One hundred cases of tularemia have been reported in 2015 among residents of Colorado, Nebraska, South Dakota, and Wyoming, according to a report by the U.S. Centers for Disease Control and Prevention. This represents a substantial increase in the annual mean number of cases (2 to 7) reported in each of these states during the past decade.
Although the cause for the increase in cases is unclear, Dr. Caitlin Pedati of the CDC’s Epidemic Intelligence Service and colleagues wrote in the Dec. 4 issue of Morbidity and Mortality Weekly Report that possible factors include increased rainfall promoting vegetation growth, pathogen survival, increased rodent and rabbit populations, and increased disease awareness (MMWR. 2015 Dec 4;64:1317-8).
The infected patients ranged in age from 10 months to 89 years, and most commonly presented with the pneumonic form of respiratory disease, skin lesions with lymphadenopathy, and a general febrile illness without localizing signs. A total of 48 people were hospitalized and one died. Possible exposure routes included animal contact, environmental aerosolizing activities, and arthropod bites.
Clinical disease signs of tularemia could include fever and chills with muscle and joint pain, cough or difficulty breathing, swollen lymph nodes with or without skin lesions, conjunctivitis, pharyngitis, or abdominal pain with vomiting and diarrhea, the authors noted. Case fatality rates range from <2% to 24%, depending on the strain. Streptomycin is considered the drug of choice for treatment.
“Health care providers should be aware of the elevated risk for tularemia within these states and consider a diagnosis of tularemia in any person nationwide with compatible signs and symptoms,” wrote Dr. Pedati and colleagues.
Read the full article in Morbidity and Mortality Weekly Report.