Diagnosis of acute leptospirosis

Abstract

Leptospirosis is a globally important zoonotic disease and an important public health problem in developing countries. Early diagnosis is essential because antibiotic treatment is most effective when initiated early in the course of the disease. Culture and the microscopic agglutination test are gold standard methods for leptospirosis diagnosis; however, they are not useful for early diagnosis. Current whole cell-based rapid serological tests have low sensitivity for early phase leptospirosis and may have low specificity in highly endemic areas. PCR is demonstrably useful for early diagnosis, but it is unavailable in most developing countries. Thus, diagnostic methods that not only have higher sensitivity and accuracy for early phase leptospirosis but are also widely applicable in developing countries remain to be developed. The availability of genome sequences and genetic tools of Leptospira spp. will accelerate our understanding of Leptospira pathogenesis and provide insights into the development of more efficient and accurate diagnostic tests for acute-phase leptospirosis.

A Review of Laboratory Diagnosis and Treatment of Leptospirosis

“…Leptospires may be demonstrated by direct microscopic observation of clinical specimens [5]. Darkfield microscopic examination (DFM) of body fluids such as blood, urine, CSF and dialysate fluid can be used to rapidly detect the presence of leptospires as well as from tissues removed for surgical or experimental reasons from animals or necropsy specimens, tissues from carcasses or abortion products [1,19].…”

“…In theory, leptospirosis can, therefore, be diagnosed by dark-field microscopy of blood taken during the first week of illness [14]. Approximately 10 4 To increase the sensitivity of direct microscopic examination of leptospires in veterinary specimens, a variety of staining methods have been used including immunofluorescence staining [4,5]. Finally, although it is relatively inexpensive, DFM test requires a dark-field microscope which is rarely available or affordable in resource-limited settings [14].…”

“…leptospires/ml is the detection threshold for one cell per field to be visible [5]. The organism is only present in blood during a short period during the acute stage of the disease; the concentration is too low to allow detection by direct microscopy and shedding in urine is intermittent [20].…”

“…Thus, results of direct examination may be supported by another laboratory irrespective of positive results. The result is also affected by the timing of sample collection and the skill of the laboratory personnel [5].…”

“…However, many experts agree that adequate laboratory tests for early diagnosis are still lacking [5]. It is not necessary to confirm the diagnosis or wait for the result of the tests before starting treatment.…”