Revisiting the role of the slit-skin smear in the diagnosis of Indian post-kala-azar dermal leishmaniasis

Background: Post kala azar dermal leishmaniasis (PKDL) is a neglected dermatosis that develops as a sequel to kala azar after apparent complete treatment. Being a non life threatening condition, patients often delay treatment thereby maintaining a reservoir of infection. The diagnosis of PKDL rests on the demonstration of the parasite in tissue smears, immune diagnosis by detection of parasite antigen or antibody in blood, or detection and quantitation of parasite DNA in tissue specimens. Sophisticated molecular tests are not only expensive but also need skilled hands and expensive equipment. To be useful, diagnostic methods must be accurate, simple and affordable for the population for which they are intended. Aims: This study was designed to assess functionality and operational feasibility of slit-skin smear examination. Methods: Sensitivity and specificity was evaluated by performing slit-skin smear and histo-pathological examination in 46 PKDL patients and the results were compared with the parasite load in both the slit aspirate and tissue biopsy specimens by performing quantitative Real-time PCR (Q-PCR). Results: The slit-skin smear examination was more sensitive than tissue biopsy microscopy. The parasite loads significantly differed among various types of clinical lesions (P < 0.05). The threshold of parasite load for detection by SSS microscopy was 4 parasites/μl in slit aspirate and 60 parasites/μg tissue DNA in tissue biopsy while that for tissue microscopy was 63 parasites/μl and 502 parasites/μg tissue DNA respectively. As detection of Leishmania donovani bodies may be challenging in inexperienced hands, the microscopic structure of these has been detailed along with a comprehensive discussion of pre analytical, analytical and post analytical variables affecting its identification. To facilitate the diagnosis of PKDL, some scenarios have been suggested taking into consideration the clinical, epidemiological, immunological and microscopic aspects. Conclusion: Such evidence based medicine helps minimize intuition, systematize clinical experience and provides a diagnostic rationale as sufficient grounds for a clinical decision.

Candiduria in catheterized intensive care unit patients : Emerging microbiological trends.

Objectives: Urinary tract infection (UTI) as a result of Candida spp. is becoming increasingly common in hospitalized setting. Clinicians face dilemma in differentiating colonization from true infection and whether to treat candiduria or not. The objective of the present study was to look into the significance of candiduria in catheterized patients admitted in the ICUs and perform microbiological characterization of yeasts to guide treatment protocols. Materials and Methods: One hundred consecutive isolates of Candida spp. from the urine sample of 70 catheterized patients admitted in the ICU were collected and stocked for further characterization. A proforma was maintained containing demographic and clinical details. Blood cultures were obtained from all these 70 patients and processed. Species identification of yeasts was done on VITEK. Results: Candiduria was more common at extremes of age. The mean duration of catheter days was 11.1 ± 6 days. Other associated risk factors such as diabetes mellitus and antibiotic usage were seen in 38% and 100% of our study group. Concomitant candidemia was seen in 4.3% of cases. Non-albicans Candida spp. (71.4%) emerged as the predominant pathogen causing nosocomial UTI. Conclusion: The present study reiterates the presence of candiduria in catheterized patients, especially in the presence of diabetes and antibiotic usage. Non-albicans Candida spp. are replacing Candida albicans as the predominant pathogen for nosocomial UTI. Hence, we believe that surveillance for nosocomial candiduria should be carried out in hospitalized patients.

Cryptococcal granulomas in an immunocompromised HIV-negative patient.

Disseminated cryptococcosis usually occurs in immunocompromised individuals with defective cell-mediated immunity, most commonly seen with HIV infection. We present a case of disseminated cryptococcosis in an HIV-negative male patient who presented with headache, fever, altered sensorium of short duration and multiple cutaneous lesions. An emergency CT scan of the head showed multiple intracranial and intraventricular granulomas. Routine laboratory investigations were within the normal range. A CSF examination revealed capsulated yeasts on India ink and a culture yielded cryptococcus neoformans. A cryptococcal antigen test by latex agglutination kit was positive. A biopsy revealed multiple capsulated yeasts cells in the cutaneous lesions, which were consistent with cryptococcus neoformans. The patient was successfully treated with Amphotericin B and Fluconazole with regression of cranial and cutaneous lesions.