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Diagnostic test for leptospirosis

Instead of clinical symptoms to ensure that someone suffering leptospirosis

can safety some test to confirm the diagnosis,the test can be divided into microscopic

demonstration,culture and serology.In culture test there are isolation of 

leptospires,identification of leptospiral isolates and susceptibility testing.Serology test

can divided into enzyme-linked immunosorbent assay (EIS!" and microscopic

agglutination test(#!$"%&'

#icroscopic demonstration is to vie leptospires in cell,leptospires may be

visualized in clinical material by dark field microscopy or by immunofluorence or 

light microscopy after appropriate staining.#icroscopy of blood is of value only

during the first fe days of the acute illness hile leptospiremia occurs.Staining

methods have been applied to increase the sensitivity of direct microscopic

e)amination.$hese include immunofluorescence staning of bovine urine,ater,and

soil immunopero)idase staining of blood and urine %&'.eptospires ere first visualized

 by silver staining,and the arthin-starry stain is idely used for histologic

e)amination.

*ulture test for leptospirosis can be mention such as isolation of leptospires,identification of leptospiral isolates and susceptibility testing.Isolation of 

leptospires is the early test for diagnose leptospirosis,blood cultures should be taken

as soon as possible after the patient+s presentation,to process the test patient must

drops of blood are inoculated into & ml of semisolid medium containing -

flurouracil at the patient bedside%&'.Inoculation of media ith dilutions of blood

samples may increase recovery,leptospires survive in conventional blood culture

media for number of days.Isolation of leptospires from clinical samples gives

definitive diagnosis and also aids in identifying the prevalent serovar.rine also can

 be also cultured from the beginning of the second eek of symptomatic

illness,survival of leptospires in voided human urine is limited,so urine should be

 process immediately by centrifugation,folloed by resuspending the sediment in

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 phosphate buffered saline and inoculating into ng into semisolid medium containing

-fluoruracil.*ulture are incubated at /0o to 1o and e)amined eekly by dark field

microscopy for up to &1 eeks before being discarded%/'.Identification of leptospiral

is task for specialized reference laboratories.2or complete identification,a

combination of procedures is used to determine &" if the isolate is a pathogen or a

saprophyte3 /" the species of  Leptospira to hich the isolate belongs3 and 1" the

serogroup and serovar of the isolate.Isolated leptospires are identified by serological

methods or by recently developed molecular techni4ues%/',hich can perform the

microscopic agglutination test to identify isolates ith relative rapidity.Susceptibility

testing is the test to kno leptospires susceptibility ith.eptospires are susceptible

to beta-lactams,macrolides,tetracyclines,fluoro4uinolones and streptomycin

%&'

.5roblem in the determination of susceptibility include the long incubation time

re4uired,the use of media containing serum and the difficulty in 4uantifying groth

accurately.

Serological testing is the laboratory procedure most fre4uently used to

confirm the clinical diagnosis, to determine herd prevalence, and to conduct

epidemiological studies. eptospiral antibodies appear ithin a fe days of onset of 

illness and persist for eeks or months and, in some cases, years. $he #!$ using live

antigens is the most idely used serological test$he #!$ using live antigens is the

most idely used serological test,after incubation,the serum antigen mi)tures are

e)amine microscopically for agglutination and the titers determined %1'.$he #!$ is

read by darkfield microscopy,the end point is the highest dilution of serum at hich

6agglutination occurs,because of the difficulty in detecting hen 6of the

leptospires are agglutinated,the end point is the presence of appro)imately 6 free.

%&'  immunoglobulin # enzyme-linked immunosorbent assay (Ig# EIS!" is

 promising because it can be performed in a greater number of laboratories throughout

the tropics, and is ine)pensive compared ith #!$. Ig# antibodies become

detectable during the first eek of illness alloing the diagnosis to be confirmed and

treatment initiated hile it is likely to be most effective%&'.!ntibody levels are

generally lo or absent during very early infection.

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&. 7ealth #, !rmy I. aboratory Diagnosis of eptospirosis. /3&(1"8&9-

/.

/. #anual :$. eptospirosis. Version Adopt by World Assem Deleg OIE un May2014./&;3(#ay"8&-&.

3. andkumar ?S, @hanna . 5olymerase chain reaction in the

diagnosis of leptospiral infection.  J Asso !"ysiians India.

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