Rocky Mountain Spotted Fever

RMSF symptoms

-fever & headache -loss of appetite -nausea (vomiting) -abdominal pain / myalgia -petechial rash (90% of cases)

% of variabilis (dog tick) that tested positive for rickettsia each year from 2000-2005

1.5% positive

RMSF incubation

2-14 days

test to confirm RMSF is treated

RMSF-specific IgG antibody/serum

RMSF occurs during what time of year

a summer disease (april-august)

what does rickettsia rickettsii do to cells?

affects endothelial cells. the bacterium causes leaks form vessel at feeding site which creates the "spot" in RMSF if bacterium reaches vital organs and leaks there, it will compromise the tissue and its function

what type of parasite is rickettsia rickettsii

an obligate intracellular parasite

RMSF treatment

antibiotics (doxycycline)

if the tick is all throughout ohio why are the cases so high in counties like Cbus and Cleveland?

cases are reported where they are diagnosed. ppl are commonly traveling to these areas to get tested and the doctors are in bigger cities

host vector for rocky mountain

dermacentor variabilis

sylvanic vector of rocky mount

dermacentor variabilis

where is the dermacentor varibilit dog tick located in the US

eastern US

is RMSF in more female or male ticks?

equally given to both males and females, becuase pathogen is passed to its offspring

spotted fever pathogen

gram negative bacterium (rickettsia rickettsii)

dog tick during off-season

hibernate in fall/winter/spring

petechial rash

leaky vessels on infected areas

obligate intracellular parasite

needs to be inside another cell to survive

why did the fatality of RMSF drop significantly in the 40's?

penicillin was discovered. fatality rates are almost zero bc we now have antibiotics

RMSF mortality?

potentially fatal

2nd vectors

rocky mountain wood tick and brown dog tick

how to test for the bacterium of RMSF (rickettsia rickettsii)

test hemolin from ticks leg

high risk for RMSF in what part of the US

the mid south

rocky mountain spotted fever vector

tick: 1 kind (dermacentor variabilis) aka american dog tick

rocky mountain spotted fever reservoir

wild rodents (mammals)

Is RMSF reportable?

yes must be reported to local health department

is the american dog tick (dermacentor variabilis) in ohio

yes this tick is extremely common in ohio