# P-179. Comparative Clinical And Therapeutic Features Between Rickettsia conorii And Rickettsia typhi Infections

## TL;DR

This study compares the clinical and treatment features of two types of rickettsiosis, finding that Rickettsia conorii infections are more severe and have distinct symptoms.

## Contribution

The study provides a detailed comparison of clinical and therapeutic features between Rickettsia conorii and Rickettsia typhi infections.

## Key findings

- Rickettsia conorii infections were more severe and had higher rates of symptoms like headache, rash, and retinitis.
- Bitherapy was more frequently prescribed for Rickettsia conorii cases compared to Rickettsia typhi.
- Rickettsia conorii was the more commonly diagnosed species in the study population.

## Abstract

Rickettsia conorii and Rickettsia typhi, although both belonging to the spotted fever group, present distinct clinical patterns that are crucial for early diagnosis and management. The aim of our work was to compare the clinical and therapeutic features between Rickettsia conorii and Rickettsia typhi infections.

We conducted a retrospective study including all patients hospitalized in the infectious diseases department for rickettsiosis between 1995 and 2024. The diagnosis was confirmed by serological tests (seroconversion) or a positive polymerase chain reaction assays for Rickettsia.

We encountered 472 cases. There were 286 cases of Rickettsia conorii (60.6%) and 186 cases of Rickettsia typhi (39.4%). A male predominance was noted among Rickettsia conorii (54.2%) and Rickettsia typhi (54.8%) cases (p=0.89). Cephalalgia (75.5% vs 63.4%; p=0.005) and arthralgie (76.9% vs 68.3% ; p=0.038) were significantly more frequent among Rickettsia conorii cases. Fever (99.7% vs 100% ; p=1) and vomiting (44.8% vs 44.9% ; p=0.98) were reported among Rickettsia conorii and Rickettsia typhi cases. The occurence of inoculation eschar (29% vs 18.3%; p=0.008), maculopapular skin rash (83.6% vs 74.6% ; p=0.017) and retinitis (12.7% vs 2%; p=0.045) was significantly higher among Rickettsia conorii cases. Severe forms of rickettsiosis were significantly more frequent with Rickettsia conorii (23.4% vs 15.7% ; p=0.041). Hepatic cytolysis (66.8% vs 69.4% ; p=0.55), leucopenia (16.4% vs 13.4% ; p=0.37) and thrombocytopenia (58.5% vs 57,8% ; p=0.88) were noted among Rickettsia conorii and Rickettsia typhi cases. Bitherapy was more frequently prescribed for cases of Rickettsia conorii (9% vs 4% ; p=0.046). Doxycycline was prescribed for Rickettsia conorii (64.7%) and Rickettsia typhi (71.5%) cases (p=0.12). Ciprofloxacine was prescribed for Rickettsia conorii (15.7%) and Rickettsia typhi (12.9%) cases (p=0.39).

Rickettsia conorii, the predominant species, was associated with severe forms of rickettsiosis. Cephalalgia, arthralgia, inoculation eschar, rash, and retinitis were significantly more common among Rickettsia conorii cases, in comparison with Rickettsia typhi. Bitherapy was more frequently prescribed for Rickettsia conorii cases.

All Authors: No reported disclosures