Background: Histoplasmosis is considered uncommon in India, and the diagnosis usually depends on invasive tissue sampling. The histoplasma urinary antigen assay is a non-invasive test that has been recently introduced in India.
Methods: This was a single centre retrospective study done from January 2013 till February 2018. Case records of patients with proven (confirmed by demonstrating intra-cellular yeast like organisms on histopathology or culture) and probable (presence of antigenuria done by IMMY Alpha Histoplasma enzyme immunoassay) histoplasmosis were analysed.
Results: A total of 37 patients (18 proven & 19 probable) with mean age of 51.59±11.17 years were studied. Diabetes was the most common co-morbidity (15 patients) followed by HIV (6), whereas no co-morbidity was found in 10 patients. Adrenals (29%), lungs (27%), lymph nodes (27%) and skin & oral mucosa (24.3%) were the most common organs involved [Figure 1]. Anti-tubercular therapy based on granulomatous inflammation was given to 10 patients prior to the diagnosis. Raised GGTP & ALP (54%) and hyperglobulinemia (40%) were the common laboratory features. Most patients (83.7%) came from endemic areas (North-Eastern states, West Bengal & Bangladesh) whereas all 6 cases from non-endemic areas were classified as probable [Figure 2]. All-cause mortality rate was 10.8%, with 27 cases (72.9%) showing improvement at a median follow-up of 6 months. Comparison of proven and probable cases revealed that the following features were significantly higher in the probable group: female sex (p=0.001), coming from non-endemic areas (p=0.009), requiring in-patient care (p=0.001), leucocytosis (p=0.043), absence of skin & oral mucosal findings (p=0.002), simultaneous alternate diagnosis (p=0.039) & death (p=0.039).
Conclusion: This study emphasises that histoplasmosis is an under recognised entity in India. Histoplasma antigenuria does help in making the diagnosis easily & needs to be more extensively utilised by clinicians. However it can yield false positive results in patients belonging to non-endemic areas & lacking typical clinical features of histoplasmosis. Further studies are needed to determine the utility of the antigen test in Indian settings.
Figure 1: Distribution of involved organs
Figure 2: Distribution of cases in the study across Indian states.
M. R, None
P. Senthur Nambi, None
S. Kumar D, None
V. Ramasubramanian, None
R. Gopalakrishnan, None