Household Transmission of SARS-CoV-2 in Bhutan

Table 2

Characteristics of secondary transmission of COVID-19 in households.

Characteristics	Household contacts ()	Positive household contacts ()	Secondary attack rate (%)	95% CI
Characteristics of household contacts
Age
<18 years	123	78	63.4	(54.5-71.5)
≥18 years	183	102	55.7
18-44 years	146	78	53.4	(44.1-61.4)
45-59 years	23	16	69.6	(47.9-85)
≥60 years	14	8	57.1	(30.7-80.1)
Sex
Male	131	78	59.5	(50.9-67.7)
Female	175	102	58.3	(50.8-65.4)
Relationship to the index case
Spouse	47	26	55.3	(40.9-68.9)
Siblings	39	16	41	(26.7-57.1)
Child	99	72	72.7	(63.1-80.6)
Parents	28	15	53.6	(35.1-71.1)
Relatives (grandparents, cousins, others)	47	22	46.8	(33-61.1)
Friend/neighbor	39	26	66.7	(50.4-79.7)
Employee	7	3	42.9	(12.9-79.2)
Clinical status
Symptomatic	105	104	99	(93.4-99.9)
Asymptomatic	201	76	37.8	(31.3-44.8)
Symptom status
Mild	102	101	99	(93.2-99.9)
Moderate	3	3	100	—
Comorbid
Yes	17	10	58.8	(34.5-79.5)
No	289	170	58.8	(53-64.4)
Vaccination
Yes	179	99	55.3	(47.9-62.5)
No	127	81	63.8	(55-71.7)
Vaccination (≥18 years of age)
Yes	178	98	55.1	(47.6-62.3)
No	5	4	80	(25.3-97.9)
Doses
1 dose	179	99	55.3	(47.9-62.5)
Past COVID infection
Yes	1	0	0	—
No	305	180	59	(53.4-64.4)
Characteristics of index case
Age of index case
<18 years	39	13	33.3	(20.3-49.6)
≥18 years	267	167	62.5	(56.6-68.2)
Index case sex
Male	156	91	58.3	(50.4-65.9)
Female	150	89	59.3	(51.2-67)
Symptom status of index case
Symptomatic index	233	142	60.9	(54.5-67)
Asymptomatic index	73	38	52.1	(40.6-63.3)
Vaccination status of index case
Yes	257	167	65	(58.9-70.6)
No	49	13	26.5	(16-40.7)