A survey on vital signs monitoring based on Wi-Fi CSI data.

The COVID-19 pandemic further highlighted the need to use low-cost remote monitoring procedures for medical patients. Since the results reported in the literature have shown that the use of Channel State Information (CSI) from Wi-Fi networks to remotely monitor patients can provide means to obtain a powerful medical information package in a non-invasive way and at low cost, a consistent review and analysis of the state of the art on this applied technique is developed in the present work. Initially, a mathematical overview of the CSI technology and its functional model is done. Subsequently, details about the technical approach necessary to use CSI in medical applications and a summary of the studies reported in the literature with such applications are presented. Based on the analyses and discussions carried out throughout this work, a better understanding of the current state of the art is achieved. Challenges and perspectives for future research are also highlighted.

Outbreak investigation of SARS-CoV-2 transmission in an emergency childcare centre.

OBJECTIVE: To characterize SARS-CoV-2 transmission following a COVID-19 outbreak in an emergency childcare centre (ECCC) in April 2020 in Quebec, Canada. METHODS: The study population consisted of all the children and employees who attended the ECCC as well as household contacts of the confirmed COVID-19 cases. Of the 120 individuals in the study, five cases were confirmed by epidemiological link and 25 were identified as COVID-19 by RT-PCR among which 19 were analyzed by viral whole genome sequencing. Descriptive epidemiology, social network visualization, and phylogenetic analysis were used to characterize viral transmission. RESULTS: Phylogenetic analysis identified two separate introductions of distinct lineages of SARS-CoV-2 and estimated an average effective reproductive number of Re = 1.9 (range 0.9-4.9) with a mean doubling time of 3.2 days (range 2.1-5.2). The first and most prevalent lineage was introduced by two asymptomatic children who were likely infected by their parent, a confirmed COVID-19 case working in a long-term care centre. Among infected household adults, attack rates were significantly higher in mothers than in fathers (risk ratio = 4.5; 95% CI 1.1-18.7). The extent of transmission makes it one of the largest documented outbreaks in a daycare in Canada. CONCLUSION: The analyses carried out showed the probable origin and direction of the transmission of the infection (adult-child, child-adult, and child-child), thus highlighting how asymptomatic children can efficiently transmit SARS-CoV-2.

RéSUMé: OBJECTIF: Caractériser la transmission du SRAS-CoV-2 à la suite d'une éclosion de COVID-19 dans un service de garde d'urgence en milieu scolaire (SGUMS) en avril 2020 au Québec, Canada. MéTHODES: La population à l'étude était composée de tous les enfants et employés ayant fréquenté le SGUMS ainsi que les contacts familiaux des cas confirmés de COVID-19. Sur les 120 personnes à l'étude, cinq cas ont été confirmés par lien épidémiologique et 25 par RT-PCR. Parmi ces derniers, 19 ont été analysés par séquençage viral du génome entier. La caractérisation de la transmission a été réalisée à l'aide d'analyses descriptives et phylogénétiques ainsi que de la visualisation de réseaux sociaux. RéSULTATS: L'analyse phylogénétique a identifié deux introductions de lignées distinctes du SRAS-CoV-2 et un taux de reproduction net Re = 1,9 (étendue 0,9­4,9) avec un temps moyen de doublement de 3,2 jours (étendue 2,1­5,2). La première lignée, et la plus répandue, a été introduite par deux enfants asymptomatiques qui ont probablement été infectés par leur parent, un travailleur de la santé atteint de COVID-19. Dans les noyaux familiaux, les taux d'attaque étaient significativement plus élevés chez les mères que chez les pères (rapport de risque = 4,5 ; IC à 95 % 1,1­18,7). L'ampleur de la transmission en fait de celle-ci la plus importante éclosion documentée dans un service de garde au Canada. CONCLUSION: Cette étude a permis de déterminer l'origine et la direction probables de la transmission de l'infection (adulte-enfant, enfant-adulte et enfant-enfant) et démontrer que les enfants asymptomatiques peuvent transmettre le SRAS-CoV-2.

Waterborne outbreaks: a public health concern for rural municipalities with unchlorinated drinking water distribution systems.

OBJECTIVES: The objective of this study is to describe an important waterborne outbreak of gastrointestinal illness observed in a rural municipality of Quebec. METHODS: A population-based retrospective cohort study was conducted to identify risk factors associated with acute gastroenteritis. Indirect surveillance data were used to estimate the extent and the resolution of the epidemic. RESULTS: The cohort consisted of 140 randomly selected individuals of whom 22 met the illness case definition (15.7% attack rate). The epidemic curve was similar to the evolution of antidiarrheal products sold by the only pharmacy in town and calls made to the Health Info Line. Bivariate analysis led to identifying five risk factors of gastrointestinal illness: consumption of municipal water, contact with someone with acute gastroenteritis (within and outside of the household), contact with a child in daycare, and being less than 35 years of age. Drinking municipal water had the highest risk ratio (RR = 24.31; 95% CI = 1.50-393.4). Drinking water from a private artesian well was a protective factor (RR = 0.28; 95% CI = 0.09-0.90). CONCLUSION: This study highlighted that managing the risks associated with the consumption of untreated drinking water remains an important public health challenge, particularly in small rural municipalities vulnerable to climate variability.

Indoor air quality in Montréal area day-care centres, Canada.

Indoor air quality (IAQ) has been understudied in day-care centres (DCCs), even though it can affect the respiratory health of children. This study was undertaken to assess IAQ in a randomly selected sample of 21 DCCs having space for at least 40 children in Montréal, Canada, and to determine associations between building characteristics and IAQ. Questionnaires on building characteristics and operation of the DCC were administered to managers. Temperature, relative humidity, and concentrations of carbon dioxide (CO(2)), formaldehyde and volatile organic compounds were measured in January and February 2008 in rooms attended by children aged between 18 and 60 months. Most DCCs (81%) had a mechanical ventilation system. Over 85% of the DCCs had a mean CO(2) concentration higher than 1000 ppm, the value generally targeted for comfort in buildings. Mean CO(2) concentrations were significantly lower in DCCs having a floor space meeting the provincial standards. The mean (standard deviation-SD) formaldehyde concentration was 22.9 (8.2) µg/m(3), with all participating DCCs being within Health Canada's Residential IAQ Guideline of 50 µg/m(3). The presence of a mechanical ventilation system and a large surface of play area per child were significantly associated with lower CO(2) levels, explaining 44% of the variance in indoor CO(2) concentrations. The presence of a mechanical ventilation system was also associated with significantly lower formaldehyde and acetaldehyde levels. Moreover, 68% of the variance in indoor acetaldehyde concentrations was explained by CO(2) levels, indicating that CO(2) was a better proxy of ventilation than the presence of a ventilation system, as this latter variable did not imply that the ventilation system was running or functioning adequately. These results demonstrate the need for on-going efforts to ensure sufficient floor space and adequate ventilation in DCCs to maintain good IAQ.

[The practice and acceptance of physician preventive medicine services in a Montreal university hospital and the obstacles that deter their implementation.]. / Pratiques cliniques préventives et besoins pour leur intégration chez des médecins d'un centre hospitalier universitaire a Montréal.

OBJECTIVES: Present a picture of physicians' preventive clinical practices (PCP) at a university medical centre, and identify the obstacles that hinder their implementation. METHOD: Self-administered questionnaire survey addressed to 367 general practitioners and specialists working at the Centre hospitalier de l'Université de Montréal (CHUM) in 2006. RESULTS: Respondents claim to be recommending PCP (often or very often) in approximately 60-82% of cases. Women physicians report a larger integration for screening and vaccination (p < 0.05). General physicians claim to apply or recommend PCP more frequently than specialists (p < 0.05), except for anti-tobacco counseling. Lack of time (82%) and deficiencies in continuity of treatment (75%) are considered by the majority of respondents as major obstacles to the realization of PCP. Most participants (99%) consider delivering preventive services to be part of their role and 98% claim to be motivated to integrate PCP into their practice. However, almost half of physicians do not apply preventive recommendations to their own life and at least two thirds of them doubt the efficacy of counseling. CONCLUSION: Despite observed encouraging results, actions must be taken to improve the integration of PCP to general and specialized health care and to bring physicians around to adopting healthy lifestyle habits themselves.

Determinants of intention to use condoms among clients of female sex workers in Haiti.

A cross-sectional survey was conducted to examine factors influencing intention of condom use among 378 clients of female sex workers (FSWs) visiting commercial sex sites in St-Marc and Gonaives, Haiti. Mean age of the study participants was 24 years. A structured questionnaire was used to collect data on socio-demographic characteristics, behaviors, and the theory of planned behavior (TPB) constructs. Seventy-four percentage of clients reported having used condoms with a FSW the last time they had had sexual intercourse. The majority (81.7%) firmly intended to use condoms during the next sexual encounter with a FSW. Multivariate logistic models revealed that subjective norms (odds ratio (OR)=1.75; 95% confidence interval (CI): 1.06-2.88), perceived behavioral control (OR=1.34; 95% CI: 1.09-1.63) and attitudes (OR=1.23; 95% CI: 1.04-1.44) were predictors of intention to use condoms, with norms being more important. Clients having used condoms the last time they had a sexual intercourse with a FSW, were more likely to have the intention to use them in the future (OR=3.17; 95% CI: 1.65-6.10), indicating an adopted behavior. Lastly, having had a previous sexually transmitted infection was associated with intention, suggesting that a negative experience can influence a future behavior. In conclusion, intention to use condoms among the clients of Haitian FSWs was well predicted by TPB constructs. Our findings provide evidence for designing interventions targeted at reducing risky sex behaviors in this population.

Clients of female sex workers in Gonaives and St-Marc, Haiti characteristics, sexually transmitted infection prevalence and risk factors.

BACKGROUND: Few data exist on the role of clients of female sex workers (FSWs) in STI transmission. This study examined sociodemographic characteristics, risk behaviors, and STI prevalence among clients of FSWs in Haiti. METHODS: A cross-sectional survey among clients of FWSs (n = 378). Clients were recruited by collaborating local FSWs directly on commercial sex sites. Dried blood spot samples were used to determine prevalence of HIV, syphilis, and herpes simplex virus 2 (HSV-2). RESULTS: Of the respondents, 88% were younger than 30 years, and 60.7% were living with a partner. Fifty-nine percent of clients reported always using condoms with FSWs, 32.8% did so with their stable partners, and 44.9% with casual partners. Clients had a high number of partners; 39.9% had 10 or more within the previous 3 months. The prevalence of HIV-1, previous or active syphilis, and HSV-2 was 7.2%, 13.4%, and 22%, respectively. Multivariate analysis indicated that clients who had tried marijuana, were practicing Voodoo, had a history of STI or were infected with HSV-2 were more often HIV-positive. Living in Gonaives, not being Protestant, being employed, and having tried marijuana were associated with syphilis infection. Older clients, residents of Gonaives and Voodoo practitioners were more likely to be infected with HSV-2. CONCLUSION: STI prevalence was remarkably high among clients of FSWs. These men had many sex partners and condom use differed, depending on the category of partner. Clients of FSWs likely act as a bridge population, facilitating the spread of STI throughout the general population in Haiti, and should be targeted in prevention programs.

A double-blind randomized controlled trial of antenatal mebendazole to reduce low birthweight in a hookworm-endemic area of Peru.

OBJECTIVE: To assess the effect on birthweight of antenatal mebendazole plus iron vs. placebo plus iron in a highly hookworm-endemic area. METHODS: Double-blind, randomized controlled trial set in rural and peri-urban communities in the Peruvian Amazon region. A total of 1042 second trimester pregnant women between the ages of 18 and 44 years were recruited from April to November 2003, and followed to July 2004. Women were randomly assigned to receive either mebendazole (500 mg single dose) plus iron supplements (60 mg elemental iron daily) or placebo plus iron supplements. The primary outcome was mean infant birthweight and secondary measures included proportion of low birthweight babies and maternal anaemia. RESULTS: The prevalence of hookworm infection was 47.5%. There were no differences between intervention groups in mean birthweight (3104 g vs. 3090 g, P = 0.629), proportion of low birthweight (<2500 g; 8.1%vs. 8.7%, P = 0.755) or maternal anaemia in the third trimester [33.0% (158/479) vs. 32.3% (152/471), P = 0.815]. However, the proportion of very low birthweight (<1500 g) was significantly lower in the mebendazole group [0% (0/479) vs. 1.5% (7/471), P = 0.007]. CONCLUSIONS: This trial provides additional evidence for the use of anthelmintics, over and above iron supplementation, within antenatal care programmes in hookworm-endemic areas. Benefits of de-worming may be higher in countries not having an antenatal iron supplementation programme or where intensity of hookworm infections is higher.

Cytomegalovirus as an occupational risk in daycare educators.

BACKGROUND: Cytomegalovirus (CMV) infection continues to be an important occupational risk in the daycare setting. A comprehensive update of scientific evidence is timely to inform and promote appropriate preventive measures. METHODS: A review of the literature was conducted to examine the evidence for an occupational risk of CMV infection in daycare educators. Sources included Medline, government documents and additional references from published bibliographies. The key words used for searches were 'child day care centres' or 'nurseries' and 'cytomegalovirus' or 'cytomegalovirus infection'. RESULTS: EIGHT CMV SEROPREVALENCE STUDIES ON DAYCARE EDUCATORS IN INDUSTRIALIZED COUNTRIES WERE FOUND: four in the United States, three in Canada and one in Italy. Risk factors for seropositivity were older age, nonwhite race, foreign birth, birth in a low- or middle-income country, diaper changing, having children at home, and a child to educator ratio greater than 6:1 in children 18 to 35 months of age. Risk factors for seroconversion were younger age and working with young children. These studies suggest that daycare centres may be a high-risk setting for CMV infection. DISCUSSION: Recommendations to prevent CMV infection in this setting include handwashing, selective serological screening, avoiding work with younger children if pregnant and, in some cases, preventive leave from work. Evaluation and expert opinion of the effectiveness of various preventive options for CMV acquisition are needed to ensure that recommendations are evidence-based.

Risk factors for cytomegalovirus seropositivity in a population of day care educators in Montréal, Canada.

BACKGROUND: Horizontal transmission of cytomegalovirus (CMV) is common in the day care setting. Day care educators appear to be at a high risk of infection; however, studies are limited. AIMS: To determine the proportion of CMV-seropositive female educators in the day care setting and to identify associated risk factors. METHODS: Educator- and day care-level risk factors for CMV seropositivity were obtained by questionnaires from day care educators and directors, respectively. Sera were collected from educators and analyzed by enzyme-linked immunosorbent assay. Significant independent risk factors for CMV seropositivity were determined using a multivariable logistic regression model which was fitted using the generalized estimating equation method. RESULTS: CMV seroprevalence in 473 female educators from 81 day care centers in Montréal, Canada, was 57%. Significant risk factors for CMV seropositivity were (i) increasing age (OR5-yr = 1.19; 95% CI = 1.05-1.35), (ii) low-income country of birth (OR = 10.23; 95% CI = 2.64-39.50) or middle-income country of birth (OR = 4.99; 95% CI = 2.39-10.40), (iii) having > or =2 children of their own (OR = 1.98; 95% CI = 1.19-3.31) and (iv) child-to-educator ratio >6 (18-35 months old) in a day care center (OR = 1.87; 95% CI = 1.25-2.81). CONCLUSIONS: Day care educators have risks for CMV infection related to their work in the day care setting, as well as personal risk factors. A review of current guidelines for the prevention of CMV infection in day care is needed to ensure that recommendations are evidence based.

High rubella seronegativity in daycare educators.

BACKGROUND: Congenital rubella syndrome, which is associated with severe malformations, can result from infants exposed in utero to maternal rubella infection. Health care workers and school-based educators are targeted for immunization, but evidence is scarce on rubella seronegativity in daycare centre educators who appear to be a high-risk occupational group. The purpose of the study was to generate new evidence on the magnitude of rubella seronegativity and associated risk factors in daycare centre educators. METHODS: Sera and questionnaires were collected between October and December 2001 from 481 female educators working in 81 daycare centres in Montréal, Québec. Rubella IgG serology was performed using ELISA. RESULTS: An overall seronegativity of 10.2% was found. The positive predictive value of previous rubella vaccination with seropositivity was high (92.1%). Ninety-one percent of the women were of childbearing age (= 49 years). Only 1.3% (n = 6) were currently pregnant, none of whom were seronegative. Significant predictors of seronegativity for educator- and daycare-level variables included lack of previous rubella vaccination (OR = 3.60; 95% CI: 1.43, 9.01), not having own children (OR = 3.76; 95% CI: 1.67, 8.55), age per 5-year increment (OR = 0.81; 95% CI: 0.66, 0.99), and increased number of colds in educators in the daycare centre in the last two weeks (OR = 1.15; 95% CI: 1.01, 1.31). INTERPRETATION: The high proportion of seronegativity, in addition to the potential increased transmission in daycare centres emphasize the need for a review of the rubella vaccination recommendations and health promotion interventions targeted to this occupational group.

Hepatitis A seroprevalence and risk factors among day-care educators.

BACKGROUND: Day-care centres play a role in the epidemiology of hepatitis A virus (HAV). Up-to-date documentation on its seroprevalence and potential risk factors among day-care educators, who may be at risk for significant HAV morbidity, is nevertheless lacking. The availability of a hepatitis A vaccine provides an additional opportunity for prevention in this population. To determine the seroprevalence of previous HAV infection among day-care educators and to identify potential risk factors, we undertook a survey. METHODS: Of 167 randomly selected centres, 81 centres participated. Directors and educators completed questionnaires on risk factors. Sera were collected during on-site visits from October through December 2001. RESULTS: Seroprevalence of previous HAV infection in 492 participating educators was 35.6%. Significant risk factors in multivariate analysis included birth in a high-versus moderate/low-income country (odds ratio [OR] 20.8; 95% confidence interval [CI] 9.4-46.0); self-reported HAV vaccination (OR 6.1, CI 2.9-13.0); travel to endemic areas (OR 2.4, CI 1.3-4.2); and age (5-yr OR 1.5, CI 1.3-1.7). When Canadian-born educators were analyzed separately, an association was found between seropositivity and the number of years worked in daycare centres (5-yr OR 1.3, CI 1.0-1.8). INTERPRETATION: This represents the first study in Canada designed to examine risk factors for previous HAV infection among adult day-care educators. As a group, their risk factors for seropositivity are similar to those in the general population. However, educators born in Canada (a low-endemicity area for hepatitis A) appear to be at additional risk by working in day-care centres. The benefits of HAV screening and routine vaccination of day-care educators need to be examined.

Perception and knowledge about some infectious diseases among travelers from Québec, Canada.

BACKGROUND: Many travelers from Québec visit tourist destinations, thereby becoming at risk of infectious diseases. Within a study of predictors of utilization of travel health consultation by travelers, knowledge about transmission and perception of risk and severity of some infectious diseases was measured. METHODS: A cross-sectional survey was conducted during winter 1999 on travelers 16 years of age and over going to Mexico and the Dominican Republic. A 34-item self-administered bilingual questionnaire was distributed to travelers during seven flights departing from Montréal Airport. RESULTS: The questionnaires were completed by 1,724 passengers (response rate: 75%). The majority (81%) of the 1,416 travelers from the province of Québec considered themselves at greater risk of diarrhea abroad. Risk perception was less important for hepatitis A and B (44% and 41%, respectively). Most travelers considered diarrhea as slightly or not severe, and hepatitis as severe illnesses. A majority had adequate knowledge about transmission of diarrhea but knowledge concerning hepatitis was less accurate. In the multivariate analysis, the most important associations were noted between perception of risk of diarrhea and knowledge about transmission of diarrhea (odds ratio [OR] 3.2); and between perception of risk of hepatitis and perception of severity of hepatitis (hepatitis A: OR 3.9; hepatitis B: OR 5.9). Consultation in a travel clinic before departure was associated with perception of higher risk of hepatitis A and of infectious diseases in general (OR 2.1). CONCLUSION: Despite its limitations, this study indicates that travelers from Québec, going to sun destinations, seem to underestimate their risk of hepatitis related to travel. Knowledge about transmission of hepatitis seems poor. Education of travelers about risks and modes of transmission of infectious diseases should be reinforced. Travel health consultation before departure or for a previous trip appeared to be associated with higher risk perception.