Describe the

Shape

Bacterial type

Chromosome shape

culturability

Toxins released

motility

For the genus Borrelia

Long-slender spirochete; loose coils

Gram Negative

Linear chromosomes

Some species cannot be cultured

No endo or exotoxins; except for low levels of LPS

Highly motile; unique morphology

A patient enters your office complaining of an abrupt onset of high fever, headache, muscle aches and malaise that have been bothering him for the past few days.

After the visit, the patients condition stays the same for 2 more days, then resolves.

Then, 8 days later the symptoms re-appear, albeit less severe.

What is a probable diagnosis? What tests should be run to back up this diagnosis?  What treatment should be used?

This is probably Louse-borne relapsing fever by the gram negative bacteria Borrelia recurrentis.

Diagnosis tests include a Giemsa or Wright stain on a blood smear to identify spirochetes in blood.

Treat with Tetracycline, erythromycin and penicillin.

Name the:

Identifying features

Virulence factors

Vector/transmission method

Of Borrelia recurrentis

Identifying features: Culturable

Virulence factors:

Antigenic variation of surface proteins (evade immunity and cause characteristic relapses)

Releases a pyrogenic factor (causes the fever, but not technically associated with its virulence)

Vector/transmission:

Human to human via body louse (Pediculus humanus corpporus) in the organism's hemolymph which is injected upon feeding.

Associated with conditions of poor hygiene (northeast Africa).

A patient comes to your office complaining of a fever that seems to come and go every 7 days or so.  He has returned from a summer visit to California where he went hiking as dusk/early night with his brother who lives there.  He notes that he was bitten by a tick, but was able to remove it within (at most) 2 hours of it biting him.  He unfortunately did not bring the specimen with him. The fever is not completely debilitating and is more of an annoyance than anything.

What is his condition most likely?  What diagnostic/situational data supports this conclusion?

This is most likely Tick-borne Relapsing Fever caused by Borrelia hermsii.

The agent that bit him was most likely a soft tick (Ornithodoros) which only need an hour or so to feed; allowing a differential of infectivity from lime's disease which usually takes 24-48 hours to feed.

It also feeds at night, which is when this patient was at risk.

Additionally, tick-borne relapsing fever is an endemic disease in the Western US; a reportable disease.

What bacteria causes Lyme Disease and what are some identifying features/virulence factors of this bacteria?

What is the method of its transmission?

Borellia burgdorfori

Identifying features:

Linear DNA genome

Culturable (difficult/impractical)

No endotoxins or exotoxins

Most common arthropod-borne disease in US

Virulence:

Variable outer membrane proteins (like other borellia species)

Spread by:

Hard tick-Ixodes scapularis in its Nymph stage (spring/summer)

A patient comes into your office with a red, circular rash with a clear-peripheral center.  He notes being bitten by an undiscovered tick that was on him for days before being removed in the same spot.  You immediately suspect...

What stage is the disease in?  How long does it take after being bitten to reach this stage?  What treatment is necessary?  What is the best way to confirm this diagnosis?

Stage 1: occurs 1-4 weeks after being bitten.

Requires amoxicillin or doxycycline treatment.

PCR is the best diagnostic mechanism, but serology can also be used.

A young female comes into your office complaining of joint pain.  On physical examination, you note that her joints seem to  be arthritic and she seems to exhibit some slight facial palusey.  On osculation of her heart, there is also a slight murmur noted.

Her history indicates a love for the out doors.  She loves to go hiking, especially during the warmer months and keeps active regularly.

What is one possible differential diagnosis?  What treatment will she require?

Most likely could be Lyme disease but in stage 2 which can occur weeks to months after being bitten by a hard tick.

Because of the stage of disease, she probably will require long term treatment.

What are 4 common characteristics of Rickettsiaceae?

What 2 family members of bacteria are included?

Gram negative

Obligate intracellular parasites (require ATP)

Transmitted by arthropods

Fever is a prominent clinical feature

Includes Rickettsia and Ehrlichia

A patient comes into your office complaining of a high fever, headache and vomiting.  On physical inspection a spotted rash can be seen on the patient's palms and soles of his feet.  Slight symptoms appeared about a week earlier when he just got back from a hiking trip with his father in law.  On one of the nights after a long day of hiking, he discovered a tick on his body and removed it.  He kept the tick as a keepsake and showed it to you; it was much bigger than a deer tick.

What is a possible diagnosis?

Is this disease vector borne?  If so, what is the vector and what is the treatment?

This could be a case of Rocky Mountain Spotted Fever caused by Rickettsia rickettsii.  It gets its name from the spotty appearance of the lesions.

The vector is a Dog (wood) tick,  Dermacentor variabilis or Dermacentor andersoni. These ticks must feed for a minimum of 6 hours to spread Rickettsia rickettsii.

Treat with doxycycline.

A patient comes into your office with a fever and a diffuse rash over all of their body.  The patient is a young girl who loves in a low income household which probably has a rodent problem.  She spends a lot of time on the rug floor playing with her dolls, when her mother discovered a small rash on her back which as how spread to her whole body.  Her palms show no visible rash.

What is a likely diagnosis?

A crowded, low income population has recently had an outbreak of fever, chills, severe headache and stupor.  Affected individuals tend to have an abdominal rash that lasts for about 2 weeks.  Sanitation in the area is poor and louse is a common problem.

What is a probable diagnosis?  How is this disease transmitted?

Louseborne (epidemic) Typhus caused by Rickettsia prowazekii.

Could also be caused by Rickettsia typhi via the rat (cat) flea causing Murine (endemic) Typhus

This disease is spread via body louse (pediculus humanus corporus) through the feces of the organism coming in contact with the bloodstream through cuts or bites from other louse.

A middle aged man from Northeastern Africa now living in New Jersey comes into your office complaining of a mild fever, headache and stupor.  While he lived in Africa during his childhood, his family came down with louseborne typhus which had similar symptoms, but he has been living in the USA away from unsanitary conditions for over 30 years since then.

What is a probable diagnosis?

This is most likely Recrudescent Typhus aka Brill's disease.

It is a relapse of louse borne typhus that often occurs 10-40 years after a primary attack and it typically milder.

It is a result of Rickettsiae that have remained dormant in reticuloendothelial cells.

A patient comes to your office complaining of headache, severe chills, and a high fever.  On physical examination there is an eschar on his right knee.  About 2 weeks ago he was in Japan doing some yard work for a family member.

What might be a probable diagnosis?

A patient comes to your office presenting a fever, headache, fatigue, myalgias, and nausea/vomiting.  Bloodwork reveals moderate leukopenia and thrombocytopenia.  No rashes are noticed on the patient on physical examination.  The patient did have a tick bite about a week ago.  The tick was described as "large, with a small spot on its back"

What is a probable diagnosis?  What steps should be taken to confirm this diagnosis? Treatment?

Possibly human monocytic ehrlichiosis (HME) caused by Ehrlichia chaffeensis and spread by the lone star tick (Amblyomma americanum)

Run serology for Ehrlichia antigens, and PCR.

Treat with Doxycycline.

An elderly patient comes to your office complaining of a fever, myalgia, headaches and malaise.  There is a bullseye shaped rash on the patients' right arm and bloodwork indicates leukopenia/thrombocytopenia.  He recently went hiking and discovered a tick on him the next morning.  The tick was likely a deer tick.

What other tests should be done?

What is the diagnosis possibly?

Treatment?

Test serology for ehrlichia or anaplasma antigens as well as PCR.

Most likely anaplasmosis caused by infection by anaplasma phagocytophilum (infects neutrophils) with a concurrent borrelia infection (due to the appearance of a rash)

Ehrlichia (causes HME)

Anaplasma (causes HGA)