key: cord-353275-pindjvhk
authors: Khurana, A.; Kaushal, G. P.; gupta, R.; Verma, V.; Sharma, K.; Kohli, M.
title: Prevalence and clinical correlates of COVID-19 outbreak among healthcare workers in a tertiary level hospital
date: 2020-07-24
journal: nan
DOI: 10.1101/2020.07.21.20159301
sha: 
doc_id: 353275
cord_uid: pindjvhk

In this study, we summarize the epidemiological characteristics of COVID-19 outbreak among Healthcare workers (HCWs) in a tertiary care hospital and compared various parameters and preventive measures taken by positive HCWs to a comparable cohort of COVID negative HCWs. 52.1% of COVID-19 positive HCWs showed symptoms of which only three needed hospitalization possibly due to a younger cohort of HCWs who got infected (35.9 +- 9.3 years). Findings of present study found some protective role of full course prophylactic hydroxychloroquine as compared to a control group (p=0.021) and use of N95 masks over others (p<0.001). Our results did not show any added protection with the use of prophylactic Vitamin C, D, Zinc, or betadine gargles. We also observed outbreak control with increased awareness, near universal testing, PPE provision, sanitization drive, and promoting social distancing among HCWs.

An epidemic caused by Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2), a positive sense single stranded RNA virus of zoonotic origin, emerged in Wuhan, Hubei Province, China, in December 2019. This infection has since been spreading rapidly globally, causing significant morbidity and mortality, with COVID-19 cases having been identified in several other countries and territories. WHO has declared it as a public health emergency of international concern. Person-to-person transmission has been widely documented. The transmission of COVID-19 is potent, and the secondary attack rate is high. There is neither a specific drug nor a vaccine for COVID-19. Treatment mainly consists of symptomatic supportive therapy. Over 1,50,000 cases have been detected in India as of 29 May 2020, leading it to become the primary cause of healthrelated concern in the country.

Governments and health bodies worldwide have been working on pandemic mitigation strategies.

These efforts aim to ensure rapid evaluation and care of patients, limiting further transmission, and to better understand risk factors for transmission. With and aim to understand the prevalence and correlates of this infection in a tertiary level hospital in Delhi, we planned the current study. We aimed to look at the infection rate, and the various factors associated with a positive COVID-19 result, which may help in formulating better strategies for preventing the illness.

A questionnaire based analysis was carried out to analyze the epidemiological and clinical parameters of healthcare workers of our hospital who had tested positive for COVID-19. A matched cohort of healthcare workers who tested negative was taken as the control group. Data collection was by telephonic surveys, as well as evaluation of health records. Responses were recorded via text, or in-person in certain cases, as the situation allowed. Various epidemiological parameters along with symptoms, co-morbidities, and preventive strategies adopted by healthcare workers were recorded after obtaining due consent. A similar survey was done for the control group.

Data was coded and recorded in MS Excel spreadsheet program. SPSS v23 (IBM Corp.) was used for statistical analysis. Normal distribution of data was assessed using the Shapiro-wilk test.

Descriptive statistics were elaborated in the form of means for continuous variables, and frequencies and percentages for categorical variables. Group comparisons for continuously distributed data were made using independent sample 't' test when comparing two groups. If data were found to be non-normally distributed, appropriate non-parametric tests were used for these comparisons. Chi-squared test was used for group comparisons for categorical data. In case the expected frequency in the contingency tables was found to be <5 for >25% of the cells, Fisher's Exact test was used instead. Statistical significance was kept at p < 0.05.

Data collection and analysis of cases was part of a continuing public health outbreak investigation and was thus considered exempt from institutional review board approval. However, permission was sought from the head of the institute prior to start of the study.

Males constituted 59.6% of total patients in the COVID positive group, whereas 69.0% participants in negative group were male. The mean age in the positive group was 35.98 years while in the negative group was 34.28 years. 16% positive patients were doctors (including faculty and residents), 43.6% were nursing officers, 29.8% were paramedical staff (including sanitary workers, housekeeping staff, and orderlies), and 10.6% security guards. There was no statistically significant difference in terms of age (P=0.231), gender (P=0.188) and designation (P=0.102) between the study and the control groups. (Table 1) 3.2 Clinical Presentation 52.1% (49/94) of the participants in the positive group were symptomatic. Fever was the most common symptom ,as experienced by 30.9% patients/participants. Other commonly reported symptoms include sore throat, myalgia, headache and cough as reported by 20.2%,20.2%,14.9%,11.7% patients/participants respectively; 4.3% rhinorrhea, 6.4% shortness of breath, 3.2% anosmia, 2.1 % nausea, 2.1% pain abdomen and 1 patient each had mucosal dryness, hemoptysis, dysgeusia and loss of appetite. (Table 2 ) Three patients in total needed hospitalization and out of the three one patient needed intensive care for recovery. There were no mortality.

The mean number of close contacts per workday (>6 hours) in the COVID Positive group was 19.13 (21.50) and in the Negative group was 17.85 (13.70 ). The close contacts per workday in the COVID Positive ranged from 0-150 . The close contacts per workday in the COVID:

Negative/Unknown ranged from 0-60. There was no significant difference between the groups in terms of close contacts per workday (W = 3794.500, p = 0.402). None of the positive participants had suspected contact at home. (Table 3) 3.4 Co-morbidity analysis 10 .6% (14/94) of the participants in the positive group suffered from chronic medical condition, while 12.6% (14/87) of the participants in the control group had chronic medical conditions. The difference between the two groups was not statistically significant (p=0.955) using non-parametric tests (Wilcoxon-Mann-Whitney U Test). The Total number of co-morbidities in the positive ranged from 0 -3 while in the negative group from 0-4. (Table 4) 3.5 Prophylactic agents used by healthcare workers Chi-squared test was used to determine the association between 'COVID positivity' and 'prophylactic hydroxychloroquine Intake'. There was a significant difference between the various groups in terms of distribution of prophylactic hydroxychloroquine Intake (X 2 = 17.159, p = <0.001). 6.4% of the participants in the positive group had taken full course of hydroxychloroquine of 7 weeks or more. 18.4% of the participants in the negative group had taken the full course of hydroxychloroquine prophylaxis. An analysis between those who had taken full course and those who had taken either incomplete course or had not taken at all revealed a statistically significant difference with p = 0.021 using the Fisher's exact test. (Table 5 and 6) Commonly used prophylactic agents other than hydroxychloroquine included Betadine gargles, Vitamin C, D, Zinc, saline gargles, and other home remedies did not reveal significant association with COVID status among healthcare workers. (p>0.05). 30.9% of the participants in the positive group used prophylaxis other than hydroxychloroquine while in the negative group 23.0% of the participants used other prophylaxis. (Table 5) . CC-BY-NC-ND 4.0 International license It is made available under a is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. (which was not certified by peer review)

The copyright holder for this preprint this version posted July 24, 2020. . 95.7% of the participants in the COVID positive healthcare workers used mask at both work and community. Similarly, 90.8% of the participants in the control group had mask usage at both places.

Chi-squared test was used to explore the association between 'COVID status' and place of mask usage. We couldn't find a significant difference (X 2 = 1.781, p = 0.182). Chi-squared test was further used to explore the association between 'COVID' and 'Minimum level of protection'.

A significant difference was seen in terms of minimum level of protection (X 2 = 15.668, p = <0.001). 30 .9% of the participants in the positive group had minimum level of protection as an N95 mask.

63.8% of the participants in the positive group had minimum level of protection as a 3-Ply Mask, whereas 5.3% of the participants in the group positive group had minimum level of protection as a bandana. The percentages in the control group were 57.5%, 34.5% and 8.0% for N95, 3ply and Bandana mask, respectively. Thus, control group had the larger fraction of people using N95 as compared to 3 ply and bandana (p<0.001) thus a significantly higher number of participants were using M-95 masks as compared to bandana in the control group.

Average days after which N95 mask was changed was not normally distributed in the 2 groups.

Thus, non-parametric tests (Wilcoxon-Mann-Whitney U Test) were used to compare groups. The mean (SD) number of days before mask was changed in the COVID Positive group was 7.81 (10.53) while in the negative group was 7.33 (9.23) . No significant difference between the groups in terms of N95 mask change frequency (W = 3821.500, p = 0.439) was observed. (Table 7 and 8) 3.7 Hand Hygiene practices among Health care Workers Participants in the group COVID positive group had the larger proportion of people who washed hands for over 20 seconds than the control group, but the difference did not attain significance. The variable Handwashing/Sanitizer-Use Frequency (Times/day) was not normally distributed in the two groups. Thus, non-parametric tests (Wilcoxon-Mann-Whitney U Test) were used to make group comparisons. The mean (SD) of Handwashing/Sanitizer-Use Frequency (Times/day) in the positive group was 20.66 (12.79) and in control group was 18.03 (13.16) . There was no significant difference between the groups in terms of Handwashing/Sanitizer-Use Frequency (Times/day) (W = 4633.000, p = 0.120). (Table 9) . CC-BY-NC-ND 4.0 International license It is made available under a is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. (which was not certified by peer review)

The copyright holder for this preprint this version posted July 24, 2020. .

We have provided an initial assessment of the epidemiology and risk mitigation dynamics of the COVID-19 outbreak among healthcare workers of our hospital. We observed a marked increase in positive cases within a few days, of which only three needed hospitalization and one required admission to intensive care unit. Only 52.1% of the positive healthcare workers showed symptoms.

A possible reason for the same is believed to be younger cohort of patients amongst the healthcare workers who got infected. Moreover, we found that the majority (about 60%) of COVID-19 cases were male, although the reason remains to be clarified.

Findings of present study found some protective role of full course (7 weeks) of prophylactic hydroxychloroquine as compared to a control group of negative healthcare workers with p=0.021 and use of N95 masks over others. Our results did not show any added protection with the use of other strategies in the form of prophylactic Vitamin C, D, Zinc, betadine gargles, or any other home remedy.

Estimation of the prevalence and transmission for undocumented novel coronavirus (SARS-CoV-2) infections is critical for understanding the total prevalence and pandemic potential. Another factor is the mode of viral transmission through aerosol and fomites. Van Doremalen found that SARS-CoV-2 was viable for over 3 hours in aerosol mode but titers decreased significantly after 3 hours. Virus is much stable on stainless steel and plastic compared to copper and cardboard and can be obtained . CC-BY-NC-ND 4.0 International license It is made available under a is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity.

The copyright holder for this preprint this version posted July 24, 2020. . https://doi.org/10.1101/2020.07.21.20159301 doi: medRxiv preprint SARS-CoV-2 shows high infectivity in the hospital setting. It has been isolated from sputum, nasopharynx, oropharynx, stool, blood, & conjunctiva but not from urine, breastmilk, amniotic fluid and cord blood. Peak infectiousness occurs about 1 day prior to symptom onset. When viremia is assessed Viral loads as previously discussed the viral load is high even in the pre-symptomatic phase and peaks at symptom onset. (19) He at al studied viral shedding by looking at 414 swabs from 94 patients of . CC-BY-NC-ND 4.0 International license It is made available under a is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity.

The copyright holder for this preprint this version posted July 24, 2020. . positive patients from symptom onset. None of them had severe symptoms on presentation although 18 developed the same during the course. They found viral load does not correlate with sex, severity, and age. They also evaluated 77 detailed transmission pairs based on serial interval (that is time from symptom onset in transmitter to symptom onset in transmittee) and they estimated that infectiousness started at 2.3 days prior to symptom onset and peaked 0.7 days prior to symptom onset. Estimated pre-symptomatic transmission was 44% in their study. (20) This is in line with the findings of Du et al and Ferretti et al. (17, 21) The authors of this study also suggest that this percentage will vary depending on the efficacy of active case finding with those places with a high percentage of case finding to have a higher percentage of presymptomatic transmission. Huang and Lin et al found that higher viral loads are found in lower respiratory specimens in critically ill. (22) Xiao et al have found in their study of 56 patients that prolonged shedding of viral RNA can be seen in mild or moderate disease and found that Nasopharyngeal PCR remains positive a median of 24 days after symptom onset with a 5% positivity at 5 weeks, however its relation with infectiousness remains unknown (23) . In mild cases, live virus isolated up to day 8 after symptom onset. In a study from Taiwan, the authors found that no secondary cases were identified from exposures occurring after 5 days from symptom onset. 

There is a spectrum of presentations for COVID-19 which include: asymptomatic, mildly symptomatic, severe symptomatic with spontaneous recovery, and severe symptomatic with development of an ARDS -proinflammatory syndrome. (23, 26, 27) Compiled series of hospitalized patients revealed fever and cough to be the most common symptoms followed by myalgias, fatigue, sore throat, nausea, vomiting, diarrhea, headache, and rhinorrhea (22,28)(12,27-29) Gastrointestinal (GI) symptoms have been given more emphasis in recent data. Pan et al found that 42% had GI symptoms as part of their syndrome.(29) Anosmia, hyposmia, and dysgeusia have been reported as per society reports that state that anecdotal evidence is accumulating. A large-scale real-time symptom monitoring study seems to confirm the importance of anosmia/ageusia. (30) Our findings are in line with available literature with most common symptom being fever, followed by bodyache, sore throat, cough, headache, pain abdomen, anosmia and in more severe cases-breathlessness and need for mask ventilation.

. CC-BY-NC-ND 4.0 International license It is made available under a is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity.

The copyright holder for this preprint this version posted July 24, 2020. hydroxychloroquine, but they excluded 6 patients from the analysis who were either shifted to ICU or got worse which suggests confounding in their data. (37, 38) The society (International society of antimicrobial chemotherapy) that published this paper said in a statement that the published study . CC-BY-NC-ND 4.0 International license It is made available under a is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity.

The copyright holder for this preprint this version posted July 24, 2020. . https://doi.org/10.1101/2020.07.21.20159301 doi: medRxiv preprint did not meet the societies expected standard relating to a lack of better explanation of inclusion criteria.

hydroxychloroquine based on faster viral clearance when a combination of the two drugs was used. with respiratory symptoms who had confirmed respiratory virus and randomized 50% to wear masks and assessed exhaled breath particles and classified them as either droplets or aerosols. There was a significant decrease in recovery of coronaviruses from droplets and aerosols with the use of masks. While this study was not done in context of COVID 19 but the findings are extrapolatable to COVID patients especially those who are symptomatic. (43) We, however, found N95 to be more effective in preventing infection as compared to other masks (3 ply mask and cloth bandana). (p<0.001) There was no difference in frequency of N95 mask change among positive and control groups and most healthcare workers who tested positive did show good compliance with mask usage in the hospital as well as in the community.

. CC-BY-NC-ND 4.0 International license It is made available under a is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity.

The copyright holder for this preprint this version posted July 24, 2020. is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity.

The copyright holder for this preprint this version posted July 24, 2020. . is less likelihood of it being effective at controlling the epidemic. The authors also support the use of a mobile phone app which is a form of digital contact tracing by keeping a temporary record of proximity events between individuals. This approach would not require coercive surveillance since the system can achieve epidemic suppression. This is a promising strategy. Epidemic control becomes feasible with contact tracing if minimal delay can be achieved. homeless shelter in Boston -36% (great majority of total infections); Town in Italy -<1% (41% of total infections); Iceland -<1% (43% of total infections) and cruise ship Diamond Princess -9% (46% of total infections) (48-50) Thus, serological data shows SARS-CoV-2 has a significant iceberg effect. Our approach to control involved near universal testing of health care workers to understand the level of the outbreak and early outbreak control.

Liu measured viral RNA in various areas in 2 hospitals. They found that ventilation and sanitization played a significant role in the number of viral RNA copies detected. Ventilated areas had a lower . CC-BY-NC-ND 4.0 International license It is made available under a is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity.

The copyright holder for this preprint this version posted July 24, 2020. . https://doi.org/10.1101/2020.07.21.20159301 doi: medRxiv preprint RNA concentration as compared to unventilated areas like toilets. Also, a rigorous sanitization drive lead to virtually undetectable detection of viral RNA. (51) This lead the hospital authorities to undertake a massive sanitization drive in the hospital.

The transmission potential of COVID-19 is very high, and the number of cases may become largely unsustainable for the healthcare system in a very short-time horizon. It is important to protect the healthcare force for effective epidemic management. We observed outbreak control with increased awareness, near universal testing, PPE provision, sanitization drive, and promoting social distancing among health care workers. This study also brings forth the role of hydroxychloroquine prophylaxis, use of N95 mask, and effect of early interventions in outbreak mitigation. Aggressive containment strategies are required to control COVID-19 spread and catastrophic outcomes for the healthcare system in the absence of a therapy/vaccine to avoid overwhelming the critical care capacity of any healthcare facility. is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity.

The copyright holder for this preprint this version posted July 24, 2020. is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity.

The copyright holder for this preprint this version posted July 24, 2020. Table 3 Contact analysis for COVID positive and control group . CC-BY-NC-ND 4.0 International license It is made available under a is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity.

The copyright holder for this preprint this version posted July 24, 2020. Table 4 Distribution of chronic medical conditions among positive healthcare workers and control group . CC-BY-NC-ND 4.0 International license It is made available under a is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity.

The copyright holder for this preprint this version posted July 24, 2020. Table 5 : Analysis of preventive and prophylactic strategies adopted by healthcare workers.

. CC-BY-NC-ND 4.0 International license It is made available under a is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. (which was not certified by peer review)

The copyright holder for this preprint this version posted July 24, 2020. Table 6 : Distribution of hydroxychloroquine prophylaxis usage among healthcare workers . CC-BY-NC-ND 4.0 International license It is made available under a is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. (which was not certified by peer review)

The copyright holder for this preprint this version posted July 24, 2020. . CC-BY-NC-ND 4.0 International license It is made available under a is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. (which was not certified by peer review)

The copyright holder for this preprint this version posted July 24, 2020. Table 8 : Analysis of mask used as minimum level of protection among healthcare workers.

. CC-BY-NC-ND 4.0 International license It is made available under a is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. (which was not certified by peer review)

The copyright holder for this preprint this version posted July 24, 2020. Table 9 Analysis of hand hygiene practices among health care workers . CC-BY-NC-ND 4.0 International license It is made available under a is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. (which was not certified by peer review)

The copyright holder for this preprint this version posted July 24, 2020. . https://doi.org/10.1101/2020.07.21.20159301 doi: medRxiv preprint

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