Zika virus infection in the Veterans Health Administration (VHA), 2015-2016

Background
Zika virus (ZIKV) is an important flavivirus infection. Although ZIKV infection is rarely fatal, risk for severe disease in adults is not well described. Our objective was to describe the spectrum of illness in U.S. Veterans with ZIKV infection.
Methodology
Case series study including patients with laboratory-confirmed or presumed positive ZIKV infection in all Veterans Health Administration (VHA) medical centers. Adjusted odds ratios of clinical variables associated with hospitalization and neurologic complications was performed.
Principal findings
Of 1,538 patients tested between 12/2015-10/2016 and observed through 3/2017, 736 (48%) were RT-PCR or confirmed IgM positive; 655 (89%) were male, and 683 (93%) from VA Caribbean Healthcare System (VACHCS). Ninety-four (13%) were hospitalized, 91 (12%) in the VACHCS. Nineteen (3%) died after ZIKV infection. Hospitalization was associated with increased Charlson co-morbidity index (adjusted odds ratio [OR] 1.2; 95% confidence interval [CI], 1.1–1.3), underlying connective tissue disease (OR, 29.5; CI, 3.6–244.7), congestive heart failure (OR, 6; CI, 2–18.5), dementia (OR, 3.6; CI, 1.1–11.2), neurologic symptom presentation (OR, 3.9; CI, 1.7–9.2), leukocytosis (OR, 11.8; CI, 4.5–31), thrombocytopenia (OR, 7.8; CI, 3.3–18.6), acute kidney injury (OR, 28.9; CI, 5.8–145.1), or using glucocorticoids within 30 days of testing (OR, 13.3; CI 1.3–133). Patients presenting with rash were less likely to be hospitalized (OR, 0.29; CI, 0.13–0.66). Risk for neurologic complications increased with hospitalization (OR, 5.9; CI 2.9–12.2), cerebrovascular disease (OR 4.9; CI 1.7–14.4), and dementia (OR 2.8; CI 1.2–6.6).
Conclusion
Older Veterans with multiple comorbidities or presenting with neurologic symptoms were at increased risk for hospitalization and neurological complications after ZIKV infection.

背景
寨卡病毒（Zika virus, ZIKV）是一种重要的黄病毒属感染性疾病。尽管寨卡病毒感染极少导致死亡，但成人重症疾病的发病风险尚未得到充分阐明。本研究旨在描述美国退伍军人感染寨卡病毒后的疾病谱特征。
研究方法
本研究为病例系列研究，纳入全美退伍军人健康管理局（Veterans Health Administration, VHA）各医疗中心内经实验室确诊或疑似寨卡病毒检测阳性的患者。研究针对与住院治疗及神经系统并发症相关的临床变量开展了校正比值比分析。
主要研究结果
本研究纳入2015年12月至2016年10月期间接受检测、并随访至2017年3月的1538例患者，其中736例（48%）逆转录聚合酶链反应（RT-PCR）阳性或经确诊的免疫球蛋白M（IgM）阳性；655例（89%）为男性，683例（93%）来自退伍军人加勒比医疗系统（VA Caribbean Healthcare System, VACHCS）。共计94例（13%）患者接受住院治疗，其中91例（12%）来自VACHCS。19例（3%）患者在感染寨卡病毒后死亡。
住院治疗风险与以下因素显著相关：查尔森合并症指数升高（校正比值比[OR] 1.2；95%置信区间[CI] 1.1~1.3）、基础性结缔组织病（OR 29.5；CI 3.6~244.7）、充血性心力衰竭（OR 6；CI 2~18.5）、痴呆（OR 3.6；CI 1.1~11.2）、以神经系统症状为首发表现（OR 3.9；CI 1.7~9.2）、白细胞增多症（OR 11.8；CI 4.5~31）、血小板减少症（OR 7.8；CI 3.3~18.6）、急性肾损伤（OR 28.9；CI 5.8~145.1），以及检测前30天内使用糖皮质激素（OR 13.3；CI 1.3~133）。而以皮疹为首发表现的患者住院风险显著更低（OR 0.29；CI 0.13~0.66）。
神经系统并发症的发病风险升高与以下因素相关：住院治疗（OR 5.9；CI 2.9~12.2）、脑血管疾病（OR 4.9；CI 1.7~14.4）以及痴呆（OR 2.8；CI 1.2~6.6）。
结论
合并多种基础疾病或出现神经系统症状的老年退伍军人，在感染寨卡病毒后发生住院治疗及神经系统并发症的风险显著升高。