Title: Lighting up of m.leprae

Authors: Shraddha Laddhad, Nafees Nomaan

 DOI: https://dx.doi.org/10.18535/jmscr/v7i11.103

Abstract

Introduction

Leprosy or Hansen’s disease is a slowly progressive infection caused by Mycobacterium Leprae that mainly affects the skin and peripheral nerves and results in disabling deformities. Despite its low communicability, leprosy remains endemic among an estimated 10 to15 million people living in poor tropical countries.

As far as tropical countries like India are concerned, it is still one of the major problems of public health importance.

The immune response of patient and the density of bacteria in the lesion (bacterial index) determine the clinical manifestation and the infectivity of the disease. Accordingly the disease manifests as a spectrum beginning from lesions having low immunity and infectivity to those having high immunity and low infectivity[1]. This clinicopathological spectrum determines the treatment regimen[2,3].

Diagnosis of leprosy is by demonstration of lepra bacilli in slit skin smears and skin biopsies[4,5]. Ziehl-neelsen (ZN) staining is the old and conventional method of detection of the organism in clinical specimens[6]. FF staining is more sensitive than ZN method in detection of Mycobacterium leprae in tissue section, it is not free from flaws[7,8]. The density of bacilli should be 1000 per cubic millimeter of the tissue to pick single bacilli in the section[1]. The laborious search for the bacilli is tiresome leading to increased chances of false negativity, under diagnosis and under grading of the disease. Many studies have been done on fluorescent techniques in this direction but its impact on bacteriological index and thus the clinical grade has been lacking in literature[7-9].

Aim

To compare the efficacy of auraminerhodamine stain with fitefaraco stain in diagnosing M.leprae in tissue sections.

References

  1. Laga AC, Milner DA. Bacterial Diseases. In: Elder DE, Elenitsas R, Rosenbach M,Murphy GE, Rubin AI, Xu X, editors. Lever’s Histopathology of Skin. Philadelphia: Wolters Kluwer; 2015. Pp. 663-72.
  2. Abulafia J, Vignale RA. Leprosy: pathogenesis updated. Int J Dermatol. 1999; 38:321-34.
  3. Jopling WH, McDougall AC. Definition, epidemiology and World distribution. In: Hand book of Leprosy. 5th New Delhi: CBS publishers and distributors; 2005. Pp. 1-8.
  4. Kumaran SM, Bhat IP, Madhukara J, Rout P, Elizabeth J. Comparison of bacillaryindex on slit skin smear with bacillary index of granuloma in leprosy and its relevance to present therapeutic regimens. Ind J Dermatol. 2015;60(1):51-54.
  5. Reja AHH, Biswas N, Biswas S, Dasgupta S, Chowdhury IH, Banerjee S, et al. Fite-Faraco staining in combination with multiplex polymerase chain reaction: A new approach to leprosy diagnosis. Indian J Dermatol Venereol Lerp. 2013;79 (5):693-700.
  6. Burdash NM, West ME, Bannister ER, Dyar C, Duncan RC. Evaluation of a dual-staining method for acid-fast bacilli. J ClinMicrbiol. 1975:149-150.
  7. Park K. Epidemiology of communicable diseases. Park’s textbook of preventive & social medicine. 20th Jabalpur (India): M/s BanarasidasBhanot Publishers; 2009. Pp. 264-78.
  8. Nayak SV, Shivarudrappa AS, Mukkamil AS. Role of fluorescent microscopyin detecting Mycobacterium lepraein tissue sections. Annals DiagnPathol. 2003;7:78-81.
  9. A N, Nagarajappa A, Prabhu D. Sensitivity of fluorescent microscopy in detecting Mycobacterium leprein tissue sections. The Internet Journal of Pathology. 2010;11(2): 01-05.

Corresponding Author

Shraddha Laddhad (M.D.Pathology)