EMBARGOED FOR RELEASE: 3 P.M. (CT) TUESDAY, NOVEMBER 18, 2008

　　Media Advisory: To contact corresponding author Jianguo Xu, M.D., Ph.D.,

　　email xujianguo@icdc.cn ; for Jun Ren, M.D.,

　　email rj@ahcdc.com.cn ; for co-author J.

　　Stephen Dumler, M.D., call Christen Brownlee at 410-955-7832.

　　Study Documents What May Be First Cases of Certain Tick-Borne Disease in China

　　CHICAGO - It appears that for the first time human granulocytic

　　anaplasmosis (HGA), an emerging tick-borne infectious disease found in

　　the U.S. and Europe, has been identified in China and apparently was

　　transmitted from person to person, according to a study in the November 19 issue of JAMA.

　　HGA was recognized in the United States in 1990 and in Europe in 1997,

　　with the annual number of infections reported in the U.S. steadily

　　increasing. Data suggests that infection rates in endemic areas are as

　　high as 15 percent to 36 percent, implying that the diagnosis is often

　　missed or that infection is mild or asymptomatic, according to

　　background information in the article. "Because epidemiological,

　　clinical, and microbiological information about HGA is limited, the

　　disease is likely underrecognized and underreported worldwide," the

　　authors write.

　　Lijuan Zhang, M.D., Ph.D., of the National Institute of Communicable

　　Disease Control and Prevention, China CDC, Beijing, and colleagues

　　conducted a study to determine the origin and transmission of the

　　apparent first cases of HGA acquired in China, as well as the first

　　finding of human-to-human transmission. A cluster of cases among health

　　care workers and family members following exposure to a patient with

　　disease symptoms consistent with HGA prompted the investigation.

　　Subsequent questioning of the patient's family revealed that she was

　　bitten by a tick 12 days before onset of fever.

　　After exposure to the index patient (initial person with symptoms),

　　whose fatal illness was characterized by fever and hemorrhage at a

　　primary care hospital and regional tertiary care hospital's isolation

　　ward, secondary cases (health care workers and family members) with

　　fever who were suspected of being exposed were tested for antibodies

　　against the bacteria Anaplasma phagocytophilum. Potential sources of

　　exposure were investigated.

　　In a regional hospital of Anhui Province, China, between November 9 and

　　17, 2006, a cluster of nine patients with fever and other symptoms were

　　diagnosed with HGA. No patients had tick bites. All nine patients had

　　contact with the index patient within 12 hours of her death from

　　suspected fatal HGA while she experienced extensive hemorrhage and

　　underwent endotracheal intubation (the placement of a flexible plastic

　　tube into the trachea for the purpose of ventilating the lungs). The

　　patients indicated they were unlikely to have used gloves or wash after

　　contact with the index patient.

　　Among the 28 individuals who reported close contact (20 inches or less)

　　with the index patient during the final 12 hours of her life, nine were

　　infected. The index patient was exposed to 20 contacts for more than 2

　　hours, and nine were infected. All nine infected patients reported

　　contact with blood and seven had contact with respiratory secretions.

　　Those persons with skin exposure to blood or respiratory secretions, or

　　those with pre-existing skin lesions or injuries followed by exposure to

　　blood were significantly more likely to be infected.

　　"The most remarkable aspect of these cases was that transmission was

　　very unlikely to be tick-borne, but was closely associated with blood or

　　respiratory secretion exposure from an index patient who died of a

　　[sudden and severe] illness with hemorrhage," the authors write.

　　"Although it is likely that routine blood and body fluid precautions

　　will protect against such future events, strict adherence to protective

　　protocols is mandatory even if communicability is deemed unlikely. The

　　lessons of this study remain relevant to the daily hospital and health

　　care unit operations to prevent any additional [hospital] outbreaks of

　　HGA. Moreover, as China advances into its future, it must also now

　　become prepared to deal with the increasing threat that tick-borne

　　rickettsial pathogens [parasitic bacteria that live in anthropods (as

　　ticks and mites) and can cause disease if transmitted to human beings]

　　have been already brought to the United States and Europe."

　　(JAMA. 2008;300[19]:2263-2270. Available pre-embargo to the media at

　　www.jamamedia.org)

　　Editor's Note: Please see the article for additional information,

　　including other authors, author contributions and affiliations,

　　financial disclosures, funding and support, etc.