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Volume 32, Number 2—February 2026
Research
Pulmonary Complications in Fatal Yellow Fever, Brazil, 2017–2019
Amaro N. Duarte-Neto
, Katia C. Dantas, Suzette C. Ferreira, Fernando R. Giugni, Marielton P. Cunha, Shahab Z. Pour, Felipe L. Ledesma, Yeh-Li Ho, Ana C.S. Nastri, Cinthya S.C. Borges, Fernanda A. Rodrigues, Ceila M.S. Malaque, Jaques Sztajnbok, Thais Mauad, Luiz F.F. Silva, Paulo H.N. Saldiva, and Marisa Dolhnikoff
, Katia C. Dantas, Suzette C. Ferreira, Fernando R. Giugni, Marielton P. Cunha, Shahab Z. Pour, Felipe L. Ledesma, Yeh-Li Ho, Ana C.S. Nastri, Cinthya S.C. Borges, Fernanda A. Rodrigues, Ceila M.S. Malaque, Jaques Sztajnbok, Thais Mauad, Luiz F.F. Silva, Paulo H.N. Saldiva, and Marisa Dolhnikoff
Table 2
Pulmonary findings in study of severe YF, Brazil, 2017–2019*
| Characteristic | Wild-type YF, n = 68 | YEL-AVD, n = 5 | Total YF, n = 73 |
|---|---|---|---|
| Pleural effusion | |||
| Any effusion | 18 (26) | 2 (40) | 20 (27) |
| Serous effusion | 13 (19) | 2 (40) | 15 (21) |
| Hemorrhagic effusion | 5 (7) | 0 | 5 (7) |
| Volume, mL (range) | 550 (400–1,000) | 400 (300–500) | 500 (400–950) |
| Pleuritis |
38 (52) |
38 (52) |
|
| Tracheal macroscopy | |||
| Mucosal congestion | 67 (99) | 5 (100) | 72 (99) |
| Mucosal edema | 67 (99) | 5 (100) | 72 (99) |
| Mucosal ulceration | 40 (59) | 1 (20) | 41 (56) |
| Mucosal hemorrhages |
55 (81) |
3 (60) |
58 (79) |
| Tracheal histology | n = 54 | n = 3 | n = 57 |
| Tracheitis | 51 (94) | 1 (33) | 52 (91) |
| Squamous metaplasia | 24 (44) | 0 | 24 (42) |
| Necrotizing tracheitis | 33 (61) | 0 | 33 (45) |
| Infectious microorganism |
19 (35) |
1 (20) |
20 (35) |
| Pulmonary macroscopic findings | |||
| Right lung weight, g (range)† | 758 (634–952) | 752 (633–895) | 755 (635–944) |
| Left lung weight, g (range)‡ | 658 (544–848) | 534 (378–707) | 654 (531–826) |
| Pulmonary cut surface with edema and hemorrhages | 68 (100) | 5 (100) | 73 (100) |
| Friable pulmonary cut surface |
59 (87) |
2 (40) |
61 (84) |
| Pulmonary microscopic findings | |||
| Alveolar edema§ | 67 (99) | 5 (100) | 72 (99) |
| Mild | 6 (9) | 0 | 6 (8) |
| Moderate | 36 (53) | 1 (20) | 37 (51) |
| Severe | 25 (37) | 4 (80) | 29 (40) |
| Alveolar hemorrhage§ | 61 (90) | 5 (100) | 66 (90) |
| Mild | 28 (41) | 3 (60) | 31 (42) |
| Moderate | 25 (37) | 1 (20) | 26 (36) |
| Severe | 8 (12) | 1 (20) | 9 (12) |
| Interstitial perivascular or peribronchial hemorrhage | 51 (70) | 51 (70) | |
| Secondary pneumonia§ | 59 (87) | 2 (40) | 61 (84) |
| Mild | 29 (43) | 1 (20) | 30 (41) |
| Moderate | 17 (25) | 0 | 17 (23) |
| Severe | 13 (19) | 1 (20) | 14 (19) |
| Bilateral | 47 (69) | 2 (40) | 49 (67) |
| Micro abscesses | 22 (32) | 1 (20) | 23 (32) |
| Bronchoaspiration | 42 (62) | 2 (40) | 44 (60) |
| Gram-positive cocci | 5 (7) | 1 (20) | 6 (8) |
| Bacilli | 55 (81) | 4 (80) | 59 (81) |
| Yeasts | 23 (34) | 4 (80) | 27 (37) |
| Hyphae | 8 (12) | 1 (20) | 9 (12) |
| Diffuse alveolar damage§ | 57 (84) | 4 (80) | 61 (84) |
| Mild | 46 (68) | 4 (80) | 50 (68) |
| Moderate | 11 (16) | 0 | 11 (15) |
| Severe | 0 | 0 | 0 |
| Proliferative | 4 (6) | 0 | 4 (5) |
| Increased siderophages in the alveolar space | 65 (96) | 5 (100) | 70 (96) |
| Increased megakaryocytes in the pulmonary parenchyma | 62 (91) | 5 (100) | 67 (92) |
| Fibrin and fibrinoid endothelial necrosis | 40 (59) | 2 (40) | 42 (58) |
| Pulmonary thrombi | 22 (32) | 1 (20) | 23 (32) |
| Macroscopic thrombi | 2 | 0 | 2 |
| Microscopic thrombi | 22 | 1 | 23 (32) |
| Hemophagocytosis¶ | 14 (21) | 2 (40) | 16 (22) |
| Bone marrow emboli | 4 (5.5) | 0 | 4 (5.5) |
| Emphysema | 37 | 0 | 37 (50.7) |
| Foci of mononuclear perivascular infiltrate |
68 |
5 |
73 (100) |
| RT-qPCR for YF | N = 61 | N = 4 | N = 65 |
| Positive | 57 (93) | 4 (100) | 61 (94) |
| Ct (range) | 28 (26–32) | 23 (22–32) | 28 (26–32) |
*Values are no. (%) except as indicated. Ct, cycle threshold; RT-PCR, reverse transcription quantitative polymerase chain reaction; YF, yellow fever; YEL-AVD, yellow fever vaccine–associated viscerotropic disease. †Mean reference weight is 465 g. ‡Mean reference weight is 400 g. §Mild, present in 1%–25%; moderate, present in 25%–50%; severe, present in >50% of the histological sample. ¶Alveolar macrophages or in macrophages within the sinuses of intrapulmonary lymph nodes.
Page created: January 20, 2026
Page updated: February 15, 2026
Page reviewed: February 15, 2026
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