LIPTOSPIROSIS Flashcards
- These organisms are 6-20 um long and ~0.1 um wide;
- They stain poorly But can be seen microscopically by dark-field examination and after silver impregnation staining of tissues.
- Leptospires require special media and conditions for growth; it may take weeks to months for cultures to become positive.
- thin, coiled and highly motile that have hooked ends
- has 2 periplasmic flagella
- polar protrusion from the cytoplasmic membrane that are responsible for motility
Leptospires
Symptoms of Leptospirosis
- fever
- headache
- rash
- abdominal pain
- red eyes
- vomoting
- muscle pain
- jaundice
- cold
Symptoms in Weil’s disease in Leptospiraemic phase (3-7 days)
- pronounced headache
- conjuctival injection
- general malaise
- fever and chills
- relative bradychardia
- polymorphic rashes (trunk)
- muscle pain (calves and tigh)
LAB TEST
- leptospira present in blood and CSF
Symptoms in Weil’s disease in Leptospiruric phase (10-30 days)
- high fever
- encephalopathy
- conjuctival haemorrhage and uvitis
- cutaneous & visceral haemorrhage (esp. pulmo)
- hepatic damage & jaundice
- renal damage
- rhabdomyolysis
LAB TEST
- AST & ALT _ Bilirubin, RBC increase
remains the GOLD standard BUT is time-consuming,
labor-intensive, requires 6 to 8 weeks for the result, needs darkfield microscopy and has low diagnostic yield. It can identify the serovar but is insensitive.
Direct Detection Method: Culture and isolation
has the advantage of early confirmation of the diagnosis especially during the acute leptospiremic phase (first week
of illness) before the appearance of antibodies.” Its utilization in the clinical setting is currently not generally available because of the cost-limiting nature of the test and the need for trained personnel.
Direct Detection Method: Polymerase Chain Reaction (PCR)
a four-fold rise of the titer from acute to convalescent sera is confirmatory of the diagnosis.’ It is highly sensitive and specific BUT time-consuming and hazardous to perform because of the risk of exposure to the live antigen. Cross-reactions may occur with syphilis, viral hepatitis, HIV, relapsing fever, Lyme’’s disease, legionellosis and autoimmune diseases.’ In endemic areas like the Philippines, a single titer of at least 1:1600 in symptomatic patients is indicative of leptospirosis.
Indirect Detection Methods: Microagglutination Test (MAT)
are serologic tests in a single test format for the quick detection of Leptospira genus-specific IgM antibodies in human sera. The sensitivity rates are between 63%-72% and specificity rates between 93%-96% when tested in illnesses of less than 7 days. If serum samples are taken beyond 7 days, sensitivity improves to > 90%. Therefore, false negative results can be a problem if the tests are performed during the early stage of the illness.** A second sample should be obtained for suspected cases with initial negative or doubtful results.
Indirect Detection Methods: Specific IgM Rapid Diagnostic Tests like LeptoDipstick®, Leptospira IgM ELISA (PanBio), MCAT and Dridot
detects Leptospira antibody in human serum through agglutination reaction which may persist for years. This is used as a screening test but is NOT sensitive. A positive result should be confirmed with MAT.
Nonspecific Rapid Diagnostic Tests like LAATS (Leptospira Antigen- Antibody Agglutination Test (Leptospira Serology Bio-Rad)
The following are non-specific laboratory tests that can support the diagnosis of leptospirosis and can be used to alert the health practitioner to monitor for the development of complications:
- CBC w/ platelet count
- urinalysis
- serum creatinine
- serum creatine phosphokinase (CK-MM)
- liver function tests
- bleeding parameters (prothrombin time, partial thromboplastin time PTT)
Tx for Mild leptospirosis
- Doxycycline
- Amoxicillin
- Ampicillin
Tx for moderate/severe leptospirosis
- Penicillin
- Cefotaxime
- Doxycycline
- ceftriaxone
Chemoprophylaxis for Leptospirosis
- Doxycycline
- Azithromycin
