Leishmaniasis: the touch preparation as a rapid means of diagnosis

Tissue Impression Smears as a Supplementary Diagnostic Method for Histopathology in Cutaneous Leishmaniasis in Sri Lanka

Cutaneous leishmaniasis (CL) is diagnosed mainly by light microscopy of smears made using lesion material. Histopathology is usually done in atypical presentations or when lesion smears are negative. Tissue impression smears (TIS) made from skin biopsy specimens were compared with histopathology for the diagnosis of CL. Out of the 111 patients included, 83 (74.8%) were positive by either methods. The TIS was positive in 70.3% whereas histopathology was positive in 56.8% of patients. Tissue impression smears can be used as a supplementary diagnostic test that gives sensitive and rapid results when tissue biopsies are used as the source of lesion material for diagnosis of CL.

An imprint method for detecting leptospires in the hamster model of vaccine-mediated immunity for leptospirosis

In determining the efficacy of new vaccine candidates for leptospirosis, the primary end point is death and an important secondary end point is sterilizing immunity. However, evaluation of this end point is often hampered by the time-consuming demands and complexity of methods such as culture isolation (CI). In this study, we evaluated the use of an imprint (or touch preparation) method (IM) in detecting the presence of leptospires in tissues of hamsters infected with Leptospira interrogans serovar Copenhageni. In a dissemination study, compared to CI, the IM led to equal or improved detection of leptospires in kidney, liver, lung and blood samples collected post-infection and overall concordance was good (kappa=0.61). Furthermore, in an evaluation of hamsters immunized with a recombinant leptospiral protein-based vaccine candidate and subsequently challenged, the agreement between the CI and IM was very good (kappa=0.84). These findings indicate that the IM is a rapid method for the direct observation of Leptospira spp. that can be readily applied to evaluating infection in experimental animals and determining sterilizing immunity when screening potential vaccine candidates.

Lymphocutaneous syndrome. A review of non-sporothrix causes

The lymphocutaneous syndrome can be caused by a number of diverse microorganisms requiring very different antimicrobial therapy for resolution. The epidemiology and geographic occurrence of the infection often can provide important first clues to the microbiologic etiology. Accurate diagnosis can be accomplished usually by punch or wedge biopsy of a primary lesion or proximal subcutaneous nodule submitted for histopathologic examination and culture. The microbiology laboratory staff should be alerted to the diagnostic possibilities so that appropriate cultural and incubation techniques, procedures, and precautions can be initiated. Provision of a correct microbiologic diagnosis and institution of appropriate antimicrobial therapy will result in a complete cure in almost all instances. Adjunctive surgical debridement may be required for certain organisms such as Nocardia or Mycobacterium chelonae.

Value of touch preparations (imprints) for diagnosis of cutaneous leishmaniasis

BACKGROUND

The clinical diagnosis of cutaneous leishmaniasis is confirmed by demonstrating the organism on a superficial smear or on a biopsy of the lesion. Misdiagnosis in a biopsy specimen may be due to scanty Leishmania organisms that may not be identified in histologic sections.

METHODS

Punch biopsies of skin lesions, suspected clinically to be cutaneous leishmaniasis, from 29 patients were taken. Touch smears on slides were air-dried, fixed with methyl alcohol, and stained with Giemsa stain. Results of routine histologic examination were then compared with those of touch preparation.

RESULTS

Twenty-one cases were positive for leishmaniasis. In 18 cases, the organisms were seen both in the biopsy and in the touch preparation. In three cases, the organisms were only identified on touch preparation.

CONCLUSIONS

A touch preparation improves the sensitivity of the diagnosis of cutaneous leishmaniasis without incurring additional cost to the laboratory.

A clinico-pathological study of cutaneous leishmaniasis in British troops from Belize

Thirty-four cases of cutaneous leishmaniasis contracted by British soldiers in Belize were studied. Pre- and post-treatment biopsies were taken from all patients. The range of histological appearances is described and the value of histological examination (including Giemsa staining and immunohistochemistry), cytological preparations and microbiological culture in diagnosis and clinical management assessed. Histology and culture were found to be complementary techniques in reaching a positive diagnosis, whilst cytological preparations were of no additional value. Histological examination of post-treatment biopsies merely confirmed the clinical impression of healing or non-healing whilst culture identified viable organisms in apparently healed lesions, which were subsequently re-treated.

Cutaneous leishmaniasis in British troops from Belize

The medical records of 306 British soldiers in whom a clinical diagnosis of cutaneous leishmaniasis had been made following a tour of duty in Belize were analysed. Parasitological confirmation of the diagnosis was established in 187 cases; leishmania were cultured in 117 cases and Leishman-Donovan bodies were identified histologically in a further 70 cases. Leishmania braziliensis braziliensis was identified in 78 cases and Leishmania mexicana mexicana in a further 29 cases. Seventy-one per cent of patients had a single lesion which, in most cases, occurred on the exposed extremities. The mean diameter of the ulcers was 14.4 mm. Treatment with sodium stibogluconate was effective. Two regimens were used, consisting of either 600-800 mg daily given initially for 10 days, or 600 mg b.d. given initially for 14 days. Of those allocated to the lower dose regimen 48.5% were cured after the initial 10-day course, and ultimately the ulcers of 93% of patients healed following more prolonged treatment at this dose. Of those allocated to the higher dose regimen 63.9% were cured after the initial 14-day course and ultimately the ulcers of all patients healed after more prolonged treatment at this dose. A transient leucopenia and a rise in liver enzymes were noted during treatment, and these changes were dose-dependent. No cases of mucocutaneous leishmaniasis were encountered.

Diagnosis of cutaneous leishmaniasis by fine-needle aspiration biopsy: report of a case

A case of cutaneous leishmaniasis diagnosed by fine-needle aspiration biopsy is presented. The cytologic smears revealed lymphocytes, plasma cells, and macrophages. Large numbers of Leishmania organisms were present within the macrophages and in the intercellular spaces. Part of the material was used for a microbiologic culture, which revealed large numbers of promastigotes. These were studied by light, transmission, and scanning electron microscopy.