Rickettsia conorii

Rickettsia conorii is a bacterium that causes boutonneuse fever, a mild typhus-like illness. It is transmitted by the dog tick Rhipicephalus sanguineus and is endemic to the Mediterranean region, with similar forms found in Africa and India caused by different subspecies.1

Rickettsiae are bacteria that primarily parasitize arthropods like ticks and can cause serious diseases in humans and animals, often characterized by self-limiting fevers. R. conorii typically causes symptoms such as fever, chills, muscle aches, and headache, followed by a rash. A characteristic lesion, the tâche noire, may appear at the tick bite site. While generally mild, severe cases can occur, particularly in older individuals or those with weakened immune systems. Boutonneuse fever is treatable with antibiotics like doxycycline, and mortality rates are low. Prevention involves avoiding tick bites.21