Borrelia recurrentis - Lab Diagnosis, AST, Therapy

Lab Diagnosis of Borrelia recurrentis

The Laboratory diagnosis of Borrelia recurrentis begins with the collection of samples.

Specimen

Specimen/samples include:

• peripheral blood (collected during fever, not during afrabile phase)

• biopsy

• joint fluid

• CSF

Microscopy

Microscopy for Borrelia recurrentis diagnosis is done by wet mount preparation of blood and visualization by dark-field or phase-contrast microscope. Organisms are identified by their dashing movements often pushing RBC around

Borrelia recurrentis can also be detected by staining thick and thin films with Wright’s or Giemsa stains with a sensitivity of upto 70%.

Culture

Because of complex nutritional requirements, long incubation time, and low sensitivity of culture, cultivation of Borrelia recurrentis is confined to research purposes.

Process

The culture of Borrelia recurrentis may be attempted. It is done by the procedure written below:

1. specimen inoculated into a tube of modified Kelly’s medium

2. incubated at 30-40°C for 12 weeks under microaerophilic condition

3. blind subcultures (0.1ml) are performed from the lower portion of broth to fresh media

4. cultures are examined by dark-field or fluorescence microscopy after staining with Acridine orange

Animal inoculation

It is done by inoculating a mouse intraperitoneally with 1-2ml of blood from infected patients. Blood is collected from the tail vein of mice after 1-10 days and examined for the presence of Borrelia recurrentis daily for 2 weeks.

Serodiagnosis

Serologic tests are not reliable for diagnosis because Borrelia recurrentis as it undergoes many antigenic shifts.

Molecular diagnosis

These methods have been used on blood, body fluids, and tissue specimens for diagnosis of Borrelia recurrentis

• PCR

AST, Therapy of Borrelia recurrentis

• Since difficult to culture, AST is not usually done

• Tetracycline or erythromycin is most effective for the treatment of relapsing fever

• Doxycycline is recommended for children and pregnant women

• No vaccines are available.