To compare and explore the differences of clinical characteristics between human adenovirus type 7 (HAdV7) and type 55 (HAdV55) infections in adults, and to provide evidences for clinical management.

The data of clinical manifestations, laboratory examinations, chest computed tomography and prognosis of 214 cases with HAdV7 and 235 cases with HAdV55 infections from 2012 to 2018 were retrospectively collected and analyzed. The chi-square test was used for the categorical variables, and the rank sum test was used for the continuous variables of non-normal distribution.

Compared with patients in HAdV55, those in HAdV7 group displayed more diarrhea (12.1%[26/214] vs 2.6%[6/235],χ²=15.583), more laryngeal lymphatic follicles (33.2%[71/214] vs 17.9%[42/235],χ²=23.566), more tonsil enlargement (56.5%[121/214] vs 20.0%[47/235],χ²=63.870) with secretions (33.2%[71/214] vs 11.5%[27/235],χ²=30.878), more leukocytosis (24.8%[53/214] vs 14.0%[33/235],χ²=8.318), more monocytosis (78.0%[167/214] vs 52.8%[124/235],χ²=31.364), more thrombocytosis (7.1%[15/212] vs 3.8%[9/235],χ²=5.835), more elevated level of C-reactive protein (80.8%[97/120] vs 64.3%[137/213],χ²=10.020), more abnormalities of liver function (alamne aminotransferase [ALT]: 13.5%[28/207] vs 5.6%[13/232],χ²=8.111) and myocardial enzymes (creatine kinase [CK]: 37.6%[77/205] vs 26.4% [61/231],χ²=6.246), creatine kinase isoenzymes ([CK-MB]: 35.6% [73/205] vs 11.1% [24/216],χ²=35.600), and all the differences were statistically significant (all P<0.05, 0.01). Compared with patients in HAdV7 group, those in HAdV55 group displayed longer duration of diseases (7[5] days vs 6[5] days,Z=-2.632), more sore throat (72.8% [171/235] vs 62.1% [133/214],χ²=0.016), more headache (62.1% [146/235] vs 16.4% [35/214],χ²=97.527), more pharyngeal congestion (93.6% [220/235] vs 74.8%[160/214],χ²=30.602), more leukopenia (14.0% [33/235] vs 24.8% [53/214],χ²=8.318), and more elevated level of lactate dehydrogenase (12.6% [29/230] vs 6.3% [13/205],χ²=4.881), more pneumonia (71.5% [168/235] vs 31.8% [68/214],χ²=70.846) (all P<0.05, 0.01).

The clinical characteristics of HAdV7 and HAdV55 infections in adults are different. The type 55 infection is more likely to develop to pneumonia, while the type 7 infection has wider tissue tropism.

Adenovirus infections, human; Pneumonia, viral; Clinical characteristics; Case analysis