spray the entire district.