Epidemic typhus

Question 1

Ricketssia (stain and shape)

Answer 1

gram negative, rod, obligate intracellular

Question 2

Epidemic typhus (organism / vector or not)

Answer 2

ricketssia prowazekii, vector borne

Question 3

Epidemic typhus (vector)

Answer 3

body louse (pediculus humanus corporis) person to person transmission. blood from infected patient and then drops as feces on another person -> autoinnoculation by scratching

Question 4

Epidemic typhus (incubation perdiod)

Answer 4

1-2 weeks

Question 5

Epidemic typhus (clinical)

Answer 5

biphasic

1) abrupt - chills, fever (38-40), extreme myalgias, exhaustion, severe headache
2) after 5 days - maculopapular exanthem -> generalised excpet face, palms and soles -> petechial

Question 6

Epidemic typhus (complications)

Answer 6

photophobia and neurological manifestations and pneumonia

Question 7

Epidemic typhus (diagnosis)

Answer 7

giemsa stain, Serology - ELISA or IF, weil-felix reaction (antigenic cross reaction between R.prowazekii and proteus OX19), PCR (skin biopsies)

Question 8

Epidemic typhus (treatment)

Answer 8

Doxycyline (200mg/day) 2 doses 2-3 days

Rifampcin and FQs