Infectious Disease Flashcards
Acute rheumatic fever
Autoimmune inflammatory process that develops as a sequela of streptococcal infection
Dx of acute rheumatic fever
There is no specific diagnostic test for dx
Focus is on prevention with tx of strep and avoid repeated untreated infections
Rheumatic heart dz
The most significant complication of acute rheumatic fever which occurs after repeated bouts of acute illness
Abx and rheumatic heart dz
Antibiotic therapy does not alter the course, frequency, or severity of cardiac involvement once a pt develops rheumatic heart dz
Clinical manifestations of acute reheumatic fever
Polyarthritis Carditis Erythema marginatum Chorea Subcutaneous nodules
PE of acute rheumatic fever
80% of pts present early on with painful migratory arthritis in large joint such as knees, ankles, elbows, or shoulders
Chorea is a rare late-onset sign
Carditis (with progressive CHF, a new murmur, or pericarditis) may be the presenting sign and most lethal
Work up of acute rheumatic fever
ASO titers should be combined with a careful clinical evaluation and other antibodies such as antistreptokinase and anti-DNAse.
Throat culture may only be positive in 25-40% at time of rheumatic fever
Tx of acute rheumatic fever
PCN: either an injection of benzathine benzylpenicillin, or pcn
OR
Oral cephalosporin if allergic to pcn and pt is ok with risk of 20% cross-reactivity and risk of allergic reaction with cephalosporin
Organisms of chlamydia
C. pneumoniae- mild pna or bronchitis in adolescents and young adults
-Older adults can have more severe infection
C. psittaci- Psittacosis after exposure to infected birds
-Transmission of both C. pneumoniae and C. psittaci is through repsiratory secretions
-Chlamydia causes 10-20% of cases of CAP
C. trachomatis- sexually transmitted
Hx/PE of chlamydia
Incubation period is 3-4 wks, with gradual onset of mild sx (low grade fever, rhinitis, laryngitis, pharyngitis, sinusitis) to more cough with scant sputum, then malaise, hoarseness and HA in 58%
Rhonchi and rales present even in mild dz
C. psittaci pneumonia when exposed to birds (sick birds) with high fever 103-105 degrees
Best test is isolation in sputum culture (for pts not responding to outpatient therapy)
Tx of chlamydia- non STI
Tetracyclines and macrolides are the drugs of choice
- Doxycycline if >9 yo and not pregnant- 100 mg BID x 10-14 days
- Clarithromycin 500 mg BID x 10 days (or azithromycin 500 mg daily for 7-10 days)
When to suspect STI chlamydia in women
If pt has deep internal pain with intercourse
With bimanual exam she will experience intense pain with manipulation of cervix
S/sx of chlamydia in women
May be asymptomatic and the onset often indolent. It can cause cervicitis, endometritis, PID, urethritis, epididymitis, neonatal conjunctivitis, and pediatric PNA
Tx for STI chlamydia
Azithromycin 1 g PO in a single dose (OK in pregnancy) OR
Doxycycline 100 mg PO BID x 7 days (NOT OK in pregnancy)
Alternatives:
Erythromycin base 500 mg PO QID x 7 days
OR
Erythromycin ethylsuccinate 800 mg PO QID x 7 days
OR
Ofloxacin 300 mg PO BID x 7 days
OR
Levofloxacin 500 mg PO once daily x 7 days
Gonorrhea
A purulent infection of ANY mucus membrane surfaced caused by N. gonorrhea, but usually affects the genital mucous membranes
What should occur in pts positive for any STI?
Should have a full eval for risk of other diseases such as Chlamydia, syphilis, Hep B and C, and HIV. If high risk- the pt should be tested.
But insurance may not always reimburse every time- pts need to be made aware of risk, cost, and importance of prophylaxis
Hx/PE of gonorrhea in females
Vaginal discharge: MC presenting symptom -Thin, purulent, and mildly odorous Dysuria Intermenstrual bleeding Dyspareunia Mild lower abdominal pain
Hx/PE of gonorrhea in females if it progresses to PID
Lower abdominal pain, the MC symptom of PID
Increased vaginal discharge or mucopurulent
Dysuria: usually without urgency or frequency
Cervical motion tenderness
Adnexal tenderness (usually bilat) or adnexal mass
Intermenstrual bleeding
Fever, chills, nausea, and vomiting (less common)
Hx/PE of gonorrhea in males
Urethritis: the major manifestation of gonococcal infection in men; initial characteristics include burning upon urination and a serous discharge; a few days later, the discharge usually becomes more profuse, purulent, and at times, tinged with blood
Acute epididymitis: Usually unilateral and often occurs in conjunction with a urethral exudate
Urethral strictures: Have become uncommon in the antibiotic era, but they can present with a decreased and abnormal urine stream, as well as with the secondary complications of prostatitis and cystitis
Tx of gonorrhea
Ceftriaxone 250 mg intramuscular single dose PLUS
Azithromycin 1 g PO single dose OR
Doxycycline 100 mg PO BID x 7 days
Diphtheria
Either an upper respiratory tract or cutaneous infection caused by aerobic Gram pos bacteria Corynebacterium diphtheria.
Occurs in spring or winter mos and continues for 2-6 wks without antibiotic tx
Who is susceptible to diphtheria?
Those not immunized or those with a weak antibody level exposed to diphtheria
Hx/PE of diphtheria
Sx start as nonspecific upper respiratory sx, then sore throat
Development of a localized pseudomembrane- dense, gray debris in the posterior pharynx
Removal of the membrane reveals a bleeding, edematous mucosa
Cervical adenopathy and swollen mucosa gives a bull’s neck appearance
Tx of diphtheria
Admit for tx
Horse serum antitoxin is given in early stages, then a macrolide
What causes infectious mononucleosis?
Epstein-Barr virus
Lab work for infectious mononucleosis
Test with the mono spot test which is usually done in primary care offices with a drop of blood.
Or a serologic test for EBV
More serious dz caused by Epstein-Barr virus
The virus persists in the body for life and can reactivate quietly without sx and lead to chronic illness
Particularly in pts with compromised immune systems, that can lead to some forms of lymphoma
What has been linked to EBV but no studies have proven a causal link?
Chronic fatigue syndrome
Central sx of infectious mononucleosis
Fatigue
Malaise
Loss of appetite
HA
Throat sx of infectious mononucleosis
Soreness
Reddening
Respiratory sx of infectious mononucleosis
Cough
Systemic sx of infectious mononucleosis
Chills
Fever
Aches
Visual sx of infectious mononucleosis
Photophobia
Tonsil sx of infectious mononucleosis
Reddening
Swelling
White patches
Lymph node sx of infectious mononucleosis
Swelling
Spleen sx of infectious mononucleosis
Enlargement
Abdominal pain
Gastric sx of infectious mononucleosis
Nausea
What is the causative organism of erythema infectiosum (fifth disease)?
Human parvovirus B19
Sx of fifth dz
Mild prodromal sx begin 1 wk after exposure and last 2-3 days HA Low-grade fever Sore throat Pruritis Rhinitis Arthralgias Then the reddened cheeks over 2-4 days Then the erythematous maculopapular rash that fades into a classic lacelike reticular pattern The rash can occur off and on for wks
Workup of fifth’s dz
No testing needed. Dx on clinical presentation only
Tx of fifth’s dz
Supportive care with NSAIDs and antihistamines if needed for pruritis.
Herpes zoster
Reactivation of the varicella-zoster virus that has remained dormant in the dorsal root ganglia after the pt’s initial illness from chickenpox
Usually this is a self-limited vesicular dermatomal rash lasting approx one week with mild to moderate pain
Sometimes it can be more serious and lead to chronic postherpetic neuralgia
What can herpes zoster be accompanied by?
Malaise
Myalgia
HA
Uncommonly fever
PE of herpes zoster
Grouped herpetiform vesicles on an erythematous base appearing unilaterally and stopping midline at the limit of the sensory coverage of the involved dermatome
Dx of herpes zoster
Usually based clinically
PCR testing is available if dx is unclear
Tx of herpes zoster
Antiviral meds if caught within first 72 hrs
-Valacyclovir- 1 gm TID x 7 days
Consider steroid taper if severe
-Prednisone pack 10 mg strength over 7 days
Neuralgia- Lyrica 75 mg BID x 7-14 days if severe pain or gabapentin 300 mg BID-TID
Warn pt of possible side effects of Lyrica and Gabapentin causing dizziness
Manifestations of HPV
Condylomata- discrete, papillary, cauliflower-like lesions on multiple sites on moist surfaces
Keratotic warts- often seen on dry surfaces such as the labia
Discrete papules 1-3 mm can present on the shaft of the penis
Testing of HPV
Dx can be made clinically or with application of acetic acid and bx
Careful exam and colposcopy is essential for cervical lesions
Detection of HPV DNA is now approved by the FDA and is valuable as a screening tool in women older than 30 yrs and is taken from the Pap test sample
Tx of HPV
No single curative tx for condylomata acuminata
Primary goal is reduction of sx and reserved for pts with visible warts
Surgical incision
Chemical ablation (aldara- apply 3 times a wk)
Cryotherapy
HIV
A blood-borne virus spread by blood exposure, sexual intercourse, shared needles, or to a fetus from an infected mother
What is a new guideline for antiretroviral drug therapy (HIV/AIDS)?
For asymptomatic pts with HIV and a CD4 count over 500/mm
Physical findings of symptomatic phase of HIV
No physical findings are specific to the asymptomatic phase
Acute seroconversion manifests as a flulike illness, with malaise and a rash
Generalized LAD is common
Screening for HIV- USPSTF
Strongly recommends that clinicians screen for HIV in all adolescents and adults at increased risk for HIV infection and all pregnant women
CDC screening recs for HIV
Recommends opt-out screening for pts in all healthcare settings
Persons at high risk for HIV infection should be screened at least annually
American College of Physicians recs for HIV screening
Clinicians adopt routine screening for HIV and encourage all pts to be tested
What should be used for HIV screening?
ELISA for screening
Positive result should be followed with confirmatory testing (e.g., Western blot assays)
HIV-2 should be tested for in pts from an endemic area or those with indeterminate results on HIV-1 Western blot testing
Early detection using combination screens may be more effective than simply using serology
CD4 T-cell counts and HIV/AIDS
Reliably reflects the current risk of acquiring opportunistic infections, as follows:
-Reference range, 500-2000 cells/microL
Because CD4 counts vary, serial counts are generally a better measure of significant changes
For surveillance, a CD4 count below 200/microL is considered AIDS-defining in the US
Viral load and progression to AIDS
Pts with viral loads >30,000/microL are 18.5 times more likely to die of AIDS than those with undetectable viral loads
Viral loads and therapy with HIV/AIDS
With therapy, viral loads can often be suppressed to an undetectable level (<20-75 copies/mL; optimal viral suppression)
Systemic sx of acute HIV infection
Fever
Weight loss
Mouth sx of acute HIV infection
Sores
Thrush
Esophagus sx of acute HIV infection
Sores
Muscle sx of acute HIV infection
Myalgia
Liver and spleen sx of acute HIV infection
Enlargement
Central sx of acute HIV infection
Malaise
HA
Neuropathy
Lymph node sx of acute HIV infection
LAD in neck and axilla
Skin sx of acute HIV infection
Rash
Gastric sx of acute HIV infection
Nausea
Vomiting
What other infections should be screened for in a person iwth an HIV infection?
PPD for TB CMV Syphilis Rapid amplification testing for gonococcal and chlamydial infection Hep A, B, and C serology Anti-Toxoplasma antibody Ophthalmologic exam
Types of antiretroviral therapy- HIV/AIDS
Nucleoside reverse transcriptase inhibitors (NRTIs)
Protease inhibitors (PIs)
Nonnucleoside reverse transcriptase inhibitors (NNRTIs)
Fusion inhibitors
CCR5 co-receptor antagonists (entry inhibitors)
HIV integrase strand transfer inhibitors
Central sx of AIDS
Encephalitis
Meningitis
Eye sx of AIDS
Retinitis
Lung sx of AIDS
Pneumocystis PNA
TB (multiple organs)
Tumors
Skin sx of AIDS
Tumors
GI sx of AIDS
Esophagitis
Chronic diarrhea
Tumors
Prophylaxis for pneumocystic jiroveci- AIDS
Septra DS- one daily or 3x/wk
Prophylaxis for Toxoplasma- AIDS
Sulfadiazine 4x daily plus pyrimethamine plus leucovirin
Prophylaxis for Mycobacterium avium complex- AIDS
Clarithromycin 500 BID plus ethambutol if CD4 <50/microL
Prophylaxis for fungal and viral infections: AIDS
Although prophylaxis for these infections is not routinely necessary, some recommend fluconazole inp ts with CD4 T-cell counts >50/microL to prevent candidial or cryptococcoal infections and to protect against endemic fungal infections
Oral ganciclovir is indicated for CMV prophylaxis in pts with advanced AIDS
Acyclovir daily to prevent herpes simplex
MRSA prevention- AIDS
Mupirocin 2% nasal ointment to each nostril twice daily
What is the goal of HIV tx?
To prevent the immune system from deteriorating to the point that opportunistic infections become more likely
Prognosis of untreated HIV/AIDS
Prognosis in pts with untreated HIV infection is poor, with an overall mortality rate of >90%. Average time from infection to death is 8-10 yrs
Once infection has progressed to AIDS, the survival period is usually <2 yrs in untreated pts
Pt education- HIV/AIDS
Be counseled about the risks of infecting their sexual partners with HIV
Safer sex practices and tx of concurrent STIs, both in the pt and in sexual partners, considerably reduces the risk of transmission
