OBJECTIVE: To determine the susceptibility of group A beta‐hemolytic streptococci (GABHS) in the lower St Lawrence region, Quebec to different antibiotics, particularly macrolides, and to compare different antibiogram methods (disk diffusion, E‐test and microdilution) and incubation atmospheres (ambient air and 5% carbon dioxide). METHODS: A total of 384 strains of GABHS isolated from 377 patients (throat 335; other sites 49) from three hospitals in the lower St Lawrence region were analyzed for their susceptibility to erythromycin, clarithromycin, azithromycin, penicillin, clindamycin, cephalothin, rifampin and vancomycin by disk diffusion on Mueller‐Hinton (MH) agar supplemented with 5% defibrinated sheep blood (MHB) at 35ºC in 5% carbon dioxide. Strains that were found to be intermediately resistant or resistant to one of the antibiotics by disc diffusion, strains from sites other than throat, and a sample of 97 pharyngeal strains were evaluated by E‐test on MHB (35ºC, 5% carbon dioxide) for their susceptibility to the antibiotics erythromycin, clarithromycin, azithromycin, penicillin, clindamycin and ceftriaxone. In addition, minimum inhibitory concentrations (MICs) were determined for erythromycin and azithromycin by broth microdilution using MH broth supplemented with 2.5 % of lysed horse blood (35ºC, ambient air) on strains that were resistant or intermediately resistant to the macrolides (erythromycin, clarithromycin, azithromycin). An evaluation was also carried out on these strains to determine the influence of the incubating atmosphere (ambient air versus 5% carbon dioxide) on susceptibility results obtained by disk diffusion (erythromycin, clarithromycin and azithromycin) and E‐test (erythromycin and azithromycin) methods. RESULTS: Nine strains (2%) from nine patients (throat eight, pus one) were resistant to all macrolides as tested by three different techniques (disk diffusion, E‐test and microdilution). All strains were susceptible to all the other antibiotics tested. For the strains intermediately resistant or resistant to macrolides, incubation in a 5% carbon dioxide atmosphere was associated with a reduction in the diameter of inhibition determined by disk diffusion (P<0.001) with frequent minor variations in interpretation, and with an increase in the MIC by E‐test (P<0.001), which had no impact on interpretation. CONCLUSIONS: Resistance of GABHS to macrolides was not common (2%) in the lower St Lawrence Region. GABHS susceptibility to erythromycin seemed to predict the susceptibility to the other macrolides. Significant variation in antibiogram results (disk diffusion and E‐test) of GABHS susceptibility to macrolides was related to the incubation atmosphere and may have an impact on the interpretation of disk diffusion results.
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 prospective human-animal comparative study was conducted with 81 shepherds from 46 farms and a control group matched for sex and age. All participants answered a standardized questionnaire to evaluate their risk factors for Q fever, including a specific section on the work practices of the shepherds. All human subjects had a blood sample taken for serology to phase I and phase II antigens of C burnetii performed by indirect immunofluorescence assay. At each participating farm, seven to nine sheep had blood samples taken for C burnetii serology to be assessed by the complement fixation test.The seroprevalence to C burnetii was higher in the group of shepherds (28.4%) than the control group (1.2%) (P<0.005). Among the group of shepherds, spending more than 5 h/week in the sheep barn (P=0.06) and buying and/or trading sheep within the past six months (P=0.004) were associated with positive C burnetii serology. A total of 137 of 334 sheep (41%) were seropositive for C burnetii. These positive sheep were distributed in 41 of the 46 flocks (89%). No correlation could be demonstrated between a serology for C burnetii in the herds and the shepherds.Q fever is highly prevalent in the LSLRR of Quebec, affecting 89% of the flocks and 28% of the shepherds. Shepherds in this region are at increased risk for C burnetii infection in comparison to the general population.
The lower Saint Lawrence river region (LSLRR), in Quebec, has a 10-fold higher incidence of Q fever compared to the provincial rate. This study aimed to review clinical cases and the Q fever risk exposure in this region.Data were retrieved from microbiology laboratory, medical records from Rimouski Regional Hospital and Public Health reports between 1991 and 2018. They were analyzed with Epi Info 7.2.2.6. Patients with confirmed acute, probable acute, and chronic Q fever were classified using standard case definitions and mapped according to the postal code, to assess the correlation between cases and sheep distribution.Out of 295 cases, 258 were included (241 confirmed acute, seven probable acute, 10 chronic). Median age was 49 years, 76% were male. For acute cases, the prominent symptoms were fever (99%), headache (83%), chills (80%), sweating (72%), myalgia (69%), and fatigue (67%). Clinical presentation was mostly febrile syndrome with mild hepatitis (84%). A seasonal peak was observed from May to July (56% of acute cases). Most cases (56%) occurred within the two counties where sheep production was highest. Exposure to sheep was prominent 93%, including 64% direct contact (15% shepherds, 49% sheepfold visitors), 14% indirect contact, and 15% sheepfold neighbors.To our knowledge, this is one of the largest retrospective studies of Q fever cases reported in Canada. Q fever in Quebec LSLRR is associated mainly with sheep exposure. Fever and hepatitis were the most common manifestations. Preventive measures should be considered in this region to protect sheepfold workers, visitors, and their neighbors.La région du Bas-Saint-Laurent, au Québec, présente une incidence de fièvre Q dix fois plus élevée que le reste de la province. La présente étude visait à analyser les cas cliniques et l’exposition au risque de fièvre Q dans cette région.Les chercheurs ont extrait les données du laboratoire de microbiologie, des dossiers médicaux de l’Hôpital régional de Rimouski et des rapports sanitaires émis entre 1991 et 2018 et les ont analysées à l’aide du logiciel Epi Info 7.2.2.6. Les patients atteints d’une fièvre Q aiguë confirmée, d’une fièvre Q aiguë probable, et d’une fièvre Q chronique ont été classés au moyen des définitions de cas standards et groupés par code postal afin d’évaluer la corrélation entre les cas et la répartition de moutons.Des 295 cas, 258 ont été inclus (241 cas aigus confirmés, sept cas aigus probables, dix cas chroniques). Ils avaient un âge médian de 49 ans, et 76 % étaient de sexe masculin. Dans les cas aigus, la fièvre (99 %), les céphalées (83 %), les frissons (80 %), la sudation (72 %), les myalgies (69 %) et la fatigue (67 %) étaient les principaux symptômes. Le tableau clinique était surtout composé d’un syndrome fébrile accompagné d’une hépatite légère (84 %). Un pic saisonnier a été observé entre mai et juillet (56 % de cas aigus). La plupart des cas (56 %) se sont manifestés dans les deux comtés où la production de moutons était la plus élevée. L’exposition aux moutons atteignait une proportion importante de 93 %, y compris 64 % de contacts directs (15 % de bergers, 49 % de visiteurs des bergeries), 14 % de contacts indirects et 15 % de travailleurs en bergerie.À la connaissance des auteurs, il s’agit de l’une des plus vastes études rétrospectives des cas de fièvre Q signalés au Canada. Dans la région du Bas-Saint-Laurent, au Québec, la fièvre Q est surtout associée à l’exposition aux moutons. La fièvre et l’hépatite en sont les principales manifestations. Il faut envisager des mesures préventives dans cette région afin de protéger les travailleurs en bergerie et leurs voisins.
Lyme disease is a tick-borne disease predominantly caused by Borrelia burgdorferi in Canada. Early disseminated disease is challenging to diagnose and requires treatment to prevent severe sequelae. We report the case of a 71-year-old woman who was admitted for a fever. Her blood tests showed a syndrome of antidiuretic hormone secretion, transaminitis, and pancytopenia. During hospitalization, the patient was noted to have an initial annular patch, which was followed by multiple diffuse erythematous patches. After a comprehensive medical history by a dermatology consultant highlighting an exposure to a tick bite, early disseminated disease was diagnosed, and a complete remission was obtained with Doxycycline. Dermatologists must maintain a high clinical suspicion for Lyme disease.
