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OBECTIVE: To determine the seroprevalence of Coxiella burnetii among the shepherds and their sheep in the lower Saint-Lawrence River region (LSLRR) of Quebec, Canada.

A surveillance program has been in place since 2000 to detect the presence of West Nile virus (WNV) in Canada. Serological assays are most appropriate when monitoring for human disease and undertaking case investigations. Genomic amplification procedures are more commonly used for testing animal and mosquito specimens collected as part of ongoing surveillance efforts. The incursion of WNV into this country was documented for the first time in 2001 when WNV was demonstrated in 12 Ontario health units during the late summer and fall. In 2002 WNV activity was documented by avian surveillance in Ontario by mid-May with subsequent expansion of the virus throughout Ontario and into Quebec, Manitoba, Saskatchewan and Nova Scotia. Human cases were recorded in both Ontario and Quebec in 2002 with approximately 800 to 1000 probable, confirmed and suspect cases detected. The possible recurrence and further spread of WNV to other parts of Canada in 2003 must be anticipated with potential risk to public health. The continued surveillance and monitoring for WNV-associated human illness is necessary and appropriate disease prevention measures need to be in place in 2003.

The first confirmed case of hantavirus pulmonary syndrome in Manitoba was diagnosed in 1999. To define better the risk of exposure to hantaviruses in this area, the clinical features and epidemiological factors pertaining to this case were described, and a serological survey of rodents collected near the patient's residence was undertaken. Small mammals were collected using live traps, were anesthetized via inhalation of isoflurane and were bled. Human and mouse serologies were undertaken using an ELISA to detect hantavirus-specific immunoglobulin G and/or immunoglobulin M antibodies. In addition, a full medical and epidemiological assessment, as well as individual risk factor and exposure analysis, were conducted. A 27-year-old Manitoba woman presented with severe respiratory distress and diffuse bilateral air space disease radiologically. Despite extremely aggressive measures, including mechanical ventilation, antibiotics, fluid management and inotropic support, the patient's condition rapidly deteriorated, and she died 8 h after admission. Hantavirus pulmonary syndrome was confirmed by the detection of immunoglobulin M and immunoglobulin G antibodies to the Sin Nombre virus (SNV) in her sera and by the demonstration of SNV genomic sequences in her lung tissue. Exposure to hantavirus likely occurred in and around the home or in the rural area in which she resided. A total of 252 small mammals, primarily deer mice (Peromyscus maniculatus), were collected from 17 different sites at or near where the patient lived. Antibodies to SNV were detected in 28 of 244 (11.5%) deer mice, which were collected within 9 km of the residence of the fatal case, indicating that these rodents are a significant reservoir for SNV in this area.

BACKGROUND: Four trappers presented to the Middlesex-London Health Unit in November, 1997 with similar clinical presentations. All four complained of fever, chills and headache, and three of the four had severe muscle aches. All gave histories of trapping raccoons before the onset of illness. Three of the four men exhibited diagnostic seroconversions to Leptospira grippotyphosa.

Coxiella burnetii appears to be endemic in animals in the Mauricie region of Quebec, and causes some human cases of Q fever annually. Unlike in other rural areas, patients in this study experienced few respiratory symptoms. To determine whether C burnetii pneumonia is underdiagnosed, adults admitted to hospital for community acquired pneumonia were included in a one-year serological study. Significant immunofluorescent antibody (IFA) titres in four of 118 patients with pneumonia (fewer than 4%) were studied. Clinical presentation, standard laboratory tests and epidemiological data did not allow identification of these cases; however, Q fever increased during the warm months. There were no detectable complement fixing (CF) antibodies in these four cases. C burnetii causes few cases of pneumonia in Mauricie. IFA seems to be a more sensitive test than CF.

Objectives: Lyme disease has been increasingly diagnosed throughout North America since the late 1970s. The clinical diagnosis and epidemiological monitoring of Lyme disease are aided by serological testing for the etiological agent, Borrelia burgdorferi. Numerous authorities have questioned the reproducibility of these serological tests. This study assessed the intra- and interlaboratory reproducibility of an elisa used to aid in the diagnosis of Lyme disease.

In June 1990 a quality control assessment was undertaken of Canadian public health laboratories testing for antibodies to Borrelia burgdorferi, the etiological agent of Lyme disease. Twenty sera were distributed to nine laboratories, including 12 obtained from patients in Lyme endemic areas and presumed to be serological positives, and eight prescreened negative controls. Seventeen serological reports were submitted, comprising nine enzyme-linked immunosorbent assays (elisa), six immunofluorescent assays and two Western blot assessments. Antibodies were detected in 11 of the 12 sera which had been presumed to be positive. Assuming 11 positive sera had been submitted, the test sensitivities varied from 88.9 to 100% by elisa, and 54.5 to 90.1% by immunofluorescent assay. Specificities were 100% for all but one elisa and one immunofluorescent assay assessment. The results indicate a satisfactory performance by elisa but a need for upgrading or replacement of some immunofluorescent assay tests.

From 1974 to 1989, sera from symptomatic patients with histories of recent travel outside Canada were tested for antibodies to several arboviruses, principally of the alphavirus and flavivirus families. Diagnostic seroconversions were documented in 84 individuals from six provinces, including one alphavirus (Chikungunya) and 83 flavivirus seroconvertors. Dengue 1 virus was isolated from the blood of one patient. Most flavivirus seroconvertors were likely infected with dengue virus, but infections with tick-borne encephalitis, St Louis encephalitis and Powassan viruses were also recognized. Patients had histories of recent travel to the Caribbean, South America, Asia, Africa, North America (outside Canada), Tahiti, Fiji and Europe. Possible imported infections due to Japanese encephalitis, Ross River, western equine encephalitis and Colorado tick fever viruses were also encountered.

Two cases of dengue fever with hemorrhagic manifestations were observed in 1990 and 1992 among travellers returning from Asia, while a third presented with classical dengue fever after the patient’s first trip to an endemic region. All experienced rash, thrombocytopenia and coagulation disorders and had flavivirus serology consistent with exposure to dengue virus.