**1. Introduction**

24 Current Topics in Tropical Medicine

Smoak, B.L., McClain, J.B., Brundage, J.F., Broadhurst, L., Kelly, D.J., Dasch, G.A. & Miller,

Socolovschi, C., Barbarot, S., Lefebvre, M., Parola, P. & Raoult, D. (2010). *Rickettsia sibirica* 

Stephany, D., Buffet, P., Rolain, J.M., Raoult, D. & Consigny, P.H. (2009). *Rickettsia africae*

Stokes, P.H. & Walters, B.J. (2009). Spotted fever rickettsiosis infection in a traveler from Sri

Tsai, Y.S., Wu, Y.H., Kao, P.T., Lin, Y.C. (2008). African tick bite fever. *Journal Formosan Medical Association*, Vol.107, No.1, (January 2008), pp. 73-76, ISSN 0929-6646 Walker, D.H. & Raoult, D. (2010). *Rickettsia prowazekii* (Epidemic or louse-borne typhus), In:

Walker, D.H. (2009). The realities of biodefense vaccines against Rickettsia. *Vaccine*, Vol. 27,

Walter, G., Botelho-Nevers, E., Socolovschi, C., Raoult, D. & Parola, P. (2011). Murine typhus

1996), pp. 217-221, ISSN 1080-6059

438, ISSN 1195-1982

(September 2010), pp.1495-1496, ISSN 1080-6059

(November 2009), pp. 1867-1870, ISSN 1080-6059

ISBN 978-0-4430-6839-3, Philadelphia-USA.

Suppl. 4 (November 2009), pp. D52-5, ISSN 0264-410X

R.N. (1996). An outbreak of spotted fever rickettsiosis in U.S. Army troops deployed to Botswana. *Emerging Infectious Diseases*, Vol.2, No.3, (July-September

*mongolitimonae* in traveler from Egypt. *Emerging Infectious Diseases*, Vol.16, No.9,

infection in man after travel to Ethiopia. *Emerging Infectious Diseases*, Vol.15, No.11,

Lanka. *Journal of Travel Medicine*, Vol.16, No.6, (November-December 2009), pp. 436-

*Mandell, Douglas, and Bennett´s Principles and Practice of Infectious Diseases*, Mandell G.L., Bennett J.E., Dolin R. (Eds.), pp. 2521-2524, Churchill Livingstone Elsevier,

in returned travelers: a report of thirty-two cases, *Proceedings of the 6th International Meeting on Rickettsiae and Rickettsial Diseases*, Heraklion, Crete, Greece, June 2011. Zanetti, G., Francioli, P., Tagan, D., Paddock, C.D. & Zaki, S.R. (1998). Imported epidemic typhus. *Lancet*, Vol.352, No.9141, (November 1998), pp. 1709, ISSN 0140-6736

Human ehrlichioses and rickettsioses are important arthropod borne infectious diseases which are transmitted by ticks, mites, lice and fleas. Infections result in mild to fatal outcomes, with clinical presentations that resemble other tropical infectious diseases such as malaria making clinical diagnosis difficult. Despite recognition as important causes of lifethreatening diseases in the United States, the geographic distribution of these diseases worldwide remains undefined due to their recent emergence, challenges in diagnosis and lack of comprehensive epidemiological studies needed to determine incidence in developing countries. Recently, the transfer of technological developments to other parts of the world especially developing countries has encouraged basic epidemiological inquiry and generated scientific interest in understanding the epidemiology of these tick borne diseases and their role as causes of undifferentiated febrile illnesses. In this chapter, we review the current knowledge of human monocytotropic ehrlichiosis (HME) and spotted fever rickettsiosis (African tick bite fever) in Cameroon.
