7 Infectious Mono And Lyme Flashcards
____________ infection causes infectious mononucleosis
Epstein-Barr Virus (EBV)
Burkitt’s Lymphoma is linked to _______ infection in some regions of the world
EBV
Really just in certain parts of Africa -
One of the strongest virus-cancer links
Incubation period for mono is …
1-2 months
Primary virus replication occurs in the oropharynx, virus eventually reaches lymph nodes
Mono is a ___ cell infection
B cell infection, inducing polyclonal expansion of lymphocytes
BUT Sx are from T-cell reaction
Dissemination of mono infection is …
Through lymphoreticular system of infected cells
Prodromal period of 3-5 days (HA, fever, malaise, fatigue)
Typical mono presentation
Sore throat, symmetrical LAD, fever
Sometimes hepatomegaly with increased liver enzymes and jaundice
More commonly, splenomegaly
What does the throat look like in mono patients?
Palatal enanthem at junction of hard and soft palate with petechial lesions
Mono is characterized by presence of _______ cells in circulation
Atypical lymphocytes (“Downey cells”)
These are mostly T cells and responsible for a lot of the Sx
How is EBV spread?
Worldwide distribution
Person-to-person transmission
Asymptomatic infection (or mild infection) of children frequent
Peak incidence of mono is in ages…
17-25
EBV virus can be found in saliva for …
About 1 month or more (makes it easier to spread)
Diagnosis of mono is difficult because…
It mimics other diseases (CMV, rubella, hepatitis, strep)
Key factors in the diagnosis of mono
Patient age (TEEN) and the presence of HETEROPHILE ANTIBODIES
Agglutination of horse RBCs in Monospot test
What is the downside of the Monospot test?
AGE-SPECIFIC REACTIVITY
Pre-teen patients may not have strong heterophile antibody response**
For younger patients, confirmation by serology (IgM anti-virus capsid antigen, anti-VCA)
Treatment for Mono?
Symptomatic relief
What happens if you mistake mono for strep and treat with penicillin?
A rash that they will forever mistake for a penicillin allergy
Which virus is considered the “troll” of transplantation?
Cytomegalovirus (CMV)
Virus similar to EBV but does not produce heterophile antibodies
CMV
CMV infection is most problematic for…
Transplant patients
Immune suppressed patients
Infections occurring during pregnancy
What is the major source of CMV infections?
Children with minor colds (snotty nosed kids)
How do you treat CMV?
Ganciclovir and immunoglobulin (Cytogam) - esp helpful for transplant patients
How is Mumps treated and prevented?
Symptomatic relief (no antivirals available)
Vaccination is the main method of control
MMR used in US contains the Jeryl Lynn attenuated virus strain
Do you end up with lifelong immunity from Mumps with the MMR?
Not if you have an egg or neomycin sensitivity
The Great 2006 Mumps outbreak in Iowa was mostly due to…
Breakthrough cases in already MMR vaccinated persons
Calls in to question the typical MMR protocol (may need to add a third booster?)
Lyme Disease is named for…
Location of definitive description (Old Lyme, CT)
What lead to the initial discovery of the etiology of Lyme disease?
Unusual cluster of juvenile arthritis
Lyme disease progresses through several stages in a pattern similar to…
Syphilis
Like syphilis, this disease can mimic other conditions complicating the diagnosis
Stage 1 of Lyme disease is characterized by…
Acute localized disease
Erythema migrants at the site of the tick bite in 70-80%
• Bulls eye pattern
• Expanding
• Fades in less than a month but can be hidden
• Patients may have flu-like symptoms
Stage 2 of Lyme disease is the _______ disease
Subacute, disseminated
70% of untreated patients go to stage 2 weeks to months after infection
Flu like symptoms
ASYMMETRIC ARTHRITIS ATTACKS with swelling and pain of large joints (60%)
MULTIPLE SECONDARY ANNULAR SKIN LESIONS days to weeks after infection (50%)
20% of untreated pt show hepatitis
MENINGITIS in 15% of untreated patients (subacute but FACIAL PALSY)
Nonspecific follicular conjunctivitis in 10% of stage 1 or 2 patients
Stage 3 of Lyme disease is …
Chronic disease
Primarily musculoskeletal manifestations
Arthritis attacks become more persistent, longer duration in second and third year after infection
In 10% arthritis is chronic (at least one year of unremitting joint inflammation)
What is the organism that causes Lyme disease in North America and Europe
Borreliella burgdorferi
In Eurasia - B. garinii and B. afzelii
90% of cases of Lyme disease in the US occur in …
Upper Midwest and east coast
CT, RI, NY, NJ, PA, DE, MD, Wi
What is the vector for Lyme disease?
Tick - specifically the deer tick or black-legged tick
Ixodes sp.***
What is the reservoir for Lyme disease?
Small mammal reservoirs (rodents, rats, MICE) and birds
Tick transmission is essential to maintain cycle (no trans-ovarian tick transmission)
Lyme disease is associated with what type of location?
Forest edge
Think MOUSE HABITAT - humans contact ticks in fields with tall grass and brush
How is Lyme diagnosed?
Clinical findings - SSx and exposure in endemic area
Serology
• EIA plus Western blot if EIA is positive**
• Patients typically positive by 4th week
What can cause false positives for Lyme?
Syphilis Mono SLE RA Oral infection with spirochete
What is the best way to prevent Lyme disease?
Control and avoidance of vector
• Repellents with DEET
• Careful checks for attached ticks after outdoor activities
• Control tick sources such as mice
What happened to the Lyme vaccine?
Taken off the market b/c it induced symptoms
There’s now a promising new anti-Lyme mouse vaccine though…
What is the treatment for Lyme disease?
For patients with Symptoms - amoxicillin or doxycycline for 10-21 days
Prophylactic treatment is not generally done (risk doesn’t justify it)
Post Treatment Lyme Disease Syndrome resembles what?
Reiter’s syndrome
10-20% of abx treated patients have lingering Sx of fatigue, pain, and joint problems
May reflect residual tissue damage and auto-immune responses
Most improve with time
