Identification of Ehrlichia chaffeensis by nested PCR in ticks from southern China

A total of 717 ticks collected from southern China were examined by nested PCR for the presence of Ehrlichia chaffeensis. Sixteen (55.2%) of 29 adult Amblyomma testudinarium ticks and 28 (11.7%) of 240 adult and at least 4.2% of 215 nymphal (pooled specimens) Haemaphysalis yeni ticks tested positive. Four other species of ticks were negative. Selected positive amplicons were confirmed by DNA sequencing.