Common epidemiology of Rickettsia felis infection and malaria, Africa.

Oleg Mediannikov,Abir Znazen,Cristina Socolovschi,Mamadou O Ndiath,Adama Tall,Jean Bernard Lekana-Douki,Georges Diatta,Didier Raoult,Philippe Parola,M’Hammed Sarih,Florence Fenollar,Sophie Edouard,Hubert Bassene,Hamidou Niangaly,Ogobara Doumbo,Nadjet Mouffok,Pavel Ratmanov,Herve Richet,Cheikh Sokhna

doi:10.3201/eid1911.130361

Abstract

This study aimed to compare the epidemiology of Rickettsia felis infection and malaria in France, North Africa, and sub-Saharan Africa and to identify a common vector. Blood specimens from 3,122 febrile patients and from 500 nonfebrile persons were analyzed for R. felis and Plasmodium spp. We observed a significant linear trend (p<0.0001) of increasing risk for R. felis infection. The risks were lowest in France, Tunisia, and Algeria (1%), and highest in rural Senegal (15%). Co-infections with R. felis and Plasmodium spp. and occurrences of R. felis relapses or reinfections were identified. This study demonstrates a correlation between malaria and R. felis infection regarding geographic distribution, seasonality, asymptomatic infections, and a potential vector. R. felis infection should be suspected in these geographical areas where malaria is endemic. Doxycycline chemoprophylaxis against malaria in travelers to sub-Saharan Africa also protects against rickettsioses; thus, empirical treatment strategies for febrile illness for travelers and residents in sub-Saharan Africa may require reevaluation.

Highlights

This study aimed to compare the epidemiology of Rickettsia felis infection and malaria in France, North Africa, and sub-Saharan Africa and to identify a common vector
The risk of developing R. felis infection was 1.6× higher during the rainy period than during the dry period
In S1–2, a significant difference was found between the incidence of R. felis for patients 15 years of age, which was 0.10 (0.06–0.15) per 100 person-months

Summary

Introduction

This study aimed to compare the epidemiology of Rickettsia felis infection and malaria in France, North Africa, and sub-Saharan Africa and to identify a common vector. Blood specimens from 3,122 febrile patients and from 500 nonfebrile persons were analyzed for R. felis and Plasmodium spp. Several studies have assessed the effect of fastidious bacterial infections in systemic febrile illness, including Rickettsia felis [4,5,6], Coxiella burnetii [7], Tropheryma whipplei [3], and Borrelia spp. Malaria, dengue, and rickettsiosis are among the most identified etiologies of febrile illness, and exposure to mosquitoes is reported as the most common source of fever [11]. During 2011, a possibly primary infection with R. felis, named “yaaf,” was hypothesized in the case of an 8-month-old girl in Senegal with polymorphous skin lesions [12]

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Conclusion