Tanzanian researchers link cattle keeping to serious bacterial disease

Dar es Salaam. Researchers have warned of an increasing risk of a bacterial infection known as leptospirosis, which causes fever in humans.

The researchers have pointed out cattle as a possible source of human leptospirosis in northern Tanzania, following a study they carried out.

In a report published in PLOS Neglected Tropical Diseases, the researchers analysed the major risk factors for contracting the bacterial disease and discovered that rice and cattle farming are associated with acute infection.

Leptospirosis is caused by bacteria which fall in the genus Leptospira, which is known for causing a wide range of symptoms and can lead to serious complications including kidney and liver problems.

Scientists say, in a study conducted in northern Tanzania, that 8.8 per cent of people with severe fevers had leptospirosis.

The scientists have so far revealed that animals can carry leptospirosis and lead to its spread throughout the environment or directly to humans.

However, the major animal reservoirs and modes of transmission have not yet been well – established by the scientists.

One of the experts, Michael Maze of the University of Otago, New Zealand, and his colleagues enrolled people with fever from two hospitals in Moshi, Tanzania from 2012 through 2014.

Each participant was tested for leptospirosis, and administered a survey on risk behaviours over the past 30 days, including exposure to livestock, rodents, and surface water.

The researchers identified 24 acute cases of leptospirosis, 252 people were found positive for lower levels of Leptospira bacteria.

Rice farming, cleaning cattle waste, feeding cattle and farm work were all found to be associated with acute leptospirosis.

Smallholder farming— which may be associated with substantial exposure to both livestock and rodents—as well as frequent sightings of rodents in one’s kitchen or food store— was associated with the bacterial infection.

“Our findings suggest that control of Leptospira infection in livestock could play a role in preventing human leptospirosis in Africa,” the researchers say.

It is estimated that seven to ten million people are infected by leptospirosis per year, says the World Health Organisation.

The number of deaths this causes is not clear, however, the disease is most common in tropical areas of the world but may occur anywhere.

Outbreaks may occur in slums of the developing world. The disease was first described by physician Adolf Weil in 1886 in Germany.