S1B5 - Spirochetes Flashcards
What are the clinical manifestations of early congenital syphilis?
Early congenital syphilis is defined as clinical manifestations before two years of age and include:
- Hepatomegaly, with or without splenomegaly, and can also cause jaundice and cholestasis.
- Rhinitis, also known as the “snuffles”, usually presents during the first week of life, and discharge contains spirochetes that can be transmitted by contact.
- Maculopapular lesions on the palms and soles.
- Generalized lymphadenopathy
- Hematologic abnormalities such as anemia and thrombocytopenia
What are the cardiovascular effects on late syphilis?
Cardiovascular syphilis classically affects the ascending thoracic aorta, manifesting as a dilated aorta and aortic valve regurgitation. The pathogenesis stems from a proliferative endarteritis that affects the vasa vasorum of the aorta, leading to medial necrosis and loss of elastic fibers.
Tertiary syphilis most often affects which of the following cardiovascular system components?
A) Aorta
B) Femoral arteries
C) Right atrium
D) Anterior communicating artery
E) Inferior vena cava
Aorta
Answer Explanation
Cardiovascular manifestations of tertiary syphilis occur as the media becomes scarred by treponemal infections over the years. The most common site is the aorta, resulting in aortitis or aneurysm. If the aneurysm affects the aortic root, it can, like all aneurysms at that site, lead to aortic valve incompetence
How long after initial infection does secondary syphilis occur? What is the colloquial term for secondary syphilis that refers to the constellation of non-specific symptoms?
Secondary syphilis occurs from a few weeks to months after primary syphilis and presents a with non-specific systemic illness, commonly referred to as the “great imitator.”
A 53-year-old man is referred to you by his neurologist, who reports that this patient has had a 1-year history of unsteady gait, gradually worsening vision, paresthesias, and diminished sensation to light touch. VDRL and FTA-ABS are both positive. Which of the following accounts for this process?
A) Dorsal column demyelination
B) Intrasynaptic acetylcholind degradation
C) Ventral column demyelination
D) Presynaptic acetylcholine degradation
E) False positive serum test results
Dorsal column demyelination
Answer Explanation
Positive VDRL and FTA-ABS is strongly indicative of syphilis. A false-positive result is suggested by VDRL(+) and FTA(-): FTA is more specific than VDRL. In the setting of syphilis, the presented set of symptoms is consistent with tabes dorsalis, a chronic demyelination of the dorsal (posterior) spinal cord.
How does congenital syphilis occur?
Congenital syphilis occurs when T. pallidum is transmitted transplacentally from a pregnant woman to her fetus.
What is clinical presentation of primary syphilis?
Primary syphilis occurs after an average incubation period of two to three weeks and is characterized by a painless ulcerating papule known as a chancre.
Syphilis, a spirochete, can cause different symptoms at different times if not properly treated after the initial infection. Which of the following might be seen in a case of tertiary syphilis?
A) Aortic aneurysm
B) Hemmorrhage, anemia, and azotemia
C) Migratory polyarthritis
D) AV block
E) Dental abnormalities (Hitchinson teeth, Mulberry molars)
Aortic aneurysm
Answer Explanation
Syphilis is caused by infection with the sexually transmitted Treponema pallidum. The signs and symptoms of a syphilis infection depend on the stage of the infection:
1st stage: painless chancre
2nd stage: painless rash on the palms of the hands and soles of the feet.
3rd stage: neurosyphilis (demyelination of the posterior column), gumma formation, and aortitis. The aortitis can result in an aortic aneurysm.
Dental abnormalities are seen in congenital syphilis.
What serologic tests can be used to diagnose secondary syphilis infection? Which is most specific?
Serologic tests for secondary syphilis includes a screening test with a nontreponemal test such as the VDRL or RPR (rapid plasma regain) test. A positive result is then confirmed as a true positive with a treponemal test, such as the FTA-ABS (fluorescent treponemal antibody-absorption) test.
A person with syphilis is treated with antibiotics and within a few hours the patient presents with a sudden onset of fever, chills, and myalgias. What is the cause of this and what is this condition called?
Administration of antibiotics for syphilis may lead to the Jarisch-Herxheimer reaction, a response to the release of endotoxin-like factors from the lysis of T. pallidum organisms that manifests as fevers, chills, and myalgias.
Can you name the “ToRCHeS” infections?
Syphilis is part of the TORCH infections, a mnemonic used to remember the infectious agents, which may cross the placenta and cause congenital infection. The mnemonic is ToRCHeS:
- Toxoplasmosis
- Rubella
- CMV
- HIV
- Herpes virus
- Syphilis
What are three broad manifestations of late syphilis?
Late (tertiary) syphilis occurs years after untreated syphilis infection and can be divided into:
- Gummatous syphilis
- Cardiovascular syphilis
- CNS syphilis
What is the diagnosis protocol for tertiary syphilis?
Serologic tests for tertiary syphilis includes testing spinal fluid with VDRL and PCR.
What are the two cutaneous manifestations of secondary syphilis?
Secondary syphilis can produce a wide variety of symptoms that include
- Maculopapular rash described as discrete copper, red or reddish-brown on the trunks and extremities, notably on the palms and soles.
- Condyloma lata, which are raised, infectious, gray to white wart-like lesions found in moist areas and mucous membranes such as the mouth and perineum.
- Systemic symptoms such as fever, headache, malaise, and myalgias.
- Lymphadenopathy
- Hepatitis
Infection with Treponema pallidum causes what disease? What is the morphology of Treponema pallidum?
Treponema pallidum is a microaerophilic spirochete that causes syphilis.
What is the diagnosis protocol for primary syphilis?
Serologic tests for primary syphilis includes a screening test with a nontreponemal test such as the VDRL (venereal disease research lab).
Describe the constellation of findings of CNS syphilis? What is the name of this manifestation? *Note not all are always present
CNS syphilis can be asymptomatic early on or may present with meningitis. Late neurosyphilis can include general paresis and/or more typically dorsal column demyelination, a condition referred to as tabes dorsalis. The constellation of findings in tabes dorsalis include
- Broad-based ataxia
- Argyll Robertson pupil, sometimes referred to as a prostitute’s pupil, where the eye accommodates to near objects but does not react to light.
- Positive Romberg sign, where swaying is noted when the person is stands with eyes closed.
- Charcot joints, a neuropathic arthropathy noted by the bony destruction and deformity of joints in this case due to decreased proprioception.
- Stroke without hypertension
What are the name of the cutaneous lesions in late syphilis called? Do these lesions contain active organisms?
Gummatous syphilis is characterized by a gumma that can occur in the skin, bones, and internal organs. On the skin, gummas present as ulcers or granulomatous lesions with a round, irregular shape. Visceral gummas may present as a mass lesion. Gummas are usually absent of any causative organisms.
What are the two methods to diagnose syphilis?
Diagnosis is for syphilis is made via direct visualization using darkfield microscopy or direct fluorescent antibody testing, and via serology.
How is Treponema pallidum transmitted?
Transmission of T. pallidum occurs via contact (sexual or casual) with skin lesions containing the spirochete, penetrating mucous membranes and causing systemic spread, or transplacentally.
Contrast the appearance and cause of condyloma lata and condyloma accuminata.
Contrast the wet, raised, gray to white lesions of condyloma lata (secondary syphilis) with condyloma accuminata (HPV infection), which is characterized by raised, cauliflower-like, bulky, dry lesions around genitalia.
What are some causes of a false positive VDRL?
False positive VDRL may be a result of:
- Viruses (mononucleosis and hepatitis)
- Drugs (for example hydrazaline and procainamide)
- Intravenous drug use
- Rheumatic fever
- Lupus and Leprosy
A patient with tertiary syphilis undergoes a biopsy of a bony lesion. The results are consistent with a gumma. Which is least likely to be found in the specimen?
A) Plasma cells
B) Necrotic center
C) Palisading macrophages
D) Treponemes
E) Fibroblasts
Treponemes
Answer Explanation
A gumma is a soft, non-cancerous granuloma that typifies tertiary syphilis. Histological features include a central region of coagulative necrosis, palisading macrophages, multinucleated giant cells, fibroblasts, lymphocytes, and plasma cells. The causative organism, Treponema pallidum, is only rarely found
What is the treatment for syphilis?
Treatment for syphilis is penicillin G.
Late congenital syphilis is characterized by scarring and persistent inflammation from early infection. Name some clinical manifestations that affect the: - Face - Eye - Ear - Mouth - Skin - CNS - Skeletal - Renal
Late congenital syphilis occurs from scarring or persistent inflammation from early infection and is characterized by gumma formation in various tissues. These can include:
- Facial features such as frontal bossing and saddle nose.
- Interstitial keratitis
- Sensorineural hearing loss
- Oropharynx abnormalities such as hutchinson teeth and mulberry molars.
- Cutaneous manifestations such as rhagades and gummas.
- Intellectual disability
- Saber shins
- Paroxysmal cold hemoglobinuria
Describe the appearance of a chancre in contrast with chancroid. What organism is responsible for each lesion?
The chancre from T. pallidum infection is noted to having a painless, non-exudative, clean, hard base with indurated margins (“punched out base with rolled edges”). This should be contrasted with granuloma inguinale from Klebsiella granulomatis infection, which presents with a painless ulcer with a beefy red base and irregular borders. In addition, this should be contrasted with a chancroid from Hemophilus ducreyi infection, described as a deep, undermined, painful purulent ulcer with soft ragged edges.
How is Borrelia burgdorferi transmitted? When and where are most cases reported?
Transmission of B. burgdorferi occurs from Ixodes tick bite, with most cases of Lyme disease being reported in the summer in the Northeastern United States.
Early detection of a tick can prevent Borrelia burgdorferi infection if the tick is removed within what time frame?
Tick feeding requires 24 hours to transmit sufficient inoculum of B. burgdorferi.
What is the characteristic cutaneous finding in early-localized (stage 1) Lyme disease?
Stage 1, or early-localized Lyme disease, is characterized erythema migrans and nonspecific findings that resemble a viral syndrome. Erythema migrans is rash that begins as a homogenous erythema and may spread to develop a central clearing resembling a Bull’s-eye rash.
What are the symptoms of early-disseminated (stage 2) Lyme disease?
Stage 2, or early-disseminated Lyme disease, presents with acute neural or cardiac involvements that occurs weeks to several months after the tick bite. This stage can present with:
- Lymphocytic meningitis
- Cranial nerve palsies, especially the facial nerve (often bilateral)
- Radiculopathy
- Peripheral neuropathy
- Mononeuropathy multiplex
- Atrioventricular heart block
- Migratory arthralgias
Because spirochetes such as Borrelia burgdorferi are so small, it is often difficult to visualize under light microscopy. This is part of the reason diagnosis is made via ELISA and Western Blot. What can be done to facilitate visualization under light microscopy? What other technique can be used to visualize spirochetes like Borrelia burgdorferi?
B. burgdorferi can be visualized under light microscopy using aniline dyes (e.g., Wright’s dye, Giemsa stain) or through dark field microscopy.
Infection with Borrelia burgdorferi causes what disease? What is the morphology of Borrelia burgdorferi?
Borrelia burgdorferi is a microaerophilic spirochete that causes Lyme disease.
A 46-year-old woman is brought in by ambulance after fainting in public. On arrival she is alert and answers questions normally. CBC and serum electrolytes are normal. Electrocardiograms alternating between normal sinus rhythm, and Types 1 and 2 second degree AV block. Which of the following pathogens can account for this?
A) Streptococcus sanguis
B) Corynebacterium diphtheriae
C) Borrelia burgdorferi
D) Coxiella burnetii
E) Bacillus anthracis
Borrelia burgdorferi
Answer Explanation
Cardiac involvement in Lyme disease (Borrelia burgdorferi) often manifests as syncope from AV blocks of varying types and degrees.
S. sanguis can cause SBE. Corynebacterium diphtheriae has been reported to cause AV block in the pediatric population, but this woman is beyond the age group. Coxiella burnetii causes Q fever and has not been reported to cause AV block. B. anthracis causes anthrax without association with AVB.
What are the treatment options for early Lyme disease? Late Lyme disease?
Treatment for Lyme disease includes doxycycline or amoxicillin for early disease, and ceftriaxone for later more serious disease.
What are the symptoms of late (stage 3) Lyme disease?
Stage 3, or late Lyme disease, presents with chronic arthritis of the large joints, usually the knee and encephalopathy.
The Ixodes tick serves as the vector for Borrelia burgdorferi and what 2 other organisms?
Ixodes tick also serves as the vector for Anaplasma and Babesia.
What disease is caused by B. burgdorferi, and what are 4 signs and symptoms of this disease?
B. burgdorferi infection causes Lyme disease. Symptoms of Lyme disease can be remembered with the mnemonic Key Lyme pie to the FACE:
- Facial nerve palsy
- Arthritis
- Cardiac block
- Erythema migrans
What are the primary hosts for Borrelia burgdorferi? What is the intermediate host?
The primary reservoir hosts for B. burgdorferi are rodents, in particular the white-footed mouse. The white-tailed deer act as intermediate hosts, and are used as a food source for the larval and nymphal stages.
How is diagnosis of Lyme disease made?
Diagnosis of Lyme disease is made via ELISA, followed by a confirmatory Western blot.
A 34-year-old man who has previously refused antibiotic therapy for confirmed Lyme disease returns with ptosis of the left side of his face, including his forehead. He is tearing from his left eye and cannot lift the left corner of his mouth. Which stage of Lyme disease does this likely represent?
A) None; this is related to a viral infection
B) First stage
C) None; this is a stroke
D) Second stage
E) Third stage
Second stage
Answer Explanation
The signs described in the question stem are consistent with Bell’s palsy, the most common neurological manifestation of Lyme disease. It most frequently occurs during the second stage of infection. Note that Bell’s palsy in itself is a constellation of signs/symptoms and is most commonly a sequela of viral infection. It is also a diagnosis of exclusion if these symptoms are encountered primarily, with stroke being on the differential. However, stroke in an otherwise healthy 34-year-old man is less likely given his history of Lyme disease.
What is Weil’s disease?
Weil’s disease is a more severe form of leptospirosis that also includes
- Jaundice
- Azotemia from liver and kidney dysfunction
- Pulmonary hemorrhage
What are 5 common symptoms of leptospirosis?
The clinical course of leptospirosis is variable, but symptoms can include:
- Flu-like symptoms (fever, headache, muscle aches)
- Jaundice
- Photophobia
- Conjunctival suffusion (erythema without exudate)
- Myalgias of the calf and lumbar spine
A 45 year-old man living in Hawaii presents to the emergency department with complaint of non-productive cough, subjective fever, myalgia, headache, and abdominal pain. On exam, his conjunctiva are injected and his skin has a yellow hue. Which of the following pathogens could be responsible for this constellation of signs/symptoms?
A) Legionella pneumophila
B) Streptococcus pneumoniae
C) Staphylococcus aureus
D) Streptococcus viridans
E) Leptospira interrogans
Leptospira interrogans
Answer Explanation
This patient presents with the classic signs/symptoms of Leptospirosis. Common epidemiological associations include tropical environment (particularly Hawaii in the US) and potential contact with animal urine (e.g. drinking from a contaminated water source). A particularly important sign is “conjunctival effusion,” which refers to conjunctival injection without presence of inflammatory exudates.
Three days into a white water rafting trip, a 19-year-old male who was otherwise healthy develops a fever to 39.5C and muscle aches. He initially shrugged it off but then noticed his skin was becoming yellow without development of a rash. At the hospital, a urine sample under darkfield microscopy reveals coiled, spiral-shaped bacteria. What is the likely pathogen?
A) Borrelia burgdorferi
B) Mycoplasma pneumoniae
C) Chlamydophilus psittaci
D) Leptospira interrogans
E) Treponema pallidum
Leptospira interrogans
Answer Explanation
Darkfield microscopy showing coiled, spiral-shaped bacteria suggests spirochetes: Leptospira, Treponema, and Borrelia. Treponema causes syphilis, Borrelia causes Lyme disease, neither of which are consistent with this presentation. Leptospirosis, one of the most common zoonotic infections in the world, is associated with recent exposure to bodies of freshwater, fever, headache, abdominal pain, and jaundice. The finding of spirochetes in urine sample further suggests Leptospirosis.
Mycoplasma pneumoniae and C. psittaci are most associated with atypical pneumonias.
Where in the United States have most cases of leptospirosis been located?
The incidence of L. interrogans infection is relatively low, with most cases reported from the southern and Pacific coastal states and surfers in Hawaii.
What two diseases can Leptospiral interrogans cause?
L. interrogans infection can lead to leptospirosis and Weil’s disease (icterohemorrhage leptospirosis).
How is Leptospira interrogans transmitted?
Transmission of L. interrogans occurs from contact exposure to environmental sources, such as animal urine (rodents, dogs, fish, and birds) and contaminated water or soil.
Three days into a lakeside vacation, a 21-year-old female who was otherwise healthy develops a fever to 39.5C, muscle aches, and yellowing of her eyes. At the hospital, a urine sample under darkfield microscopy reveals coiled, spiral-shaped bacteria. What is the source of the likely pathogen?
A) Arthropod vector
B) Human reservoir
C) White-tailed deer reservoir
D) Animal urine
E) Aerosol transmission from birds
Animal urine
Answer Explanation
Darkfield microscopy showing coiled, spiral-shaped bacteria suggests spirochetes: Leptospira, Treponema, and Borrelia. Leptospirosis, one of the most common zoonotic infections in the world, is associated with recent exposure to bodies of freshwater, fever, headache, abdominal pain, and jaundice. The finding of spirochetes in urine sample further suggests Leptospirosis. Leptospirosis is transmitted to humans when they come into contact with water that has been contaminated with animal urine from infected animals. The spirochetes can live in water for several weeks.
Arthropod vectors are involved in many diseases (e.g. Rickettsial infections) but not Leptospirosis. The white-tailed deer is not a reservoir for Borrelia burgdorferi; it is a host for the Ixodes tick whose bite transmits Borrelia burgdorferi. Aerosol transmission from birds is suggestive of C. psittaci and Mycobacterium avium complex.
An organism is viewed under dark field microscopy and is described as having “ice tong” ends. What organism is this?
Leptospira interrogans is an aerobic, motile spirochete and is described as having “ice tong” ends.
Patient presents with whole body annular lesions and tests positive in RPR. Pathogen?
A) Borrelia burgdorferi
B) Borrelia recurrentis
C) Chlamydia trachomatis
D) Leptospira interrogans
E) Treponema pallidum
Treponema pallidum
Patient presents with fever of 6 week duration that comes and goes away. Three months ago, the patient was camping and had tick exposure. Pathogen?
A) Borrelia burgdorferi
B) Borrelia hermsii
C) Chlamydia trachomatis
D) Leptospira interrogans
E) Treponema pallidum
Borrelia hermsii
Patient appears jaundiced and also seems to have hemorrhagic conjunctiva. Positive for antibodies against a spirochete. Pathogen?
A) Borrelia burgdorferi
B) Borrelia hermsii
C) Chlamydia trachomatis
D) Leptospira interrogans
E) Treponema pallidum
Leptospira interrogans
2 yo presents with rhinitis, edematous appearance. Positive RPR serology. Pathogen?
A) Borrelia burgdorferi
B) Borrelia hermsii
C) Chlamydia trachomatis
D) Leptospira interrogans
E) Treponema pallidum
Treponema pallidum
History of tick bite. In 3 wk a circular expanding lesion of ~20 cm. Pathogen?
A) Borrelia burgdorferi
B) Borrelia hermsii
C) Chlamydia trachomatis
D) Leptospira interrogans
E) Treponema pallidum
Borrelia burgdorferi
