. 2021 Jul 26;77(Suppl 2):S413–S423. doi: 10.1016/j.mjafi.2021.05.025

Table 1.

Characteristics of studies.

S no	Study	Age and sex	Country	Sympt-omatic	Comor-bidity	Clinical severity	First COVID 19 (PCR)	Test Done	Serological test done after first episode	RT PCR negative after first episode	Symptomatic again after period of weeks	Date of Second COVID 19	Test done	Outcome
1	Batisse et al.⁶
	1	19, F	France	Yes	7 Cormo-bidity: 4 No co-morbitiy	Mild	D2	RT-PCR^a	Available for 9 patients 5 were positive, one slightly positive and three negatives	NM	Yes	D29,	RT- PCR^a	3 Dead and 8 Alive
	2	32, F		Yes		Mild	D18			NM	Yes	D36,55
	3	33, F		Yes		Mild	D3			NM	Yes	D28
	4	43, M		Yes		Mild	D1			NM	Yes	D38
	5	85, M		Yes		Mild	D16			NM	Yes	D46
	6	54, M		Yes		Mild	D38,44			NM	Yes	D45
	7	91, F		Yes		Mild	D3			NM	Yes	D26
	8	55, M		Yes		Mild	D6			NM	Yes	D31
	9	72, M		Yes		Mild	D7			NM	Yes	D23, 32, 36
	10	73, M		Yes		Mild	D6			NM	Yes	D35
	11	84, F		Yes		Mild	D11			NM	Yes	D50
2	Lafai et al.⁷
	1	84, F	France	Yes	Yes	Severe	26 March	PCR	Yes∗∗	No	Yes	26 days	RT PCR^a	Death
	2	90, F		Yes	Yes	Severe	05 April	PCR	No	No	Yes	15 days		Death
	3	84, F		Yes	Yes	Severe	15 April	PCR^a (neg)	Yes∗∗	Yes	Yes	11 days		Death
3	Enrico et al.⁸	69, F	Italy	Yes	Yes	Mild	24 March	RT-PCR	Yes IgG Positive	Yes (two)	Yes	32 days	RT PCR	Alive
4	Ye et al.⁹
	1	30, M	China	Yes	No	Mild	NM	NM	NM	Yes	NM	4–17 days after negative test	RT PCR^a	Alive
	2	42, M		Yes	No	Mild	NM	NM	NM	Yes	NM			Alive
	3	32, F		Yes	No	Mild	NM	NM	NM	Yes	NM			Alive
	4	27, F		No	No	Mild	NM	NM	NM	Yes	NM			Alive
	5	31, F		Yes	No	Mild	NM	NM	NM	Yes	NM			Alive
5	Ravioli et al.¹⁰
	1	81, F	Switzerland	Yes	Yes	Moderate	09 March	RT-PCR^a	NM	Yes	Yes	21	RT-PCR^a	Died
	2	77, F	Switzerland	Yes	Yes	Moderate	23 March	RT-PCR^a	NM	Yes	Yes	14	RT-PCR^a	Alive
6	Loconsole et al.¹¹	48, M	Italy	Yes	No	Severe	17 March	RT-PCR	Yes	Yes	Yes	30	RT PCR	Alive
7	Jiang et al.¹²
	1	35 F	China	Yes	No	Mild	30 January	RT-PCR^a	No	Yes	Yes	9 days	RT-PCR^a	Re-hosp
	2	56 F		Yes	Yes	Mild	30 January		No	Yes	No	14 days		Alive
	3	F		Yes	No	Mild	03 February		No	Yes	Yes	8 days		Alive
	4	F		Yes	No	Mild	03 February		No	Yes	No	7 days		Alive
	5	F		Yes	Yes	Mild	05 February		No	Yes	No	9 days		Alive
	6	F		Yes	No	Mild	06 February		No	Yes	No	5 days		Alive
8	Chang et al.¹³
	1	14M	China	No	No	Mild-6 Moderate - 1	01 February	RT-PCR^a	No	Yes	No	7	4RS 2 RT-PCR^a 1RT-PCR^a and 1 Rs	Alive
	2	13M		No	No		01 February		No	Yes	No	11		Alive
	3	0.8F		Yes	No		05 February		No	Yes	No	9		Alive
	4	35M		Yes	No		02 February		No	Yes	No	9		Alive
	5	35M		No	No		31 January		No	Yes	No	8		Alive
	6	33M		No	No		27 January		No	Yes	No	5		Alive
	7	26M		Yes	No		26 January		No	yes	No	11		Alive
9	Yoo et al.¹⁴	8M	Korea	Yes	No	Mild	03 March	RT-PCR	No	Yes	Yes	14	RT-PCR	Alive
10	Liu et al.¹⁵	35 M	China	yes	No	Mild	30 January	RT-PCR	Yes	Yes	Yes	15	RT-PCR	Alive
11	Yuan et al.¹⁶
	1	38M	China	19- Yes 1 - No	6 people had comorbidities	Mild to moderate	NM for all	RT-PCR^a	14 were tested and all of them have antibodies	Yes	No for all	13- retested at 07 days 7 retested 14 days	14 nasopharyngeal and 7 anal swabs	Alive (all)
	2	53M
	3	40F
	4	61F
	5	64F
	6	53F
	7	33F
	8	1F
	9	34F
	10	43M
	11	34F
	12	38M
	13	50F
	14	50F
	15	5F
	16	55F
	17	72F
	18	54M
	19	8M
	20	12M
12	Lan et al.¹⁷
	1	30-36, 2 M	China	3-Yes 1- No	NM	Mild to moderate	NM	RT-PCR^a	NM	Yes	No	5–13 days after discharge	RT-PCR^a	Alive
	2				NM		NM		NM	Yes	No			Alive
	3				NM		NM		Nm	Yes	No			Alive
	4				NM		NM		NM	Yes	No			Alive
13	Cao et al.¹⁸
	1	54F	China	Yes	No	Severe	NM	RT-PCR^a	NM	Yes	No	12	RT-PCR^a	Alive
	2	72F		Yes	No	Moderate	NM		NM	Yes	No	14		Alive
	3	60F		Yes	No	Moderate	NM		NM	Yes	No	09		Alive
	4	65F		Yes	Yes	Moderate	NM		NM	Yes	No	12		Alive
	5	58M		Yes	No	Moderate	NM		NM	Yes	No	16		Alive
	6	64M		Yes	No	Severe	NM		NM	Yes	No	29		Alive
	7	36F		Yes	No	Moderate	NM		NM	Yes	No	06		Alive
	8	26M		No	No	Moderate	NM		NM	Yes	No	06		Alive
14	Deng et al.¹⁹	Age - 54.8 years, F- 36	China	NM	24 (39.3%)	Severe-3 (4.9%)	NM	RT-PCR^a	Not done	Yes	38-No	0 (7–13)	36-RT-PCR 17- AS; 8- sputum	Alive (All)
15	Peng et al.²⁰
	1	67M	China	Yes	NM	Mild	24 January	PCR	NM	Yes	No	4	RT-PCR	Alive
	2	- M		Yes	NM	Mild	24 January	PCR	NM	Yes	No	6	RT-PCR	Alive
	3	- F		Yes	NM	Mild	27 January	PCR	NM	Yes	No	3	RT-PCR	Alive
	4	- M		Yes	NM	Mild	28 January	PCR	NM	Yes	No	7	RT-PCR	Alive
	5	38F		Yes	NM	Mild	24 January	PCR	NM	Yes	No	6	AS	Alive
	6	29M		Yes	NM	Mild	29 January	PCR	NM	Yes	No	6	AS	Alive
	7	21F		Yes	NM	Mild	31 January	PCR	NM	Yes	No	5	RT-PCR	Alive
16	Wu et al.²¹
	1	>70	China	NM	Yes	NM	01 February	NM	NM	NM	Yes	3	RT-PCR	Alive
	2	>70		NM	Yes	NM	02 February’	NM	NM	NM	Yes	5	RT-PCR/AS	Alive
	3	NM		NM	NM	NM	02February	NM	NM	NM	No	6	AS	Alive
	4	NM		NM	NM	NM	23 January	NM	NM	NM	No	25	RT-PCR	Alive
	5	NM		NM	NM	NM	27 January	NM	NM	NM	No	16	RT-PCR	Alive
	6	NM		NM	NM	NM	30 January	NM	NM	NM	No	9	RT-PCR	Alive
	7	NM		NM	NM	NM	29 January	NM	NM	NM	No	22	AS	Alive
	8	NM		NM	NM	NM	28 January	NM	NM	NM	No	23	AS	Alive
	9	NM		NM	NM	NM	07 February	NM	NM	NM	No	11	AS	Alive
	10	NM		NM	NM	NM	07 February	NM	NM	NM	No	07	AS	Alive
17	Zhou et al.²²	40M	China	Yes	Yes	Severe	23 January	RT-PCR	Yes	Yes	Yes	5 days after discharge	RT-PCR	Alive
18	Zhao et al²³
18	(7/14)	5.7 (Median) (2.9–7.3)Range F-4	China	5 Yes 2 No	No Co-morbidity	Mild (All)	NM (All)	RT-PCR^a	NM (All)	Yes(all)	6-No 1- Yes	14 days from discharge (7–17)	RT-PCR^a	Alive (All)
19	Li et al.²⁴	50M	China	Yes	Yes	Mild	D13	RT-PCR	Yes on D 40. IgM and IgG positive	Yes	No	14	RT-PCR	Alive
20	Chen et al.²⁵
	1	29M	China	Yes	NM	Mild	01 February	RT-PCR^a	NM	Yes	No	3	RT-PCR^a	Alive
	2	49F		Yes	NM	Mild	02 February		NM	Yes	No	3		Alive
	3	12F		No	NM	Mild	05 February		NM	Yes	No	3		Alive
	4	38M		Yes	NM	mild	30 January		NM	Yes	No	3		Alive
21	Hu et al²⁶ (11)	median age 27, range 4–58 years F-4	China	Yes (All)	3-Co-morbidities	Mild-1 Moderate- 9 Severe-1	NM(All)	RT-PCR^a	NM(All)	Yes (All)	No (All)	14 (9–17)	RT-PCR^a	Alive (All)
22	Jianghong An et al.²⁷	Median age 20 (5–64) 7-F (Mild) 38 (2–60) 15-F	China	Yes	1/11 1/27	Mild −11 Moderate 27	Patient were discharged, January 23 to February 25 (14 days)	RT PCR, Anal swab	Yes no difference between the two groups	Yes (All)	No (All)	Weekly after discharge	RT PCR^a	Alive (All)
23	Chen et al.²⁸	46 F	China	Yes	No	Mild	24 January	RT-PCR	No	Yes	No	03 days after last negative test	RT-PCR	Alive
24	Duggan et al.²⁹	82 M	USA	Yes	Yes	Severe	Early April	RT-PCR	No	Yes	No	10 days post discharge	RT-PCR	Alive
25	Ye-min et al.³⁰	49 M	China	Yes	NM	Mild	22 January	RT-PCR	NM	Yes	No	3 days after discharge	Sputum positive PCR -ve	Alive
26	To et al.³¹	33M	Hong kong	Yes	No Co-morbidity	Mild	29 March	RT- PCR	NM	Yes	No	123 days after discharge	RT-PCR	Alive
27	Tillet et al.³²	25M	USA	Yes	No	Mild	18 April	RT- PCR	Yes	Yes	Yes	10 days after last negative test	RT-PCR	Alive
28	Elslande et al.³³	51F	Belgium	Yes	Asthma	Moderate	March 20	RT-PCR	Yes (second time)	No	Yes	10 weeks after home quarantine	RT-PCR	Alive
29	Prado-Vivar B et al.³⁴	46M	Eucadorian	Yes	NM	Mild	May 12	RT-PCR	Yes	Yes	Yes	6 weeks after being negative	RT-PCR	Alive
30	Gupta et al.³⁵	25M	India	Yes	No	No	05 May	RT-PCR^a	NM NM	Yes	No	100 days after tested negative	RT-PCR	Alive
30	Gupta et al.³⁵	28F	India	Yes	No	No	17 May	RT-PCR^a	NM NM	Yes	No	101 days	RT-PCR	Alive

AS, anal swab; F, female; M, male; NM, not mentioned; RT-PCR, reverse transcriptase polymerase chain reaction (naso-pharyngeal swab).

Same for all.