Paediatric inflammatory multisystem syndrome in Canada: population-based surveillance and role of SARS-CoV-2 linkage

BACKGROUND

Paediatric inflammatory multisystem syndrome (PIMS) is a rare condition temporally associated with SARS-CoV-2 infection. Using national surveillance data, we compare presenting features and outcomes among children hospitalized with PIMS by SARS-CoV-2 linkage, and identify risk factors for intensive care (ICU).

METHODS

Cases were reported to the Canadian Paediatric Surveillance Program by a network of >2800 pediatricians between March 2020 and May 2021. Patients with positive versus negative SARS-CoV-2 linkages were compared, with positive linkage defined as any positive molecular or serologic test or close contact with confirmed COVID-19. ICU risk factors were identified with multivariable modified Poisson regression.

RESULTS

We identified 406 children hospitalized with PIMS, including 49.8% with positive SARS-CoV-2 linkages, 26.1% with negative linkages, and 24.1% with unknown linkages. The median age was 5.4 years (IQR 2.5-9.8), 60% were male, and 83% had no comorbidities. Compared to cases with negative linkages, children with positive linkages experienced more cardiac involvement (58.8% vs. 37.4%; p < 0.001), gastrointestinal symptoms (88.6% vs. 63.2%; p < 0.001), and shock (60.9% vs. 16.0%; p < 0.001). Children aged ≥6 years and those with positive linkages were more likely to require ICU.

CONCLUSIONS

Although rare, 30% of PIMS hospitalizations required ICU or respiratory/hemodynamic support, particularly those with positive SARS-CoV-2 linkages.

IMPACT

We describe 406 children hospitalized with paediatric inflammatory multisystem syndrome (PIMS) using nationwide surveillance data, the largest study of PIMS in Canada to date. Our surveillance case definition of PIMS did not require a history of SARS-CoV-2 exposure, and we therefore describe associations of SARS-CoV-2 linkages on clinical features and outcomes of children with PIMS. Children with positive SARS-CoV-2 linkages were older, had more gastrointestinal and cardiac involvement, and hyperinflammatory laboratory picture. Although PIMS is rare, one-third required admission to intensive care, with the greatest risk amongst those aged ≥6 years and those with a SARS-CoV-2 linkage.

'First in family' experiences in a Canadian medical school: A critically reflexive study

BACKGROUND

Medical students from affluent and highly educated backgrounds remain overrepresented in Canadian medical schools despite widespread efforts to improve diversity. Little is known of the medical school experiences of students who are first in their family (FiF) to attend university. Drawing on Bourdieu and a critically reflexive lens, this study explored the experiences of FiF students in a Canadian medical school to better understand the ways in which the medical school environment can be exclusive and inequitable to underrepresented students.

METHODS

We interviewed 17 medical students who self-identified as being FiF to attend university. Utilising theoretical sampling, we also interviewed five students who identified as being from medical families to test our emerging theoretical framework. Participants were asked to discuss what 'first in family' meant to them, their journey into medical school and their experiences at medical school. Bourdieu's theories and concepts were used as sensitising concepts to explore the data.

RESULTS

FiF students discussed the implicit messages they received about who belongs in medical school, challenges in shifting from their pre-medical lives to a medical identity and competing with peers for residency programmes. They reflected on the advantages they perceived they had over their fellow students due to their less 'typical' social backgrounds.

CONCLUSION

While medical schools continue to make strides when it comes to increasing diversity, inclusivity and equity require increased attention. Our findings highlight the ongoing need for structural and cultural change at admissions and beyond-change that recognises the much-needed presence and perspectives that underrepresented medical students, including those who are FiF, bring to medical education and healthcare. Engaging in critical reflexivity represents a key way that medical schools can continue to address issues of equity, diversity and inclusion.

Missing and murdered Indigenous women, girls, and Two Spirit people: a paediatric health crisis

Indigenous children and adolescents across the USA and Canada experience increased emotional, physical, and sexual violence resulting from the longstanding effects of colonialism and historical trauma. There is a substantial lack of research exploring these issues and scarce efforts outside of Indigenous communities to support victims. However, the association between exposure to violence and abuse and adverse health outcomes among Indigenous children and adolescents is clear. In this Viewpoint, we explore this association, discuss historical context, highlight important work by governments and community organisations, and suggest actions for paediatricians and paediatric health-care providers.

Resource use and disease severity of children hospitalized for COVID-19 versus multisystem inflammatory syndrome in children (MIS-C) in Canada

Background

Direct comparisons of paediatric hospitalizations for acute coronavirus disease 2019 (COVID-19) and multisystem inflammatory syndrome in children (MIS-C) can inform health system planning. We describe the absolute and relative hospital burden of acute paediatric COVID-19 and MIS-C in Canada.

Methods

This national prospective study was conducted via the Canadian Paediatric Surveillance Program from March 2020-May 2021. Children younger than 18 years old and hospitalized for acute COVID-19 or MIS-C were included in the analysis. Outcomes included supplemental oxygen (low-flow oxygen or high-flow nasal cannula), ventilation (non-invasive or conventional mechanical), vasopressors, paediatric intensive care unit (PICU) admission, or death. Adjusted risk differences (aRD) and 95% confidence intervals (CI) were calculated to identify factors associated with each diagnosis.

Results

Overall, we identified 330 children hospitalized for acute COVID-19 (including five deaths) and 208 hospitalized for MIS-C (including zero deaths); PICU admission was required for 49.5% of MIS-C hospitalizations versus 18.2% of acute COVID-19 hospitalizations (aRD 20.3; 95% CI, 9.9-30.8). Resource use differed by age, with children younger than one year hospitalized more often for acute COVID-19 (aRD 43.4% versus MIS-C; 95% CI, 37.7-49.1) and more children 5-11 years hospitalized for MIS-C (aRD 38.9% vs. acute COVID-19; 95% CI, 31.0-46.9).

Conclusion

While there were more hospitalizations and deaths from acute paediatric COVID-19, MIS-C cases were more severe, requiring more intensive care and vasopressor support. Our findings suggest that both acute COVID-19 and MIS-C should be considered when assessing the overall burden of severe acute respiratory syndrome coronavirus 2 in hospitalized children.

50 Risk factors for severe COVID-19 in hospitalized children in Canada: A national prospective study from March 2020–May 2021

Background

Children living with chronic comorbid conditions are at increased risk for severe COVID-19 disease, though there is limited evidence regarding the risks associated with specific conditions and which children may benefit from targeted COVID-19 therapies. Age-specific baseline indicators of COVID-19 severity are also needed to evaluate the effectiveness of SARS-CoV-2 vaccination strategies in the paediatric population.

Objectives

In this study, we aimed to 1) identify factors associated with severe COVID-19 in children, and 2) describe rates of hospitalization, intensive care unit (ICU) admission, and severe COVID-19 within specific pediatric age groups.

Design/Methods

We conducted a national prospective study on hospitalized children with microbiologically confirmed SARS-CoV-2 infection via the Canadian Paediatric Surveillance Program from March 2020–May 2021. Cases were reported voluntarily by a network of >2800 paediatricians and paediatric subspecialists. SARS-CoV-2 hospitalizations were classified as COVID-19-related, incidental infection, or infection control/social admissions. Severe disease was defined as intensive care, ventilatory or hemodynamic requirements, select organ system complications, or death. Outcomes were described among children aged <6 months, 6–23 months, 2–4 years, 5–11 years, and 12–17 years. Risk factors for severe disease were identified using multivariable Poisson regression, adjusting for child age and sex, coinfections, and timing of hospitalization.

Results

We identified 541 children hospitalized with SARS-CoV-2 infection, including 329 (60.8%) with COVID-19-related disease. Median age at admission was 2.8 years (IQR 0.3-13.5) and 42.9% (n=232) had at least one comorbidity. Among COVID-19-related hospitalizations, severe disease occurred in 29.5% of children (n=97/329), including a higher proportion of children aged 2–4 years (48.7%) and 12–17 years (41.3%) (Table 1). Comorbidities associated with severe disease are described in Figure 1, and included technology dependence (adjusted risk ratio [aRR] 1.96, 95% confidence interval [CI] 1.31-2.95), neurologic conditions (e.g. epilepsy and chromosomal/genetic conditions) (aRR 1.87, 95% CI 1.34-2.61), and pulmonary conditions (e.g. bronchopulmonary dysplasia and uncontrolled asthma) (aRR 1.66, 95% CI 1.13-2.42).

Conclusion

While severe outcomes were detected at all ages and among patients with and without comorbidities, neurologic and pulmonary conditions as well as technology dependence were associated with increased risk of severe COVID-19. Children aged 2–4 years more commonly experienced severe COVID-19 in this study, which was conducted at a time when no children were eligible for SARS-CoV-2 vaccines. Notably, this high-risk group remains without access to approved vaccines. These findings may help guide vaccination programs and prioritize targeted COVID-19 therapies for children.

Caractéristiques des hospitalisations au Canada d’enfants ayant contracté une infection aiguë par le SRAS-CoV-2 en 2020

Contexte:

Les facteurs de risque de complications graves de l’infection par le SRAS-CoV-2 n’ont pas été bien établis chez les enfants. Nous avons voulu décrire les hospitalisations pédiatriques associées au SRAS-CoV-2 au Canada et identifier les facteurs de risque de maladie grave.

Méthodes:

Nous avons procédé à une étude prospective nationale en utilisant l’infrastructure du Programme canadien de surveillance pédiatrique (PCSP). Les hospitalisations d’enfants ayant contracté une infection par le SRAS-CoV-2 confirmée en laboratoire de microbiologie ont été rapportées du 8 avril au 31 décembre 2020 au moyen de questionnaires hebdomadaires en ligne distribués au réseau du PCSP, qui compte plus de 2800 pédiatres. Nous avons catégorisé les hospitalisations comme suit : liées à la COVID-19, infections découvertes fortuitement, ou hospitalisations pour des raisons sociales ou de contrôle des infections, et dégagé les facteurs de risque associés à la gravité de la maladie chez les patients hospitalisés.

Résultats:

Sur les 264 hospitalisations d’enfants ayant contracté le SRAS-CoV-2 au cours de la période de l’étude de 9 mois, 150 (56,8 %) ont été associées à la COVID-19 et 100 (37,9 %) étaient des cas découverts fortuitement (admission pour d’autres raisons et découverte fortuite du SRAS-CoV-2 par dépistage positif). Les nourrissons (37,3 %) et les adolescents (29,6 %) représentaient la majorité des cas. Parmi les hospitalisations liées à la COVID-19, 52 patients (34,7 %) étaient atteints d’une forme grave de la maladie, dont 42 (28,0 % des cas liés à la COVID-19) ont eu besoin d’une forme d’assistance respiratoire ou hémodynamique, et 59 (39,3 %) présentaient au moins 1 comorbidité sous-jacente. Les enfants atteints d’obésité, de maladies neurologiques chroniques ou de maladies pulmonaires chroniques, à l’exclusion de l’asthme, étaient plus susceptibles de présenter une forme grave ou critique de la COVID-19.

Interprétation:

Parmi les enfants hospitalisés au Canada chez lesquels on a diagnostiqué une infection par le SRAS-CoV-2 au début de la pandémie de COVID-19, la découverte fortuite du SRAS-CoV-2 a été fréquente. Chez les enfants hospitalisés pour une COVID-19 aiguë, l’obésité et les comorbidités neurologiques et respiratoires ont été associées à une gravité accrue.

Characteristics of children admitted to hospital with acute SARS-CoV-2 infection in Canada in 2020

Background:

Risk factors for severe outcomes of SARS-CoV-2 infection are not well established in children. We sought to describe pediatric hospital admissions associated with SARS-CoV-2 infection in Canada and identify risk factors for more severe disease.

Methods:

We conducted a national prospective study using the infrastructure of the Canadian Paediatric Surveillance Program (CPSP). Cases involving children who were admitted to hospital with microbiologically confirmed SARS-CoV-2 infection were reported from Apr. 8 to Dec. 31 2020, through weekly online questionnaires distributed to the CPSP network of more than 2800 pediatricians. We categorized hospital admissions as related to COVID-19, incidental, or for social or infection control reasons and determined risk factors for disease severity in hospital.

Results:

Among 264 hospital admissions involving children with SARS-CoV-2 infection during the 9-month study period, 150 (56.8%) admissions were related to COVID-19 and 100 (37.9%) were incidental infections (admissions for other reasons and found to be positive for SARS-CoV-2 on screening). Infants (37.3%) and adolescents (29.6%) represented most cases. Among hospital admissions related to COVID-19, 52 (34.7%) had critical disease, 42 (28.0%) of whom required any form of respiratory or hemodynamic support, and 59 (39.3%) had at least 1 underlying comorbidity. Children with obesity, chronic neurologic conditions or chronic lung disease other than asthma were more likely to have severe or critical COVID-19.

Interpretation:

Among children who were admitted to hospital with SARS-CoV-2 infection in Canada during the early COVID-19 pandemic period, incidental SARS-CoV-2 infection was common. In children admitted with acute COVID-19, obesity and neurologic and respiratory comorbidities were associated with more severe disease.

Exploring the approaches of non-Indigenous researchers to Indigenous research: a qualitative study

BACKGROUND

Given the history of unethical research in Indigenous communities, there is often apprehension among Indigenous communities toward research carried out by non-Indigenous researchers. We examined the approaches, experiences and motivations among non-Indigenous researchers at a research-intensive Canadian university conducting research with Indigenous communities to understand approaches to ethical research with Indigenous peoples.

METHODS

We performed a critical constructivist qualitative study incorporating decolonizing methodologies. We conducted semistructured interviews with 8 non-Indigenous University of Toronto researchers with a research focus/interest related to Indigenous health between August and October 2017. The interviews were transcribed and thematically analyzed through an iterative process. Shared experiences among the researchers were arranged into primary themes.

RESULTS

We identified 4 primary themes related to the conduct of Indigenous research by non-Indigenous researchers: 1) relationships with communities are foundational to the research process, 2) non-Indigenous researchers experience a personal self-reflective journey grounded in reconciliation, allyship and privilege, 3) accepted knowledge frameworks in Indigenous research are familiar to most but are inconsistently applied and 4) institutions act as barriers to and facilitators of ethical conduct of Indigenous research. Four core principles - relationships, trust, humility and accountability - unified the primary themes.

INTERPRETATION

We identified strengths and areas for improvement of current policies and practices in Indigenous research by non-Indigenous researchers. Although non-Indigenous researchers value relationships, and their research is informed by Indigenous knowledge, institutional barriers to implementing recommended elements exist, and certain policy statements such as the Tri-Council Policy Statement 2 lack applicability to secondary data analysis for some non-Indigenous researchers.

Final Results of National Surveillance of Childhood Tuberculosis in Canada: 2013–2016

BACKGROUND

There is little detailed epidemiologic and clinical data about tuberculosis (TB) disease in children in Canada.

OBJECTIVES

This study characterizes the epidemiologic, clinical, and treatment data for all cases of TB in children under age 15 in Canada surveyed through the Canadian Paediatric Surveillance Program’s (CPSP) Childhood Tuberculosis Study from October 2013 to September 2016.

DESIGN/METHODS

New active TB cases were identified through a monthly form sent by the CPSP to approximately 2500 active paediatricians, paediatric subspecialists, and select non-paediatricians who manage childhood TB. For cases meeting inclusion criteria, a detailed questionnaire was sent to the treating physician to collect clinical, epidemiological, and treatment data, followed by 6-month follow-up surveys until 6 months after treatment completion. Cases were reviewed by at least one TB specialist for inclusion and classification of disease.

RESULTS

Of 285 unique incident cases reported, 188 cases met inclusion criteria, returned a detailed questionnaire, and were classified. Selected demographic data are shown in Table 1.

92% of cases had intrathoracic involvement (N=172, 91%), but a minority were confirmed by culture or nucleic acid amplification (62/172, 36%). The most common sites of intrathoracic involvement were lymph nodes (N=118, 69%) and lungs (N=54, 31%). There were 143 attempted respiratory microbiological studies, with 32 (22%) yielding a positive culture or NAAT in sputum and 33 (23%) in gastric aspirate. Highest yield was in the 10+ age group with 54% (20/37) positivity.

31 cases of extrathoracic TB were recorded, with 19/35 (54%) having simultaneous intrathoracic TB. The most common forms of extrathoracic TB included CNS or meningeal disease (N=13) and extrathoracic lymphadenopathy (N=11). Miliary or disemminated disease (2 or more non-continguous sites involved) was found in 15 cases (8%).

16 cases reported at least one adverse drug reactions, with pyrazinamide (N=10) and isoniazid (N=5) being most common. 4 children were hospitalized and the most common ADR was hepatotoxicity. There was one case of multi-drug resistant TB.

CONCLUSION

This study suggests a high incidence of TB in Inuit and First Nations children, as well as a higher proportion of extrathoracic TB and greater success in culture positivity in children aged 10+. It also shows a significant number of adverse drug reactions to anti-TB treatment. Further analysis of this data will serve to refine practice in monitoring, detecting, and treating this infection.

Midpoint Results of National Surveillance of Childhood Tuberculosis

BACKGROUND: There is little detailed epidemiologic and clinical data about tuberculosis (TB) disease in children in Canada.

OBJECTIVES: To characterize the epidemiologic, clinical, and treatment data for all cases of TB in children under age 15 in Canada through the Canadian Pediatric Surveillance Program’s (CPSP) Childhood Tuberculosis Study. The initial results of the 3 year study presented here includes cases from September 2013 to October 2015.

DESIGN/METHODS: TB cases were identified through a monthly form sent by the CPSP to approximately 2500 active pediatricians, pediatric subspecialists, and select non-pediatricians who manage childhood TB. For cases meeting inclusion criteria, a detailed questionnaire was sent to collect clinical, epidemiological, and treatment data, followed by 6-month follow-up surveys until 6 months after treatment completion.

RESULTS: Of 164 unique incident cases reported, 84 met inclusion criteria and returned a detailed questionnaire. Selected demographic data is shown here:

vanD and vanG-like gene clusters in a Ruminococcus species isolated from human bowel flora

A vancomycin-resistant, anaerobic, gram-positive coccus containing the vanD and vanG-like genes (strain CCRI-16110) was isolated from a human fecal specimen during a hospital surveillance program to detect carriers of vancomycin-resistant enterococci. Comparison of the 16S rRNA gene sequence of strain CCRI-16110 with databases revealed a potentially novel Ruminococcus species that was most similar (<94% identity) to Clostridium and Ruminococcus species. Strain CCRI-16110 was highly resistant to vancomycin and teicoplanin (MICs of >256 microg/ml). The complete DNA sequence of the vanD cluster was most similar (98.2% identity) to that of Enterococcus faecium BM4339, containing the vanD1 allele. An intD gene with 99% identity with that of this E. faecium strain was found to be associated with the vanD gene cluster of this novel anaerobic bacterium. Strain CCRI-16110 also harbors genes encoding putative VanS(G), VanG, and VanT(G) proteins displaying 56, 73.6, and 55% amino acid sequence identity, respectively, compared to the corresponding proteins encoded by the vanG1 and vanG2 operons of Enterococcus faecalis BM4518 and N03-0233. This study reports for the first time an anaerobic bacterium containing the vanD gene cluster. This strain also harbors a partial vanG-like gene cluster. The presence of vanD- and vanG-containing anaerobic bacteria in the human bowel flora suggests that these bacteria may serve as a reservoir for the vanD and vanG vancomycin resistance genes.

High prevalence of glycopeptide resistance genes vanB, vanD, and vanG not associated with enterococci in human fecal flora

The presence of Enterococcus-associated vancomycin resistance genes vanA, vanB, vanD, vanE, and vanG in rectal swabs was investigated in two hospitals using PCR. All vanA genes detected were associated with vancomycin-resistant enterococci (VRE), whereas VRE-associated vanB genes were detected in only one hospital (4.7%). However, in both hospitals, high prevalences of vanB (6.2 and 2.3%), vanD (43.8 and 26.7%), and vanG (10.5 and 6.9%) genes not associated with enterococci were found.

Characterization of a Tn5382-like transposon containing the vanB2 gene cluster in a Clostridium strain isolated from human faeces

OBJECTIVES

During a hospital surveillance programme to detect VRE carriers, an anaerobic vancomycin-resistant bacterial strain CCRI-9842 containing a vanB gene was isolated from a human faecal specimen. In this study, we have characterized this strain and its vanB-containing element.

METHODS

Strain CCRI-9842 was characterized by 16S rDNA sequencing and susceptibility testing. PCR mapping and sequencing of the vanB-containing element, as well as plasmid extraction and mating experiments, were carried out to investigate the genetic basis of vancomycin resistance in this strain.

RESULTS

Strain CCRI-9842 was identified as a Clostridium species closely related to Clostridium bolteae (96.8% 16S rDNA identity). This strain was resistant to a high level of vancomycin (MIC of 256 mg/L), but was susceptible to teicoplanin and ampicillin. The complete sequence of the CCRI-9842 vanB gene exhibited 99.1% identity with that of vanB2. PCR mapping and sequencing showed that the genetic element carrying vanB2 was similar to transposon Tn5382/Tn1549. This Tn5382-like transposon forms circular intermediates and is flanked on the left and right ends by repeat sequences of at least 700 bp in the opposite direction. No plasmid was detected in this strain, suggesting that the Tn5382-like transposon was integrated into the chromosome. The vancomycin resistance was not transferable to enterococci.

CONCLUSIONS

Our report shows for the first time the presence of a Tn5382-like transposon carrying vanB2 in a Clostridium species of the human intestinal flora. This suggests that the vanB2 Tn5382-like transposon is an important vector for the spread of vancomycin resistance in several bacterial species.

New real-time PCR assay for rapid detection of methicillin-resistant Staphylococcus aureus directly from specimens containing a mixture of staphylococci

Molecular methods for the rapid identification of methicillin-resistant Staphylococcus aureus (MRSA) are generally based on the detection of an S. aureus-specific gene target and the mecA gene. However, such methods cannot be applied for the direct detection of MRSA from nonsterile specimens such as nasal samples without the previous isolation, capture, or enrichment of MRSA because these samples often contain both coagulase-negative staphylococci (CoNS) and S. aureus, either of which can carry mecA. In this study, we describe a real-time multiplex PCR assay which allows the detection of MRSA directly from clinical specimens containing a mixture of staphylococci in <1 h. Five primers specific to the different staphylococcal cassette chromosome mec (SCCmec) right extremity sequences, including three new sequences, were used in combination with a primer and three molecular beacon probes specific to the S. aureus chromosomal orfX gene sequences located to the right of the SCCmec integration site. Of the 1,657 MRSA isolates tested, 1,636 (98.7%) were detected with the PCR assay, whereas 26 of 569 (4.6%) methicillin-susceptible S. aureus (MSSA) strains were misidentified as MRSA. None of the 62 nonstaphylococcal bacterial species or the 212 methicillin-resistant or 74 methicillin-susceptible CoNS strains (MRCoNS and MSCoNS, respectively) were detected by the assay. The amplification of MRSA was not inhibited in the presence of high copy numbers of MSSA, MRCoNS, or MSCoNS. The analytical sensitivity of the PCR assay, as evaluated with MRSA-negative nasal specimens containing a mixture of MSSA, MRCoNS, and MSCoNS spiked with MRSA, was approximately 25 CFU per nasal sample. This real-time PCR assay represents a rapid and powerful method which can be used for the detection of MRSA directly from specimens containing a mixture of staphylococci.

[Myocardial infarction with normal or near normal coronary arteries: late outcome of seven patients]

Myocardial infarction with normal or near normal coronary arteries: Late outcome of seven patients Myocardial infarction with normal or near normal coronary arteries probably results from thrombotic occlusion that is followed by lysis and recanalization; in about a third of affected patients, coronary spasm appears to be the trigger. The clinical profile of this syndrome is well known: patients are young and without coronary risk factors except cigarette smoking, and they have no angina before or after their infarction. However, the late prognosis remains controversial. Between December 1976 and April 1984, myocardial infarction with normal or near normal coronary arteries was diagnosed in seven patients who were subsequently followed for a mean of 19 years. Observations during this follow-up show that the majority of patients experienced one or more recurrences that, in three cases, initiated the development of a severe ischemic cardiomyopathy.

Nongaussian distribution curve of heterophorias among children

The purpose of this study was to measure the distribution curve of horizontal and vertical phorias among children. Kolmogorov-Smirnov goodness of fit tests showed that these distribution curves were not Gaussian among (N = 2048) 6- to 13-year-old children. The distribution curve of horizontal phoria at far and of vertical phorias at far and at near were leptokurtic; the distribution curve of horizontal phoria at near was platykurtic. No variation of the distribution curve of heterophorias with age was observed. Comparisons of any individual findings with the general distribution curve should take the nonGaussian distribution curve of heterophorias into account.

[Recurrent infarction without coronary atheromatosis]

Acute myocardial infarction without obstructive atherosclerosis is a well known entity characterized by the young age of the patients, the low incidence of risk factors and the absence of pre- and post infarction angina. The myocardial necrosis is probably caused by a thrombotic phenomenon perhaps initiated and/or exacerbated by a coronary spasm. It is generally thought that recurrence is rare and long term prognosis relatively benign but this may be a misconception. Three cases are reported of patients who had a second myocardial infarction, transmural infarction in each case, 17 to 36 months after the initial event. Prophylactic treatment after the second accident seems undoubtedly indicated. Until large randomized trials have established the best treatment, it appears logical to prescribe antithrombotic drugs (antiplatelet or anticoagulant drugs) with, perhaps, coronary spasmolytic drugs like calcium antagonists.

Reliability and validity of the dot visual acuity test

The reliability of the dot visual acuity test (DVAT) was demonstrated using the test-retest method. The test, however, was not found to be valid when comparing it with the Sjögren test. Since the DVAT has previously been shown to be valid when compared to the Tumble E test, these results bring into question the validity of the Sjögren test when compared to the Tumble E test.