Volume 20, Number 9—September 2014
Dispatch
Risk Factors for Severe Influenza A–Related Pneumonia in Adult Cohort, Mexico, 2013–14
, Martin Magaña-Aquino, Sofía Bernal-Silva, Javier Araujo-Meléndez, Andreu Comas-García, Emma Alonso-Zúñiga, Eliana Torres-Torres, and Daniel E. Noyola
Table 2
Demographic features of adult patients admitted with confirmed influenza virus pneumonia during December 5, 2013–February 7, 2014 compared with patients with confirmed influenza A(H1N1)pdm09 infection during the 2009–10 pandemic period, San Luis Potosí, Mexico*
| Characteristics | 2009–10, n = 100 | 2013–14, n = 55 | p value |
|---|---|---|---|
| Age, y, mean (SD) median (range) | 38.9 (13.1), 37 (15–71) | 46.1 (14), 45 (19–79) | 0.002 |
| Sex, no. (%) | |||
| M | 52 (52) | 28 (50.9) | 0.89 |
| F | 48 (48) | 27 (49.1) | |
| Presence of ≥1 underlying conditions, no. (%) | 68 (68) | 47 (85.5) | 0.017 |
| Obesity (body mass index>30)† | 39 (39.8) | 40 (74.1) | <0.001 |
| Diabetes mellitus | 20 (20) | 15 (27.3) | 0.3 |
| Immunosuppression | 8 (8) ‡ | 3 (5.5) § | 0.75 |
| Asthma-COPD-bronchiectasis | 9 (9) | 2 (3.6) | 0.33 |
| Other | 19 (19) | 4 (7.3) # | 0.049 |
| Any underlying disorder excluding obesity, no. (%) | 45 (45) | 23 (41.8) | 0.7 |
| Influenza vaccination during most recent season, no. (%)** | 4 (4) | 3 (5.5) | 0.7 |
| Clinical findings | |||
| Body mass index, mean (SD) † | 28.9 (5.9) | 31.9 (3.9) | <0.001 |
| PaO2/FiO2, mean (SD) †† | 152.1 (102.5) | 156.2 (69.3) | 0.32 |
| Total WBCs, K/μL, mean (SD) † | 8.4 (5.3) | 6.4 (3.2) | 0.02 |
| Lymphocytes, K/μL, mean (SD) ‡‡ | 0.94 (0.5) | 0.85 (0.72) | 0.37 |
| C-reactive protein, mg/dL, mean (SD) § § | 14.1 (9.8) | 17.9 (10.9) | 0.03 |
| Lactate dehydrogenase, U/L, mean (SD) ¶¶ | 1,099.4 (769.6) | 581.8 (387.9) | <0.001 |
| Creatine phosphokinase, U/L, mean (SD) ## | 530 (820.6) | 480.6 (513.9) | 0.69 |
| Duration of symptoms before dyspnea, days, mean (SD) *** | 2.1 (3.5) | 3 (3.4) | 0.13 |
| Dyspnea duration before admission, days, mean (SD) ††† | 2.7 (2.7) | 3.8 (2.6) | 0.03 |
| Duration of symptoms before hospital admission, days, mean (SD) ** | 4.7 (6.6) | 6.6 (3.8) | 0.003 |
| Other features | |||
| Requirement for mechanical ventilation, no. (%) | 47 (47) | 36 (65.5) | 0.03 |
| Death within 5 d from admission, no. (%) | 6 (6) | 6 (10.9) | 0.35 |
*Statistical analyses used included Fisher exact test, chi-square test, Student t test, and Mann Whitney u test; S/D, standard deviation; COPD, chronic obstructive pulmonary disease; PaO2/FiO2, partial pressure arterial oxygen and fraction of inspired oxygen ratio; U/L, units per liter.
† Data was available for 152 patients.
‡ Includes chronic renal failure (4 cases), chronic steroid use (3 cases), and leukemia (1 case).
§ HIV infection (1 case), autoimmune disorder (2 cases; 1 had renal transplant),
¶ Some patients had >1 underlying condition: heart failure (6 cases), pregnancy/puerperium (6 cases), hypothyroidism (4 cases), seizure disorder (2 cases), ischemic cardiopathy (1 case), microcephaly (1 case), Down syndrome (1 case), obstructive sleep apnea (1 case).
# Down syndrome (2 cases); hypothyroidism (1 case), cardiopathy (1 case).
** Data available for 154 patients.
†† Data available for 147 patients.
‡‡ Data available for 151 patients.
§ § Data available for 144 patients.
¶¶ Data available for 135 patients.
## Data available for 131 patients.
*** Data available for 139 patients
††† Data available for 138 patients