Web and phone-based COVID-19 syndromic surveillance in Canada: A cross-sectional study

BACKGROUND

Syndromic surveillance through web or phone-based polling has been used to track the course of infectious diseases worldwide. Our study objective was to describe the characteristics, symptoms, and self-reported testing rates of respondents in three different COVID-19 symptom surveys in Canada.

METHODS

This was a cross-sectional study using three distinct Canada-wide web-based surveys, and phone polling in Ontario. All three sources contained self-reported information on COVID-19 symptoms and testing. In addition to describing respondent characteristics, we examined symptom frequency and the testing rate among the symptomatic, as well as rates of symptoms and testing across respondent groups.

RESULTS

We found that over March- April 2020, 1.6% of respondents experienced a symptom on the day of their survey, 15% of Ontario households had a symptom in the previous week, and 44% of Canada-wide respondents had a symptom in the previous month. Across the three surveys, SARS-CoV-2-testing was reported in 2-9% of symptomatic responses. Women, younger and middle-aged adults (versus older adults) and Indigenous/First nations/Inuit/Métis were more likely to report at least one symptom, and visible minorities were more likely to report the combination of fever with cough or shortness of breath.

INTERPRETATION

The low rate of testing among those reporting symptoms suggests significant opportunity to expand testing among community-dwelling residents of Canada. Syndromic surveillance data can supplement public health reports and provide much-needed context to gauge the adequacy of SARS-CoV-2 testing rates.

Global trends in air travel: implications for connectivity and resilience to infectious disease threats

BACKGROUND

Increased connectivity via air travel can facilitate the geographic spread of infectious diseases. The number of travellers alone does not explain risk; passenger origin and destination will also influence risk of disease introduction and spread. We described trends in international air passenger numbers and connectivity between countries with different capacities to detect and respond to infectious disease threats.

METHODS

We used the Fragile States Index (FSI) as an annual measure of country-level resilience and capacity to respond to infectious disease events. Countries are categorized as: Sustainable, Stable, Warning or Alert, in order of increasing fragility. We included data for 177 sovereign states for the years 2010 to 2019. Annual inbound and outbound international air passengers for each country were obtained for the same time period. We examined trends in FSI score, trends in worldwide air travel and the association between a state's FSI score and air travel.

RESULTS

Among countries included in the FSI rankings, the total number of outbound passengers increased from 0.865 billion to 1.58 billion between 2010 and 2019. Increasing fragility was associated with a decrease in travel volumes, with a 2.5% (95% CI: 2.0-3.1%) reduction in passengers per 1-unit increase in FSI score. Overall, travel between countries of different FSI categories either increased or remained stable.

CONCLUSIONS

The world's connectivity via air travel has increased dramatically over the past decade. There has been notable growth in travel from Warning and Stable countries, which comprise more than three-quarters of international air travel passengers. These countries may have suboptimal capacity to detect and respond to infectious disease threats that emerge within their borders.

Travel Surveillance and Genomics Uncover a Hidden Zika Outbreak during the Waning Epidemic

The Zika epidemic in the Americas has challenged surveillance and control. As the epidemic appears to be waning, it is unclear whether transmission is still ongoing, which is exacerbated by discrepancies in reporting. To uncover locations with lingering outbreaks, we investigated travel-associated Zika cases to identify transmission not captured by reporting. We uncovered an unreported outbreak in Cuba during 2017, a year after peak transmission in neighboring islands. By sequencing Zika virus, we show that the establishment of the virus was delayed by a year and that the ensuing outbreak was sparked by long-lived lineages of Zika virus from other Caribbean islands. Our data suggest that, although mosquito control in Cuba may initially have been effective at mitigating Zika virus transmission, such measures need to be maintained to be effective. Our study highlights how Zika virus may still be "silently" spreading and provides a framework for understanding outbreak dynamics. VIDEO ABSTRACT.

Projecting the end of the Zika virus epidemic in Latin America: a modelling analysis

BACKGROUND

Zika virus (ZIKV) emerged in Latin America and the Caribbean (LAC) region in 2013, with serious implications for population health in the region. In 2016, the World Health Organization declared the ZIKV outbreak a Public Health Emergency of International Concern following a cluster of associated neurological disorders and neonatal malformations. In 2017, Zika cases declined, but future incidence in LAC remains uncertain due to gaps in our understanding, considerable variation in surveillance and the lack of a comprehensive collation of data from affected countries.

METHODS

Our analysis combines information on confirmed and suspected Zika cases across LAC countries and a spatio-temporal dynamic transmission model for ZIKV infection to determine key transmission parameters and projected incidence in 90 major cities within 35 countries. Seasonality was determined by spatio-temporal estimates of Aedes aegypti vectorial capacity. We used country and state-level data from 2015 to mid-2017 to infer key model parameters, country-specific disease reporting rates, and the 2018 projected incidence. A 10-fold cross-validation approach was used to validate parameter estimates to out-of-sample epidemic trajectories.

RESULTS

There was limited transmission in 2015, but in 2016 and 2017 there was sufficient opportunity for wide-spread ZIKV transmission in most cities, resulting in the depletion of susceptible individuals. We predict that the highest number of cases in 2018 would present within some Brazilian States (Sao Paulo and Rio de Janeiro), Colombia and French Guiana, but the estimated number of cases were no more than a few hundred. Model estimates of the timing of the peak in incidence were correlated (p < 0.05) with the reported peak in incidence. The reporting rate varied across countries, with lower reporting rates for those with only confirmed cases compared to those who reported both confirmed and suspected cases.

CONCLUSIONS

The findings suggest that the ZIKV epidemic is by and large over within LAC, with incidence projected to be low in most cities in 2018. Local low levels of transmission are probable, but the estimated rate of infection suggests that most cities have a population with high levels of herd immunity.

Infectious disease implications of large-scale migration of Venezuelan nationals

Background

The ongoing economic and political crisis in Venezuela has resulted in a collapse of the healthcare system and the re-emergence of previously controlled or eliminated infectious diseases. There has also been an exodus of Venezuelan international migrants in response to the crisis. We sought to describe the infectious disease risks faced by Venezuelan nationals and assess the international mobility patterns of the migrant population.

Methods

We synthesized data on recent infectious disease events in Venezuela and among international migrants from Venezuela, as well as on current country of residence among the migrant population. We used passenger-level itinerary data from the International Air Transport Association to evaluate trends in outbound air travel from Venezuela over time. We used two parameter-free mobility models, the radiation and impedance models, to estimate the expected population flows from Venezuelan cities to other major Latin American and Caribbean cities.

Results

Outbreaks of measles, diphtheria and malaria have been reported across Venezuela and other diseases, such as HIV and tuberculosis, are resurgent. Changes in migration in response to the crisis are apparent, with an increase in Venezuelan nationals living abroad, despite an overall decline in the number of outbound air passengers. The two models predicted different mobility patterns, but both highlighted the importance of Colombian cities as destinations for migrants and also showed that some migrants are expected to travel large distances. Despite the large distances that migrants may travel internationally, outbreaks associated with Venezuelan migrants have occurred primarily in countries proximate to Venezuela.

Conclusions

Understanding where international migrants are relocating is critical, given the association between human mobility and the spread of infectious diseases. In data-limited situations, simple models can be useful for providing insights into population mobility and may help identify areas likely to receive a large number of migrants.

Dissecting multi-photon resonances at the large hadron collider

We examine the phenomenology of the production, at the 13 TeV Large Hadron Collider (LHC), of a heavy resonance X, which decays via other new on-shell particles n into multi-(i.e. three or more) photon final states. In the limit that n has a much smaller mass than X, the multi-photon final state may dominantly appear as a two-photon final state because the γ s from the n decay are highly collinear and remain unresolved. We discuss how to discriminate this scenario from X → γ γ : rather than discarding non-isolated photons, it is better to relax the isolation criteria and instead form photon jets substructure variables. The spins of X and n leave their imprint upon the distribution of pseudo-rapidity gap Δ η between the apparent two-photon states. Depending on the total integrated luminosity, this can be used in many cases to claim discrimination between the possible spin choices of X and n, although the case where X and n are both scalar particles cannot be discriminated from the direct X → γ γ decay in this manner. Information on the mass of n can be gained by considering the mass of each photon jet.

The Effect of Changes in Cervical Cancer Screening Guidelines on Chlamydia Testing

PURPOSE

Many chlamydia infections are identified through screening, which is frequently offered to females concomitantly with cervical cancer screening. Recent cervical cancer screening guidelines recommend screening less frequently and starting later. We sought to evaluate the impact of the May 2012 Ontario, Canada, cervical cancer screening guideline change on Papanicolaou (Pap) and chlamydia trachomatis (chlamydia) testing and incidence.

METHODS

We extracted population-based physician billing claims data to identify Pap and chlamydia tests and public health surveillance data to identify chlamydia cases. We used interrupted time series analysis of quarterly data spanning 2 years before and after the guideline change and fitted segmented linear regression or rational functions to the outcomes using autoregressive integrated moving average models. Outcomes were stratified by sex and age group.

RESULTS

Two years after the guideline change, we observed reduced chlamydia testing in females, with the greatest relative reduction (25.5%) among those aged 15 to 19 years. We also observed decreases in reported chlamydia incidence for females aged 15 to 19 years and 20 to 24 years (relative reductions of 16.8% and 14.4%, respectively). Chlamydia incidence remained the same for males, despite increased chlamydia testing.

CONCLUSIONS

Recent cervical cancer screening guideline changes in Ontario were associated with reduced chlamydia testing and reported new cases of chlamydia in females. Females aged 15 to 19 years, who are at high risk for chlamydia if sexually active, and who no longer warrant cervical cancer screening, were disproportionately affected. Females should be tested for chlamydia based on risk, regardless of need for Pap testing.

Hypoxia Inducible Factor 1: A Urinary Biomarker of Kidney Disease

Identifying noninvasive biomarkers of kidney disease is valuable for diagnostic and therapeutic purposes. Hypoxia inducible factor 1 (HIF-1) expression is known to be elevated in the kidneys in several renal disease pathologies. We hypothesized that the urinary HIF-1a mRNA level may be a suitable biomarker for expression of this protein in chronic kidney disease (CKD). We compared HIF-1a mRNA levels from urine pellets of CKD and healthy subjects. To ensure that urinary HIF-1a mRNA is of kidney origin, we examined colocalization of HIF-1a mRNA with two kidney specific markers in urine cells. We found that HIF-1a mRNA is readily quantifiable in urine pellets and its expression was significantly higher in CKD patients compared with healthy adults. We also showed that the urinary HIF-1a mRNA comes primarily from cells of renal origin. Our data suggest that urinary HIF-1a mRNA is a potential biomarker in CKD and can be noninvasively assessed in patients.

An unusual cause of meningitis

A 57 year old man patient presented with fever and frontal headache. He had a background history of sero-positive rheumatoid arthritis which was well controlled on immunomodulatory disease modifying anti-rheumatoid drugs (DMARDS) including methotrexate and lef lunomide. Six months earlier he had returned from Massachussetts in the USA after a one year period of residence there. On examination his vital signs were within normal limits and he was afebrile with a temperature of 36.1oC. His left elbow joint was warm, tender and swollen; examination was otherwise normal.

Immediate coronary artery bypass surgery after platelet inhibition with eptifibatide: results from PURSUIT. Platelet Glycoprotein IIb/IIIa in Unstable Angina: Receptor Suppression Using Integrelin Therapy

BACKGROUND

The platelet GP IIb/IIIa inhibitor eptifibatide improves outcomes in patients with acute coronary syndromes. Patients requiring emergent coronary artery bypass grafting, however, may be at increased risk for bleeding if exposed to eptifibatide. Data from the PURSUIT trial were reviewed to assess this risk in patients undergoing coronary surgery immediately after exposure to eptifibatide.

METHODS

In PURSUIT, 10,948 patients who presented with non-ST segment elevation acute coronary syndromes were prospectively randomized to receive eptifibatide (180 microg/kg bolus plus 2 microg/kg/min infusion) or placebo. A total of 78 patients underwent immediate coronary artery bypass surgery within 2 hours of cessation of study drug (placebo, n = 46; eptifibatide, n = 32). Clinical outcome, bleeding, and transfusion requirements within this subset were examined.

RESULTS

Major bleeding was not different between groups, occurring in 64% of patients receiving placebo and 63% of patients receiving eptifibatide. The incidence of blood transfusion was similar as well (57% vs 59%). Postoperative thrombocytopenia occurred less often after eptifibatide exposure. Perioperative myocardial infarction was significantly reduced in patients who received eptifibatide (46% vs 22%, p < 0.05). There was no difference in perioperative stroke (2.2% vs 6.3%) or mortality (6.3% vs 6.5%).

CONCLUSIONS

Patients may safely undergo coronary artery bypass surgery within 2 hours of discontinuation of eptifibatide. Eptifibatide infusion in the immediate preoperative period had no adverse clinical effects, but did significantly decrease the incidence of perioperative myocardial infarction. Additionally, platelet counts after surgery were higher in the group of patients who received eptifibatide, perhaps indicative of a platelet-sparing effect during cardiopulmonary bypass.

Sternal instability after midline sternotomy

The purpose of this paper is to discuss sternal instability a problem occasionally associated with midline sternotomy, including the etiology, predisposing conditions, diagnosis and management. Among the methods of repair, sternal weaving and pectoralis muscle advancement are thought to be especially effective.

Preconception counseling and women's compliance with folic acid supplementation

QUESTION

I am counseling patients to take folic acid when they plan pregnancy and during early pregnancy. Is there any proof that counseling really causes women to comply?

ANSWER

A recent Motherisk study showed that counseling women who were planning pregnancy about folic acid use is very effective: 71% of those counseled took folic acid, compared with only 17% of those who were not counseled.

Inhibitors of the platelet receptor glycoprotein IIb-IIIa and complications during percutaneous coronary revascularization. Management strategies for the cardiac surgeon

Platelet-mediated thrombosis has a pivotal role in the pathophysiology of acute ischemic coronary syndromes (AICS) and the acute complications of percutaneous coronary interventions. Because cross-linking of the activated platelet receptor glycoprotein (GP) IIb-IIIa by plasma fibrinogen represents the final common pathway to coronary thrombus formation, several GP IIb-IIIa inhibitors have been developed as a potentially more effective antithrombotic therapy than agents currently used for this purpose, namely aspirin and heparin. However, use of GP IIb-IIIa inhibitors in patients with AICS and those scheduled for percutaneous coronary interventions may increase the risk of serious clinical and bleeding events among patients who require emergency or urgent bypass surgery. This review describes clinical experience with various GP IIb-IIIa inhibitors and suggests management strategies for patients undergoing emergency or urgent bypass surgery shortly after treatment with GP IIb-IIIa inhibitors.

Steroid-DNA conjugates: improved triplex formation with 5-amido-(7-deoxycholic acid)-dU incorporated oligonucleotides

The synthesis of oligodeoxyribonucleotides incorporating 7-deoxycholic acid conjugated at C5 of dU is described. When used as third strand, these form oligonucleotide triplexes with higher stability compared to unmodified controls at physiological pH.

Percutaneous bailout therapy of a perforated vein graft using a stent-autologous vein patch

A 74-yr-old man with two prior coronary bypass surgeries experienced perforation of an occluded aortocoronary vein graft during a transluminal extraction catheter (TEC) procedure for unstable angina. The perforation was successfully closed using a Palmaz 154 stent covered with a short segment of autologous antecubital vein.

Imaging in phaeohyphomycosis of the brain: case report

A case of multiple, conglomerated brain abscesses due to Xylohypha bantiana, with unique imaging features, is presented. This is the first culture-proven case of brain infection due to this fungus in the neuroimaging literature.

Laparoscopic cholecystectomy: the Dammam Central Hospital experience

Over a one year period (June 1992-June 1993), 260 patients (208 females and 52 males) with mean age of 37 years (range 13-80), underwent laparoscopic cholecystectomy (LC) for symptomatic gallstones. Thirty patients were admitted as emergency (20 acute cholecystitis, 10 acute pancreatitis). The procedure was performed successfully in 232 cases (89%). In 28 patients (18 electives, 10 emergencies), the procedure was converted to open for a variety of reasons, difficult anatomy being the commonest. Our mean operative time was 99.9 minutes (range 30-290 minutes). There were 3 major complications (2 common bile duct injuries and one abdominal aortic injury) and 4 minor complications (2 wound infections, one prolonged ileus and one chest infection). There was one death due to sickle cell crisis on the fifth post-operative day. The mean hospital stay was 2.3 days and 6.5 days for LC and converted cases, respectively. Our results suggest that laparoscopic cholecystectomy can be offered and conducted safely and effectively in the great majority of patients presenting acutely or electively with cholelithiasis, and that the results we achieved during the first year of our experience with LC is comparable to those reported from Europe and North America.

Long-term results of core decompression for ischaemic necrosis of the femoral head

We have studied the long-term results of core decompression as the sole treatment for Ficat stages I, II and III ischaemic necrosis of 128 femoral heads in 90 patients. The 5-, 10- and 15-year survival rates for the three stages were respectively: stage I 100%, 96% and 90%; stage II 85%, 74% and 66%; and stage III 58%, 35% and 23%. At a mean follow-up of 11 years (4.5 to 19), 55 hips had failed (43%). No further surgery had been needed for 88% of stage-I, 72% of stage-II and 26% of stage-III hips; but despite the generally satisfactory clinical results, 56% of the hips had progressed radiographically by at least one Ficat stage. Complications of the core procedure included four fractures, all from postoperative falls, and one head perforation due to technical error. We conclude that core decompression delays the need for total hip replacement in young patients with ischaemic necrosis.

Anatomical restraints to dislocation of the second metatarsophalangeal joint and assessment of a repair technique

The aim of this study was to determine the anatomical restraints to dislocation of the second metatarsophalangeal joint and to assess the biomechanical efficacy of a technique that is commonly used to stabilize this joint. Cadaveric feet were disarticulated at the ankle, with preservation of the long flexor tendons at the medial malleolus. The hindfoot was transfixed to an aluminum jig, and a contoured nylon block was secured to the dorsum of the second metatarsal. A Kirschner wire was passed transversely through the proximal phalanx and was attached to a wire loop through which a constant vertical displacement was applied with a universal testing machine. A preload of five newtons was applied, followed by a constant displacement of two millimeters per minute, and the load-displacement curves were measured. The volar plate and the collateral ligaments were divided in five feet each. In another ten feet, both of these structures were divided simultaneously. Each load cycle was repeated four times. The force required to dislocate the joint, in the position in which testing was performed, was reduced by a mean of 30 per cent when the volar plate was divided and by a mean of 46 per cent when the collateral ligaments were divided. Division of both of these structures created an unstable joint, which dislocated at an applied load of five to ten newtons. The metatarsophalangeal joint was then repaired with use of a flexor tendon transfer in all twenty feet. This repair technique restored the load-displacement curves to that of the normal toe.

Growth performance in anemia and following iron supplementation

The growth status of anemic (n = 117, Hb 7-10 g/dl) and normal (n = 53, H > or = 11 g/dl) children 3-5 years of age living under similar environmental and socio-economic conditions was evaluated. The dietary intake was assessed on a random subsample of the anemic and normal children. The anemic children had a poorer growth status than normal children as indicated by their significantly (p < 0.001) lower body weight, height and weight for age and significantly (p < 0.001) larger number in Grades II and III malnutrition. Iron supplementation (40 mg elemental iron/day) for six months produced a significant (p < 0.001) increase in Hb levels of both groups (1.6 g/dl in the anemic and 0.8 g/dl in the non-anemic) compared to their respective controls who received sugar placebos. The growth performance of the anemic children supplemented with iron was superior to that of anemic placebo treated children as indicated by a better weight gain and a significantly higher weight for height (p < 0.05). Weight for age was a good differentiator of the anemic from normal while weight for height was a good indicator of the impact of iron supplements on growth.

Factors affecting the strength of flexor tendon repair

The effects of different thicknesses and configurations of core sutures were studied in human cadaveric flexor tendon repairs. Both straight and cyclic load tests were employed. To exploit the full strength of 4/0 suture material, the Kessler repair using four locked single knots would seem to be appropriate.

Salicylate induced exacerbation of ulcerative colitis

The oral administration of mesalazine (5-aminosalicylic acid) resulted in the exacerbation of ulcerative colitis in two patients intolerant to sulphasalazine whose colitis had previously been quiescent. Although sulphasalazine intolerance is usually attributable to the sulphapyridine moiety, the possibility of salicylate sensitivity should be considered in colitic patients who fail to respond appropriately to sulphasalazine or who experience abdominal pain or diarrhoea while taking the drug.