Further spread of Rhodesian sleeping sickness in Uganda likely due to livestock movements

Dec 15, 2009

The northwards spread of human Rhodesian sleeping sickness in Uganda is likely due to the movement of infected livestock, according to new findings from an interdisciplinary research group including members from the Centre for Infectious Diseases, University of Edinburgh; the Ministry of Health, Uganda; and the Universities of Oxford and Southampton.

The current study, published December 15 in the open-access journal PLoS Neglected Tropical Diseases, provides evidence that the spatial distribution of the in a recently affected area is constrained by the location of livestock markets, indicating the role of cattle (the predominant reservoir of disease) in its spread. A complex interaction of environmental and climatic factors was also found to affect distribution of the disease.

Human African trypanosomiasis (HAT, or ) is a fatal disease transmitted by the tsetse fly in sub-Saharan Africa. Endemic in some regions, it spreads across 36 countries. It is estimated that around 60,000 people are currently infected. There are two forms of the disease (an acute "Rhodesian" form, which the research focuses on, and a chronic "Gambian" form), but fears are growing that they may overlap in Uganda, which could render current diagnosis and treatment protocols ineffective.

Previous work implicated livestock movements in the spread of this disease. Regulations were therefore reinforced that required the treatment of all cattle from endemic areas prior to sale at livestock markets. The primary aim of the new research was to investigate potential reasons for this subsequent spread of the disease. The researchers conducted both a one-step logistic regression analysis of HAT prevalence and a two-step logistic regression method, which enabled separate analysis of both occurrence and prevalence of the disease. Both the occurrence and prevalence were negatively correlated with distance to the closest livestock market in all models.

To prevent the overlap of the two disease forms, a large-scale intervention, Stamp Out Sleeping Sickness (stampoutsleepingsickness.org), has been applied. This public-private partnership has treated over 250,000 animals to clean the disease from the overlap zone. However, continued movements of untreated animals into the cleaned zones present an ongoing risk. The authors conclude that "the stringent implementation of regulations requiring the treatment of cattle prior to sale at markets should be a priority for the Ugandan Government."

Future research by the group will aim to extend this study by assessing the risk of further Rhodesian HAT spread and the potential for overlap with the Gambian form of the disease.

Explore further: Success short treatment against drug-resistant tuberculosis confirmed

More information: Batchelor NA, Atkinson PM, Gething PW, Picozzi K, Fe`vre EM, et al. (2009) Spatial Predictions of Rhodesian Human African Trypanosomiasis (Sleeping Sickness) Prevalence in Kaberamaido and Dokolo, Two Newly Affected Districts of Uganda. PLoS Negl Trop Dis 3(12): e563. doi:10.1371/journal.pntd.0000563

add to favorites email to friend print save as pdf

Related Stories

Revealing secrets of 'African sleeping sickness'

Oct 27, 2008

Scientists in the United Kingdom and Russia are reporting identification of a long-sought chink in the armor of the parasite that causes African sleeping sickness, a parasitic disease that kills at least 50,000 people each ...

USDA plans voluntary cattle tracking

Jun 21, 2006

The U.S. Department of Agriculture still has no system to track livestock during an outbreak of infection, such as mad cow disease.

Recommended for you

Poll: Many doubt hospitals can handle Ebola

2 hours ago

A new poll finds most Americans have some confidence that the U.S. health care system will prevent Ebola from spreading in this country, but they're not so sure their local hospital can safely handle a patient.

Number of Ebola cases nears 10,000

3 hours ago

The number of people with Ebola is set to hit 10,000 in West Africa, the World Health Organization said, as the scramble to find a cure gathered pace.

'Breath test' shows promise for diagnosing fungal pneumonia

3 hours ago

Many different microbes can cause pneumonia, and treatment may be delayed or off target if doctors cannot tell which bug is the culprit. A novel approach—analyzing a patient's breath for key chemical compounds made by the ...

Where Ebola battles are won

12 hours ago

(HealthDay)—Four hospitals that are home to advanced biocontainment facilities have become America's ground zero in the treatment of Ebola patients.

User comments : 0