The Risk of SARS-CoV-2 Transmission in Community Indoor Settings: A Systematic Review and Meta-Analysis.

BACKGROUND: Quantifying the risk of SARS-CoV-2 transmission in indoor settings is crucial for developing effective non-vaccine prevention strategies and policies. However, summary evidence on the transmission risks in settings other than households, schools, elderly care and healthcare facilities is limited. We conducted a systematic review to estimate the secondary attack rates (SARs) of SARS-CoV-2 and the factors modifying transmission risk in community indoor settings. METHODS: We searched Medline, Scopus, Web of Science, WHO COVID-19 Research Database, MedrXiv, and BiorXiv from January 1, 2020, to February 20, 2023. We included articles with original data for estimating SARS-CoV-2 SARs. We estimated the overall and setting-specific SARs using the inverse variance method for random-effects meta-analyses. RESULTS: We included 34 studies with data on 577 index cases, 898 secondary cases, and 9173 contacts. The pooled SAR for community indoor settings was 20.4% (95% confidence interval [CI] 12.0-32.5%). The setting-specific SARs were highest for singing events (SAR 44.9%, 95% CI 14.5-79.7%), indoor meetings and entertainment venues (31.9%, 10.4-65.3%), and fitness centers (28.9%, 9.9-60.1%). We found no difference in SARs by index case, viral, and setting-specific characteristics. CONCLUSIONS: The risk of SARS-CoV-2 transmission was highest in indoor settings where singing and exercising occurred. Effective mitigation measures such as assessing and improving ventilation should be considered to reduce the risk of transmission in high-risk settings. Future studies should systematically assess and report the host, viral, and setting-specific characteristics that may modify the transmission risks of SARS-CoV-2 and other respiratory viruses in indoor environments.

Knowledge, risk perception and uptake of COVID-19 vaccination among internally displaced persons in complex humanitarian emergency setting, Northeast Nigeria.

BACKGROUND: Owing to crowded and unsanitary conditions, internally displaced persons (IDPs) have an increased risk of COVID-19 infection. Adoption of COVID-19 preventive measures among this population is premised on accurate information, adequate knowledge, and risk perception. We assessed COVID-19 knowledge and risk perception and investigated the association between risk perception and COVID-19 preventive measures, including vaccination among IDPs in Northeast Nigeria. METHODS: We conducted a cross-sectional study during July-December 2022 and sampled 2,175 IDPs using stratified sampling. We utilized a 12-point assessment tool to evaluate COVID-19 knowledge. Participants who scored ≥ 6 points were considered to have adequate knowledge. We used a 30-item Risk Behavior Diagnosis Scale to assess COVID-19 risk perception and evaluated each item on a 5-point Likert scale. Participants were divided into risk perception categories by the median of Likert scale scores. We performed weighted logistic regression analysis to identify factors associated with risk perception. Pearson's chi-squared with Rao-Scott adjustment was used to determine the relationship between risk perception and COVID-19 preventive measures. RESULTS: Of 2,175 participants, 55.7% were 18-39 years old, 70.9% were females, and 81.7% had no formal education. Among the IDPs, 32.0% (95% CI: 28.8 - 35.0) were considered to have adequate COVID-19 knowledge, and 51.3% (95% CI: 47.8 - 54.8) perceived COVID-19 risk as high. Moreover, 46.3% (95% CI: 42.8 - 50.0) had received one dose of COVID-19 vaccine, and 33.1% (95% CI: 29.8 - 36.0) received two doses. Adequate knowledge (Adjusted Odds Ratio (AOR) = 2.10, [95% CI: 1.46 - 3.03]) and post-primary education (AOR = 3.20, [95% CI: 1.59 - 6.46]) were associated with risk perception. Furthermore, high risk perception was significantly associated with wearing face masks (χ2 = 106.32, p-value < .001), practicing hand hygiene (χ2 = 162.24, p-value < .001), physical distancing (χ2 = 60.84, p-value < .001) and vaccination uptake (χ2 = 46.85, p-value < .001). CONCLUSIONS: This study revealed gaps in COVID-19 knowledge, risk perception, and vaccination uptake but demonstrated a significant relationship between risk perception and COVID-19 preventive practices. Health education and risk communication should be intensified to improve knowledge, elicit stronger risk perception, and enhance COVID-19 preventive practices.

Vaccination coverage and the factors influencing routine childhood vaccination uptake among communities experiencing disadvantage in Vellore, southern India: a mixed-methods study.

BACKGROUND: In 2015, the Vellore district in southern India was selected for intensified routine immunization, targeting children from communities experiencing disadvantage such as migrant, tribal, and other hard-to-reach groups. This mixed-methods study was conducted to assess routine immunization coverage and the factors influencing childhood vaccination uptake among these communities in Vellore. METHODS: We conducted a cross-sectional household survey (n = 100) and six focus group discussions (n = 43) among parents of children aged 12-23 months from the known communities experiencing disadvantage in Vellore during 2017 and 2018. Multivariate logistic regression was conducted to examine associations between the parental characteristics and children's vaccination status in the household survey data; the qualitative discussions were analyzed by using the (previously published) "5As" taxonomy for the determinants of vaccine uptake. RESULTS: In the household survey, the proportions of fully vaccinated children were 65% (95% CI: 53-76%) and 77% (95% CI: 58-88%) based on information from vaccination cards or parental recall and vaccination cards alone, respectively. Children whose mothers were wage earners [Adjusted prevalence odds ratio (aPOR): 0.21, 95% CI = 0.07-0.64], or salaried/small business owners [aPOR: 0.18, 95% CI = 0.04-0.73] were less likely to be fully vaccinated than children who had homemakers mothers. In the focus group discussions, parents identified difficulties in accessing routine immunization when travelling for work and showed knowledge gaps regarding the benefits and risks of vaccination, and fears surrounding certain vaccines due to negative news reports and common side-effects following childhood vaccination. CONCLUSIONS: Vaccination coverage among children from the surveyed communities in Vellore was suboptimal. Our findings suggest the need to target children from Narikuravar families and conduct periodic community-based health education campaigns to improve parental awareness about and trust in childhood vaccines among the communities experiencing disadvantage in Vellore.

Vaccination coverage and factors associated with routine childhood vaccination uptake in rural Vellore, southern India, 2017.

BACKGROUND: Vellore district in southern India was selected for intensified immunization efforts through India's Mission Indradhanush campaign based on 74% coverage in the National Family Health Survey in 2015. As rural households rely almost entirely on the Universal Immunization Program (UIP), we assessed routine immunization coverage and factors associated with vaccination status of children in rural Vellore. METHODS: We conducted a cross-sectional household survey among parents or primary caretakers of children aged 12-23 months during August-September 2017 using two-stage, EPI cluster sampling. We verified vaccination histories from vaccination cards and collected data on sociodemographic and non-socio-demographic characteristics by using mobile data capture. Associations with vaccination status were examined with univariate and multivariate logistic regression models. RESULTS: A total of 643 children were included. Coverage of BCG, third dose pentavalent/DPT, measles/MR vaccines and full vaccination (BCG, three doses of polio and pentavalent/DPT and measles/MR vaccines) among children with vaccination cards (n = 606) was 94%, 96%, 93% and 84%, respectively. Of children with vaccination cards, 70.8% had received all recommended doses according to the UIP schedule. No socio-demographic differences were identified, but parents' familiarity with the schedule (Adjusted Prevalence Odds Ratio (aPOR): 2.06, 95%CI = 1.26-3.38) and receiving information on recommended vaccinations during antenatal visits (aPOR: 2.16, 95% CI = 1.13-4.12) were significantly associated with full vaccination status of the children. CONCLUSIONS: We found higher UIP antigen coverage and proportion of fully vaccinated children than previously reported from rural Vellore. However, adherence to the recommended schedule was still not optimal. Our study highlights the potential of improving parental awareness of vaccination schedule and targeting health education interventions at pregnant women during antenatal visits to sustain and improve routine immunization coverage.

Factors associated with routine childhood vaccine uptake and reasons for non-vaccination in India: 1998-2008.

BACKGROUND: Despite almost three decades of the Universal Immunization Program in India, a little more than half the children aged 12-23months receive the full schedule of routine vaccinations. We examined socio-demographic factors associated with partial-vaccination and non-vaccination and the reasons for non-vaccination among Indian children during 1998 and 2008. METHODS: Data from three consecutive, nationally-representative, District Level Household and Facility Surveys (1998-99, 2002-04 and 2007-08) were pooled. Multinomial logistic regression was used to identify individual and household level socio-demographic variables associated with the child's vaccination status. The mother's reported reasons for non-vaccination were analyzed qualitatively, adapting from a previously published framework. RESULTS: The pooled dataset contained information on 178,473 children 12-23months of age; 53%, 32% and 15% were fully vaccinated, partially vaccinated and unvaccinated respectively. Compared with the 1998-1999 survey, children in the 2007-2008 survey were less likely to be unvaccinated (Adjusted Prevalence Odds Ratio (aPOR): 0.92, 95%CI=0.86-0.98) but more likely to be partially vaccinated (aPOR: 1.58, 95%CI=1.52-1.65). Vaccination status was inversely associated with female gender, Muslim religion, lower caste, urban residence and maternal characteristics such as lower educational attainment, non-institutional delivery, fewer antenatal care visits and non-receipt of maternal tetanus vaccination. The mother's reported reasons for non-vaccination indicated gaps in awareness, acceptance and affordability (financial and non-financial costs) related to routine vaccinations. CONCLUSIONS: Persisting socio-demographic disparities related to partial-vaccination and non-vaccination were associated with important childhood, maternal and household characteristics. Further research investigating the causal pathways through which maternal and social characteristics influence decision-making for childhood vaccinations is needed to improve uptake of routine vaccination in India. Also, efforts to increase uptake should address parental fears related to vaccination to improve trust in government health services as part of ongoing social mobilization and communication strategies.

Effectiveness of Membrane Filtration to Improve Drinking Water: A Quasi-Experimental Study from Rural Southern India.

Since point-of-use methods of water filtration have shown limited acceptance in Vellore, southern India, this study evaluated the effectiveness of decentralized membrane filtration 1) with safe storage, 2) without safe storage, versus 3) no intervention, consisting of central chlorination as per government guidelines, in improving the microbiological quality of drinking water and preventing childhood diarrhea. Periodic testing of water sources, pre-/postfiltration samples, and household water, and a biweekly follow up of children less than 2 years of age was done for 1 year. The membrane filters achieved a log reduction of 0.86 (0.69-1.06), 1.14 (0.99-1.30), and 0.79 (0.67-0.94) for total coliforms, fecal coliforms, and Escherichia coli, respectively, in field conditions. A 24% (incidence rate ratio, IRR [95% confidence interval, CI] = 0.76 [0.51-1.13]; P = 0.178) reduction in diarrheal incidence in the intervention village with safe storage and a 14% (IRR [95% CI] = 1.14 [0.75-1.77]; P = 0.530) increase in incidence for the intervention village without safe storage versus no intervention village was observed, although not statistically significant. Microbiologically, the membrane filters decreased fecal contamination; however, provision of decentralized membrane-filtered water with or without safe storage was not protective against childhood diarrhea.

Perception of drinking water safety and factors influencing acceptance and sustainability of a water quality intervention in rural southern India.

BACKGROUND: Acceptance and long-term sustainability of water quality interventions are pivotal to realizing continued health benefits. However, there is limited research attempting to understand the factors that influence compliance to or adoption of such interventions. METHODS: Eight focus group discussions with parents of young children--including compliant and not compliant households participating in an intervention study, and three key-informant interviews with village headmen were conducted between April and May 2014 to understand perceptions on the effects of unsafe water on health, household drinking water treatment practices, and the factors influencing acceptance and sustainability of an ongoing water quality intervention in a rural population of southern India. RESULTS: The ability to recognize health benefits from the intervention, ease of access to water distribution centers and the willingness to pay for intervention maintenance were factors facilitating acceptance and sustainability of the water quality intervention. On the other hand, faulty perceptions on water treatment, lack of knowledge about health hazards associated with drinking unsafe water, false sense of protection from locally available water, resistance to change in taste or odor of water and a lack of support from male members of the household were important factors impeding acceptance and long term use of the intervention. CONCLUSION: This study highlights the need to effectively involve communities at important stages of implementation for long term success of water quality interventions. Timely research on the factors influencing uptake of water quality interventions prior to implementation will ensure greater acceptance and sustainability of such interventions in low income settings.

Prevalence and clustering of soil-transmitted helminth infections in a tribal area in southern India.

OBJECTIVES: To estimate the prevalence, spatial patterns and clustering in the distribution of soil-transmitted helminth (STH) infections, and factors associated with hookworm infections in a tribal population in Tamil Nadu, India. METHODS: Cross-sectional study with one-stage cluster sampling of 22 clusters. Demographic and risk factor data and stool samples for microscopic ova/cysts examination were collected from 1237 participants. Geographical information systems mapping assessed spatial patterns of infection. RESULTS: The overall prevalence of STH was 39% (95% CI 36%­42%), with hookworm 38% (95% CI 35­41%) and Ascaris lumbricoides 1.5% (95% CI 0.8­2.2%). No Trichuris trichiura infection was detected. People involved in farming had higher odds of hookworm infection (1.68, 95% CI 1.31­2.17, P < 0.001). In the multiple logistic regression, adults (2.31, 95% CI 1.80­2.96, P < 0.001), people with pet cats (1.55, 95% CI 1.10­2.18, P = 0.011) and people who did not wash their hands with soap after defecation (1.84, 95% CI 1.27­2.67, P = 0.001) had higher odds of hookworm infection, but gender and poor usage of foot wear did not significantly increase risk. Cluster analysis, based on design effect calculation, did not show any clustering of cases among the study population; however, spatial scan statistic detected a significant cluster for hookworm infections in one village. CONCLUSION: Multiple approaches including health education, improving the existing sanitary practices and regular preventive chemotherapy are needed to control the burden of STH in similar endemic areas.

Perceptions of farmers' and farmworkers' wives on the use and hazards of agrochemicals in rural Vellore.

Poor handling, storage, and application of agrochemicals have resulted in a steep rise in mortality and morbidity associated with their use. This study aimed at assessing the awareness of wives of farmers and farmworkers in rural Vellore on the use and health effects of agrochemicals to identify gaps in their knowledge. A cross-sectional survey among 512 wives was conducted. Nearly 75 percent of the wives (384/512) did not know that agrochemicals could pass through skin. Also, wives who owned between 1 and 5 acres of land had a higher odds of knowing that agrochemicals were harmful (OR: 1.71(1.03-2-85), p < 0.05) and need to be disposed safely (OR: 4.76 (1.47-15.36), p < 0.05), than those owning less than an acre or no land. There is a need to educate women associated with agriculture in India on the harms and proper use of agrochemicals in order to better protect and inform their households and communities.