scholarly journals Secondary Attack Rate among Non-Spousal Household Contacts of Coronavirus Disease 2019 in Tsuchiura, Japan, August 2020–February 2021

2021 ◽  
Vol 18 (17) ◽  
pp. 8921
Author(s):  
Tsuyoshi Ogata ◽  
Fujiko Irie ◽  
Eiko Ogawa ◽  
Shifuko Ujiie ◽  
Aina Seki ◽  
...  
Keyword(s):  
Risk Factors ◽  
Attack Rate ◽  
Transmission Rate ◽  
Diagnostic Delay ◽  
Household Size ◽  
Household Contacts ◽  
Size Number ◽  
Mixed Regression ◽  
Household Members ◽  
Linear Mixed Regression Model

Household secondary attack rate (HSAR) by risk factor might have a higher transmission rate between spouses. We investigated risk factors for the HSAR among non-spousal household contacts of patients with coronavirus disease 2019 (COVID-19). We studied household contacts of index cases of COVID-19 in Tsuchiura, Japan, from August 2020 through February 2021. The HSARs of the whole household contacts and non-spousal household contacts were calculated and compared across risk factors. We used a generalized linear mixed regression model for multivariate analysis. We enrolled 496 household contacts of 236 index COVID-19 cases. The HSAR was higher for spousal household contacts (37.8%) than for other contacts (21.2%). The HSAR was lower for non-spousal household contacts with a household size (number of household members) of two (18.2%), compared to the HSAR for contacts with a household size ≥4. The HSAR was higher for non-spousal household contacts of index patients with ≥3 days of diagnostic delay (period between onset and diagnosis) (26.0%) compared to those with ≤2 days’ delay (12.5%) (p = 0.033). Among non-spousal household contacts, the HSAR was low for those with a household size of two and was high for contacts of index patients with a long diagnostic delay.

scholarly journals Characteristics of Household Transmission of COVID-19

2020 ◽  
Vol 71 (8) ◽  
pp. 1943-1946 ◽  
Author(s):  
Wei Li ◽  
Bo Zhang ◽  
Jianhua Lu ◽  
Shihua Liu ◽  
Zhiqiang Chang ◽  
...  
Keyword(s):  
Risk Factors ◽  
Attack Rate ◽  
Rt Pcr ◽  
Spousal Relationship ◽  
Telephone Interviews ◽  
Household Contacts ◽  
Household Transmission ◽  
Household Members ◽  
Baseline Characteristics ◽  
Index Cases

Abstract Background Since December 2019, SARS-CoV-2 has extended to most parts of China with >80 000 cases and to at least 100 countries with >60 000 international cases as of 15 March 2020. Here we used a household cohort study to determine the features of household transmission of COVID-19. Methods A total of 105 index patients and 392 household contacts were enrolled. Both index patients and household members were tested by SARS-CoV-2 RT-PCR. Information on all recruited individuals was extracted from medical records and confirmed or supplemented by telephone interviews. The baseline characteristics of index cases and contact patients were described. Secondary attack rates of SARS-CoV-2 to contact members were computed and the risk factors for transmission within the household were estimated. Results Secondary transmission of SARS-CoV-2 developed in 64 of 392 household contacts (16.3%). The secondary attack rate to children was 4% compared with 17.1% for adults. The secondary attack rate to the contacts within the households with index patients quarantined by themselves since onset of symptoms was 0% compared with 16.9% for contacts without quarantined index patients. The secondary attack rate to contacts who were spouses of index cases was 27.8% compared with 17.3% for other adult members in the households. Conclusions The secondary attack rate of SARS-CoV-2 in household is 16.3%. Age of household contacts and spousal relationship to the index case are risk factors for transmission of SARS-CoV-2 within a household. Quarantine of index patients at home since onset of symptoms is useful to prevent the transmission of SARS-Co-2 within a household.

scholarly journals Transmission and serotype features of hand foot mouth disease in household contacts in Dong Thap, Vietnam

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Cuong Quoc Hoang ◽  
Thao Thanh Thi Nguyen ◽  
Nguyen Xuan Ho ◽  
Hai Duc Nguyen ◽  
An Binh Nguyen ◽  
...  
Keyword(s):  
Attack Rate ◽  
Neutralizing Antibodies ◽  
Index Case ◽  
Fold Increase ◽  
Mouth Disease ◽  
Rt Pcr ◽  
Household Contacts ◽  
Two Samples ◽  
Household Members ◽  
Index Cases

Abstract Background Hand, foot and mouth disease (HFMD) has emerged as a major public health issue in Vietnam since 2003. We aimed to investigate the household transmission of HFMD and its causative viruses from 150 households in a high incidence province in Vietnam. Methods A longitudinal study was conducted in patients presenting to the provincial hospital with a HFMD-like syndrome, along with their household members between April and August 2014 in Dong Thap Province. Each participant was followed up for 2 weeks. We enrolled 150 patients aged under 15 who were clinically diagnosed with HFMD in Dong Thap Hospital, 600 household members, and 581/600 household members completed the study. All participants were interviewed using a standard questionnaire. Throat swabs and blood samples were taken for molecular detection of viruses and assessment of neutralizing antibodies, respectively. Index cases were defined using a clinical case definition, household contact cases were defined using a similar definition applied to the 2 weeks before admission and 2 weeks after discharge of the index case. Characteristics of index cases, household contacts, the attack rate, serotype features and related factors of HFMD were reported. Result Among 150 index cases, 113 were laboratory confirmed: 90/150 were RT-PCR-positive, 101/142 had a ≥ 4-fold increase of neutralizing antibody against Enterovirus A71 (EV-A71), Coxsackievirus (CV) A6 or CV-A16 across the two samples collected. 80/150 (53%) were males, and 45/150 (30%) were under the age of 1. The predominant serotype was CV-A6, identified in 57/87 (65.5%) of the specimens. No deaths were reported. Among 581 household contacts, 148 were laboratory confirmed: 12/581 were RT-PCR-positive, 142/545 had a ≥ 4-fold increase of neutralizing antibodies against EV-A71, CV-A6 or CV-A16; 4 cases experienced HFMD in the past 4 weeks. Attack rate among household contacts was 148/581 (25.5%). In 7/12 (58%) instances, the index and secondary cases were infected with the same serotype. Having a relationship to index case was significantly associated with EV infection. Conclusion The attack rate among household contacts was relatively high (25.5%) in this study and it seems justified to also consider the household setting as an additional target for intervention programs.

scholarly journals Secondary Attack Rate (SAR) in household contacts of expired primary cases of COVID-19: A study from Western India

2020 ◽  
Author(s):  
Komal Shah ◽  
Nupur Desai ◽  
Dileep Mavalankar
Keyword(s):  
Disease Transmission ◽  
Attack Rate ◽  
Western India ◽  
Gujarat State ◽  
Household Contacts ◽  
Household Members ◽  
Government Records ◽  
New Research ◽  
Previous Pilot Study ◽  
Repeated Contact

AbstractSecondary attack rate (SAR) in household contacts of expired primary COVID-19 cases is not well studied yet. Based on our previous pilot study conducted in Gandhinagar district of Gujarat state, we developed a new research protocol to understand SAR statistics in household contacts of COVID-19 cases that died/expired. The details of expired COVID positive primary cases were obtained from Government records and the details of secondary cases were retrieved using telephonic interviews of the household members. Forty-nine expired cases were registered between March to August, 2020. Out of 49 deaths, 28 families could be reached on phone. Rest were not reachable or refused to give information. These were interviewed after taking verbal consent. The study reported 25% SAR in household contact of expired primary cases with 7.4% of mortality in secondary cases. Though this is representative data only from a single district, it was observed that 75% of the household contacts were still not infected in spite of repeated contact with the sever cases. More such studies in various regions are needed to understand disease transmission.

scholarly journals Unrestricted Social Interaction: Underappreciated Cause of COVID 19 Surge

2021 ◽  
Author(s):  
Jayendrakumar Patel ◽  
Shalin Parikh ◽  
Rakesh Patel ◽  
Shwetaben Patel ◽  
Ronak Patel ◽  
...  
Keyword(s):  
Social Interaction ◽  
Social Interactions ◽  
Attack Rate ◽  
Household Size ◽  
Age Group ◽  
Incidence Proportion ◽  
Short Time Span ◽  
Household Members ◽  
Short Time ◽  
Second Wave

Abstract India had the worst conditions during the second wave, and yet, its cause for the enormous spike of COVID-19 cases in short time span remains unexplained. We retrospectively studied the comparative secondary attack rate, incidence proportion rate and extent of unrestricted social interactions’ contribution between the first and second wave of COVID-19 to decipher what caused the second wave's enormous spike in COVID-19 cases. We found that the unrestricted social interaction accounted equally, i.e., >42% of all COVID-19 cases in the both waves. Overall secondary attack rate rose 58% in the second wave's, among which, we find increment of 2.5-fold and 88% for the age group <10 years and >50years, respectively, while it remains stable in the age group 10-50years. We find significantly higher incidence proportion rate, ~39%, in household size of two- and three members in the second wave while it was significant in household size of four or more members in the first wave. We anticipated that changes in the pattern of unrestricted social interaction amongst household members escalated the secondary attack rate and higher incidence proportion rate even in two members family size could lead to the unprecedented surge of COVID-19 cases in the second wave.

scholarly journals Variola minor in Braganca Paulista County, 1956: household aggregation of the disease and the influence of household size on the attack rate

1979 ◽  
Vol 82 (1) ◽  
pp. 1-6 ◽  
Author(s):  
Juan J. Angulo ◽  
Stephen D. Walter
Keyword(s):  
Attack Rate ◽  
Rural Households ◽  
Transmitted Disease ◽  
Household Size ◽  
Size Number

SUMMARYHousehold aggregation of cases, one possible characteristic of person-to-person transmitted disease, was formally tested in one epidemic of variola minor by using a pair statistic. A significant result was found for all households as well as for households grouped by the type of environment, or by the phase of the epidemic growth in time. Secondary attack rates, when related to household size (number of susceptibles) showed only a marginal trend in rural households but no trend in urban or semi-rural households.

scholarly journals Risk of Secondary Household Transmission of COVID-19 from Health Care Workers in a Hospital in Spain

Epidemiologia ◽  
2021 ◽  
Vol 3 (1) ◽  
pp. 1-10
Author(s):  
Miren Remón-Berrade ◽  
Sara Guillen-Aguinaga ◽  
Isabel Sarrate-Adot ◽  
Maria Pilar Garcia-Garcia ◽  
Maria del Carmen Lerga-Berruezo ◽  
...  
Keyword(s):  
Risk Factors ◽  
Health Care ◽  
Health Care Workers ◽  
Attack Rate ◽  
Index Case ◽  
Acute Infection ◽  
Transmission Risk ◽  
Household Contacts ◽  
Care Workers ◽  
Index Cases

Background: Hospital health care workers are at high risk of developing COVID-19 and transmitting the disease to their family upon returning home; the aim here is to estimate the secondary attack rate of COVID-19 in household contacts of health care workers and their transmission risk factors. Material and Methods: COVID-19 cases in the health care workers of an academic hospital in Pamplona, Spain, from 2 March to 26 May 2020, were followed up. The secondary attack rate (SAR) was estimated from cases in household contacts of index cases and their risk factors by Poisson regression. Results: 89 index cases were studied from 99 notified cases in health care workers (89.0%), excluding secondary cases or those who lived alone. Forty-six secondary cases confirmed by the laboratory were found among 326 household contacts, a secondary attack rate of 14.11% (95% CI 10.75–18.31), and 33 household contacts with acute infection symptoms without microbiologic confirmation 10.12% (95% CI 7.30–13.87). Considering all the cases, the secondary attack rate was 27.3 (95% CI 22.75–32.38). Risk factors were the gender and profession of the index case, the number of people living in the household, and the number of persons per bedroom. When the index case health worker used a single room, it had a protective effect, with an incidence rate ratio (IRR) of 0.493 (95% CI 0.246–0.985); Conclusions: The secondary attack rate found among household contacts of health care workers is high. The preventive isolation of health care workers in individual rooms in their house may reduce the transmission in their families.

scholarly journals Efficacy of baloxavir marboxil on household transmission of influenza infection

2020 ◽  
Vol 6 (1) ◽  
Author(s):  
Takumi Umemura ◽  
Yoshikazu Mutoh ◽  
Takato Kawamura ◽  
Masayuki Saito ◽  
Takahito Mizuno ◽  
...  
Keyword(s):  
Risk Factors ◽  
Influenza Virus ◽  
Attack Rate ◽  
Influenza Infection ◽  
Alternative Therapy ◽  
Virus Transmission ◽  
Household Transmission ◽  
Independent Risk Factors ◽  
Household Members ◽  
Oseltamivir Phosphate

Abstract Background Baloxavir marboxil (baloxavir) is a new anti-influenza virus agent that is comparable to oseltamivir phosphate (oseltamivir). Since the efficacy of baloxavir in preventing household transmission of influenza is not well established, we compared the secondary household influenza virus transmission rates between patients on baloxavir vs oseltamivir. Methods Between October 2018 and March 2019, we enrolled index patients (diagnosed with influenza and treated with baloxavir or oseltamivir) and household members. The secondary attack rate of household members was compared between index patients treated with baloxavir vs oseltamivir. Risk factors of household transmission were determined using multivariate logistic analyses. Results In total, 169 index patients with influenza type A were enrolled. The median age was 27.0 (interquartile range; 11–57) years. The number of index patients treated with baloxavir and oseltamivir was 49 and 120, respectively. The secondary attack rate was 9.0% (95% confidence interval [CI]: 4.6–15.6) in the baloxavir group and 13.5% (95% CI: 9.8–17.9) in the oseltamivir group. In the multivariate analysis, independent risk factors were 0–6 years of age (odds ratio [OR] 2.78, 95% CI: 1.33–5.82, p < 0.01) and not being on baloxavir treatment. (OR: 0.63, 95% CI: 0.30–1.32, p = 0.22). Conclusion The household secondary attack rate of influenza was comparable in patients treated with baloxavir vs oseltamivir. Therefore, baloxavir can be used as an alternative therapy to oseltamivir in reducing household transmission of influenza. Trial registration Patients in this study were retrospectively registered. https://www.tosei.or.jp/clinical/pdf/2_influenza.pdf.

scholarly journals Household secondary attack rate of COVID-19 by household size and index case characteristics

2021 ◽  
Author(s):  
Semra Tibebu ◽  
Kevin A. Brown ◽  
Nick Daneman ◽  
Lauren A. Paul ◽  
Sarah A. Buchan
Keyword(s):  
Symptom Onset ◽  
Attack Rate ◽  
Index Case ◽  
Household Size ◽  
Residential Address ◽  
Household Contacts ◽  
Household Transmission ◽  
Case Characteristics ◽  
Index Cases

AbstractIn this population-wide study in Ontario, Canada, we investigated the household secondary attack rate (SAR) to understand its relationship to household size and index case characteristics. We identified all patients with confirmed COVID-19 between July 1 and November 30, 2020. Cases within households were matched based on reported residential address; households were grouped based on the number of household contacts. The majority of households (68.2%) had a SAR of 0%, while 3,442 (11.7%) households had a SAR ≥75%. Overall household SAR was 19.5% and was similar across household sizes, but varied across index case characteristics. Households where index cases had longer delays between symptom onset and test seeking, households with older index cases, households with symptomatic index cases, and larger households located in diverse neighborhoods, were associated with greater household SAR. Our findings present characteristics associated with greater household SARs and proposes immediate testing as a method to reduce household transmission and incidence of COVID-19.

scholarly journals Prevalence of BRD-Related Viral Pathogens in the Upper Respiratory Tract of Swiss Veal Calves

Animals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1940
Author(s):  
Eveline Studer ◽  
Lutz Schönecker ◽  
Mireille Meylan ◽  
Dimitri Stucki ◽  
Ronald Dijkman ◽  
...  
Keyword(s):  
Risk Factors ◽  
Welfare Economic ◽  
Economic Losses ◽  
Nasopharyngeal Swab ◽  
Upper Respiratory Tract ◽  
Convenience Sample ◽  
Veal Calves ◽  
Mixed Regression ◽  
Influenza C Virus ◽  
Syncytial Virus

The prevention of bovine respiratory disease is important, as it may lead to impaired welfare, economic losses, and considerable antimicrobial use, which can be associated with antimicrobial resistance. The aim of this study was to describe the prevalence of respiratory viruses and to identify risk factors for their occurrence. A convenience sample of 764 deep nasopharyngeal swab samples from veal calves was screened by PCR for bovine respiratory syncytial virus (BRSV), bovine parainfluenza-3 virus (BPI3V), bovine coronavirus (BCoV), influenza D virus (IDV), and influenza C virus (ICV). The following prevalence rates were observed: BRSV, 2.1%; BPI3V, 3.3%; BCoV, 53.5%; IDV, 4.1%; ICV, 0%. Logistic mixed regression models were built for BCoV to explore associations with calf management and housing. Positive swab samples were more frequent in younger calves than older calves (>100 days; p < 0.001). The probability of detecting BCoV increased with increasing group size in young calves. Findings from this study suggested that young calves should be fattened in small groups to limit the risk of occurrence of BCoV, although an extended spectrum of risk factors for viral associated respiratory disorders such as nutritional aspects should be considered in future studies.

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