scholarly journals Latino Household Transmission of SARS-CoV-2

2021 ◽  
Author(s):  
Diego A Martinez ◽  
Eili Y Klein ◽  
Cassandra Parent ◽  
Diana Prieto ◽  
Benjamin F Bigelow ◽  
...  
Keyword(s):  
Risk Factors ◽  
Attack Rate ◽  
Temporal Changes ◽  
Household Transmission ◽  
Alpha Variant

Abstract We assessed temporal changes in the household secondary attack rate of SARS-CoV-2 and identified risk factors for transmission in vulnerable Latino households of Baltimore, Maryland. The household SAR was 45.8%, and it appeared to increase as the alpha variant spread, highlighting the magnified risk of spread in unvaccinated populations.

scholarly journals Household transmission of SARS-CoV-2 in Norway; a prospective, longitudinal study showing increased transmissibility of the Alpha variant (B.1.1.7) compared with other variants

2021 ◽  
Author(s):  
Cathinka Halle Julin ◽  
Anna Hayman Robertson ◽  
Olav Hungnes ◽  
Gro Tunheim ◽  
Terese Bekkevold ◽  
...  
Keyword(s):  
Risk Factors ◽  
Longitudinal Study ◽  
Close Contact ◽  
Questionnaire Data ◽  
Primary Case ◽  
Prospective Longitudinal Study ◽  
Household Contacts ◽  
Household Transmission ◽  
Alpha Variant ◽  
Prospective Longitudinal

ABSTRACT Background We studied the secondary attack rate (SAR), risk factors, and precautionary practices of household transmission in a prospective longitudinal study. Moreover, we compared household transmission between the Alpha (B.1.1.7) variant and non-variants of concern (non-VOCs). Methods We recruited households of confirmed COVID-19 cases from May 2020 to May 2021. Households received 8 home visits over 6 weeks. Biological samples and questionnaire data were collected. Results We recruited 70 confirmed COVID-19 cases and 146 household contacts. Transmission occurred in 60% of the households; the overall SAR for household contacts was 49.6%. The SAR was significantly higher for the Alpha variant (77.8%) compared with non-VOC variants (42.5%) and was associated with a higher viral load. SAR was higher in household contacts aged ≥40 years (64%) than in younger contacts (40-47%), and for contacts of cases with loss of taste/smell. Close contact prior to confirmation of infection tended to give a higher SAR. A significantly lower SAR was found for sleeping separately from the primary case after confirmation of infection. Conclusion We found substantial household transmission, particularly for the Alpha variant. Precautionary practices seem to reduce SAR; however, prevention of transmission within households may become difficult with more transmissible variants.

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 Increased transmissibility of SARS-CoV-2 lineage B.1.1.7 by age and viral load

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Frederik Plesner Lyngse ◽  
Kåre Mølbak ◽  
Robert Leo Skov ◽  
Lasse Engbo Christiansen ◽  
Laust Hvas Mortensen ◽  
...  
Keyword(s):  
Risk Factors ◽  
Viral Load ◽  
Administrative Data ◽  
Attack Rate ◽  
Neutralizing Antibodies ◽  
Primary Case ◽  
Alpha Variant ◽  
Full Population

AbstractNew lineages of SARS-CoV-2 are of potential concern due to higher transmissibility, risk of severe outcomes, and/or escape from neutralizing antibodies. Lineage B.1.1.7 (the Alpha variant) became dominant in early 2021, but the association between transmissibility and risk factors, such as age of primary case and viral load remains poorly understood. Here, we used comprehensive administrative data from Denmark, comprising the full population (January 11 to February 7, 2021), to estimate household transmissibility. This study included 5,241 households with primary cases; 808 were infected with lineage B.1.1.7 and 4,433 with other lineages. Here, we report an attack rate of 38% in households with a primary case infected with B.1.1.7 and 27% in households with other lineages. Primary cases infected with B.1.1.7 had an increased transmissibility of 1.5–1.7 times that of primary cases infected with other lineages. The increased transmissibility of B.1.1.7 was multiplicative across age and viral load.

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 High variability in transmission of SARS-CoV-2 within households and implications for control

PLoS ONE ◽  
2021 ◽  
Vol 16 (11) ◽  
pp. e0259097
Author(s):  
Damon J. A. Toth ◽  
Alexander B. Beams ◽  
Lindsay T. Keegan ◽  
Yue Zhang ◽  
Tom Greene ◽  
...  
Keyword(s):  
Test Data ◽  
Attack Rate ◽  
Serological Test ◽  
Close Contact ◽  
Antibody Test ◽  
High Variability ◽  
Test Accuracy ◽  
Household Transmission ◽  
Wide Range ◽  
Test Specificity

Background Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) poses a high risk of transmission in close-contact indoor settings, which may include households. Prior studies have found a wide range of household secondary attack rates and may contain biases due to simplifying assumptions about transmission variability and test accuracy. Methods We compiled serological SARS-CoV-2 antibody test data and prior SARS-CoV-2 test reporting from members of 9,224 Utah households. We paired these data with a probabilistic model of household importation and transmission. We calculated a maximum likelihood estimate of the importation probability, mean and variability of household transmission probability, and sensitivity and specificity of test data. Given our household transmission estimates, we estimated the threshold of non-household transmission required for epidemic growth in the population. Results We estimated that individuals in our study households had a 0.41% (95% CI 0.32%– 0.51%) chance of acquiring SARS-CoV-2 infection outside their household. Our household secondary attack rate estimate was 36% (27%– 48%), substantially higher than the crude estimate of 16% unadjusted for imperfect serological test specificity and other factors. We found evidence for high variability in individual transmissibility, with higher probability of no transmissions or many transmissions compared to standard models. With household transmission at our estimates, the average number of non-household transmissions per case must be kept below 0.41 (0.33–0.52) to avoid continued growth of the pandemic in Utah. Conclusions Our findings suggest that crude estimates of household secondary attack rate based on serology data without accounting for false positive tests may underestimate the true average transmissibility, even when test specificity is high. Our finding of potential high variability (overdispersion) in transmissibility of infected individuals is consistent with characterizing SARS-CoV-2 transmission being largely driven by superspreading from a minority of infected individuals. Mitigation efforts targeting large households and other locations where many people congregate indoors might curb continued spread of the virus.

Temporal changes in the distribution of population risk factors attenuate the reduction in perinatal mortality

2005 ◽  
Vol 58 (12) ◽  
pp. 1299-1307 ◽  
Author(s):  
S GLINIANAIA ◽  
J RANKIN ◽  
R BELL ◽  
M PEARCE ◽  
L PARKER
Keyword(s):  
Risk Factors ◽  
Perinatal Mortality ◽  
Temporal Changes

Risk factors associated with Dengue fever outbreak in Islamabad, Pakistan (Preprint)

2021 ◽  
Author(s):  
Chaudhry Amjad Mehmood ◽  
Fawad Khalid Khan ◽  
Zakir Hussain ◽  
Mumtaz Ali Laghari ◽  
Ambreen Chaudhry ◽  
...  
Keyword(s):  
Risk Factors ◽  
Dengue Fever ◽  
Attack Rate ◽  
Disease Surveillance ◽  
Signs And Symptoms ◽  
Open Water ◽  
Bed Nets ◽  
Stagnant Water ◽  
Blood Samples ◽  
Active Case

BACKGROUND On 23rd Oct 2016, 79 dengue fever cases were reported from the Union Council (UC) Tarlai to Federal Disease Surveillance and Response Unit Islamabad. A team was deputed to investigate the suspected dengue outbreak. OBJECTIVE This study was aimed to determine the extent of the outbreak and identify the possible risk factors. METHODS Active case finding was conducted through a house-to-house survey. A case was defined as, acute onset of Fever ≥ 38 ℃ in a resident of Tarlai from Oct 2-Nov 11, 2016, with a positive NS-1 test, and any two of the following signs and symptoms; retro-orbital/ocular pain, headache, rash, myalgia, arthralgia, and hemorrhagic manifestations. A structured questionnaire was used to collect data. Age and sex-matched controls (1:1) were identified from the same area. Blood samples were taken and sent to the National Institute of Health for genotype identification. RESULTS During the active case search, 145 cases of dengue fever were identified by surveying 928 houses from 23rd Oct to 11th Nov 2016. Attack rate (AR) was 17.0/10,000 population. The mean age was 34.4±14.4 years. More than half of the cases were male (n=80, 55.2%). Among all cases, 29% belong to the 25-34 years age group while the highest attack rate was found in 35-44 years (AR 35.6/10,000) followed by 55-64 years (AR 35.5/10,000). All five blood samples tested positive for NS-1 (genotype DENV-2). The most frequent presenting sin/symptom was fever and headache (100%). Stagnant water around houses (OR = 4.86, CI: 2.94 -8.01, P<0.0001), presence of flower pots in-home (OR = 2.73, CI: 1.67-4.45, P<0.0001), and open water container (OR 2.24, CI: 1.36-3.60, P<0.0001) showed higher odds among cases. While. use of bed nets (OR 0.44, CI: 0.25-0.77, P 0.003), insecticidal spray (OR 0.33, CI: 0.22-0.55, P<0.0001), door screening (OR 0.27, CI: 0.15-0.46, P<0.0001), use of mosquito coil/mat (OR 0.26, CI: 0.16-0.44, P<0.0001) and cleanliness in house (OR 0.12, CI: 0.05-0.26, P<0.0001) showed a significant protective effect. CONCLUSIONS Stagnant water acting as breeding grounds for vector was the probable cause of the spread of the outbreak. The establishment of a surveillance and early reporting system and the use of protective measures against the vector is strongly recommended.

scholarly journals The role of young children in a community-wide outbreak of hepatitis A

1997 ◽  
Vol 118 (3) ◽  
pp. 243-252 ◽  
Author(s):  
P. F. SMITH ◽  
J. C. GRABAU ◽  
A. WERZBERGER ◽  
R. A. GUNN ◽  
H. R. ROLKA ◽  
...  
Keyword(s):  
Risk Factors ◽  
Risk Factor ◽  
Relative Risk ◽  
Jewish Community ◽  
Attack Rate ◽  
Odds Ratio ◽  
Hepatitis A ◽  
Age Group ◽  
Recurrent Hepatitis

An Hasidic Jewish community has experienced recurrent hepatitis A outbreaks since 1980. To assess risk factors for illness during a 1985–6 outbreak, the authors reviewed case records and randomly selected 93 households for an interview and serologic survey. In the outbreak, 117 cases of hepatitis A were identified, with the highest attack rate (4·2%) among 3–5 year olds. Among the survey households, the presence of 3–5 year olds was the only risk factor that increased a household's risk of hepatitis A (indeterminant relative risk, P=0·02). Furthermore, case households from the outbreak were more likely to have 3–5 year olds than were control households from the survey (odds ratio=16·4, P<0·001). Children 3–5 years old were more likely to have hepatitis A and may have been the most frequent transmitters of hepatitis A in this community. Hepatitis A vaccination of 3–5 year olds can protect this age group and might prevent future outbreaks in this community.

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