Granuloma Inguinale at a Glance
- Granuloma inguinale or donovanosis is a chronic ulcerative debilitating disease that mainly affects the genital organs.
- Caused by the Gram-negative bacteria Klebsiella granulomatis.
- Affects mostly people of lower socioeconomic status living in the tropical and subtropical areas.
- Diagnosis is made by demonstrating intracellular Donovan bodies on histology.
The mode of transmission of granuloma inguinale (GI) is controversial. It is generally considered sexually transmitted, but fecal contamination and autoinoculation remain a possibility, especially in the setting of infected children and adults without sexual activity and primary involvement of remote extragenital sites.1,2 Transmission rate between sexual partners is low compared with other sexually transmitted diseases and was found to be not more than 50%. The incidence of GI is also relatively low among both prostitutes and their conjugal partners. Nevertheless, this disease predominantly affects sexually active individuals.3 Moreover, donovanosis, being an ulcerative disease, increases the risk of human immunodeficiency virus (HIV) transmission.4–6 Transvaginal transmission of donovanosis during delivery has been reported, with an apparent predilection to ear structures of the newborn.7,8 Patients tend to belong to the low socioeconomic classes. No racial predilection has been proved,9–11 and both male and female predominance have been reported.5,6,11 Afflicted people are likely to delay seeking medical attention due to the painless nature of the ulcers and the possible embarrassment or fear from medical or surgical intervention. Late cases can be very debilitating and are much more difficult to manage.12
GI is endemic in warm, moderately humid areas like South Africa, India, Southern China, and Brazil.5,13 There are new endemic areas of donovanosis, mainly South and Central America, India, and Papua New Guinea,12 but the overall incidence of GI seems to be decreasing, especially in Papua New Guinea.1 The disease has nearly been eradicated from Australia, with only five cases reported in 2004,14 and is rare in North America and Europe.15–17
Donovanosis is caused by the organism Klebsiella granulomatis, previously called Calymmatobacterium granulomatis. The name has been changed after sequencing the phoE and 16S ribosomal RNA genes and demonstrating close homology with Klebsiella pneumoniae and Klebsiella rhinoscleromatis.5,12
K. granulomatis is a Gram-negative, nonmotile, pleomorphic bacterium that stains well with Giemsa, Wright's, or silver stains but is periodic acid-Schiff-negative. The mature form is encapsulated, while the immature form is not. The immature nonencapsulated form may assume a closed-safety-pin appearance due to bipolar chromatin densities.
It is difficult to culture and store this organism; however, it may be cultured using embryonic chick heart or chick embryo amniotic fluid. It has also been cultured in human peripheral blood mononuclear cells after decontaminating the specimen with amikacin, vancomycin, and metronidazole,12 and in HEp-2 cells after adding gentamicin and ...