Knowledge, attitude, and practice towards face mask use among residents of Greater Chennai Corporation, India, March 2021

Background Wearing a mask is one of the simplest ways to reduce the spread of COVID-19. Studies reported poor mask compliance in Greater Chennai Corporation, India. Hence, we described the knowledge, attitude, and practice regarding mask use among adults (≥18 years) in Greater Chennai Corporation, Tamil Nadu, India. Methods We conducted a cross-sectional survey among residents of Greater Chennai Corporation in March 2021. We estimated the sample size to be 203 per strata (slum and non-slum). We used a simple random sampling technique to select 20 locations using a digital map in the slum and non-slum areas. After reaching the location chosen, we selected 10 consecutive households and one adult (≥18 years of age) from each household. We used a validated, semi-structured questionnaire for collecting data regarding knowledge, attitudes, and practices for mask use. We estimated proportions and 95% CI for key variables and compared the variables between slums and non-slums. Results Of 430 participants included in the study, 51.4% were males. The mean (S.D.) age of the participants is 41.1 (14.6) years. The majority (86.7%) of the participants felt that wearing a mask helped in reducing the spread of coronavirus and the knowledge differed (p-value < 0.05) between the slum (81.4%) and non-slum (92.3%). Nearly half (46.5%) of the participants did not like being forced to wear the mask. About 63.9% of the participants reported the practice of mask use while going out which was similar across slums and non-slums. Conclusion Although the knowledge regarding mask use was good among the public, the attitude was unfavorable. We suggest continuous reinforcement by spreading awareness and educating the community on the appropriate use of the mask.

Epidemiology of COVID-19 and effect of public health interventions, Chennai, India, March-October 2020: an analysis of COVID-19 surveillance system.

OBJECTIVES: To describe the public health strategies and their effect in controlling the COVID-19 pandemic from March to October 2020 in Chennai, India. SETTING: Chennai, a densely populated metropolitan city in Southern India, was one of the five cities which contributed to more than half of the COVID-19 cases in India from March to May 2020. A comprehensive community-centric public health strategy was implemented for controlling COVID-19, including surveillance, testing, contact tracing, isolation and quarantine. In addition, there were different levels of restrictions between March and October 2020. PARTICIPANTS: We collected the deidentified line list of all the 192 450 COVID-19 cases reported from 17 March to 31 October 2020 in Chennai and their contacts for the analysis. We defined a COVID-19 case based on the real-time reverse transcriptase-PCR (RT-PCR) positive test conducted in one of the government-approved labs. OUTCOME MEASURES: The primary outcomes of interest were incidence of COVID-19 per million population, case fatality ratio (CFR), deaths per million, and the effective reproduction number (Rt). We also analysed the surveillance, testing, contact tracing and isolation indicators. RESULTS: Of the 192 450 RT-PCR confirmed COVID-19 cases reported in Chennai from 17 March to 31 October 2020, 114 889 (60%) were males. The highest incidence was 41 064 per million population among those 61-80 years. The incidence peaked during June 2020 at 5239 per million and declined to 3627 per million in October 2020. The city reported 3543 deaths, with a case fatality ratio of 1.8%. In March, Rt was 4.2, dropped below one in July and remained so until October, even with the relaxation of restrictions. CONCLUSION: The combination of public health strategies might have contributed to controlling the COVID-19 epidemic in a large, densely populated city in India. We recommend continuing the test-trace-isolate strategy and appropriate restrictions to prevent resurgence.

Secondary attack rate of COVID-19 among contacts and risk factors, Tamil Nadu, March-May 2020: a retrospective cohort study.

OBJECTIVE: To describe the characteristics of contacts of patients with COVID-19 case in terms of time, place and person, to calculate the secondary attack rate (SAR) and factors associated with COVID-19 infection among contacts. DESIGN: A retrospective cohort study SETTING AND PARTICIPANTS: Contacts of cases identified by the health department from 14 March 2020to 30 May 2020, in 9 of 38 administrative districts of Tamil Nadu. Significant proportion of cases attended a religious congregation. OUTCOME MEASURE: Attack rate among the contacts and factors associated with COVID-19 positivity. RESULTS: We listed 15 702 contacts of 931 primary cases. Of the contacts, 89% (n: 14 002) were tested for COVID-19. The overall SAR was 4% (599/14 002), with higher among the household contacts (13%) than the community contacts (1%). SAR among the contacts of primary cases with congregation exposure were 5 times higher than the contacts of non-congregation primary cases (10% vs 2%). Being a household contact of a primary case with congregation exposure had a fourfold increased risk of getting COVID-19 (relative risk (RR): 16.4; 95% CI: 13 to 20) than contact of primary case without congregation exposure. Among the symptomatic primary cases, household contacts of congregation primaries had higher RR than household contacts of other cases ((RR: 25.3; 95% CI: 10.2 to 63) vs (RR: 14.6; 95% CI: 5.7 to 37.7)). Among asymptomatic primary case, RR was increased among household contacts (RR: 16.5; 95% CI: 13.2 to 20.7) of congregation primaries compared with others. CONCLUSION: Our study showed an increase in disease transmission among household contacts than community contacts. Also, symptomatic primary cases and primary cases with exposure to the congregation had more secondary cases than others.

Epidemiology of hospital-based COVID- 19 cluster in a tertiary care cancer hospital, Chennai, India 2020.

OBJECTIVES: To identify risk factors associated with Coronavirus disease 2019 (COVID-19) in a Tertiary care cancer hospital-based cluster and recommend control measures. METHODS: We conducted tracing and confirmation among hospital and community contacts. We telephonically interviewed and abstracted information from hospital records and registers. We described the cluster by time, place and person. We conducted unmatched case-control study to compare risk factors and computed Odds Ratio (OR) and 95% confidence interval. RESULTS: We confirmed COVID-19 in 21 of 1478 tested (1.4%). Secondary attack (%) of COVID-19 among 824 contacts was higher among in-patients of block A (18), household contacts (3.4), housekeeping staff (3.3) and nurses (1.7). The cluster started on April 22 with two successive peaks five days apart and lasted until May 8. Being male, patients aged >33 years [OR = 30·7; 95% CI = 3·6 to 264], having hypertension [OR = 4·3; 95% CI = 1·1 to 16·7] or diabetes [OR = 3·8; 95% CI = 1·0 to 14·1] were associated with COVID-19. Mask compliance was poor (20%) among hospital workers. DISCUSSION: We recommended screening of all patients for diabetes and hypertension and isolation/testing of anyone with influenza-like illness for preventing COVID-19 clusters in hospital settings.

Surveillance for face mask compliance, Chennai, Tamil Nadu, India, October-December, 2020.

PURPOSE: Government of Tamil Nadu, India, mandated the face mask wearing in public places as one of the mitigation measures of COVID-19. We established a surveillance system for monitoring the face mask usage. This study aimed to estimate the proportion of the population who wear face masks appropriately (covering nose, mouth, and chin) in the slums and non-slums of Chennai at different time points. METHODS: We conducted cross-sectional surveys among the residents of Chennai at two-time points of October and December 2020. The sample size for outdoor mask compliance for the first and second rounds of the survey was 1800 and 1600, respectively, for each of the two subgroups-slums and non-slums. In the second round, we included 640 individuals each in the slums and non-slums indoor public places and 1650 individuals in eleven shopping malls. We calculated the proportions and 95% confidence interval (95%CI) for the mask compliance outdoors and indoors by age, gender, region, and setting (slum and non-slum). RESULTS: We observed 3600 and 3200 individuals in the first and second surveys, respectively, for outdoor mask compliance. In both rounds, the prevalence of appropriate mask use outdoors was significantly lower in the slums (28%-29%) than non-slum areas (36%-35%) of Chennai (p<0.01). Outdoor mask compliance was similar within slum and non-slum subgroups across the two surveys. Lack of mask use was higher in the non-slums in the second round (50%) than in the first round of the survey (43%) (p<0.05). In the indoor settings in the 2nd survey, 10%-11% among 1280 individuals wore masks appropriately. Of the 1650 observed in the malls, 947 (57%) wore masks appropriately. CONCLUSION: Nearly one-third of residents of Chennai, India, correctly wore masks in public places. We recommend periodic surveys, enforcement of mask compliance in public places, and mass media campaigns to promote appropriate mask use.

Self-reported and clinically identified loss of smell and taste among persons tested for COVID-19 in Chennai, southern India, July-August 2020: A cross sectional study.

BACKGROUND: Early detection of symptoms of loss of smell and taste lately added for Coronavirus disease 2019 (COVID-19) has the potential for improving pandemic response. In the Indian context, we compared proportion experiencing new loss of smell or taste among COVID-19 positive and negative individuals in Chennai city, Southern India. METHODS: We did an analytical cross-sectional study among individuals aged 18-80 years undergoing testing at COVID-19 sample collection centres. We ascertained loss of smell and taste using standardised self-reporting and clinical examination procedures. We administered Sino Nasal Outcome (SNOT 22) questionnaire for comprehensive understanding of these symptoms. We compared proportion having symptoms between COVID-19 positive and negative persons. We compared the two assessment methods to compute diagnostic validity indicators. RESULTS: Of the 277 participants, 169 (61%) were men and mean age of 40.7 years [SD = 13.3]. Fifty eight (21%) had COVID-19 and 12 (36%) of them were asymptomatic. Predominantly reported symptoms were fever (30%), headache (18%) and cough (18%). Self-reported or clinically identified new loss of smell or taste was higher among COVID-19 positive (n = 13; 22%) than negative persons (n = 23; 11%) [p = 0.02]. Sensitivity was higher for self-reported or clinically identified loss of smell (17.2%) than that of loss of taste (6.9%). Negative predictive value for loss of smell or taste, self-reported or clinically identified was 81%. Likelihood ratio of positive test was 2.13. CONCLUSION: Loss of smell or taste are predominantly reported by COVID-19 confirmed individuals. Objective and subjective assessments of smell and taste may be required to identify those requiring COVID-19 testing.