Detection of Cryptococcus by conventional, serological and molecular methods.
The rising incidence of cryptococcosis in India is posing a serious threat. Due to lack of sensitive methods for diagnosis, high morbidity and mortality are associated with the disease. Early diagnosis is essential to prevent serious complications. Therefore, we attempted to find highly sensitive and specific detection methods. A comparative evaluation of the detection of cryptococcosis was done by conventional (direct microscopy and culture) and rapid diagnostic [latex agglutination test (LAT), enzyme immunoassay (EIA) and PCR] methods. The study was done on 359 samples from 52 positive patients and 30 negative controls in an Indian set-up. Evaluation was done for cerebrospinal fluid (CSF), serum and urine separately. The diagnostic value of the tests was assessed in pre-treatment samples, and follow-up tests were also done on samples obtained after initiation of treatment. PCR had the highest sensitivity, followed by EIA and LAT, both before and after treatment. The positive detection by LAT, EIA and PCR was the longest in CSF (>90 days), followed by serum ( approximately 65 days) then urine ( approximately 45 days) after initiation of treatment. Our results indicated that the sensitivity and specificity of PCR and EIA were comparable in urine, CSF and serum for diagnosis of cryptococcosis.
Saha
Dolan Champa
DC
Department of Microbiology, All India Institute of Medical Sciences, New Delhi, India.
Xess
Immaculata
I
Department of Microbiology, All India Institute of Medical Sciences, New Delhi, India.
Biswas
Ashutosh
A
Department of Medicine, All India Institute of Medical Sciences, New Delhi, India.
Bhowmik
Dipankar M
DM
Department of Nephrology, All India Institute of Medical Sciences, New Delhi, India.
Padma
M V
MV
Department of Neurology, All India Institute of Medical Sciences, New Delhi, India.
D000293:Adolescent; D000328:Adult; D003453:Cryptococcosis / Q000097:blood / Q000150:complications / Q000175:diagnosis* / Q000652:urine; D003454:Cryptococcus / Q000302:isolation & purification*; D015658:HIV Infections / Q000150:complications; D006801:Humans; D007124:Immunoenzyme Techniques; D007841:Latex Fixation Tests; D008853:Microscopy; D008875:Middle Aged; D016133:Polymerase Chain Reaction; D012680:Sensitivity and Specificity; D055815:Young Adult