U.S-Acquired Human Rabies with Symptom Onset and Diagnosis Abroad, 2012

On July 8, 2012, a U.S. resident was admitted to a hospital in Dubai, United Arab Emirates, for evaluation of right arm spasticity, anxiety, and malaise. By the next day, the patient had become comatose following a period of agitation. On July 31, he died. Investigators from CDC, state, and local health departments determined that the patient acquired rabies from contact in March with a bat in California. Person-to-person transmission of rabies has been documented in cases of organ and tissue transplantation and is theoretically possible if infectious saliva or tears are introduced into fresh open wounds or onto mucous membranes (1–8). Once symptoms begin, rabies is almost always fatal. While he was potentially infectious, during June 11–July 31, the patient traveled on eight international flights through six countries. To date, 59 persons have been identified as contacts, and 23 persons have been administered postexposure prophylaxis (PEP); no secondary cases have been identified. Bites or scratches from bats or other animals suspected of having rabies should be regarded seriously; victims should promptly seek consultation with public health practitioners and medical-care providers. This report highlights the need for collaboration to 1) identify persons who potentially had contact with infectious materials from a person infected with rabies, 2) conduct a risk assessment, and 3) provide prophylaxis to all those with a reasonable risk for contact with infectious materials (e.g., tears, saliva, or neural tissue from a person with rabies contacting open wounds or mucous membranes of an uninfected person).

Case Report

On June 25, 2012, a previously healthy California resident aged 34 years developed right arm and shoulder pain and exhaustion while vacationing in Thailand (Figure). On July 5, he traveled from Bangkok, Thailand, to Dubai, United Arab Emirates, to Iraq, where he returned to his civilian job in Basra. Upon arrival in Basra, he visited medical clinic A, where he was prescribed a topical steroid and phenobarbital for arm tremors and spasticity. On July 8, he visited medical clinic B with spastic arm movements, sweating, anxiety, and malaise. He was afebrile, had a pulse of 72 beats per minute, respiratory rate of 14 breaths per minute, and a blood pressure of 151/89 mmHg. He was treated with lorazepam and referred to a hospital in Dubai for suspected dystonia.

On July 8, the man flew from Iraq to Dubai, where he was hospitalized on the same day. On July 9, he developed progressive agitation and coma, and was intubated. Computed tomographic imaging demonstrated cerebral edema but no evidence of brain herniation. His persistent muscle spasms were treated with sedatives and paralytics. He developed rhabdomyolysis. On July 29, at his family's request, he was flown by air ambulance to Zurich, Switzerland. On July 31, he died; physicians at Uster Hospital in Zurich suspected rabies.

Laboratory Diagnostic Testing at Swiss Rabies Center

Banked serum collected on July 29 and tested on August 8 was positive for antibodies to rabies virus by rapid fluorescent focus inhibition test. A rabies diagnosis was confirmed by fluorescent antibody testing of brain tissue at the Swiss Rabies Center on August 22. Reverse transcriptase polymerase chain reaction showed that the patient's viral RNA sequence was similar to a viral variant associated with the insectivorous Mexican free-tailed bat, Tadarida brasiliensis, a species common in the southern United States and Mexico (Andrea Nina Deubelbeiss, Institute of Veterinary Virology, Berne, Switzerland, personal communication, 2012).

Public Health Investigation

On August 27, a friend of the deceased telephoned CDC to report the U.S. resident's death in Switzerland from rabies. The friend said Swiss doctors had recommended that she receive rabies PEP. On August 28, the National Focal Point (NFP)* of Switzerland notified the NFP of the United States and CDC that a U.S. resident died of laboratory-confirmed rabies in Switzerland. The patient was considered to have been potentially infectious during June 11–July 31, the period from 2 weeks before onset of symptoms (when humans can begin to shed rabies virus in saliva and tears) until his death. CDC collaborated with international, state, and local public health officials to interview friends, family, and coworkers to identify persons with potential physical contact with the patient and determine how the patient was exposed to rabies. For countries with residents potentially exposed to the patient (e.g., via saliva or tears), CDC notified NFPs via e-mail that a public health investigation was ongoing.

During June 11–July 31, while potentially infectious, the patient had traveled extensively, including to California, the United Arab Emirates, Iraq, Taiwan, Thailand, and Switzerland (Table). During June 11–13, the patient worked in Iraq. During June 13–14, he flew from Iraq to Dubai to San Francisco, California. An in-flight contact was defined, per CDC rabies program guidelines, as anyone sitting immediately next to the patient. Two in-flight contacts were identified. The first, a resident of Iran, initiated PEP after risk assessment by the Iran Ministry of Health. The second was interviewed by officials in India, who identified no risk for exposure.

During June 14–18, the patient visited family and friends in California. Three of four contacts in California reported having possible exposure to the patient's saliva, and PEP was recommended. The patient flew from San Francisco to Thailand via Taiwan during June 18–19. One U.S. resident sat next to the patient during the flight from San Francisco to Taiwan. This person was interviewed, and no exposure to the patient's saliva or tears was identified. The patient vacationed in Thailand from June 19 to July 5 and reportedly had two close contacts who were potentially exposed to infectious saliva or tears. One contact was a Thai national who received PEP. The second contact could not be located.

On July 5, the patient flew from Bangkok, Thailand, to Dubai, to Basra to report for work. On arrival in Basra he sought care at medical clinic A. Eight persons (one medical staff member and seven coworkers) were identified by the patient's employer as in physical contact with the patient and subsequently received risk assessments. One contact was administered PEP after risk assessment by a local physician. On July 8, the patient visited medical clinic B, where he had contact with four health-care workers. Of these, one was administered PEP after reporting direct contact with the patient's saliva. On July 8 the patient flew from Basra to Dubai, where he was immediately hospitalized. Eighteen health-care workers at the Dubai hospital were assessed for risk by the Ministry of Health. No Dubai hospital contacts had indications for PEP. On July 29, the patient was flown by emergency air ambulance to Switzerland where he was hospitalized until his death on July 31. Four contacts were identified on the medical flight; none were indicated for PEP. Thirteen medical providers and three family members received PEP because of potential exposure at the Swiss hospital where he was treated.

Investigation of Animal Exposures

Numerous potential animal exposures were investigated, including potential contact with roosting bats while working on a bridge at night, potential feral cat contact, and bat sightings by neighbors, all occurring in 2012 in California, and a bat sighting inside his home in Texas in 2010. Definitive bat contact was not identified with any of these potential exposures. However, 3 weeks after initiating the investigation, on September 14, local public health officials in California were contacted by an acquaintance who reported that in late March 2012 she had observed the patient touch a bat while in California. The acquaintance recalled that the patient pulled his hand back as if the bat had bitten him, but they did not discuss this event further or seek medical assistance at that time. Subsequent investigation into this reported bat contact identified one other person who had contact with the bat. This person received PEP.

Reported by

Susan Farley, Sheila Zarate, MSN, Erika Jenssen, MPH, Contra Costa Health Svcs. Curtis Fritz, DVM, California Dept of Public Health. EB Bachli, MD, Uster Hospital, Switzerland, Hans-Peter Zimmermann, MD, Swiss Federal Office of Public Health. Jesse Blanton, MPH, Richard Franka, DVM, Charles Rupprecht, VMD, Kim Hummel, PhD, Div of High-Consequence Pathogens and Pathology, Clare A. Dykewicz, MD, Div of Global Migration and Quarantine, National Center for Emerging and Zoonotic Infectious Diseases; Kira Christian, DVM, Div of Global Disease Detection and Emergency Response, Center for Global Health; Ryan M. Wallace, DVM, Neil Vora, MD, Emily Lankau, DVM, EIS officers, CDC. Corresponding contributor: Ryan M. Wallace, [email protected], 404-639-2018.

Editorial Note

This is the first report of rabies acquired in the United States but with symptom onset, medical management, and diagnosis abroad. This case highlights the importance of continued efforts to raise awareness of the risk for rabies virus exposure posed by bats in the United States (1). Rabid bats have been documented in every state except Hawaii. Since 2002, 21 of 24 reported human rabies cases in the United States were linked epidemiologically to bats. Transmission of rabies virus can occur from minor or unrecognized bites from bats (2). The source of exposure in this case could not be confirmed by laboratory diagnostics because the bat was not available for testing. However, the reported contact with a bat in March 2012 as well as virus variant testing indicating a North American bat species makes this bat contact the likely source of rabies virus exposure.

Person-to-person rabies virus transmission has been documented only in cases of tissue or organ transplantation (3–8). However, person-to-person rabies transmission also is theoretically possible if infectious material, such as saliva or tears, are introduced into fresh open wounds or onto mucous membranes (2). For contact investigation purposes, any potential exposure to saliva, tears, or nervous tissue should be investigated. For this investigation, the patient's family, friends, coworkers, and health-care workers were contacted, as were travelers seated immediately next to the patient on flights, to assess their risk for exposure to the patient and their need for PEP. Health-care professionals should adhere to standard personal protection protocols for bacterial and viral pathogens when caring for a patient suspected of having rabies (2,9). Health-care workers should take particular precautions to avoid direct contact with saliva during intubation, extubation, and suctioning.

This patient's extensive travel during his 7-week potentially infectious period presented a challenge to identify contacts in four states, nine countries, four medical facilities, and on eight international flights and two train trips. Eventually, 59 contacts were identified, 23 of whom received PEP. The only international flights that CDC has jurisdiction over are those arriving into the United States; other in-flight information was voluntarily provided to CDC when available, from the responsible health authority. All countries were notified of flight numbers of the patient for their own investigations. CDC recommendations for contact investigation and PEP administration were provided to partner countries; however, the decisions on how and when to administer PEP were the responsibility of the ministries of health for each country, and information regarding persons who received risk assessments and PEP was reported in aggregate.

Although the patient was a global traveler, he was infected by a rabid bat near his residence in the United States. Bat rabies is the most common type of rabies virus infecting humans in the United States (1). Bites or scratches from any domestic or wild animal should be washed with soap and water immediately (2). Once symptoms begin, rabies is almost always fatal. Consequently, any exposure to or contact with bats or other wildlife should be promptly reported to the state and local health department so that the person's viral exposure can be assessed quickly, and PEP administered appropriately. This case report highlights the importance of international public health collaboration to identify, notify, assess, and provide prophylaxis to contacts potentially exposed to rabies virus during international travel.

Acknowledgments

Sharon Messenger, PhD, California Dept of Public Health. Carl Williams, DVM, North Carolina Dept of Public Health. Susan Weinstein, DVM, Arkansas Dept. of Public Health. Laura E. Robinson, DVM, Texas Dept of State Health Svcs. Frew Benson, South Africa Ministry of Health. Wan-Ting Huang, MD, Taiwan Centers for Disease Control. Pakasorn Hajarnis, MD, Thailand Ministry of Health. Easa Bin Jakka Al-Mansoori, PhD, Fikree Mohmoud, MD, Ministry of Health, United Arab Emirates. Karim A.K. Muftin A-Zadawi, MD, Ministry of Health, Iraq. Reto Zanoni, PhD, Univ of Berne, Institute of Veterinary Virology; Frédéric Eynard, Swiss National International Health Regulations Focal Point, Swiss Federal Office of Public Health; Christian Trachsel, MD, Virginie Spicher, MD, Clinic of Internal Medicine, Uster Hospital, Zurich, Switzerland. L.S. Chauhan, MD, India Ministry of Health. Mohammad Mehdi Gouya, MD, Center for Disease Control, Ministry of Health and Medical Education, Iran; Alireza Zavareh, MD, Firouzeh Farahtaj, MD, Pasteur Institute of Iran, WHO Collaborating Center for Reference and Research on Rabies, Iran. Mike Dolce, Bur of Consular Affairs, U.S. Department of State. Inger Damon, MD, Sergio Recuenco, MD, Chris Cox, Div of High-Consequence Pathogens and Pathology; Nicole Cohen, MD, Chris Schembri, MPH, Karen Marienau, MD, Peter Houck, MD, Francisco Alvarado-Ramy, MD, Susan Dwyer, Robynne Jungerman, MPH, Div of Global Migration and Quarantine, National Center for Emerging and Zoonotic Infectious Diseases; Susan A. Maloney, M.D, Henry C. Baggett, Rachel Eidex, PhD, Div Global Disease Detection and Emergency Response, Mitchell Wolfe, MD, Div of Global HIV/AIDS, Center for Global Health, CDC.

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