Antimicrobial Treatment Patterns and Illness Outcome Among United States Patients With Plague, 1942-2018.

BACKGROUND: Plague is a rare and severe zoonotic illness with limited empiric evidence to support treatment recommendations. We summarize treatment information for all patients with plague in the United States (US) as collected under the auspices of public health surveillance. METHODS: We reviewed use of specific antimicrobials and illness outcome among cases of plague reported from 1942-2018. Antimicrobials were a priori classified into high-efficacy (aminoglycosides, tetracyclines, fluoroquinolones, sulfonamides, and chloramphenicol) and limited-efficacy classes (all others). Logistic regression models were created to describe associations between use of specific antimicrobial classes and illness outcome while controlling for potential confounding factors. RESULTS: Among 533 total reported plague cases during 1942-2018, 426 (80%) received high-efficacy antimicrobial therapy. Mortality differed significantly among those receiving high-efficacy therapy (9%) and only limited-efficacy therapy (51%). Aminoglycosides and tetracyclines were used more commonly than other classes, and their use was associated with increased odds of survival of plague. Gentamicin use was associated with higher mortality than streptomycin, and aminoglycoside use was linked to higher mortality than for tetracyclines. Fluoroquinolones have been used in treatment of >30% of patients in recent years and limited data suggest clinical effectiveness. CONCLUSIONS: Most US patients with plague have received effective antimicrobials. Aminoglycosides and tetracyclines substantially improve survival of plague, and fluoroquinolones may be equally as effective, yet lack sufficient data. Early recognition and early treatment with any of these antimicrobial classes remain the most important steps to improving survival of plague.

Animal Exposure and Human Plague, United States, 1970-2017.

Since 1970, >50% of patients with plague in the United States had interactions with animals that might have led to infection. Among patients with pneumonic plague, nearly all had animal exposure. Improved understanding of the varied ways in which animal contact might increase risk for infection could enhance prevention messages.

Evaluating the risk of tick-borne relapsing fever among occupational cavers-Austin, TX, 2017.

Tick-borne relapsing fever (TBRF) is a potentially serious spirochetal infection caused by certain species of Borrelia and acquired through the bite of Ornithodoros ticks. In 2017, Austin Public Health, Austin, TX, identified five cases of febrile illness among employees who worked in caves. A cross-sectional serosurvey and interview were conducted for 44 employees at eight organizations that conduct cave-related work. Antibodies against TBRF-causing Borrelia were detected in the serum of five participants, four of whom reported recent illness. Seropositive employees entered significantly more caves (Median 25 [SD: 15] versus Median 4 [SD: 16], p = 0.04) than seronegative employees. Six caves were entered more frequently by seropositive employees posing a potentially high risk. Several of these caves were in public use areas and were opened for tours. Education of area healthcare providers about TBRF and prevention recommendations for cavers and the public are advised.