Tick- and flea-borne rickettsial emerging zoonoses.

Area of Science:

• * Infectious Diseases
• * Microbiology
• * Public Health

Background:

• * Over the past two decades, nine new species/subspecies of spotted fever rickettsiae have emerged as tick-borne pathogens.
• * Bacteria in the family Anaplasmataceae, previously considered veterinary pathogens, are now implicated in human diseases.
• * Examples include Rickettsia parkeri, Rickettsia felis, Ehrlichia chaffeensis, Anaplasma phagocytophilum, and Ehrlichia ewingii.

Purpose of the Study:

• * To provide an overview of emerging tick- and flea-borne rickettsial zoonoses.
• * To focus on the ecological, epidemiological, and clinical characteristics of these diseases.
• * To highlight the recent identification of new pathogens and their impact on human health.

Main Methods:

• * Literature review of emerging tick- and flea-borne rickettsial zoonoses.
• * Analysis of ecological, epidemiological, and clinical data.
• * Focus on pathogens identified between 1984 and 2004.

Main Results:

• * Nine new spotted fever rickettsiae species/subspecies identified as emerging agents.
• * Six of these were first isolated from ticks and later found pathogenic to humans.
• * Three Anaplasmataceae species (Ehrlichia chaffeensis, Anaplasma phagocytophilum, Ehrlichia ewingii) implicated in human diseases.

Conclusions:

• * Tick- and flea-borne rickettsial zoonoses represent a growing global health concern.
• * Continued surveillance and research are crucial for understanding and managing these emerging infectious diseases.
• * The emergence of novel pathogens necessitates updated diagnostic and treatment strategies.