Tickborne Infections Likely to Increase.

• Position: LYME DISEASE

The incidence of tickborne infections in the U.S. has risen significantly within the past decade. It is imperative, therefore, that public health officials and scientists build a robust understanding of pathogenesis, design improved diagnostics, and develop preventive vaccines, implores a commentary in the New England Journal of Medicine from leading scientists at the National Institute of Allergy and Infectious Diseases.

Bacteria are responsible for most tickborne diseases in the U.S., with Lyme disease representing 82% of reported cases. The spirochete Borrelia burgdorferi is the primary cause of Lyme disease in North America; it is carried by hard-bodied ticks that then feed on smaller mammals, such as white-footed mice, and larger animals, such as white-tailed deer.

Although there likely are many factors contributing to increased Lyme disease incidence in the U.S., greater tick densities and their expanding geographical range have played a key role, the authors write. For instance, the Ixodes scapularis, or deer tick, which is the primary source of Lyme disease in the northeastern U.S., had been detected in nearly 50% more counties by 2015 than was previously reported in 1996.

Although most cases of Lyme disease are treated successfully with antibiotics, 10% to 20% of patients report lingering symptoms after effective antimicrobial...