Yong Loo Ling School of Medicine, Singapore, Singapore.
Department of Internal Medicine, Singapore General Hospital, Singapore, Singapore.
Am J Case Rep. 2021 May 17;22:e931519. doi: 10.12659/AJCR.931519.
BACKGROUND Dengue virus is a common arbovirus with uncertain neurotropism. Dengue encephalitis is a rare but fatal manifestation of severe dengue. Diagnosis requires high clinical suspicion. It should be routinely considered in patients with encephalopathy, especially in countries where dengue virus is endemic. Unlike other forms of severe dengue, the typical warning signs and biochemical derangements are not reliable markers for dengue encephalitis. Alternative biochemical markers of dengue encephalitis are needed. CASE REPORT We present a case of dengue encephalitis with distinctly raised procalcitonin (13.2 μg/L), in the absence of the typical warning signs and biochemical derangements of severe dengue. The patient was a 65-year-old man with fever and sudden loss of consciousness in the absence of other localizing signs/symptoms. Inflammatory markers were raised, with findings of leptomeningeal enhancement on brain computed tomography suggestive of meningoencephalitis. Septic workup was unremarkable (normal renal and liver functions, negative blood and urine cultures). The typical neurotropic microorganisms were not detected in the cerebrospinal fluid. On day 4 of admission, the patient reported abdominal pain and hematuria with a new onset of bicytopenia. Subsequent investigations for dengue infection were positive for serum dengue NS1 antigen and dengue RNA (type 2 strain) in cerebrospinal fluid, confirming the diagnosis of dengue encephalitis. The patient was managed supportively and experienced full clinical recovery. CONCLUSIONS Dengue encephalitis is a rare condition with nonspecific biochemical and imaging abnormalities. We demonstrated that a raised procalcitonin level can occur in the setting of dengue encephalitis. In endemic countries, this finding may prompt further investigations for dengue encephalitis in patients with meningoencephalitis.
登革热病毒是一种常见的虫媒病毒，其神经嗜性不确定。登革脑炎是一种罕见但致命的重症登革热表现。诊断需要高度的临床怀疑。在发生脑病的患者中，特别是在登革热流行的国家，应常规考虑这种疾病。与其他形式的重症登革热不同，典型的预警信号和生化异常并不是登革脑炎的可靠标志物。需要替代的登革脑炎生化标志物。
我们报告了一例登革脑炎病例，其降钙素原明显升高（13.2 μg/L），而无重症登革热的典型预警信号和生化异常。患者为 65 岁男性，发热，突发意识丧失，无其他定位体征/症状。炎症标志物升高，脑计算机断层扫描显示脑膜增强，提示脑膜脑炎。全身性检查未见异常（肾功能和肝功能正常，血和尿培养均为阴性）。脑脊液中未检测到典型的神经嗜性微生物。入院第 4 天，患者出现腹痛和血尿，伴有双系细胞减少症的新发。随后对登革热感染的检查显示血清登革 NS1 抗原和脑脊液登革 RNA（2 型株）阳性，确诊为登革脑炎。患者接受了支持性治疗，完全康复。
登革脑炎是一种罕见的疾病，具有非特异性的生化和影像学异常。我们证明了降钙素原水平升高可发生在登革脑炎中。在流行地区，这种发现可能会促使对脑膜脑炎患者进行进一步的登革脑炎检查。
