6. フランス:80名にHCQ400mg/日+AZM投与
Day5で97.5%がウイルス培養陰性(鼻咽頭検体),
Day9ですべてウイルス培養陰性化
Black bars: number of patients with available results, grey bars: number of patients with positive culture, solid
line: percentage of patients with a positive culture, dashed line: logarithmic regression curve.
Gautret P, Lagier J-C, Parola P, Hoang VT, Meddeb L, Sevestre J, et al. Clinical and microbiological
effect of a combination of hydroxychloroquine and azithromycin in 80 COVID-19 patients with at least
a six-day follow up: A pilot observational study. Travel Medicine and Infectious Disease. 2020 Apr 11.
7. 米国skilled nursing facility
−9 −8 −7 −6 −5 −4 −3 −2 −1 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
Days from First Evidence of Fever, Cough, or Shortness of Breath
CycleThresholdValuesforN1Target
15
10
20
25
35
30
40
No culturePositive culture Negative culture
発熱,咳,息切れが最初に確認された日から日数
N1を標的にしたCyclethreshold値
培養陽性 培養陰性 培養採取なし
発症6日前から9日目までウイルス培養陽性になりえた
Arons MM, Hatfield KM, Reddy SC, Kimball A, James A, Jacobs JR, et al. Presymptomatic SARS-
CoV-2 Infections and Transmission in a Skilled Nursing Facility. N Engl J Med. 2020;382:2081‒90.
8. ウイルス培養陽性になる中央値は4日間
(IQR: 1‒8; 幅: -13 ~ 12)
15
20
25
30
35
40
Ctvalue
-20 0 20 40 60
Days from symptom onset
A. Culture positivity, Ct value and timing of each
individual sample.
Culture-positive
Culture-negative
B. Mixed effects logistic regression analysis.
0
20
40
60
80
100
%culture-positive -10 0 10 20 30 40
Days from symptom onset
Ct=cycle threshold.
Singanayagam A, Patel M, Charlett A, Lopez Bernal J, Saliba V, Ellis J, et al.
Duration of infectiousness and correlation with RT-PCR cycle threshold values in
cases of COVID-19, England, January to May 2020. Euro Surveill. 2020;25(32).
9. 発症7~15日後に
ウイルス培養陽性の割合
Table 1
Estimated percentage of SARS-CoV-2 samples culture-positive 7–15 days after symptom onset, England, January–May 2020
(n = 121)
Day post symptom onset Estimateda percentage culture-positive (95% CI) N (observed number tested) R (observed number culture-positive
7 40.1 (22.8–60.4) 14 10
8 25.8 (11.0–49.4) 33 9
9 13.7 (3.7–39.6) 34 10
10 6.0 (0.9–31.2) 23 6
11 2.2 (0.2–23.9) 6 1
12 0.7 (0.0–17.9) 3 1
13 0.2 (0.0–13.1) 4 0
14 0.03 (0.0–9.4) 2 0
15 0.006 (0.0–6.7) 2 0
CI: confidence interval.
a
From mixed effects logistic regression model.
Singanayagam A, Patel M, Charlett A, Lopez Bernal J, Saliba V, Ellis J, et al.
Duration of infectiousness and correlation with RT-PCR cycle threshold values in
cases of COVID-19, England, January to May 2020. Euro Surveill. 2020;25(32).
12. 台湾の接触者調査
• 確定患者100人の濃厚接触者2761人を調査
• 濃厚接触の定義:
- 適切な防護具なしで15分を超える対面接触あり
- 医療機関では適切な防護具なしで2m以内接触あり
• 発症前の接触から二次感染あり
発症後6日目以降の接触開始では二次感染なし
ずっと無症状だった患者(9名)からは二次感染なし
軽症例に比べると重症例,ARDS/敗血症例からの感染リス
クが高かった
Cheng H-Y, Jian S-W, Liu D-P, Ng T-C, Huang W-T, Lin H-H, et al. Contact Tracing
Assessment of COVID-19 Transmission Dynamics in Taiwan and Risk at Different
Exposure Periods Before and After Symptom Onset. JAMA Intern Med. 2020 May 1.
13. 発症から6日目以降の
接触開始では二次感染なし
All types of contactA
Clinicalattackrate,%
<0 0-3 4-5 6-7 8-9 >9
1.5
1.0
0.5
0
Counts
Days from onset to exposure
1000
750
500
50
0
Household and family contactB
Clinicalattackrate,%
<0 0-3 4-5 6-7 8-9 >9
12
8
0
4
Counts
Days from onset to exposure
120
90
60
30
0
Case
Contact
すべての接触 同居と同居でない家族との接触
接触からの日数 接触からの日数
二次感染割合(%)
二次感染割合(%)
人数
人数
感染者
接触者
Cheng H-Y, Jian S-W, Liu D-P, Ng T-C, Huang W-T, Lin H-H, et al. Contact Tracing
Assessment of COVID-19 Transmission Dynamics in Taiwan and Risk at Different
Exposure Periods Before and After Symptom Onset. JAMA Intern Med. 2020 May 1.
14. 0
5
Secondarycases,No.
10
15
20
–5 5 10 15 20 25 30
Exposure time, days
0
Secondary casesA
発端者の発症日からの接触の日数(0が発症日)
二次感染例
・発症後5日以内に接触開始した人の中に6日目以降も接触が続いている人がいる
→6日目以降は感染性なし,は言い過ぎ(いつ感染したかは不明なので)
・6日目以降にしか接触がなかった人では二次感染が確認されていないことから6日
目以降は感染性が低下すると推定はできる
Cheng H-Y, Jian S-W, Liu D-P, Ng T-C, Huang W-T, Lin H-H, et al. Contact Tracing
Assessment of COVID-19 Transmission Dynamics in Taiwan and Risk at Different
Exposure Periods Before and After Symptom Onset. JAMA Intern Med. 2020 May 1.