McConnochie K M, Hall C B, Walsh E E, Roghmann K J
Department of Pediatrics, Rochester General Hospital, NY 14621.
J Pediatr. 1990 Jul;117(1 Pt 1):52-62. doi: 10.1016/s0022-3476(05)82443-6.
Two major subtypes of respiratory syncytial virus have been identified. This study assessed the hypothesis that A-subtype infections were more severe than B-subtype infections among the 157 infants hospitalized in two hospitals in Rochester, N.Y., during two winters. Severity was measured both by specific clinical observations and by a severity index that was derived empirically. Among all subjects, several clinical observations suggested that A-subtype infections were more severe. For example, mechanical ventilation was required in 12.6% of those with A-subtype compared with 1.6% of those with B-subtype infection (relative risk = 7.88; p = 0.01). Among high-risk infants (infants with underlying conditions or age 3 months or less at admission), carbon dioxide tension greater than 45 mm Hg was found in 37.0% of those with A-subtype compared with 12.0% of those with B-subtype infection (relative risk = 3.08; p = 0.04). In discrete multivariate (logit) analysis, effects of subtype (odds ratio = 6.59; p less than 0.01) on severity remained after adjustment for other statistically significant effects of age less than 3 months, underlying condition, and premature birth. The finding that A-subtype infections were more severe might have important implications for vaccine development, studies of the virulence of respiratory syncytial virus, clinical management (e.g., selection for antiviral therapy), and long-term prognosis.
呼吸道合胞病毒已被鉴定出两种主要亚型。本研究评估了一种假设，即在纽约州罗切斯特市两家医院住院的157名婴儿中，在两个冬季期间，A亚型感染比B亚型感染更严重。严重程度通过特定的临床观察和根据经验得出的严重程度指数来衡量。在所有受试者中，多项临床观察表明A亚型感染更严重。例如，A亚型感染患者中有12.6%需要机械通气，而B亚型感染患者中这一比例为1.6%（相对风险=7.88；p=0.01）。在高危婴儿（入院时患有基础疾病或年龄在3个月及以下的婴儿）中，A亚型感染患者中有37.0%的二氧化碳分压大于45 mmHg，而B亚型感染患者中这一比例为12.0%（相对风险=3.08；p=0.04）。在离散多变量（logit）分析中，在对年龄小于3个月、基础疾病和早产等其他具有统计学意义的影响进行调整后，亚型对严重程度的影响（优势比=6.59；p<0.01）仍然存在。A亚型感染更严重这一发现可能对疫苗研发、呼吸道合胞病毒毒力研究、临床管理（如抗病毒治疗的选择）以及长期预后具有重要意义。
