Pierre A. Pilon

Shigella spp. with Reduced Azithromycin Susceptibility, Quebec, Canada, 2012–2013

During 2012–2013 in Montreal, Canada, 4 locally acquired Shigella spp. pulse types with the mph(A) gene and reduced susceptibility to azithromycin were identified from 9 men who have sex with men, 7 of whom were HIV infected. Counseling about prevention of enteric sexually transmitted infections might help slow transmission of these organisms.

Ciprofloxacin-resistant Shigella sonnei among men who have sex with men, Canada, 2010.

In 2010, we observed isolates with matching pulsed-field gel electrophoresis patterns from 13 cases of ciprofloxacin-resistant Shigella sonnei in Montréal. We report on the emergence of this resistance type and a study of resistance mechanisms. The investigation suggested local transmission among men who have sex with men associated with sex venues.

Campylobacter coli Outbreak in Men Who Have Sex with Men, Quebec, Canada, 2010–2011

During September 2010–November 2011, a cluster of erythromycin-susceptible, tetracycline- and ciprofloxacin-resistant Campylobacter coli pulsovar 1 infections was documented, involving 10 case-patients, in Montreal, Quebec, Canada. The findings suggested sexual transmission of an enteric infection among men who have sex with men.

Long-Lasting Outbreak of Erythromycin- and Ciprofloxacin-Resistant Campylobacter jejuni Subspecies jejuni From 2003 to 2013 in Men Who Have Sex With Men, Quebec, Canada

From January 2003 to December 2013, sexual transmission of 2 clades of Campylobacter jejuni subspecies jejuni isolates resulted in a prolonged outbreak among men who have sex with men living in Quebec, Canada. The outbreak isolates were acquired locally and were resistant to erythromycin and ciprofloxacin.

Shigella flexneri with Ciprofloxacin Resistance and Reduced Azithromycin Susceptibility, Canada, 2015.

ompA, and htrA); 11 of these ticks were from the patient’s dogs. In all properties where ticks were collected, at least 1 was PCR positive. Thus, we detected R. parkeri in half (4/8) of investigated households. All the sequences generated for the ompA and htrA genes showed 100% identity to sequences from the Rickettsia parkeri strain Portsmouth (GenBank accession no. CP003341.1). We deposited into GenBank the sequences of the ompA gene (KX196265) and htrA gene (KX196266) from samples analyzed in this study. The ompA sequence we obtained for R. parkeri showed 98% identity with Rickettsia sp. strain Atlantic Rainforest (GenBank accession no. GQ855237.1). Although Rickettsia sp. strain Atlantic Rainforest had previously been considered the only SFG Rickettsia in southern Brazil, we demonstrate here the presence of R. parkeri in Rio Grande do Sul in the Pampa biome. We detected R. parkeri infection in A. tigrinum ticks collected at the probable site of infection (the patient’s home) of a confirmed case of human spotted fever. Considering the A. tigrinum tick abundance in southern Brazil and its remarkable ability to parasitize domestic and wild animals (8), in addition to the high R. parkeri infection rate observed (28%), further epidemiologic studies are needed to address the role of A. tigrinum ticks as vector of spotted fever in the Pampa biome. Finally, our results show that, in addition to R. rickettsii and Rickettsia sp. strain Atlantic Rainforest, R. parkeri occurs and might be associated with cases of spotted fever in Brazil. Additional surveys are needed to assess the infection prevalence of R. parkeri in A. tigrinum ticks in other areas of Pampa and in other regions of Brazil.

Identification of Shigella flexneri isolates carrying the Shiga toxin 1-producing gene in Quebec, Canada, linked to travel to Haiti

Shiga toxins (Stx1 and Stx2, also called verocytotoxins) are commonly associated with Shiga toxin-producing Escherichia coli (STEC) and Shigella dysenteriae type 1 (Tesh and O’Brien 1991). Recent studies have documented cases of stx carriage in other Shigella species, including S. sonnei linked to travel to Morocco (Nyholm et al. 2015) and S. flexneri with travel history to Caribbean (Gray et al. 2014, 2015). In the province of Quebec, more than 40% of Shigellosis cases are travel-related (Trepanier et al. 2014). Therefore, a retrospective laboratory study was performed by the Laboratoire de sante publique du Quebec to assess the presence of stx gene among the 210 strains of Shigella isolated between 2013 and 2014. The collection included 131 S. sonnei ,7 5S. flexneri ,3 S. boydii, and 1 S. dysenteriae type 12. Polymerase chain reaction targeting genes stx1 and stx2 was performed according to the methods of Paton and Paton (1998). Three isolates of S. flexneri isolated from stool were positive for the stx1 gene and belonged to serotype 2a (n = 2) and serotype y (n = 1). The amplified fragments were sequenced and identity was confirmed. Cases of shigellosis are systematically investigated as provincial regulations of notifiable diseases permits. The first case was a 62-year-old man of Haitian origin living in Montreal (isolate ID 123699). He was admitted to a hospital for bloody diarrhea, fever, and abdominal pain. Empirical antimicrobial treatment with ciprofloxacin was prescribed and the patient was discharged 2 days after admission. The second case was a 55-year-old man of Haitian origin living in Montreal (isolate ID 132104). Ciprofloxacin was prescribed in an outpatient clinic, where he consulted for bloody diarrhea, fever, and abdominal

First documented case of human infection with ovine Shiga-toxin-producing Escherichia coli serotype O52:H45

We report a concurrent case of infection with non-O157 Shiga-toxin-producing Escherichia coli (STEC) strain in an 8-month-old child. Laboratory and epidemiological investigations indicated child exposure to contaminated sheep meat following the Muslim feast of sacrifice (Eid al-Adha). Microbiological and molecular typing confirmed that the ovine strain O52:H45 (stx1+, eae-, hlyA-) was the causal agent. This is the first documented case of human infection to this STEC serotype.

Campylobacter fetus Cluster Among Men Who Have Sex With Men, Montreal, Quebec, Canada, 2014–2016

From March 2014 to December 2016, a cluster of 13 cases of Campylobacter fetus intestinal and extraintestinal infections, including 2 patients with an aortic mycotic aneurysm, caused significant morbidity. The cluster likely resulted from sexual transmission between men having sex with men living in the greater Montreal area, Quebec, Canada.

Multidrug-Resistant Campylobacter coli in Men Who Have Sex with Men, Quebec, Canada, 2015

To the Editor: In 2015, an outbreak of multidrug-resistant Campylobacter coli was documented in Montreal, Quebec, Canada. We report results of an epidemiologic and molecular investigation suggesting a sexually transmitted enteric infection among men who have sex with men (MSM).

Streptococcal Infections and Varicella.

TO THE EDITOR—Frère et al [1] recently reported the effects of a universal varicella immunization program on admissions to a pediatric hospital for invasive group A streptococcal infections (IGASI). We wish to draw readers’ attention to 2 points concerning this study, hoping to help interpret its results. The first point is that the quantities the authors call “rates of IGASI per 1000 hospital admissions” are in fact proportions of admissions due to IGASI. As such, they are as dependent on changes in numbers of hospitalizations for any other cause as they are on hospitalizations for IGASI. Only true population-based hospitalization rates, with person-time denominators, would generally be independent of each other. The reservation expressed in the last sentence of the article is therefore not supported by the results reported: the varicella immunization program could have decreased the hospitalization rate for IGASI; we simply do not know, based on these proportions, if it did. The second, related point is that it is not meaningful that the difference between the proportions of admissions due to IGASI before and after the implementation of the varicella immunization program was not statistically significant, because the study had a very low power for detecting as statistically significant a difference in proportions of the size observed. After the denominators had been retrieved by a rule of three, one calculator [2] estimated that the study had a power of 6%, another [3] a power of 7%. A statistical power of about 80%, with a significance threshold of 0.05, is the usual target, giving a 20% risk of failing to detect as statistically significant a true difference in effect of the size judged important (type II error). Here the risk of a type II error is about 93%. These reservations bear only on the epidemiologic findings of the study and not on the clinical finding that the number of pediatric patients admitted each year to the study hospital for varicellaassociated IGASI decreased from a yearly mean of 3.4 (24 in 7 years) before the implementation of the varicella immunization program to 0.9 (7 in 8 years) afterward. Testing the significance of the apparently large difference between these 2 means is a very straightforward matter, given the corresponding sample sizes and variances. The authors’ data on varicella-related IGASI suggest that the decrease is significant. Confirming this with absolute numbers instead of proportions would support the hypothesis of a population effect of the program in the absence of an alternate explanation, such as a decrease in the pediatric population served or a change in consultation patterns.