Global phylogeny of Treponema pallidum lineages reveals recent expansion and spread of contemporary syphilis.

Funder: Queensland GovernmentSyphilis, which is caused by the sexually transmitted bacterium Treponema pallidum subsp. pallidum, has an estimated 6.3 million cases worldwide per annum. In the past ten years, the incidence of syphilis has increased by more than 150% in some high-income countries, but the evolution and epidemiology of the epidemic are poorly understood. To characterize the global population structure of T. pallidum, we assembled a geographically and temporally diverse collection of 726 genomes from 626 clinical and 100 laboratory samples collected in 23 countries. We applied phylogenetic analyses and clustering, and found that the global syphilis population comprises just two deeply branching lineages, Nichols and SS14. Both lineages are currently circulating in 12 of the 23 countries sampled. We subdivided T. p. pallidum into 17 distinct sublineages to provide further phylodynamic resolution. Importantly, two Nichols sublineages have expanded clonally across 9 countries contemporaneously with SS14. Moreover, pairwise genome analyses revealed examples of isolates collected within the last 20 years from 14 different countries that had genetically identical core genomes, which might indicate frequent exchange through international transmission. It is striking that most samples collected before 1983 are phylogenetically distinct from more recently isolated sublineages. Using Bayesian temporal analysis, we detected a population bottleneck occurring during the late 1990s, followed by rapid population expansion in the 2000s that was driven by the dominant T. pallidum sublineages circulating today. This expansion may be linked to changing epidemiology, immune evasion or fitness under antimicrobial selection pressure, since many of the contemporary syphilis lineages we have characterized are resistant to macrolides

Twelve-month observational study of children with cancer in 41 countries during the COVID-19 pandemic

Introduction Childhood cancer is a leading cause of death. It is unclear whether the COVID-19 pandemic has impacted childhood cancer mortality. In this study, we aimed to establish all-cause mortality rates for childhood cancers during the COVID-19 pandemic and determine the factors associated with mortality. Methods Prospective cohort study in 109 institutions in 41 countries. Inclusion criteria: children <18 years who were newly diagnosed with or undergoing active treatment for acute lymphoblastic leukaemia, non-Hodgkin's lymphoma, Hodgkin lymphoma, retinoblastoma, Wilms tumour, glioma, osteosarcoma, Ewing sarcoma, rhabdomyosarcoma, medulloblastoma and neuroblastoma. Of 2327 cases, 2118 patients were included in the study. The primary outcome measure was all-cause mortality at 30 days, 90 days and 12 months. Results All-cause mortality was 3.4% (n=71/2084) at 30-day follow-up, 5.7% (n=113/1969) at 90-day follow-up and 13.0% (n=206/1581) at 12-month follow-up. The median time from diagnosis to multidisciplinary team (MDT) plan was longest in low-income countries (7 days, IQR 3-11). Multivariable analysis revealed several factors associated with 12-month mortality, including low-income (OR 6.99 (95% CI 2.49 to 19.68); p<0.001), lower middle income (OR 3.32 (95% CI 1.96 to 5.61); p<0.001) and upper middle income (OR 3.49 (95% CI 2.02 to 6.03); p<0.001) country status and chemotherapy (OR 0.55 (95% CI 0.36 to 0.86); p=0.008) and immunotherapy (OR 0.27 (95% CI 0.08 to 0.91); p=0.035) within 30 days from MDT plan. Multivariable analysis revealed laboratory-confirmed SARS-CoV-2 infection (OR 5.33 (95% CI 1.19 to 23.84); p=0.029) was associated with 30-day mortality. Conclusions Children with cancer are more likely to die within 30 days if infected with SARS-CoV-2. However, timely treatment reduced odds of death. This report provides crucial information to balance the benefits of providing anticancer therapy against the risks of SARS-CoV-2 infection in children with cancer

Q Fever Presenting as Recurrent, Culture-Negative Endocarditis with Aortic Prosthetic Valve Failure: A Case Report and Review of the Literature

The present report describes a case of recurrent, culture-negative endocarditis presenting with aortic prosthetic valve dysfunction in a 62-year-old man who required four valve replacement surgeries. On each occasion, he presented with valve failure. Fever was only documented during his first presentation. Furthermore, no vegetations were detectable on his aortic valve at transesophageal echocardiography. On the occasion of his most recent presentation, a detailed history of animal exposure -- including hunting and skinning deer, moose and other large animals with his bare hands -- was the only clue to his diagnosis. Serum antibodies against Coxiella burnetii were strongly positive, and C burnetii DNA was detected by polymerase chain reaction from his resected aortic valve tissue. Q fever is a worldwide zoonotic infection with diverse reservoirs. This diagnosis should be considered when evaluating unexplained prosthetic valve dysfunction, particularly in the setting of animal exposure

Detection of Salmonella typhi agglutinins in sera of patients with other febrile illnesses and healthy individuals

Background and Purpose : Widal test is frequently applied for the detection of Salmonella agglutinins to diagnose Salmonella enterica serotype Typhi infection. There are however a number of controversies challenging the diagnostic utility of this test. This study was performed to determine the prevalence of Salmonella agglutinins in patients with other febrile illnesses and healthy blood donors. Materials and Methods : Sera from 50 healthy blood donors were compared for the presence of Salmonella agglutinins in various groups of patients with other febrile illnesses using Widal test in the division of Serology and Immunology at King Khalid University Hospital, Riyadh. The patient groups of other febrile illnesses included infections with Beta-hemolytic streptococcus (n = 50), Brucella (n = 46), Helicobacter pylori (n = 24), Treponema pallidum (n = 30), Toxoplasma (n = 44), and other parasites (n = 20). Results : Majority of the patients and normal individuals were tested positive for Widal test at dilution of less than 1 : 40 both for the O (62.5%) and H (64.6%) antigen. A decreasing trend in Widal reactivity was observed with increasing dilutions of the serum samples. At 1 : 160 titer, which is generally considered as a cut off point for positive Widal test, 6.4 and 11% individuals had positive Widal test for O and H Salmonella antigens, respectively. Conclusion : Detection of a significant number of positive Widal tests in conditions where it is expected to be nonreactive appears to be a serious problem in making a correct diagnosis of typhoid fever, thus challenging the diagnostic utility of the Widal test

Detection of Salmonella typhi agglutinins in sera of patients with other febrile illnesses and healthy individuals

Background and Purpose : Widal test is frequently applied for the detection of Salmonella agglutinins to diagnose Salmonella enterica serotype Typhi infection. There are however a number of controversies challenging the diagnostic utility of this test. This study was performed to determine the prevalence of Salmonella agglutinins in patients with other febrile illnesses and healthy blood donors. Materials and Methods : Sera from 50 healthy blood donors were compared for the presence of Salmonella agglutinins in various groups of patients with other febrile illnesses using Widal test in the division of Serology and Immunology at King Khalid University Hospital, Riyadh. The patient groups of other febrile illnesses included infections with Beta-hemolytic streptococcus (n = 50), Brucella (n = 46), Helicobacter pylori (n = 24), Treponema pallidum (n = 30), Toxoplasma (n = 44), and other parasites (n = 20). Results : Majority of the patients and normal individuals were tested positive for Widal test at dilution of less than 1 : 40 both for the O (62.5%) and H (64.6%) antigen. A decreasing trend in Widal reactivity was observed with increasing dilutions of the serum samples. At 1 : 160 titer, which is generally considered as a cut off point for positive Widal test, 6.4 and 11% individuals had positive Widal test for O and H Salmonella antigens, respectively. Conclusion : Detection of a significant number of positive Widal tests in conditions where it is expected to be nonreactive appears to be a serious problem in making a correct diagnosis of typhoid fever, thus challenging the diagnostic utility of the Widal test

Low prevalence of Helicobacter pylori infection in Canadian children: A cross-sectional analysis

BACKGROUND: The incidence and prevalence rates of childhood Helicobacter pylori infection vary greatly by nation, with infection rates of 8.9% to 72.8% reported in developed and developing countries, respectively. To date, few studies have assessed the prevalence of H pylori in Canadian children, with studies limited to Aboriginal communities and single tertiary care centres from Ontario and Quebec

Detection of Lyme Disease Spirochete, Borrelia burgdorferi sensu lato, Including Novel Genotypes in Ticks (Acari: Ixodidae) Collected from Songbirds (Passeriformes) across Canada.

ABSTRACT: Lyme disease is reported across Canada, but pinpointing the source of infection has been problematic. In this three-year, bird-tick-pathogen study (2004)(2005)(2006), 366 ticks representing 12 species were collected from 151 songbirds (31 passerine species/subspecies) at 16 locations Canada-wide. Of the 167 ticks/pools tested, 19 (11.4%) were infected with Borrelia burgdorferi sensu lato (s.l.). Sequencing of the rrf-rrl intergenic spacer gene revealed four Borrelia genotypes: B. burgdorferi sensu stricto (s.s.) and three novel genotypes (BC genotype 1, BC genotype 2, BC genotype 3). All four genotypes were detected in spirochete-infected Ixodes auritulus (females, nymphs, larvae) suggesting this tick species is a vector for B. burgdorferi s.l. We provide first-time records for: ticks in the Yukon (north of 60° latitude), northernmost collection of Amblyomma americanum in North America, and Amblyomma imitator in Canada. First reports of bird-derived ticks infected with B. burgdorferi s.l. include: live culture of spirochetes from Ixodes pacificus (nymph) plus detection in I. auritulus nymphs, Ixodes scapularis in New Brunswick, and an I. scapularis larva in Canada. We provide the first account of B. burgdorferi s. l. in an Ixodes muris tick collected from a songbird anywhere. Congruent with previous data for the American Robin, we suggest that the Common Yellowthroat, Golden-crowned Sparrow, Song Sparrow, and Swainson's Thrush are reservoir-competent hosts. Song Sparrows, the predominant hosts, were parasitized by I. auritulus harboring all four Borrelia genotypes. Our results show that songbirds import B. burgdorferi s.l.-infected ticks into Canada. Bird-feeding I. scapularis subadults were infected with Lyme spirochetes during both spring and fall migration in eastern Canada. Because songbirds disperse millions of infected ticks across Canada, people and domestic animals contract Lyme disease outside of the known and expected range. Journal of Vector Ecology 35 (1): 124-139. 2010

Spread of Cryptococcus gattii in British Columbia, Canada, and Detection in the Pacific Northwest, USA

Cryptococcus gattii, emergent on Vancouver Island, British Columbia (BC), Canada, in 1999, was detected during 2003–2005 in 3 persons and 8 animals that did not travel to Vancouver Island during the incubation period; positive environmental samples were detected in areas outside Vancouver Island. All clinical and environmental isolates found in BC were genotypically consistent with Vancouver Island strains. In addition, local acquisition was detected in 3 cats in Washington and 2 persons in Oregon. The molecular profiles of Oregon isolates differed from those found in BC and Washington. Although some microclimates of the Pacific Northwest are similar to those on Vancouver Island, C. gattii concentrations in off-island environments were typically lower, and human cases without Vancouver Island contact have not continued to occur. This suggests that C. gattii may not be permanently colonized in off-island locations