Ehrlichia infection in Italy

Area of Science:

• Medical Entomology
• Infectious Diseases
• Public Health

Background:

• Ehrlichiosis is a tick-borne illness caused by Ehrlichia species.
• Previous studies have documented Ehrlichia infections in various regions, but data from Sardinia and Alpine areas require further investigation.
• Understanding the prevalence and seroconversion rates is crucial for public health surveillance.

Purpose of the Study:

• To investigate the incidence of Ehrlichia chaffeensis seroconversion in U.S. citizens exposed to ticks in Sardinia.
• To assess the prevalence of Ehrlichia phagocytophila antibodies in high-risk groups and controls in Alpine regions.
• To evaluate the laboratory confirmation of suspected ehrlichiosis cases in local residents.

Main Methods:

• Serological testing for Immunoglobulin M (IgM) antibodies against Ehrlichia chaffeensis in U.S. citizens.
• Laboratory confirmation of suspected ehrlichiosis cases in local Sardinian residents.
• Antibody detection for Ehrlichia phagocytophila in foresters, hunters, and control groups in Alpine areas.
• Follow-up serological testing of individuals bitten by ticks.

Main Results:

• Immunoglobulin M seroconversion to Ehrlichia chaffeensis was confirmed in U.S. citizens exposed to ticks in Sardinia.
• Seven suspected cases of ehrlichiosis in local Sardinian residents were not laboratory-confirmed.
• Antibodies to Ehrlichia phagocytophila were detected in 8.6% of foresters, 5.5% of hunters, and 1.5% of controls in Alpine areas.
• Only one out of 153 individuals bitten by ticks showed Ehrlichia antibodies after six months.

Conclusions:

• Tick exposure in Sardinia can lead to Ehrlichia chaffeensis infection in U.S. citizens.
• Ehrlichiosis diagnosis in local populations requires rigorous laboratory confirmation.
• Ehrlichia phagocytophila antibodies are present in individuals occupationally exposed in Alpine regions, indicating enzootic circulation.