Severe Japanese encephalitis of a pregnant woman in the first trimester of pregnancy: a case report
Severe Japanese encephalitis of a pregnant woman in the first trimester of pregnancy: a case report

Severe Japanese encephalitis of a pregnant woman in the first trimester of pregnancy: a case report

BMC Infect Dis. 2025 Sep 25;25(1):1123. doi: 10.1186/s12879-025-11342-2.

ABSTRACT

BACKGROUND: Japanese encephalitis (JE) is a natural zoonotic epidemic disease, mostly prevalent from July to September every year in China. JE is increasingly affecting adults in China, but severe JE patients who are pregnant are rarely reported in this country and in other countries. We report a case of pregnant Chinese woman who was diagnosed with JE, to highlight treatment points in the gestational state.

PATIENT PRESENTATION: A 27-year-old pregnant woman at 7 + weeks of gestation was admitted to the hospital due to a 7-day history of fever and progressive confusion, accompanied by urinary incontinence and febrile convulsions lasting for 3 days. The patient was comatose, required mechanical ventilation at admission, and had a history of splenectomy. JE virus sequences and IgG antibodies were detected in the cerebrospinal fluid (CSF). A head CT scan of the patient revealed no obvious abnormalities, whereas brain magnetic resonance imaging (MRI) revealed progressively marked high signal intensities in the bilateral thalami. Therefore, she was diagnosed with JE, whose manifestations included fever, intracranial hypertension, coma and respiratory failure. We treated her symptomatically with anti-infection, antivirals, anti-epileptics, and mannitol, to lower intracranial pressure (ICP). Nutritional conditions and coagulation function were monitored. The patient’s respiratory function was restored on day 14. When the condition became stable and the patient had no serious infection, curettage was performed on day 22. After curettage, we comprehensively enhanced the anti-inflammatory effects, nutritional support, anti-epilepsy, acid‒base balance and other treatments, and the patient’s condition was relatively stable. The adverse reactions to treatment included transaminitis and continued hyponatremia.

CONCLUSION: Pregnancy may have contributed to the pathogenesis of severe JE infection in this patient. The administration of the vaccines in high-risk women considering fertility may prolong protective cell-mediated immunity and maintain IgM response to protect from severe JE virus infection. The treatment of pregnant JE patients was symptomatic, and attention was given to the patient’s nutritional status, acid balance and coagulation function. The incidence of secondary anti-NMDAR encephalitis in JE pregnant patients is also worthy of inquiry.

PMID:40999350 | DOI:10.1186/s12879-025-11342-2