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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 1
Clinical characteristics of patients in study of severe YF, Brazil, 2017–2019*
| Characteristic | Wild-type YF, n = 68 | YEL-AVD, n = 5 | Total YF, n = 73 |
|---|---|---|---|
| Sex | |||
| M | 59 (86.8) | 3 (60.0) | 62 (84.9) |
| F |
9 (13.2) |
2 (40.0) |
11 (15.1) |
| Age, y (range) |
49 (35.5–60) |
37 (32–49) |
48 (34–60) |
| Previous medical condition | |||
| Hypertension | 19 (27.9) | 2 (40.0) | 21 (28.8) |
| Diabetes | 8 (11.8) | 0 | 8 (11.0) |
| Heart disease | 5 (7.4) | 0 | 5 (6.8) |
| Asthma/COPD |
4 (5.9) |
0 |
4 (5.5) |
| Habits | |||
| Alcoholism | 36 (52.9) | 1 (20.0) | 37 (50.7) |
| Smoking | 26 (38.2) | 1 (20.0) | 27 (37.0) |
| Illicit drug use |
11 (16.2) |
0 |
11 (15.1) |
| Diagnostic criteria for YF | |||
| Clinical criteria | 68 (100) | 5 (100) | 73 (100) |
| Epidemiologic criteria | 68 (100) | 5 (100) | 73 (100) |
| Live near to epizootic areas | 46 (63) | NA | 46 (63) |
| Travel to epizootic areas | 35 (48) | NA | 35 (48) |
| Serology, IgM, no. (%), n = 47 |
37 (80) |
NA |
37 (80) |
| Time interval, d (range) | |||
| Symptoms to hospitalization | 4 (3–6) | 5 (4–7) | 4 (3–6) |
| Symptoms to death | 9 (7–11) | 8 (7–11) | 9 (7–11) |
| Hospitalization to death | 5 (3–6) | 3 (2–5) | 5 (3–6) |
| Intubation to death |
2 (1–4) |
2 (1–5) |
2 (1–4) |
| Respiratory symptoms at admission | |||
| Hemoptysis | 6 (8.9) | 1 (20) | 7 (9.6) |
| Tachypnea | 6 (8.9) | 1 (20) | 7 (9.6) |
| Cough |
2 (3) |
1 (20) |
3 (4.1) |
| In-hospital events and interventions | |||
| Shock or vasopressor use | 68 (100) | 5 (100) | 73 (100) |
| Dialysis | 58 (85.3) | 4 (80.0) | 62 (84.9) |
| Mechanical ventilation | 68 (100) | 5 (100) | 73 (100) |
| Liver transplant for YF hepatitis | 4 (5.9) | 0 | 4 (5.5) |
| Secondary infection | 53 (77.9) | 3 (60.0) | 56 (76.7) |
| Clinical diagnosis of pneumonia | 5 (7) | 0 | 5 (7) |
| SAPS 3, no. (range) |
62 (31–104) |
0 |
62 (31–104) |
| Vaccine status | |||
| YF vaccine | 9 (13.2) | 5 (100) | 14 (19.2) |
| Vaccination >10 d before symptoms |
2 (2.9) |
0 |
2 (2.7) |
| Laboratory tests, no. (range) | n = 64 | n = 0 | n = 64 |
| Initial absolute neutrophil count, cells/µL | 4,466 (2,433–6,633) | 4,466 (2,433–6,633) | |
| Initial lymphocyte count, cells/µL | 675 (440–1,095) | 675 (440–1,095) | |
| Aspartate aminotransferase, U/L† | 14,829 (3,523–75,000) | 14,829 (3,523–75,000) | |
| Alanine aminotransferase, U/L‡ | 6,074 (1,758–14,998) | 6,074 (1,758–14,998) | |
| Direct bilirubin, mg/dL§ | 7.26 (3.06–31.67) | 7.26 (3.06–31.67) | |
| Initial PaO2/ FiO2 ratio | 380 (281–471) | 380 (281–471) | |
| PaO2/FiO2 ratio during hospitalization, no. positive/no. tested (%) | |||
| Moderate or severe, <200 | 36/64 (56) | 36/64 (56) | |
| Severe, <100 | 12/64 (19) | 12/64 (19) |
*Values are no. (%) except as indicated. COPD, chronic obstructive pulmonary disease; NA, not applicable; PaO2/FiO2, ratio of the partial pressure of oxygen in arterial blood to the inspired oxygen; SAPS 3, Simplified Acute Physiology Score III; YF, yellow fever; YEL-AVD, yellow fever vaccine–associated viscerotropic disease. †Reference range 10–40 U/L. ‡Reference range 4–36 U/L. §Reference value<0.3 mg/dL.
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Page updated: February 15, 2026
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