Rickettsia africae: identifying gaps in the current knowledge on vector-pathogen-host interactions.

Estere Mazhetese,Vlademiro Magaia,Luis Neves,Elisa Taviani,Darshana Morar-Leather

doi:10.3855/jidc.13291

Abstract

Rickettsia africae is a bacterium of zoonotic importance, which causes African tick bite fever (ATBF) in humans. This pathogen is transmitted by ticks of the genus Amblyomma, with Amblyomma hebraeum and Amblyomma variegatum being the major vectors. Tick species other than the above-mentioned have also been reported to carry R. africae DNA. There is scarcity of information on the epidemiology of this pathogen, yet several cases have been recorded in foreign travellers who visited endemic areas, especially southern Africa. The disease has rarely been described in people from endemic regions. The aim of this study was to discuss the information that is currently available on the epidemiology of R. africae, highlighting the gaps in this field. Furthermore, ATBF cases, clinical signs and the locations where the cases occurred are also listed in this review.

Highlights

Rickettsia africae is a bacterium that was first reported as a species 24 years ago [1]
It is mainly transmitted by African Amblyomma tick species, causing African tick bite fever (ATBF) in humans; mostly in tourists visiting southern Africa [2]
This paper reviews R. africae from the epidemiological perspective, looking at the occurrence of ATBF among individuals from presumed naïve populations never exposed to African Amblyomma bites, and those from endemic regions, where the populations are commonly exposed to R. africae challenge, the potential vectors of this disease in Africa and other continents, and the possible role of mammalian hosts as reservoirs

Summary

Introduction

Rickettsia africae is a bacterium that was first reported as a species 24 years ago [1]. It is mainly transmitted by African Amblyomma tick species, causing African tick bite fever (ATBF) in humans; mostly in tourists visiting southern Africa [2]. This paper reviews R. africae from the epidemiological perspective, looking at the occurrence of ATBF among individuals from presumed naïve populations never exposed to African Amblyomma bites, and those from endemic regions, where the populations are commonly exposed to R. africae challenge, the potential vectors of this disease in Africa and other continents, and the possible role of mammalian hosts as reservoirs

Objectives

Results

Discussion

Conclusion