Infectious Disease Block II

What are the two neurologic complications that are of great concern with the vertical transmission of Zika?

Microcephaly and Guillain-Barre

Which illness typically presents with a productive cough, fever, weight loss, hemoptysis, chest pain, anorexia, fatigue, night sweats, and abnormal breath sounds (especially over the upper lobes)?

Pulmonary TB

Where are outbreaks of Blastomycosis common (more prevalent in male population)?

North America (states near Mississippi/Ohio rivers, Midwestern states) along streams or rivers with moist soil enriched with decaying vegetation

What are the signs and symptoms of primary Blastomycosis?

Acutely presents like bacterial pneumonia, Chronic is clinically indistinguishable from TB
If cutaneous blastomycosis, presents with verrucous, nodular, or ulcerative lesions on face and extremities

What is the treatment for Blastomycosis (must treat all patients even if asymptomatic)?

Itraconazole for mild-moderate infections
Liposomal Amphotericin B for life threatening or CNS infections

Where are the endemic areas for Coccidioidomycosis?

Arizona (accounts for up to 29% of CAP), Central California, New Mexico, and West Texas
Disease is worse in Filipino and pregnant patients

What are the signs and symptoms of Coccidioidomycosis?

Pulmonary disease that acutely presents with cough, pleuritic chest pain, constitutional symptoms, hilar/mediastinal adenopathy, and erythema multiforme
Chronically presents like TB with thin-walled cavities
Can become disseminated and fulminant disease i

When should Coccidioidomycosis be treated?

Acute pulmonary is symptomatic treatment only
Severe/disseminated disease is treated with Amphotericin B
Meningeal disease requires life-long Fluconazole

Which mycotic disease is AKA Darling's disease, is mostly found in the Ohio and MS River valleys, grows in soil, is associated with bats/chickens/birds, usually presents as a mild flu-like disease, but can affect those who smoke more severely (can become

Histoplasmosis (diagnosed through Giemsa/Wright stain instead of typical KOH)

Which patients are usually affected by disseminated Histoplasmosis, and present with low-grade fever, weight loss, oral and cutaneous lesions?

Seen in immunocompromised patients (AIDS) may require antigen testing and life-long suppression with Itraconazole

Which mycotic disease is associated with pigeon droppings, more common in men and especially in AIDS when CD4 count is < 200, can present as pulmonary disease, papules/pustules/draining sinuses, can infect the medullary cavity of bones, but most commonly

Cryptococcosis (requires treatment with Amphotericin B)

Where can superficial infections of candidiasis manifest?

Thrush (patients not properly using inhaled steroids and neonates), vaginitis (often follows antibacterial use), onychomycosis, esophagitis, and intertrigo (diaper rash)

What is the treatment for intertrigo (Candidiasis in moist skin folds)?

Nystatin or other powders (must be dry at application)

Which type of Candidiasis is associated with malignancy? Which one is common in patients receiving TPN? Which one is found in unitary tract infections?

Tropicalis- malignancy
Parapsilosis- TPN
Glabrata- UTI

Which non-albicans candida yeasts are resistant to fluconazole?

Candida krusei and glabrata

What is the treatment for vaginal candidiasis?

Single dose of oral Fluconazole

Which mycotic disease is responsible for 10% of all nosocomial blood stream infections, has a high rate of mortality, and can be difficult to diagnose?

Candida spp.

How does invasive diarrhea present differently than non-invasive diarrhea?

Non-invasive is usually afebrile, presents with abdominal cramping with watery diarrhea
Invasive presents with febrile patients and RBC and WBCs in the stool

What is the term for a diarrheal disease that presents with 1-5 days of watery diarrhea, N/V, and can be caused by infections, drugs, toxins, or systemic disease?

Acute Gastroenteritis (will likely require oral rehydration)

What is the difference between a short and long incubation time in food poisoning?

Short (1-6 hours) toxin is pre-formed and in food
Long (8-16) organism is present in food and toxin is produced after consumption

Which conditions can pre-dispose to patients to diarrhea caused by Plesiomonas spp?

Liver disease or malignancy

Patients with intestinal dysmotility, malnutrition, achlorhydria, hemolytic anemia, sickle cell disease, immunosuppression, and malaria are more predisposed to developing diarrhea due to which organism?

Salmonella spp

Patients with agammaglobulinemia, chronic pancreatitis, achlorhydria, and cystic fibrosis are more predisposed to developing diarrhea due to which organism?

Giardia spp

If a patient with AGE presents with prominent vomiting, 14+ hour incubation, no bacterial warning signs, and the illness is over in less than 3 days, what should be the suspected cause?

Virus should be suspected

Which viral cause of diarrhea presents with diarrhea that is more prolonged and can cause multiple viral illnesses?

Adenovirus

Which viral cause of diarrhea is a common cause of pediatric diarrhea with possible association with intussusception?

Calicivirus

Which common cause of AGE in children and infants may cause URIs and can be vaccinated against?

Rotavirus

Which viral cause of diarrhea is common in immunocompromised patients, can cause dysentery, and patient may benefit from antivirals like Ganciclovir?

CMV

Which bacterial cause of diarrhea causes severe cramping, is associated with polyarticular arthritis, and is often misdiagnosed as appendicitis?

Yersinia enterocolitica

Which bacterial cause of diarrhea is caused by toxin in the food (no organism in the body), and presents with "I want to die" severe gastroenteritis?

Staph aureus

Which bacterial cause of diarrhea comes from contaminated fried rice and has systematic movement through the GI tract?

Bacillus cereus

Which bacterial cause of diarrhea is known for causing gas gangrene and mild GI symptoms?

Clostridium perfringens

Which organism is responsible for community-acquired inflammatory enteritis, is transmitted through the fecal/oral route, chickens and sick pets account for most infections, and causes abdominal tenderness (pseudoappendicitis), high fever, headache, myalg

Campylobacter jejuni (treat with Azithromycin)

Which organism is responsible for food borne illnesses from eggs/poultry/cheese or from reptiles and amphibians, and presents with non-bloody loose stools, nausea/vomiting, and mild abdominal cramping?

Salmonellosis (treat with Ciprofloxacin)

Which systemic bacterial infection (enteric fever) is more common in people with a travel history, is transmitted through food contaminated with feces/urine, and presents with a hallmark of mononuclear phagocytic cells in the liver, spleen, and lymph node

Typhoid Fever (vaccine available) can treat with Ciprofloxacin or Ceftriaxone if acquired in Asia

What are the stages of Typhoid fever?

Asymptomatic during incubation period (usually 7-14 days)
Transient diarrhea leading to headache, malaise, and rising remittent fever in the 1st week
Days 7-12 develop crops of 2-4 mm diameter pink papules (rose spots) and dicrotic pulse
3rd week shows in

Which organism causes bacillary dysentery by invading the colonic epithelium and production of an enterotoxin and presents with acute bloody diarrhea, tenesmus, passage of mucus, fever, and has a self-limited course (3 days-1 week)?

Shigellosis

Which organism is responsible for "Traveler's Diarrhea", presents with abdominal cramping, frequent explosive bowel movements, N/V, and requires treatment with Loperamide and Ciprofloxacin?

ETEC (enterotoxigenic E coli)

Which organism produces the "Shiga toxin", begins as a watery diarrhea followed by a grossly bloody stool, and can present with hemolysis/thrombocytopenia/uremia and death in 10% of cases?

EHEC (Enterohemorrhagic E coli O157:H7) do not treat with antibiotics, treat HUS with dialysis PRN

Which diarrheal disease presents as "rice water stools" with a fishy odor, quickly becomes voluminous and is often followed by vomiting and abdominal cramps, does NOT present with a fever, but can cause death after rapidly onset hypovolemic shock?

Cholera (requires fluid replacement)

Which diarrheal disease has a high fatality rate (especially in pregnant patients or newborns), and is caused by unpasteurized milk, soft cheeses, ice cream, vegetables and produce, and deli meats, and presents with noninvasive diarrhea and possibly bacte

Listeria monocytogenes
Requires empiric therapy for at risk patients with Ampicillin or TMP-SMX

Which type of illnesses are all caused by RNA viruses that are enveloped in a lipid coating, damage the microvasculature, and do not have humans a s a natural reservoir (and no cure/established drug treatments)?

Viral Hemorrhagic Fevers

Which disease of the tropics is spread by the Aedes aegypti mosquito (domestic, prefers to feed on humans during the day), and presents with a very saddleback high fever (105.8F), a retro-orbital headache, N/V, truncal scarlatiniform rash, severe myalgias

Dengue Fever (AKA Breakbone fever)

What are the physical manifestations of Dengue Fever?

97% get a pharyngeal infection
50% get a scarlatiniform rash
Petechiae or purpura if hemorrhagic manifestation
Conjunctival infection

What is the diagnostic test for Dengue Fever?

Tourniquet Test- Inflate a BP cuff on the upper arm for 5 minutes, 20 petechiae or more per sq inch are positive for Dengue Fever

How does Dengue Fever appear on labs (CBC and BMP)?

CBC will show lymphocytosis before defervesce or shock
HCT rise > 20% (hemoconcentration) precedes shock
Thrombocytopenia
BMP will show hyponatremia (MC metabolic disturbance)

What is the treatment for self-limited Dengue Fever? What is the treatment if DF evolves into DHF?

Self-limited- acetaminophen
DHF- Admit for IV fluids and possible blood transfusion

Which illness is caused by a virus that replicates in the reticuloendothelial system (in the liver) which results in jaundice, mucosal and GI tract bleeding that causes "black water" vomit, and a fever with a saddleback pattern in 3 stages?

Yellow Fever

What are the three stages of Yellow Fever?

Acute phase (presents with fever/headache, nausea and bilious black vomiting, and conjunctival injection) 85% stop here
24-hour remission
Toxic phase (presents with jaundice, oliguria/dark urine, petechiae, epistaxis, coffee ground emesis, melena, and myo

What is the treatment for a patient with Yellow Fever?

Supportive therapy
Isolation with mosquito netting
Actively bleeding patients need FFP

What is the natural reservoir of Ebola and Marburg (Filoviruses)?

Bats (also non-human primates)

How do the Ebola and Marburg viruses present?

Early on presents with severe headache, pharyngitis, fever +/- chills, rash, and conjunctival injection
Followed by GI symptoms (N/V/D)
Late in disease presents with expressionless "Ghost" facies and bleeding from mucous membranes and GI tract
Terminally

What are the potential complications for a patient that survives Ebola or Marburg (mortality rates of 80% and 20%)?

Ocular manifestations
Tinnitus
Unilateral orchitis
Suppurative parotitis
Arthralgias

Which illness is endemic in W Africa, has a rodent to human transmission and a secondary human to human transmission, and is especially harmful in the 3rd trimester of pregnancy?

Lassa (treat with Ribavirin)

What is the most common sequelae of Lassa virus?

Deafness (seen in 1/3 of cases)
Facial edema is also common "Swollen Baby Syndrome

Which lab value will be substantially higher in patients with Lassa?

AST levels will be much higher than ALT levels

Which illness is AKA Hemorrhagic Fever with Renal Failure Syndrome (HFRS), presents with the triad of fever, hemorrhage, and renal insufficiency, and has a Febrile stage and potentially a HOTN stage (seen in 11% of patients), an oliguric stage and finally

Hantavirus (NOT the Hantavirus Pulmonary Syndrome)

Which illness presents initially as flu-like symptoms, hemorrhage begins after 3-5 days, massive ecchymosis, epistaxis, hepatomegaly, and erythema?

Crimean-Congo Hemorrhagic Fever

What are the potential complications of Crimean-Congo Hemorrhagic Fever (carried by ticks)?

Encephalitis and up to a 50% mortality rate

How is TB transmitted?

Airborne droplet nuclei transmission that is deposited in the terminal airspaces and ingested by macrophages that transport TB to regional lymph nodes
(M tuberculosis is acid-fast, non-motile, non-spore forming, and non-encapsulated)

Which medical conditions predispose individuals that have a latent TB infection to develop the active disease?

HIV infection is greatest risk
DM
Substance abuse (IVDU)
Low body weight (10% or more below ideal)

How can non-respiratory TB manifest in the immunocompromised and elderly?

TB meningitis (headache, mental status change, coma, fever)
Skeletal TB (MC in spine- Pott's disease, back pain, stiffness, extremity paralysis)
Genitourinary, cutaneous, and GI manifestations also possible

Which type of TB is a widespread hematogenous dissemination that frequently affects the immunocompromised and has a mortality rate close to 100% if untreated?

Miliary TB

Which test is the cornerstone of diagnosing latent TB?

PPD (AKA Mantoux test or TST)
Size of induration (NOT ERYTHEMA) read at 72 hours is diagnostic
All positive PPD must get CXR

What is the definition of a positive PPD test (for area of induration 5 mm, 10 mm, and 15 mm or more)?

Induration larger than or equal to 5 mm in patients in close contact to newly diagnosed TB, HIV positive, organ transplant patients, long term steroid use, or if fibrotic lesions on CXR
Area of induration is greater than or equal to 10 mm in patients with

Which lab test can provide the first mycobacteriologic indication of TB disease? Which lab test is the only one that can definitively identify TB?

Sputum smear showing acid fast bacilli for first evidence
Culture for definitive ID

Why must baseline labs with CBC, AST/ALT, T bilirubin, and HIV testing be accomplished prior to treating TB?

Treatment affects liver, must ensure liver function before treatment begins

How does reactivation TB appear on CXR?

Cavity formation, calcified peripheral nodules (Ghon lesions) and calcified hilar nodes

What is the empiric initial treatment for active TB?

4-drug regimen of INH, Pyrazinamide, Rifampin, and Ethambutol for 6 months
(Pyrazinamide and Ethambutol for first 2 months only, INH and Rifampin continued for full 6 months)

Which vaccination is used in some countries against TB, but is not effective in adults and may cause a false positive on a PPD?

Bacille Calmette-Guerin (BCG)

What is the two-step testing for tuberculosis?

Initial PPD may stimulate reaction causing a negative initial skin test, and so a second test may be performed 1-3 weeks later if there is a high clinical suspicion for TB
If facility has sufficient budget, QTF-G is used over two-step testing

What is the preventive therapy for LTBI?

INH daily for 9 months with Pyridoxine (Vitamin B6) to prevent peripheral neuropathy

How often must the AST/ALT levels be monitored for patients being treated for latent TB?

Monthly

Which disease starts out as a minor, seemingly innocuous laceration or abrasion that rapidly progresses to involve the deep tissue and destroys fascia, fat and patient develops gangrene, severe pain (*out of proportion), and mental status changes?

Necrotizing fasciitis (initiated by GAS, Staph aureus, Vibrio, or Aeromonas)

What treatment should be started while awaiting lab results if necrotizing fasciitis is suspected?

Pen G and Clindamycin
Early open extensive debridement (or Hyperbaric Oxygen Therapy) also reduces mortality

A patient with sore throat, enlarged and red tonsils with exudate, dysphagia, and generalized symptoms (fever, chills, malaise, anterior cervical LAD) is most likely suffering from which condition?

Strep Throat caused by Group A B-hemolytic Strep
Requires treatment with Benzathine Penicillin IM for non-compliant patients or 10-day course of Pen V

When does Rheumatic Fever (sequelae of Gp A B-hemolytic strep infection) generally occur?

2-3 weeks after an infection, MC affects mitral valve deformity in patients 5-15 years of age

What are the major and minor criteria for diagnosing rheumatic fever (2 major or 1 major and 2 minor required)?

Major- Carditis, Erythema marginatum, subcutaneous nodules, Sydenham chorea, and polyarthritis
Minor- Fever, polyarthralgias, PR interval prolongation, elevated ESR or CRP

What is the treatment for Rheumatic fever?

Bedrest, ASA, PCN, and corticosteroids

A patient presenting with fever, chills, headache, vomiting, pharyngitis, tongue dorsum with a white exudate and projecting edematous papillae, and a coarse sandpaper rash is most likely suffering from which condition?

Scarlet Fever, caused by the erythrogenic toxin of Gp A B-hemolytic strep
Requires treatment with Pen V

Which infection is similar to Scarlet Fever, but is caused by an exotoxin mediated response resulting in fever, TTP, warm skin, a diffuse erythematous rash, positive Nikolsky's sign, and dehydration?

Staphylococcal Scalded Skin Syndrome
Requires treatment with supportive care and IV Nafcillin

A patient that presents with influenza-like symptoms, high fever, HOTN < 90 mmHg SBP, confusion, signs of soft tissue infection, rash, desquamation (on palms and soles), chills, myalgia, and N/V/D secondary to a trivial staphylococcal infection is most li

Toxic Shock Syndrome
Requires aggressive supportive therapy with Nafcillin (anti-staph) and Pen G + Clindamycin (anti-step)

What are the diagnostic criteria for TSS?

Evidence of multisystem involvement of at least 3 or more of following systems: GI, Muscular (CK elevation), Mucous Membrane erythema, Renal (BUN/Cr 2x ULN), Hepatic (Bilirubin 2x ULN), Platelets < 100,000, CNS

Which illness is seen in neonates within the first week of life, presents with respiratory distress (pneumonia/respiratory distress syndrome), lethargy, and HOTN, meningitis (seizures) and is associated with fever, prolonged labor, and prematurity?

Early-onset Group B Strep Infection (acquired during or shortly after birth due to colonized maternal tract)

Which illness is seen usually between the 3rd and 4th week of life in infants and presents as bacteremia, osteomyelitis, facial cellulitis, and septic arthritis?

Late-onset Group B Strep Infection
Requires treatment with Pen G

How should single MRSA abscesses or lesions < 5 cm be treated?

Possible to do outpatient treatment with oral abx effective against MRSA
TMP-SMX, Doxycycline, and Clindamycin

How should MRSA abscesses and lesions that are larger than 5 cm multiple lesions be treated?

Inpatient management with Vancomycin

How can HCWs who have been identified as MRSA carriers be treated to prevent additional infections?

Bactroban applied to nares and wounds and Chlorhexidine baths (5-day course is effective)

Which form of tetanus is the active type?

Vegetative cell that releases 3 toxins into contaminated wounds (tetanospasmin is the one responsible for the disease)

What are the 4 types of tetanus?

Generalized (MC- affects all skeletal muscles)
Local tetanus
Cephalic tetanus
Neonatal tetanus (umbilical cord contamination)

How do the seizures caused by tetanus present?

Resembles epileptic seizures, patient does not lose consciousness, causes extreme pain
Will see opisthotonos (arching of back), flexion and abduction of arms, clenching fists on thorax, and extension of lower extremities

What is the treatment for tetanus?

Treat seizure with Diazepam
Treat the infection with tetanus immune globulins

Which highly communicable viral disease presents with a prodrome of fever, conjunctivitis, coryza, cough, and then presents with Koplik spots on the buccal mucosa and a red/blotchy rash that appears on the 3rd day (begins of face and then spreads), and is

Measles (Rubeola)

What are the most serious complications from measles that contribute the mortality rate?

Pneumonia and encephalitis

Which mild febrile viral disease presents with a diffuse, punctate, maculopapular rash and a low-grade fever, headache, malaise, lymphadenopathy that precedes the rash, and Forscheimer Spots in the mouth?

Rubella (German Measles)

What is the most devastating complication of Rubella (German Measles), and the main reason that a Rubella infection must be differentiated from other exanthems?

Potential for intrauterine death or fetal anomalies (deafness, cataracts, glaucoma, MR) if there is a maternal infection early in pregnancy (especially in the first 16 weeks, 80% lead to Congenital Rubella Syndrome)

How is a diagnosis of Rubella confirmed?

Must look for rubella-specific IgM on ELISA and a 4-fold rise in specific antibody titer (collected initially and repeat 2-3 weeks later)
Diagnose with CSF in newborn

Which virus causes severe generalized infections in infants, especially in the CNS and liver (icterus, purpura, convulsions, etc) and can result in MR, microcephaly, hearing loss, or death in-utero?

CMV

How does CMV affect immunocompromised patients (post-transplant or HIV)?

Retinitis (cotton wool spots), pneumonia, and GI tract disorders

Which acute viral syndrome presents with fatigue (extreme tiredness), fever, exudative sore throat, cervical lymphadenopathy, and splenomegaly that may rupture?

Epstein-Barr Virus (Mononucleosis) AKA the "Kissing Disease" due to its oropharyngeal spread, recovery takes several weeks to months

What lab tests can be used to identify and diagnose EBV/Mononucleosis?

May see lymphocytosis > 50%, abnormal AST, and diagnose with Monospot test

Which acute viral illness presents with fever, salivary gland tenderness (usually parotid), and can cause unilateral orchitis, oophoritis (but does not usually cause sterility), pancreatitis, potentially neurologic involvement?

Mumps (spread by droplets or direct contact with saliva)

What is the hallmark of poliomyelitis (90% of infections are subacute)?

Acute onset of flaccid paralysis without sensory loss (classically asymmetric/unilateral)
Major illness will also have severe muscle pain and neck/back stiffness

What is the difference between non-paralytic and paralytic poliomyelitis?

Non-paralytic causes meningeal irritation and muscle spasm (presents like meningitis)
Paralytic causes paralysis to spinal nerves, cranial nerves, and respiratory muscles (life-threatening)

How is polio diagnosed?

Isolate virus in stool (or CSF) and look for four-fold rise in antibody levels

What is the difference between the OPV and the IPV forms of the polio vaccine?

OPV is the oral polio virus vaccine which contains a live trivalent that can associated with virus-vaccine strains that can cause polio*
IPV is the inactivated form of the vaccine, which has higher levels of GI excretion

Which viral illness begins as a maculopapular rash that becomes vesicular for 3-4 days, followed by a granular scab (infectious until scabs), and lesions commonly occur in crops with several stages of maturity simultaneously?

Varicella

What are the common causes of death in a Varicella infection?

Primary viral pneumonia in adults (may have severe fever/constitutional symptoms especially in adults)
Septic compilations and encephalitis in children

What is the infectious agent that causes Varicella and Herpes Zoster?

HHV 3

What is the common complication associated with Herpes Zoster (especially in the elderly)?

Severe pain and paresthesia (post-herpetic neuralgia) can be prevented by starting Acyclovir early in prodrome

Which viral infection is common during the winter and spring, commonly affects children ages 5-15, presents with a "slapped cheek" appearance that results in a rash that spreads from the face to the trunk and extremities, and is caused by Parvovirus B19?

Fifth Disease (AKA Erythema Infectiosum)

What is the infectious agent in Roseola Infantum (AKA 6th Disease)?

HHV 6

Which viral illness presents with a high fever that lasts for 3-5 days followed by an abrupt appearance of a rose-pink macular rash as the fever subsides?

Roseola Infantum (6th Disease)

Which viral illness is a mosquito borne illness that can be transmitted vertically (from pregnant women to fetus) and through sexual transmission to cause fever, maculopapular rash, arthralgias in the patient, and devastating birth defects in a fetus?

Zika Virus