A retrospective longitudinal study of animal and human rabies in Botswana 1989-2006.

The study investigates the patterns and trends of animal and human rabies in Botswana over an 18-year period, from 1989 to 2006. It confirms that majority of rabies cases were found in domestic animals, fewer in wild animals and a minimal percentage in humans.

Study Design and Execution

• The research is a retrospective longitudinal study, which means the data was gathered after the events have taken place over a lengthy period.
• The study spanned 18 years from 1989 to 2006 and the analysis was conducted to understand the epidemiological patterns and trends of rabies in Botswana.
• 4,306 brain specimens were collected from animals and humans showing clinical signs consistent with rabies. These specimens were subsequently submitted to the National Veterinary Laboratory in Gaborone for diagnosis.
• The test results revealed that 2,419 cases tested positive for the lyssavirus antigen, which indicates the presence of rabies.

Findings: Prevalence of Rabies

• Overall, the prevalence rate of rabies was calculated to be 56.18%, meaning over half of the tested cases were rabies-positive.
• The vast majority (85.7%) of these cases were found in domestic animals, with a smaller proportion (14.2%) in wild animals. Only two cases (0.1%) were from human subjects.
• The prevalence of the disease was higher in the first half of the study period (1989-1997) compared to the second half (1998-2006). The difference in these rates was found to be statistically significant.

Breakdown by Species

• Within the species, ruminant animals (which include bovines, caprine, and ovine) accounted for nearly 80% of the cases, while dogs accounted for 16.01% and cats for only 0.87% of the cases.
• Rabies was also found in horses (1.35%) and donkeys (1.78%) both part of the equine category which accounted for 3.13% of the total cases.
• In the case of wild animals, the jackal was most affected, accounting for over 60% of the total wild animal cases.

Comparison with Previous Studies and Implications

• The findings were compared with the previous epidemiological data (1979-1988) to understand how the disease pattern has changed over time.
• The article also discusses the socio-economic impact of rabies, given its high prevalence among domestic and farm animals which play a critical role in many people’s livelihoods.
• The study’s findings highlight the need for ongoing monitoring and more effective control measures to curb the spread of rabies in Botswana’s animal and human populations.