A Case of Brain Tuberculosis With an Unusual Presentation Mimicking Viral Fever During a Dengue Outbreak in Bangladesh.

Both dengue and tuberculosis are endemic in South Asian countries, including Bangladesh. Here we report an interesting case presenting as suspected dengue fever and eventually diagnosed as a case of brain tuberculosis. A 27-year-old immunocompetent male presented to us with fever, headache, retro-orbital pain, and photophobia for five days. He had no other complaints, and clinical examination findings were normal. Full blood count revealed neutrophilic leukocytosis; dengue antigen test and anti-dengue antibody test were negative. Magnetic resonance imaging (MRI) of the brain showed both supra and infra-tentorial multiple small (2-4 mm) gadolinium-enhancing lesions suggestive of tuberculomas. A cerebrospinal fluid study revealed lymphocytic pleocytosis with raised protein, low sugar level, and positive Gene Xpert MTB/RIF (Cepheid, California, US) assay test. Investigations did not reveal the involvement of other organs except for the brain. We started standard anti-tuberculosis therapy (HRZE) along with steroids and pyridoxine, and the patient became symptom-free within one week. The patient was discharged with the advice of follow-up after one month. The clinical course and all investigation findings of this case are presented. Central nervous system tuberculosis may present with non-specific signs and symptoms and may be misdiagnosed as other infections, including dengue, particularly during an ongoing epidemic. It may cause significant morbidity and mortality when the diagnosis is delayed due to its vague clinical presentation.