Avian influenza A(H5N1) was detected in the respiratory samples and CSF [cerebrospinal fluid] of a young adult, who died from the infection 7 days after returning from a vacation in Beijing, China accompanied by a family member.
The individual left Canada for China on 6 Dec 2013 and was exclusively in Beijing, in urban locations. There was no contact reported with live poultry, no visits to wet markets, or handling of fresh poultry. Work is ongoing to obtain a detailed account of activities during the trip.
During the return flight on 27 Dec 2013, the individual experienced symptoms of malaise, chest pain, and fever and presented to the local Emergency Department on 28 Dec 2013. The complete blood count (CBC) showed a total white blood count (WBC) of 12.6 x 10 to the power of 9/L (reference range 4.0 - 10.0 x10 to the power of 9/L) with raised neutrophils (11.1 x 10 to the power of 9/L) and low lymphocytes (0.8 x 10 to the power of 9/L). A chest X-ray and CT scan revealed a right apical infiltrate. A diagnosis of pneumonia was made; the patient was prescribed levofloxacin and discharged home.
The individual returned to the same Emergency Department on 1 Jan 2014, now with worsening pleuritic [inflammation of the membrane surrounding the lung] chest pains and shortness of breath, a mild headache, exacerbated by head movement, right upper quadrant and epigastric pain, nausea and vomiting with no diarrhea. A chest X-ray showed a multi-lobar pneumonia, with moderate effusion, reflecting significant progression when compared with the X-ray from the 1st ED visit. A thoracentesis [a procedure to remove excess fluid in the space between the lungs and the chest wall], performed while in the ED, revealed a dark amber cloudy fluid that was sterile in bacterial culture. The CBC again showed a WBC count of 10.2 x 10 to the power of 9/L, neutrophil count of 9.5 x 10 to the power of 9/L, platelet count within the normal range, normal ALT, slightly elevated AST at 46 U/L (reference range 7 - 40 U/L) and LDH at 288 U/L (reference range 100 - 225 U/L).
Admission to a general medicine ward for investigation was facilitated, and treatment was initiated with intravenous piperacillin-tazobactam. On 2 Jan 2014, the individual reported visual changes and ongoing headache, and, coupled with increasing oxygen requirements, was admitted to the ICU for intubation and ventilation. In the early morning of 3 Jan 2014, the individual developed a sudden episode of tachycardia and severe hypertension followed by hypotension requiring inotropic support. At this point, pupils were dilated, and there was no response to pain.
A CT brain scan suggested diffuse encephalitis and intracranial hypertension. The neurological examination was consistent with brain death. An MRI/MRA showed significant generalized edema, evidence of meningitis and ventriculitis [inflammation of the ventricles in the brain] and significant reduction in cerebral blood flow. A lumbar puncture was performed after brain death determination and prior to removal of ventilatory and inotropic support.
The attending physician felt that, while unlikely, avian influenza was possible given the travel history and neurological symptoms, and contacted the local Medical Officer of Health on 3 Jan 2014 to report to public health. Contact tracing of family and hospital contacts was initiated as a precaution, given the severity of the illness and its rapid progression.
Later in this extensive report, we learn "An autopsy was not done due to concerns regarding the risk of virus transmission." It concludes: "Finally, this infection of a Canadian resident is the 1st case of Influenza A(H5N1) occurring in North America. With the rapidity of travel between countries and continents and the globalization of many cultures, this will likely not the be the last case to occur in North America."