Nairobi - Four people have died in an outbreak of visceral leishmaniasis, a parasitic disease also known as kalazar or black fever, in Isiolo and Wajir in northeastern Kenya, according to a senior health official.

Shahnaaz Sharif, the senior deputy director of medical services in Kenya's health ministry, said 66 people had been infected in the outbreak that was first reported in Wajir in April 2008.

Sharif said the most affected age group was children between the age of one and five.

"This is due to lowered immunity and the prevailing malnutrition problem in the northern region," he said.

The most affected areas in Wajir are the districts of Wajir West with 50 percent of the total cases (in the localities of Arbijahan, Eldas, Giristu, Wara and Malale), Wajir East and Wajir North. In Isiolo, the Merta Alba area was the most affected.

Sharif said the health ministry and other stakeholders were carrying out case management and distributing drugs to the sick in treatment centres in Wajir and Isiolo.

The affected communities are also being provided with health education on disease prevention and control, while therapeutic feeding of malnourished children is also taking place.

Control measures for kalazar include the use of insecticide treated bed nets and skin repellents as well as early diagnosis, complete treatment and effective surveillance.

Sharif said it had not been possible to reach all of those potentially affected by the outbreak as some had travelled in search of water and pasture for their livestock. Isiolo and Wajir are located in Kenya's pastoral-nomadic region.

Kalazar is endemic in northern Kenya and outbreaks are common in times of drought

Once it enters the body, the leishmaniasis parasite, which is carried by sand flies, migrates to internal organs and bone marrow. If an infection progresses to disease and is left untreated, it almost always results in death.

Sand flies thrive in the cracks of mud-covered dwellings, in cow dung, rat burrows, anthills, dry river beds and vegetation. In Wajir, the flies often bite people as they dig for water in the bed of the Ewaso Nyiro River or graze their livestock on nearby bushes.

Kalazar is endemic in northern Kenya and outbreaks are common in times of drought.

The most effective methods of diagnosing kalazar can only be conducted in large hospitals located far from the worst-affected areas.