Dog-associated risk factors for human plague

Area of Science:

• Zoonotic diseases
• Epidemiology
• Public Health

Background:

• Plague is a rare, fatal zoonotic disease found in the western United States.
• Pet contact has been previously identified as a potential risk factor for plague infection.
• The specific risks associated with pets at household and individual levels require further definition.

Purpose of the Study:

• To investigate the association between pet ownership and plague infection.
• To identify specific household and individual-level risk factors related to pets in plague cases.
• To better understand the role of pets in the transmission of plague.

Main Methods:

• A matched case-control study was conducted.
• Nine surviving plague patients, 12 household members, and 30 matched controls were surveyed.
• A written questionnaire assessed household and individual exposures to pets and flea control measures.

Main Results:

• No significant differences in dog or cat ownership or flea control use were found between case and control households.
• Case households were more likely to report a sick dog (44% vs. 0%) compared to control households.
• Plague patients were more likely to sleep in the same bed with a pet dog (44% vs. 10%) compared to controls.
• Sleeping in the same bed with a pet dog remained a significant risk factor in multivariate analysis (P=0.046).

Conclusions:

• Dogs may play a role in facilitating flea transfer into households.
• Close and extended contact with dogs, such as sharing a bed, increases the risk of plague infection.
• Public health recommendations should consider close pet contact as a potential risk factor for plague exposure.