Coinfection of tuberculosis and cryptococcosis: a one-two punch

The 'single and unifying diagnosis' principle of clinical medicine suggesting that a single organism causes infection of one or more organs might not stand steadfast in the presence of profound immunodeficiency. Despite both tuberculosis (TB) and cryptococcosis share common predisposition and host factors, e.g. human immunodeficiency virus (HIV), solid-organ or stemcell transplant recipients receiving immunosuppressive agents, chronic steroid therapy, their coinfection is rarely reported. olobe 1 has rightly mentioned that TB/cryptococcosis coinfection may not be uncommon and frequently missed. It is likely because of similarities in the clinical spectrum, involvement of organ systems (mainly central nervous system [CNS] and lung), clinical features, chronicity (usually subacute or chronic), radioimaging characteristics or initial cerebrospinal fluid (CSF) analysis. A search in the Chinese database of >50 years' period resulted in only 197 such coinfection cases. 2 Our recent singlecenter prospective series of 401 adult CNS infections over 1 year detected 205 TB meningitis, 25 cryptococcal meningitis and only 1 with the dual infection. The coinfection also poses difficulties at the therapeutic font-adjuvant dexamethasone improves mortality in TB meningitis but worsens outcomes in cryptococcal meningitis, and antimicrobial therapies share common adverse effects and have drug interactions. B/cryptococcosis coinfection is primarily associated with immunodeficiencies like HIV. diabetes mellitus, malignancies causing immunosuppression or requiring chemotherapy, conditions requiring corticosteroids or other immunosuppressive agents like chronic lung diseases or autoimmune disorders. However, the extensive Chinese