Plague is a serious flea-borne disease caused by the bacteria Yersinia pestis. Today, this bacterium is maintained in nature between fleas and rodents and occasionally affects humans (primarily bubonic plague in the western United States) through flea bites, handling infected animals or inhaling infectious particles. In the Middle Ages, this disease was known as The Black Death and resulted in a high mortality rate experienced by afflicted people.
Plague can be experienced in three forms:
1. Bubonic (confined to lymph nodes)
2. Pneumonic (lungs)
3. Septicemic (reduced blood flow to tissues)
Murine typhus is caused by the flea-borne bacterium Rickettsia typhi that is primarily maintained in rats in nature. Fleas can also transmit tapeworms that affect dogs, cats and humans. Children are primarily infected through ingestion of contaminated feces.
FLEA BIOLOGY
Fleas are wingless ectoparasites that blood feed on mammals and birds. They have a characteristic body that is flattened and are extraordinary jumpers. Fleas can transmit pathogens that cause disease, and their itchy bites can cause skin irritation. Both male and female fleas blood feed and can play roles as pests and pathogen transmitters. Most fleas live from 30-75 days, but some fleas can live up to 12 months. Female fleas can lay approximately 25 eggs per day.
Eggs hatch within five days, depending on flea species and environmental conditions. Flea larvae live in cracks/crevices and/or in debris in houses, animal nests or burrows. They feed on organic debris, such as adult flea excrement or other types of organic material. The typical larval developmental period is about two weeks, but this may be lengthened due to low food supply or low temperatures. A cocoon is formed during the flea’s pupal stage, and adult fleas emerge one to two weeks later. The emergence of adults can take longer (e.g., in a vacant home for up to a year) and can be stimulated by vibration or carbon dioxide emitted by potential hosts.
HOW CAN I GET RID OF FLEAS IN MY HOME AND YARD?
Repellents containing DEET or commercially available insecticide-treated clothing (e.g., permethrin-treated clothing) can protect against flea bites during the cleanup process.
When determining how to get rid of fleas in residential cases of infestations, all clutter should be removed from the home. This will allow a proper assessment of the infestation and help with cleanup and treatment. All carpeted and uncarpeted areas of the home should be vacuumed thoroughly every other day for several days to a month, depending on the degree of infestation. Make sure you dispose of the vacuum cleaner bag properly after each cleaning. The bag should be sealed in an outer bag to prevent any fleas from escaping and discarded outside of the home. Uncarpeted areas can be mopped regularly to remove possible debris and cocoons.
Several species of fleas have developed some degree of resistance to insecticides commonly used for control. Pest control professionals should be consulted for flea surveillance and targeted treatment. Insecticide dusts can be applied to both larval and adult fleas on floors. Residual insecticides and insect growth regulators can also be used against fleas. Potential rodent harborage areas that may be a source of fleas should also be treated in consultation with a pest control professional. In a disease outbreak situation, immediate removal/control of rodents may be necessary to interrupt the cycle of pathogen transmission.
Pets (e.g., dogs and cats) can be a source of fleas and can be treated for fleas, in consultation with your veterinarian.
Dr. Stephanie L. Richards is an Associate Professor of Health Education and Promotion in the Environmental Health Sciences program at East Carolina University. She received a B.S. in Biology and M.S. in Environmental Health from East Carolina University. She completed her Ph.D. in Entomology with a minor in geographic information science at North Carolina State University. She completed her post-doctoral work in Arbovirology at University of Florida, Florida Medical Entomology Laboratory. Learn more.
