Eosinophilic Liver Abscess: A Case of Locally Acquired Fasciola hepatica in Alberta, Canada.

Fasciola hepatica is a trematode causing acute and chronic infection. A 33-year-old Canadian woman with eosinophilic liver abscesses and no relevant travel was diagnosed with F hepatica infection. F hepatica is reported in livestock in Alberta. This is the first case of locally acquired fascioliasis in Canada in >100 years.

Epidemiology of ticks submitted from human hosts in Alberta, Canada (2000-2019).

ABSTRACTThe geographic range and occurrence of tick species is dynamic. This has important public health implications due to important tick species that can transmit pathogens. This study presents a retrospective review of tick genera recovered from humans and submitted for identification in Alberta, Canada, over a 19-year period. The total number of ticks and proportion of genera were analyzed over time. Molecular testing for a number of pathogens associated with Ixodes scapularis and I. pacificus was conducted. A total of 2,358 ticks were submitted between 2000 and 2019, with 98.6% being acquired in Alberta. The number of ticks submitted increased significantly over time (p < 0.0001). Dermacentor ticks were the most abundant genus, followed by Ixodes and Amblyomma. There was a significant decrease in the proportion of Dermacentor ticks between 2013 and 2019 (p = 0.02), with a corresponding increase in the proportion of Ixodes ticks over the same time (p = 0.04). No statistically significant change in seasonality was identified. Borrelia burgdorferi was detected in 8/76 (10.5%; 95% CI 5.4-19.4%) of all I. scapularis and I. pacificus ticks submitted. This translated to a B. burgdorferi positivity of 0.35% (95% CI 0.15-0.68%) among all ticks received. Dermacentor species (especially D. andersoni) remains the most common tick feeding on humans in Alberta. Small numbers of vector species (including I. scapularis/pacificus) are encountered annually over widely separated geographic areas in the province. The risk of exposure to tick-borne pathogens (e.g. Lyme disease) in Alberta remains low.

Epidemiological and Clinical Characteristics of Alveolar Echinococcosis: An Emerging Infectious Disease in Alberta, Canada.

Human alveolar echinococcosis (AE) is a zoonotic cestode infection which is usually fatal in the absence of treatment. Treatment involves major surgery or indefinite antiparasitic therapy. The incidence is rising in Europe and Asia, with an increased risk observed in immunocompromised individuals. Previously, AE acquisition in North America was extremely rare, except for one remote Alaskan Island. Recent studies have demonstrated a new European-like strain of Echinococcus multilocularis (Em) in wildlife and in human AE in western Canada. We report the experience of all AE patients diagnosed in Alberta. Each was diagnosed by histopathology, serology, and PCR-confirmed by a reference laboratory. Seventeen cases of human AE, aged 19-78 years, nine females, were diagnosed between 2013 and 2020: all definitely or probably acquired in Alberta. Six lived in urban areas, and 14 had kept dogs. In eight, the lesions were found incidentally on abdominal imaging performed for other indications. Six were immunocompromised to varying degrees. Six were first diagnosed at surgery. All have been recommended benzimidazole therapy. One died of surgical complications. Clinicians should be aware of this diagnostic possibility in patients presenting with focal nonmalignant hepatic mass lesions. Greater urbanization of coyotes, the predominant definitive host of Em in Alberta, and growing numbers of immune suppressed individuals in the human population may lead to increasing recognition of AE in North America.

Sarcocystis myopathy in a patient with HIV-AIDS.

Sarcocystosis is a zoonotic infection that causes intestinal and muscular illnesses in humans. Sarcocystosis was until recently considered rare in humans. To complete their life cycle, Sarcocystis species require both a definitive and an intermediate host. Humans are the definitive host when infected by one of two species: Sarcocystis hominis (from eating undercooked beef) or Sarcocystis suihominis (from eating uncooked pork). Infection with either of these species results in intestinal sarcocystosis, causing a self-limited disease characterized by nausea, abdominal pain, and diarrhea. Humans act as the intermediate host when infected by Sarcocystis nesbitti, resulting in the markedly different clinical picture of muscular sarcocystosis. Most documented cases of muscular sarcocystosis were assumed to be acquired in Malaysia, in addition to other regions of Southeast Asia and India. Published cases of muscular sarcocystosis from the Middle East, Central and South America, and Africa are all rare. Although the clinical presentation of muscular sarcocystosis remains to be fully characterized, fever, myalgia, and headache are among the most common symptoms. Here, we report a patient from sub-Saharan Africa with chronic Sarcocystis myopathy and well-controlled HIV-AIDS.

Eosinophilia: A poor predictor of Strongyloides infection in refugees.

BACKGROUND: Canada resettles 10,000 to 12,000 refugees annually. Despite this being a highly vulnerable population, there are little Canadian data on subclinical tropical diseases harboured in this population over the past 20 years. OBJECTIVES: To determine the seroprevalence and predictors of Strongyloides infection in refugees arriving in Edmonton, Alberta. METHODS: A retrospective chart review of all refugees seen at the New Canadians Clinic between March 2009 and April 2010 was performed. Demographic, symptom and physical examination data were collected from the charts. Laboratory results were obtained from the electronic laboratory records. RESULTS: A total of 350 subjects were studied. The overall seroprevalence of strongyloidiasis was 4.6%. Equivocal results were found in 6.3%. In the positive group, the majority were male (62.5%); 75% were born in Africa (P=0.004) and 81.2% lived in refugee camps in Africa (P=0.002). Eosinophilia was present in 25% of the positive subjects (P=0.05), in none of the equivocal group and in 8.7% of the negative group. DISCUSSION: Persistent asymptomatic Strongyloides infection is maintained for years through autoinfection. Traditionally, eosinophilia was used as one of the key tools to diagnose chronic but stable diseases, but it was shown to have a poor predictive value for strongyloidiasis in returning expatriates as well as in those presenting with a disseminated form of the disease. It is important to raise awareness of the severe limitations of eosinophilia as a marker for strongyloidiasis when managing patients who either are immunocompromised, or about to start immunosuppressive therapy. CONCLUSIONS: The present study indicated that eosinophilia is a poor predictor of seropositivity and, thus, Strongyloides infection. Residence in Africa (birth/refugee camps) proved to be a significantly better predictor of Strongyloides seropositivity.

HISTORIQUE: Le Canada accueille de 10 000 à 12 000 réfugiés par année. Même s'il s'agit d'une population hautement vulnérable, depuis 20 ans, peu de données canadiennes ont porté sur les maladies tropicales subcliniques, dont cette population est atteinte. OBBJECTIF: Déterminer la séroprévalence et les prédicteurs de l'infection à Strongyloides chez les réfugiés qui arrivent à Edmonton, en Alberta. MÉTHODOLOGIE: Les chercheurs ont procédé à l'examen rétrospectif des dossiers de tous les réfugiés vus à la New Canadians Clinic de mars 2009 à avril 2010. Ils ont colligé les renseignements démographiques et les données relatives aux symptômes et à l'examen physique à partir des dossiers et obtenu les résultats de laboratoire dans les dossiers électroniques de laboratoire. RÉSULTATS: Au total, les chercheurs ont étudié 350 sujets. Ils ont constaté une séroprévalence globale de strongyloïdiase de 4,6 % et ont obtenu des résultats équivoques dans 6,3 % des cas. Dans le groupe positif, la majorité était de sexe masculin (62,5 %), 75 % étaient nés en Afrique (P=0,004) et 81,2 % avaient vécu dans des camps de réfugiés d'Afrique (P=0,002). Ils ont observé la présence d'éosinophiles chez 25 % des sujets positifs (P=0,05), chez aucun des sujets du groupe aux résultats équivoques et chez 8,7 % des sujets du groupe négatif. EXPOSÉ: L'infection à Strongyloides asymptomatique persistante perdure des années à cause de l'auto-infection. On avait l'habitude d'utiliser les éosinophiles comme l'un des principaux outils diagnostiques des maladies chroniques, mais stables, mais les chercheurs ont établi qu'ils ont une mauvaise valeur prédictive de strongyloïdiase chez les expatriés et chez les personnes atteintes de la forme disséminée de la maladie. Il est important de sensibiliser les médecins aux limites importantes des éosinophiles comme marqueur de la strongyloïdias dans la prise en charge des patients qui sont soit immunodéprimés, soit sur le point d'entreprendre un traitement immunosuppressif. CONCLUSIONS: Selon la présente étude, les éosinophiles sont un mauvais prédicteur de séropositivité et, par conséquent, de l'infection à Strongyloides. Le fait d'avoir résidé en Afrique (y être né ou avoir habité dans un camp de réfugiés) constituait un prédicteur beaucoup plus fiable de séropositivité à Strongyloides.

Post-arrival screening for malaria in asymptomatic refugees using real-time PCR.

Malaria is a significant health risk to refugee populations originating from endemic areas, but there is little consensus on screening and/or treatment approaches for malaria in this population. Furthermore, detection of malaria in semi-immune asymptomatic refugees is limited by the sensitivity of diagnostic tests used for screening. We determined the prevalence of malaria by microscopy and real-time polymerase chain reaction (PCR) in a consecutive population of 324 asymptomatic refugees examined in Edmonton, Canada, during 2009-2010. Although all thick and thin blood smear results were negative, 10 subjects (3.1%) tested PCR positive for Plasmodium DNA. Interestingly, 6 of 10 PCR positive subjects are at risk of malaria relapse by P. vivax or P. ovale infections. These results suggest that appropriate guidelines for malaria screening should consider the risk of relapsing infections, and they highlight the potential usefulness of real-time PCR in the diagnosis of asymptomatic malaria.

Enterobius vermicularis infection of the fallopian tube in an infertile female.

Enterobius vermicularis (EV) is the most common nematode to infect humans. It inhabits the intestinal lumen, but rare, ectopic infections have been documented. The female genital tract is the most common ectopic site. We present a unique case of an EV infection of the fallopian tube resulting in inflammation, tubal obstruction, and infertility. A 30-year-old woman presented with infertility. Investigations included a laparoscopy with hydrotubation using methylene blue dye. This showed a left fallopian tube obstruction and extensive pelvic adhesions. A left salpingectomy was performed. Microscopic examination of the fallopian tube revealed numerous calcified and non-calcified ova associated with granulomatous reaction. The microscopic features were compatible with EV infection. Ectopic EV infections of the female genital tract result when the gravid female worm migrates from the perianal area to the vagina and ascends through the uterus and fallopian tubes to the peritoneal cavity. Microscopic examination of these ectopic sites can reveal adult worms or ova with granulomata formation, eosinophilic infiltrate, chronic inflammatory reaction, and fibrosis. The ova have a characteristic asymmetric oval configuration with flattening on one side. We postulate that our patient's salpingitis due to EV with accompanying fibrosis is a cause of her infertility.

Empirical treatment of community-acquired pneumonia and the development of fluoroquinolone-resistant tuberculosis.

UNLABELLED: BACKGROUND" Fluoroquinolone (FLQ) antibiotics are not uncommonly prescribed for community-acquired pneumonia that is later proven to be pulmonary tuberculosis (TB). Such FLQ monotherapy may result in FLQ-resistant pulmonary TB. METHODS: To assess outpatient FLQ use by patients with culture-proven pulmonary TB before diagnosis, TB registries in Alberta and Saskatchewan, Canada, were linked with provincial and federal drug benefit plans. To assess FLQ resistance, a case-control study was performed. RESULTS: Of 428 patients with pulmonary TB who were covered by a drug benefit plan, 74 (17.3%) had received > or = 1 FLQ prescription during the 6 months immediately before receipt of the diagnosis. Older patients (age, >64 years) were more likely than younger patients (age, 15-64 years) to be prescribed an FLQ (P < .05). Patients who were prescribed an FLQ received a total of 103 prescriptions. Most (54 [73.0%] of 74) patients who were prescribed an FLQ received a single prescription. Most (69 [67.0%] of 103) FLQ prescriptions were written within 90 days before the diagnosis of pulmonary TB. Patients who were prescribed an FLQ were not statistically significantly more likely than matched patients who were not prescribed an FLQ (control subjects) to be infected with FLQ-resistant Mycobacterium tuberculosis. Of 148 isolates of M. tuberculosis from patients and control subjects, 3 were FLQ resistant; all of these isolates were from patients who had received multiple FLQ prescriptions. Patients who had received multiple FLQ prescriptions were more likely than patients who had received a single FLQ prescription to be infected with FLQ-resistant M. tuberculosis (15.0% vs. 0.0%; odds ratio, 11.4; P = .04). CONCLUSIONS: Outpatient FLQ use, ostensibly for community-acquired pneumonia, is not uncommon among patients with pulmonary TB, especially older patients. Single FLQ prescriptions were not associated with FLQ-resistant M. tuberculosis, whereas multiple FLQ prescriptions were associated with FLQ resistance.

Multiplexed real-time PCR assay for discrimination of Plasmodium species with improved sensitivity for mixed infections.

The implementation of real-time PCR for the diagnosis of malaria has been hampered by poor sensitivity for the detection of mixed infections. We have optimized a method that enhances the sensitivity of detection of minor species in mixed infections within a single multiplex reaction. Our assay uses species-specific forward primers in combination with a conserved reverse primer and largely overcomes primer competition for the minor species DNA. With a blind panel of clinical samples, we successfully identified the species in 13/16 mixed infections. This assay was further validated with 91 blood samples and demonstrated a specificity and sensitivity for single infections of 100% compared with nested PCR as the "gold standard." This test has been implemented for routine confirmation of malaria species in Alberta, Canada. In comparison with species identification by microscopy, the real-time PCR test demonstrated greater sensitivity for the identification of species causing low-level and mixed infections and for the discrimination of Plasmodium species other than Plasmodium falciparum. Our experience supports a role for real-time PCR in the identification of malarial species in conjunction with microscopy.

The use of donor and recipient screening for toxoplasma in the era of universal trimethoprim sulfamethoxazole prophylaxis.

BACKGROUND: Toxoplasmosis is a serious complication of solid organ transplantation. The highest risk of infection and disease occurs in heart recipients with primary infection transmitted by a seropositive donor to a seronegative recipient (donor-recipient mismatch). Toxoplasmosis has been reported to occur in noncardiac transplant recipients; however, no large studies examining the frequency of such events or the need for serologic screening exist. METHODS: A retrospective cohort study of 1,006 solid organ transplant recipients transplanted in our center between 1984 and 1997 was performed to examine the incidence of Toxoplasma seroconversion, reactivation, and clinical toxoplasmosis and to evaluate the impact of trimethoprim sulfamethoxazole (TMP/SMX) prophylaxis on these outcomes. RESULTS: Pretransplant Toxoplasma seroprevalence was 13.4% in donors and 17.8% in recipients. The incidence of Toxoplasma donor-recipient mismatch was 9.5% during the 14-year study period, and only 39.1% of mismatched recipients received TMP/SMX prophylaxis. Only four patients seroconverted, of whom two had received prophylaxis. There were no cases of clinical disease; either primary or reactivation. CONCLUSIONS: We therefore conclude that in transplant centers with low Toxoplasma seroprevalence, routine screening for Toxoplasma in solid organ donors and recipients is not necessary, particularly in the era of routine TMP/SMX prophylaxis.

Nontuberculous mycobacterial breast implant infections.

BACKGROUND: For reasons that are unclear, the incidence of nontuberculous mycobacterial disease is increasing worldwide. Periprosthetic nontuberculous mycobacterial infections following augmentation mammaplasty and breast reconstruction have been reported previously in the form of case reports. METHODS: This retrospective case series examines periprosthetic nontuberculous mycobacterial infections in two western Canadian cities (Edmonton, Alberta, and Vancouver, British Columbia) over a 10-year time period. RESULTS: Ten patients were identified, four of whom had bilateral infections. The most common isolate was Mycobacterium fortuitum. Clinical features were similar to nonmycobacterial periprosthetic infections. The median time to onset of symptoms was 4.5 weeks and the median time to culture an organism was 5.4 weeks. The median duration of antibiotic therapy was 22 weeks. Patients required a mean of three additional operations after diagnosis. Nine patients underwent explantation of the involved implant(s). Reimplantation was performed in six patients a median of 11.5 months after explantation. All cases of reimplantation were successful. CONCLUSIONS: Experience with this postoperative complication is limited, as nontuberculous mycobacteria represent a minority of the pathogens responsible for periprosthetic infections. In the absence of specific features with which to identify patients at risk, the surgeon must be aware of the possibility of this infection. To achieve earlier diagnosis, the clinician should have a high index of suspicion in a patient with delayed onset of symptoms, negative preliminary cultures, and a periprosthetic infection that fails to resolve following a course of conventional antimicrobial treatment. With appropriate treatment, nontuberculous mycobacterial periprosthetic infections can be managed successfully.

pVir and bloody diarrhea in Campylobacter jejuni enteritis.

The plasmid pVir may play a role in the virulence of Campylobacter jejuni, a leading cause of bacterial gastroenteritis. The pVir plasmid was identified in 17% of 104 C. jejuni clinical isolates studied and was significantly associated with the occurrence of blood in patient stool, a marker of invasive infection. The pVir plasmid was not associated with greater occurrence of diarrhea, fever, pain, vomiting, or need for patient hospitalization. Isolates containing pVir were also associated with the presence of a tetracycline-resistance plasmid, but pVir did not transfer with tetracycline-resistance plasmids to recipient strains of C. jejuni. The association of pVir and bloody stool suggests that pVir may be clinically relevant in C. jejuni infections.

An outbreak of E. coli O157:H7 hemorrhagic colitis associated with unpasteurized gouda cheese.

BACKGROUND: A cluster of E. coli O157:H7 hemorrhagic colitis was identified in metro Edmonton, Alberta through notifiable disease surveillance in late 2002. METHODS: Environmental health officers collected food histories and clinical information from cases in the cluster. The provincial public health laboratory conducted pulsed field gel electrophoresis (PFGE) analysis on E. coli O157:H7 isolates from cluster cases. Public health and food regulatory agencies conducted an investigation when a food source (unpasteurized gouda cheese) was implicated. RESULTS: PFGE analysis revealed an "outbreak" profile in 13 cases. Onset dates for the outbreak cases ranged between October 2002 and February 2003. Two cases, aged 22 months and 4 years, developed hemolytic uremic syndrome as a result of their infection. Consumption of unpasteurized gouda cheese produced at a local dairy farm was reported by 12 of 13 outbreak cases in the 2 to 8 days prior to illness. E. coli O157:H7 was isolated from 2 of 26 cheese samples manufactured by the implicated producer. The cheese isolates had indistinguishable PFGE profiles as compared with outbreak case isolates. Implicated cheese was found to be contaminated with E. coli O157:H7 104 days after production, despite having met regulated microbiological and aging requirements. CONCLUSION: To our knowledge, this is the first confirmed outbreak of E. coli O157:H7 infection in Canada associated with raw milk hard cheese. A review of federal legislation vis-à-vis raw milk hard cheese may be in order.

First report of Schistosoma mekongi infection with brain involvement.

We describe, to our knowledge, the first reported case of Schistosoma mekongi infection with brain involvement. S. mekongi is a distinct species most closely related to Schistosoma japonicum that is endemic in a defined area of the Mekong River in Laos and Cambodia and characteristically associated with hepatosplenic disease. The patient had an excellent response to praziquantel therapy but required repeated courses of corticosteroid therapy to suppress recrudescent neurological symptoms.

Infection of placental trophoblasts by Toxoplasma gondii.

How the intracellular parasite Toxoplasma gondii causes placental inflammation and infects the fetus is unknown. By use of a culture model of primary human trophoblasts, we examined the consequences of infection by a virulent strain of T. gondii. Infection fractions (parasitophorous vacuoles per trophoblast nuclei) < or =0.9 were observed 1 day after challenge at an inoculum ratio of T. gondii to nuclei of 10. The culture content of infectious T. gondii increased 45-fold in 48 h. Two days after infection, almost 30% of trophoblast nuclei became apoptotic, and 30%-35% of nuclei were lost. Almost 90% of apoptotic nuclei were not adjacent to a parasitophorous vacuole, suggesting infection protected against apoptosis. However, there was no T. gondii-dependent accumulation of putative cytotoxic factors, such as tumor necrosis factor-alpha, that could mediate paracrine killing. Both mature and immature trophoblasts can be productively infected, and uninfected, but not infected, cells undergo apoptosis.