Risk of COVID-19 infection among frontline healthcare workers during the COVID-19 pandemic

Table 5 Studies on seroprevalence among healthcare workers

Ref.	Country	Period	Sample size	Sero-prevalence
Current study	India	April 2020 (T1)	283	1.1%
		June 2020 to July 2020 (T2)	168	17.9%
		October 2020 (T3)	214	34.1%
		March 2021(T4)	156	44.9%
		June 2021(T5)	175	60.1%
Milazzo et al[19]	Italy	March 2020	697	0.5%
		May 2020		5.4%
Piccoli et al[22]	Switzerland	April 16th to April 30th 2020	4726	9.6%
Shields et al[25]	United Kingdom	April 2020	545	24.4%
Rudberg et al[24]	Sweden	April 2020 to May 2020	2149	19.1%
Self et al[21]	United States	April 2020 to June 2020	3248	6%
Airoldi et al[27]	Italy	May 2020 to June 2020	2252	17.1%
Oliveira et al[20]	Brazil	June 2020	1996	5.5%
Recanatini et al[23]	Netherlands	June 2020 to July 2020	2328	13.9%
Kataria et al[28]	United States	July 2020	1743	5.5%
Prakash et al[26]	India	August 2020	1710	23.65%
Sonmezer et al[30]	Turkey	October 2020	1974	19%
Halili et al[29]	Kosovo	October 2020 to December 2020	647	17.5%
Wiggen et al[31]	United States	November 2020 to February 2021 December 2020 to February 2021	459	9.47% 17.7%
Ige et al[32]	Nigeria	December 2020 to July 2021	413	30.9%
Kanamori et al[18]	Japan	2020	3788	0.3%
		2021		1.6%
		2022		17.7%
Taher et al[33]	Saudi Arabia	June 2022 to September 2022	404	94%

The presence of nucleocapsid (N) antibodies has been taken into account for the seroprevalence across the different time periods (T1 to T5).