Tularemia case reported in Colorado

Photo: Dr_Microbe/Adobe Stock

Colorado public health officials recently announced that the first case of tularemia this year was detected in a resident of Wheat Ridge, Colorado.¹ The disease primarily affects rural areas but has been found throughout the country except Hawaii.²

Tularemia is caused by bacteria Francisella tularensis It is commonly seen in wildlife.² The infection occurs most commonly in rodents, rabbits and hares and is associated with very high mortality rates during outbreaks.³ It is also found in insects such as ticks and deer flies. Human infection occurs through the bite of an infected insect, skin contact with an infected animal, drinking or eating contaminated water or food, or inhaling the airborne bacteria via contaminated aerosols or agricultural or landscaping dust.^1,3

Approximately 200 cases of tularemia are reported each year in the United States, with most found in western and south-central states.² In 2023, nine cases were reported in Colorado.^Four

“Although tularemia is rare, it is important that residents recognize the symptoms and take preventative measures,” Rachel Reichardt, environmental health specialist with Jefferson County Public Health, said in a news release.¹ “Early diagnosis and medical attention are important as prompt treatment with antibiotics is effective.”

Symptoms of tularemia include fever, non-healing skin ulcers at the site of infection, swollen and painful lymph glands, inflamed eyes, sore throat, mouth sores, diarrhea and pneumonia. If infected through ingestion of contaminated food or water, symptoms include sore throat, abdominal pain and diarrhea. F. tularensis It can cause pneumonia and symptoms include fever, chills, headache, muscle aches, dry cough and progressive weakness.¹

The incubation period for the disease is 3-5 days but can vary from 1-14 days.² Treatment is with antibiotics. In humans, tularemia can be effectively treated and cured. If you experience symptoms related to tularemia after possible contact with a wild animal, it is advisable to seek medical attention.¹

Tularemia infection in pets

Cases of the disease have been reported in dogs, cats, pigs and horses, but it is most commonly infected in sheep.^Five Tularemia infection is rare in dogs, but like humans, dogs can become infected through insect or spider bites, drinking contaminated water, or eating infected wild animals. Dogs may also develop short-term loss of appetite, lethargy, and a low-grade fever. Conjunctivitis, uveitis, draining abscesses, and swollen lymph nodes are also possible, but these symptoms are rare. Infected dogs are treated with antibiotics.^Five

The disease is rare in cats, but they can become infected and develop tularemia. Signs of feline tularemia vary depending on the route of infection and the type of bacteria, but can include high fever, swollen and painful lymph nodes in the neck and head, abdominal pain, tick infestation, jaundice, and organ failure.^6,7 Other symptoms include loss of appetite, stiffness, decreased ability to move, coughing, diarrhea, frequent urination, sores on opening of the mouth and throat, and rapid pulse and breathing rates.⁷ Cats infected with tularemia require hospitalization with effective supportive care, including intravenous therapy, in addition to antibiotics. Cats infected with tularemia have a high mortality rate, collapsing and dying within hours to days.⁷

Measures that can be taken to prevent exposure to humans and pets include:¹:

• Always use insect repellent when outdoors
• Avoid contact with wild rodents
• Don't feed rodents or rabbits or allow them into your garden or patio
• Remove piles of wood, trash, and weeds around the house
• Avoid touching sick or dead animals, and wear gloves if you must handle them
• Avoid drinking untreated surface water from lakes, ponds, rivers, etc.
• Cook meat thoroughly before eating
• Keep pets on a lead where they may come into contact with wildlife
• Consult a veterinarian after your pet comes into contact with wildlife
• Provide prompt veterinary care for sick pets and avoid handling sick pets without using hand and face protection

References

1. First case of tularemia discovered in Jefferson County in 2024. News release. Jefferson County Public Health, Colorado. July 3, 2024. Accessed July 9, 2024. https://www.jeffco.us/CivicAlerts.aspx?AID=2247
2. Frequently Asked Questions (FAQs) About Tularemia. Centers for Disease Control and Prevention. April 4, 2018. Accessed July 9, 2024. https://emergency.cdc.gov/agent/tularemia/faq.asp#:~:text=Tularemia%2C%20also%20known%20as%20%E2%80%9Crabbit,Q.
3. About Tularemia. Centers for Disease Control and Prevention. Accessed July 9, 2024. https://www.cdc.gov/tularemia/about/index.html
4. Zoonotic Diseases in Colorado, 2018-2023. Colorado Department of Public Health and Environment. Accessed July 9, 2024. https://docs.google.com/document/d/e/2PACX-1vQiHGHnuA3a1eItYaqFdusko0oPPOXTDqc84Vre5iVq1hPgTF7oafN5_lUNiDdsDvy-PmFFpPw0L6iV/pub
5. Weir M, Williams K, Downing R. Canine tularemia. VCA Animal Hospitals. Accessed July 10, 2024. https://vcahospitals.com/know-your-pet/tularemia-in-dogs
6. Weir M, Williams K, Downing R. Feline tularemia. VCA Animal Hospitals. Accessed July 10, 2024. https://vcahospitals.com/know-your-pet/tularemia-in-cats
7. Foley JE. Feline tularemia. Merck Veterinary Manual. August 2018. Accessed July 10, 2024. https://www.merckvetmanual.com/cat-owners/disorders-affecting-multiple-body-systems-of-cats/tularemia-in-cats