Ehrlichia ruminantium: an emerging human pathogen?

To the Editor: Ehrlichia ruminantium, transmitted by ticks of the genus Amblyomma, causes heartwater in ruminants in subSaharan Africa, Madagascar and some Caribbean islands, but there are no authenticated reports that the organism can cause disease in non-ruminants or humans. No reliable vaccine is available and infected animals frequently die before treatment with tetracyclines can be initiated. Serological tests for E. ruminantium lack specificity and the most reliable and sensitive test for the organism involves polymerase chain reaction (PCR) amplification and probing for a section of the organism genome.