Infectious Disease Flashcards
1
Q
FEVER IN INFANT
For neonates <30 days of age with >38C, the likelihood of serious bacterial infection is 10-15%, and a thorough evaluation for a cause should be performed.
- Work-up:
- Peripheral blood cultures x2, CBC with manual diff, peripheral blood glucose, urinalysis, urine culture, and CSF analysis and culture.
- If any concern exists for HSV, an HSV CSF PCR should be run.
- ____ and ____ are the appropriate antimicrobials for a neonate in whom sepsis is being ruled out.
- In children <3 weeks, ______ is also often indicated for HSV prophylaxis.
Infants age 30-90 days with >38C should be promptly evaluated; however, the likelihood of occult bacteremia in these patients is relatively low.
- GBS and E coli are the most common causes of bacteremia, meningitis, and osteomyelitis in this age group. Listeria is an infrequent cause.
3-36 months with fever without a source
- Work-up:
- Obtain blood cultures if you suspect occult bacteremia or if the pt is to receive empiric antibiotics. This includes blood cultures for temp >102.2F (39C) without localizing signs of infection and with WBC >15,000/uL
- Do a LP if you suspect meningitis
- Do urine cultures on all boys
Management
- A well-appearing with fever <102.2 (39) is unlikely to have occult bacteremia and does not require further lab testing.
A
FEVER IN INFANT
For neonates <30 days of age with >38C, the likelihood of serious bacterial infection is 10-15%, and a thorough evaluation for a cause should be performed.
- Work-up:
- Peripheral blood cultures x2, CBC with manual diff, peripheral blood glucose, urinalysis, urine culture, and CSF analysis and culture.
- If any concern exists for HSV, an HSV CSF PCR should be run.
- Ampicillin and cefotaxime are the appropriate antimicrobials for a neonate in whom sepsis is being ruled out.
- In children <3 weeks, acyclovir is also often indicated for HSV prophylaxis.
Infants age 30-90 days with >38C should be promptly evaluated; however, the likelihood of occult bacteremia in these patients is relatively low.
- GBS and E coli are the most common causes of bacteremia, meningitis, and osteomyelitis in this age group. Listeria is an infrequent cause.
3-36 months with fever without a source
- Work-up:
- Obtain blood cultures if you suspect occult bacteremia or if the pt is to receive empiric antibiotics. This includes blood cultures for temp >102.2F (39C) without localizing signs of infection and with WBC >15,000/uL
- Do a LP if you suspect meningitis
- Do urine cultures on all boys <6 months and girls <1 year with fever without source
Management
- A well-appearing with fever <102.2 (39) is unlikely to have occult bacteremia and does not require further lab testing.
2
Q
CSF
- Normal: WBC ___, glucose ___, protein ___ (___ pred), glucose ____
- Aseptic/Viral meningitis (echovirus, coxsackievirus): WBC __ (__predom), glucose __, protein <100
- Acute Cerebellar Ataxia of Childhood is similar (WBC to 30)
- Bacterial meningitis: WBC >__ (__ pred), glucose __
- Tuberculosis meningitis: WBC ___ (___ predom), glucose ___
- Guillain-Barre: WBC ___, glucose ___, protein ____
A
CSF
- Normal: WBC 0-5, glucose 40-70, protein <40
- Aseptic/Viral meningitis (echovirus, coxsackievirus): WBC 100-1000 (lymphocyte predom), glucose 4-70, protein <100
- Acute Cerebellar Ataxia of Childhood is similar (WBC to 30)
- Bacterial meningitis: WBC >1000 (neutrophil pred), glucose <40, protein >250
- Tuberculosis meningitis: WBC 5-1000 (lymphocyte/monocyte predom), glucose <10 (lowest), protein >250
- Guillain-Barre: WBC 0-5, glucose 40-70, protein 45-1000
3
Q
Bacterial meningitis
- <1mo: __, __, __
- 1mo - 18yo: ___, __, ___
- Adults >18yo: S pneumonia, N meningitis, __
- Tx:
- __, __
- If younger than _mo, add ampicillin (for listeria)
- In younger than __mo, use __as the 3rd gen cephalosporin bc ceftriaxone can displace bilirubin from albumin binding sites
- Prophylaxis with __is also indicated for __ disease. You do not need to give chemoprophylaxis to contacts or someone with pneumococcal meningitis bc they are not at increased risk of contracting the disease.
- __is approved for use in __ meningitis to reduce __complications (including hearing loss and neurologic sequelae) and is most effective if started prior to or concurrent with the 1st dose of antibiotics.
In neonates with meningitis, persistent fever or new focal neurologic symptoms, such as seizure, occurring more than 3 days after starting antibiotics should raise suspicion for a new neurologic process.
A
Bacterial meningitis
- <1mo: GBS, E coli, Listeria
- 1mo - 18yo: S pneumonia, N meningitides, H influenza
- Adults >18yo: S pneumonia, N meningitis, Listeria
- Tx:
- Vancomycin, cephalosporin
- If <3mo, add ampicillin (for listeria)
- In <1mo, use cefotaxime as the 3rd gen cephalosporin bc ceftriaxone can displace bilirubin from albumin binding sites
- Prophylaxis with rifampin is also indicated for invasive H influenzae Type b disease. You do not need to give chemoprophylaxis to contacts or someone with pneumococcal meningitis bc they are not at increased risk of contracting the disease.
- Dexamethasone is approved for use in H influenzae meningitis to reduce neurologic complications (including hearing loss and neurologic sequelae) and is most effective if started prior to or concurrent with the 1st dose of antibiotics.
In neonates with meningitis, persistent fever or new focal neurologic symptoms, such as seizure, occurring more than 3 days after starting antibiotics should raise suspicion for a new neurologic process.
4
Q
Aseptic meningitis
- Non-polio _____ are the most common etiology of viral meningitis
- CSF of individuals with viral meningitis has no organisms seen on Gram stain, a relatively low WBC count, and mildly elevated protein levels.
- Opening pressure can be normal or elevated, CSF WBC is 10-1,000 with predominance of lymphocytes, and protein and glucose levels are normal to slightly elevated
- Any pt with neurologic deficits in the setting of viral meningitis should be started on acyclovir, and admitted to the hospital until HSV encephalitis can be ruled out.
TB Meningitis
- Pt: Sometimes manifested by cranial nerve palsies, esp involving CN _____ (abducens; presents with double vision and strabismus).
- CSF typically shows only mild-moderate WBC elevation with monocytic predominance, very high protein, and low glucose
- CT head: Look esp for basilar enhancement
Lyme Meningitis
- Pt: Meningitis can occur alone, but a classic presentation is the indolent onset of lymphocytic meningitis with a cranial nerve palsy (esp CN ___).
- Tx: Ceftriaxone for 21 days
A
Aseptic meningitis
- Non-polio enteroviruses are the most common etiology of viral meningitis
- CSF of individuals with viral meningitis has no organisms seen on Gram stain, a relatively low WBC count, and mildly elevated protein levels.
- Opening pressure can be normal or elevated, CSF WBC is 10-1,000 with predominance of lymphocytes, and protein and glucose levels are normal to slightly elevated
- Any pt with neurologic deficits in the setting of viral meningitis should be started on acyclovir, and admitted to the hospital until HSV encephalitis can be ruled out.
TB Meningitis
- Pt: Sometimes manifested by cranial nerve palsies, esp involving CN 6 (abducens; presents with double vision and strabismus).
- CSF typically shows only mild-moderate WBC elevation with monocytic predominance, very high protein, and low glucose
- CT head: Look esp for basilar enhancement
Lyme Meningitis
- Pt: Meningitis can occur alone, but a classic presentation is the indolent onset of lymphocytic meningitis with a cranial nerve palsy (esp CN 7).
- Tx: Ceftriaxone for 21 days
5
Q
Encephalitis
- Inflammation of the brain parenchyma.
- Path: Cause of many causes remains unknown. The majority of cases of encephalitis with an identified etiology are viral in origin
- ______ remain the single most typical cause of infectious encephalitis in the US.
- Pt: Fever and signs of meningeal irritation and alteration of mental status/level of consciousness
- Dx: LP for CSF analysis
- CSF can be bloody due to hemorrhagic necrosis of the temporal lobes, but blood in the CSF is not pathognomonic for herpes.
- About half of pts have an increased number of RBCs, usually >1000/mL
- CSF demonstrate lymphocytic pleocytosis (few hundred WBCs)
- CSF can be bloody due to hemorrhagic necrosis of the temporal lobes, but blood in the CSF is not pathognomonic for herpes.
- Tx:
- Herpes simplex infections should be treated empirically with acyclovir until ruled out with directed testing. Order PCR on CSF.
A
Encephalitis
- Inflammation of the brain parenchyma.
- Path: Cause of many causes remains unknown. The majority of cases of encephalitis with an identified etiology are viral in origin
- HSV-1 and HSV-2 remain the single most typical cause of infectious encephalitis in the US.
- Pt: Fever and signs of meningeal irritation and alteration of mental status/level of consciousness
- Dx: LP for CSF analysis
- CSF can be bloody due to hemorrhagic necrosis of the temporal lobes, but blood in the CSF is not pathognomonic for herpes.
- About half of pts have an increased number of RBCs, usually >1000/mL
- CSF demonstrate lymphocytic pleocytosis (few hundred WBCs)
- CSF can be bloody due to hemorrhagic necrosis of the temporal lobes, but blood in the CSF is not pathognomonic for herpes.
- Tx:
- Herpes simplex infections should be treated empirically with acyclovir until ruled out with directed testing. Order PCR on CSF.
6
Q
Brain abscess
- Path: Can develop from direct spread (eg sinusitis, mastoiditis) or from hematogenous spread.
- Certain bacteria, such as _____ species including C koseri, Serratia marcescens, Proteus mirabilis, and Cronobacter sakazakii are particularly associated with brain abscesses.
- Citrobacteri koseri is the most common cause of neonatal brain abscess formation.
- Cysticercosis (caused by ingesting the pork tapeworm, T solium) is the most common cause of brain lesions in developing countries.
- A classic presentation would be a teenager from Mexico with new-onset seizures and a ring-enhancing lesion on CT scan: Think _____.
- ____ is the most likely etiologic agent if the pt is immunodeficient - esp if there are multiple lesions.
- Certain bacteria, such as _____ species including C koseri, Serratia marcescens, Proteus mirabilis, and Cronobacter sakazakii are particularly associated with brain abscesses.
- Pt:
- Most common manifestations is headache localized to the size of the abscess.
- 25% of pts develop seizures.
- Look for focal neurologic deficits on the physical exam. Fever is an uncommon finding.
- Dx:
- Brain imaging to evaluate for epidural, subdural, or parenchymal abscess, or for cavernous sinus thrombosis (>95% sensitivity)
- MRI brain, with and without contrast, to diagnose abscess.
- Brain imaging to evaluate for epidural, subdural, or parenchymal abscess, or for cavernous sinus thrombosis (>95% sensitivity)
- Tx:
- When source is not obvious:
- Use ___, ___, and ____
- When source is not obvious:
A
Brain abscess
- Path: Can develop from direct spread (eg sinusitis, mastoiditis) or from hematogenous spread.
- Certain bacteria, such as Citrobacter species including C koseri, Serratia marcescens, Proteus mirabilis, and Cronobacter sakazakii are particularly associated with brain abscesses.
- Citrobacteri koseri is the most common cause of neonatal brain abscess formation.
- Cysticercosis (caused by ingesting the pork tapeworm, T solium) is the most common cause of brain lesions in developing countries.
- A classic presentation would be a teenager from Mexico with new-onset seizures and a ring-enhancing lesion on CT scan: Think neurocysticercosis.
- Toxoplasma is the most likely etiologic agent if the pt is immunodeficient - esp if there are multiple lesions.
- Certain bacteria, such as Citrobacter species including C koseri, Serratia marcescens, Proteus mirabilis, and Cronobacter sakazakii are particularly associated with brain abscesses.
- Pt:
- Most common manifestations is headache localized to the size of the abscess.
- 25% of pts develop seizures.
- Look for focal neurologic deficits on the physical exam. Fever is an uncommon finding.
- Dx:
- Brain imaging to evaluate for epidural, subdural, or parenchymal abscess, or for cavernous sinus thrombosis (>95% sensitivity)
- MRI brain, with and without contrast, to diagnose abscess.
- Brain imaging to evaluate for epidural, subdural, or parenchymal abscess, or for cavernous sinus thrombosis (>95% sensitivity)
- Tx:
- When source is not obvious:
- Use vancomycin, cefotaxime, and metronidazole
- When source is not obvious:
7
Q
Clues:
- Recent travel: ___ or ____
- Exposure to pet reptiles: _____
- Fever and high WBC count: ____
- HUS: E coli O157:H7; differs from other causes of dysentery in that ___ is rare
- Swimming in lakes or drinking well water: ___
- Consumption of pork intestine: ___
A
Clues:
- Recent travel: ETEC or Giardia
- Exposure to pet reptiles: Salmonella
- Fever and high WBC count: Shigella
- HUS: E coli O157:H7; differs from other causes of dysentery in that fever is rare
- Swimming in lakes or drinking well water: Giardia
- Consumption of pork intestine: Yersinia
8
Q
Certain things that prompt further evaluation. If >1 of these are present, order further stool studies to look for invasive bacterial infections.
- Infants <2 months of age (but many infants have watery/loose stools, and it’s normal)
- Gross blood in the stool
- WBCs on microscopic exam of the stool
- Toxic-appearing child
- Immunocompromised child
- Diarrhea developing during hospitalization or following a course of antibiotics
Depending on your suspicions, stool studies can include a rotavirus ELISA; stool cultures for bacteria including Salmonella, Shigella, Campylobacter, Yersinia, E coli, or Aeromonas; C difficile toxin; Giardia or Cryptosporidium ELISA.
A
Certain things that prompt further evaluation. If >1 of these are present, order further stool studies to look for invasive bacterial infections.
- Infants <2 months of age (but many infants have watery/loose stools, and it’s normal)
- Gross blood in the stool
- WBCs on microscopic exam of the stool
- Toxic-appearing child
- Immunocompromised child
- Diarrhea developing during hospitalization or following a course of antibiotics
Depending on your suspicions, stool studies can include a rotavirus ELISA; stool cultures for bacteria including Salmonella, Shigella, Campylobacter, Yersinia, E coli, or Aeromonas; C difficile toxin; Giardia or Cryptosporidium ELISA.
9
Q
When to do stool studies
- Do stool cultures in febrile children with bloody or mucoid stools, in immunocompromised pts, in those with prolonged symptoms, in epidemic outbreaks, and in those with foreign travel
- Routine cultures of stool are NOT recommended for nonbloody diarrhea of brief duration in otherwise healthy children.
Antibiotic use
- Do NOT use antibiotics for children with acute bloody diarrhea unless a specific pathogen is identified.
- Antibiotics can prolong ____ infection and are relatively contraindicated in ______ infections.
- Do NOT give antimotility agents for any diarrhea when there are fecal WBCs
A
When to do stool studies
- Do stool cultures in febrile children with bloody or mucoid stools, in immunocompromised pts, in those with prolonged symptoms, in epidemic outbreaks, and in those with foreign travel
- Routine cultures of stool are NOT recommended for nonbloody diarrhea of brief duration in otherwise healthy children.
Antibiotic use
- Do NOT use antibiotics for children with acute bloody diarrhea unless a specific pathogen is identified.
- Antibiotics can prolong Salmonella infection and are relatively contraindicated in E coli O157:H7 infections.
- Do NOT give antimotility agents for any diarrhea when there are fecal WBCs
10
Q
Acute Diarrhea (less than \_\_ days) - Calciviruses (\_\_ and sapovirus) cause 50% of viral gastroenteritis. It is the most common etiology of cruise-associated outbreaks
A
Acute Diarrhea (<14 days) - Calciviruses (Norovirus and sapovirus) cause 50% of viral gastroenteritis. It is the most common etiology of cruise-associated outbreaks
11
Q
- E coli
- Most common cause of bacterial diarrhea (usually without blood or WBCs)
- Do NOT treat EHEC/STEC with ____ bc of increased risk of HUS and bc antibiotics do not shorten the duration.
A
- E coli
- Most common cause of bacterial diarrhea (usually without blood or WBCs)
- Do NOT treat EHEC/STEC with antibiotics bc of increased risk of HUS and bc antibiotics do not shorten the duration.
12
Q
- ETEC: Traveler’s diarrhea
- Tx primarily supportive. Antibiotics are not routinely recommended; it can be used in pts with a prolonged disease course
- Tx with azithromycin, quinolone, or TMP/SMX
A
- ETEC: Traveler’s diarrhea
- Tx primarily supportive. Antibiotics are not routinely recommended; it can be used in pts with a prolonged disease course
- Tx with azithromycin, quinolone, or TMP/SMX
13
Q
- Vibrio - think ____
A
- Vibrio - think seafood and shellfish
14
Q
- C diff:
- Antibiotic-associate colitis. Symptoms can occur up to ____ weeks after the antibiotics are stopped.
- Do not test neonates and infants less than __yo (commonly asymptomatic carriers)
- Note: C difficile toxin assays in children less than __ year of age are not reliable bc enterocytes in infants have not yet developed the receptor for the toxin.
- Mild-moderate: __ (less expensive) for __ days
- 1st relapse: __
- 2nd relapse: __
- Severe disease (fever, leukocytosis) __ for 10 days
- Severe and complicated disease: __ and __ for 10 days
A
- C diff:
- Antibiotic-associate colitis. Symptoms can occur up to 3 weeks after the antibiotics are stopped.
- Do not test neonates and infants <1yo (-3yo) (commonly asymptomatic carriers)
- Note: C difficile toxin assays in children <1 year of age are not reliable bc enterocytes in infants have not yet developed the receptor for the toxin.
- Mild-moderate: PO metronidazole (less expensive) for 10 days
- 1st relapse: PO metronidazole
- 2nd relapse: PO vancomycin
- Severe disease (fever, leukocytosis) PO vancomycin for 10 days
- Severe and complicated disease: PO vancomycin and IV metronidazole for 10 days
15
Q
- Bacillus cereus
- Can cause 2 forms of gastroenteritis:
- 1) Short-incubation (1-__hours) ____ type, due to preformed heat-stable toxin
- Often results from consuming fried rice left at room temperature.
- 2) A longer-incubation (__-16 hours) _____ type, due to heat-labile enterotoxin production in vivo in the GI tract.
- 1) Short-incubation (1-__hours) ____ type, due to preformed heat-stable toxin
- Dx: Clinical
- Tx: ____
- Can cause 2 forms of gastroenteritis:
A
- Bacillus cereus
- Can cause 2 forms of gastroenteritis:
- 1) Short-incubation (1-6 hours) emetic type, due to preformed heat-stable toxin
- Often results from consuming fried rice left at room temperature.
- 2) A longer-incubation (8-16 hours) diarrheal type, due to heat-labile enterotoxin production in vivo in the GI tract.
- 1) Short-incubation (1-6 hours) emetic type, due to preformed heat-stable toxin
- Dx: Clinical
- Tx: Self-limited, symptomatic tx
- Can cause 2 forms of gastroenteritis:
16
Q
- Cryptosporidium:
- Found on acid-fat stains of the stool
- Leading cause of _____-related diarrheal illness. Resistant to ___; can survive days/over a week in a properly chlorinated swimming pool.
- Dx:
- PCR is test of choice
- Can be diagnosed by____of the stool (small round red organisms on a green background)
A
- Cryptosporidium:
- Found on acid-fat stains of the stool
- Leading cause of swimming pool-related diarrheal illness. Resistant to chlorine; can survive days/over a week in a properly chlorinated swimming pool.
- Dx:
- PCR is test of choice
- Can be diagnosed by acid-fast stains of the stool (small round red organisms on a green background)
17
Q
- Giardia
- (Remember: Shigella is also found among kids in child care and men who have sex with men)
- Pt:
- Most cases (75%) are asymptomatic.
- When symptomatic, acute watery smelly diarrhea, ______, and flatulence. With abdominal cramping, nausea, vomiting
- Dx: Stool testing
- Direct microscopic examination of a diarrhea stool (ova and parasite examination) or Giardia antigen detection on a single stool specimen.
- Tx:
- Tx is seldom indicated in asymptomatic individuals.
- Asymptomatic carriers should be tx if 1) there is a pregnant woman in the household, 2) there is an immunocompromised person in the household, 3) the pt is a food handler, 4) Child is in a daycare setting.
- ______ for 5 days, tinidazole, nitazoxanide
- Because not all post-treatment diarrhea represents reinfection or resistance, stool studies should be repeated before initiating any additional treatment.
- Tx is seldom indicated in asymptomatic individuals.
A
- Giardia
- (Remember: Shigella is also found among kids in child care and men who have sex with men)
- Pt:
- Most cases (75%) are asymptomatic.
- When symptomatic, acute watery smelly diarrhea, steatorrhea, and flatulence. With abdominal cramping, nausea, vomiting
- Dx: Stool testing
- Direct microscopic examination of a diarrhea stool (ova and parasite examination) or Giardia antigen detection on a single stool specimen.
- Tx:
- Tx is seldom indicated in asymptomatic individuals.
- Asymptomatic carriers should be tx if 1) there is a pregnant woman in the household, 2) there is an immunocompromised person in the household, 3) the pt is a food handler, 4) Child is in a daycare setting.
- Metronidazole for 5 days, tinidazole, nitazoxanide
- Because not all post-treatment diarrhea represents reinfection or resistance, stool studies should be repeated before initiating any additional treatment.
- Tx is seldom indicated in asymptomatic individuals.
18
Q
- Campylobacter:
- Leading cause of food borne gastroenteritis
- Curved gram ____with ____motility
- Transmission: Unpasteurized milk, undercooked poultry, contaminated water
- Pt:
- Fever, diarrheal gastroenteritis, crampy abdominal pain
- Diarrhea may be watery but can become mucoid with frank blood.
- Tx
- Self-limited within 1 week
- 3 days of ___ or ___ or ____(but resistance is common) decreases the duration of diarrheal illness
- Complications: ____, ____, ____
A
- Campylobacter:
- Leading cause of food borne gastroenteritis
- Curved gram negative with corkscrew motility
- Transmission: Unpasteurized milk, undercooked poultry, contaminated water
- Pt:
- Fever, diarrheal gastroenteritis, crampy abdominal pain
- Diarrhea may be watery but can become mucoid with frank blood.
- Tx
- Self-limited within 1 week
- 3 days of azithromycin or erythromycin or fluoroquinolones (but resistance is common) decreases the duration of diarrheal illness
- Complications: Guillain-Barre syndrome, reactive arthritis, erythema nodosum
19
Q
- Entamoeba histolytica
- Pt: _____ abscesses- fever, abdominal pain, and hepatomegaly
- Dx: Serology - serum antibodies
- Tx: Invasive dx requires tx with _____ or tinidazole
A
- Entamoeba histolytica
- Pt: Liver abscesses- fever, abdominal pain, and hepatomegaly
- Dx: Serology - serum antibodies
- Tx: Invasive dx requires tx with metronidazole or tinidazole
20
Q
URINARY TRACT INFECTION
- Path: ___causes the majority of infections (75-90%)
- ____ species - most common gram positive
- Dx: Presence of both pyuria and >50,000 colonies/mL of a single urologic pathogen in an appropriately collected urine specimen (ie suprapubic aspiration or catheterized urine). Any bacterial growth in a suprapubic aspiration, >50,000 CFU of a single organism in a catheterized urine sample, >100,000 CFU in a voided urine sample (bag or clean catch) is considered significant.
- Significant colony counts are:
- Clean void: >____ CFU/ml
- Catheter specimen: >____ CFU/mL
- Suprapubic aspiration: ____
- Significant colony counts are:
- Tx:
- Empiric antibiotic choices usually cover the most common causes of UTI in this age group (eg E coli, Klebsiella, gram negatives) and can typically be given orally, such as ____ or ____ (oral 3rd generation).
- Routine UTI: ____ for 3 days in adolescents/adults and longer in those younger (7-14 days)
- Empiric antibiotic choices usually cover the most common causes of UTI in this age group (eg E coli, Klebsiella, gram negatives) and can typically be given orally, such as ____ or ____ (oral 3rd generation).
- TMP-SMX is contraindicated in infants less than __mo age. Sulfonamides displace bilirubin from albumin-binding sites, leading to increases in bilirubin plasma levels.
- __should not be used in febrile UTI in young children bc it does not have adequate kidney tissue penetration.
- CDC recommends __for 2nd line therapy of UTI and pyelonephritis in children 1-17 years of age.
- Consider ciprofloxacin if Pseudomonas is an issue.
- For community-acquired UTIs with extended-spectrum beta-lactamase (ESBL)-producing E coli, a carbapenem is the DOC. - Tx of pregnant pts:
- Tx asymptomatic bacteriuria in pregnant pts (⅓ of those who go untreated go on to pyelonephritis).
- Pregnancy-safe antibiotics to use for pyelonephritis are __, aminoglycosides, cephalosporins, and TMP/SMX; but do not give TMP/SMX in late pregnancy or to early nursing mothers bc it might cause kernicterus in the infant. Also do not use tetracycline/doxycycline or quinolones.
- Always admit pregnant pts with pyelonephritis and tx with 3rd generation cephalosporin, IV ampicillin and gentamicin, or TMP/SMX (except in late pregnancy)
A
URINARY TRACT INFECTION
- Path: E coli causes the majority of infections (75-90%)
- Enterococcus species - most common gram positive
- Dx: Presence of both pyuria and >50,000 colonies/mL of a single urologic pathogen in an appropriately collected urine specimen (ie suprapubic aspiration or catheterized urine). Any bacterial growth in a suprapubic aspiration, >50,000 CFU of a single organism in a catheterized urine sample, >100,000 CFU in a voided urine sample (bag or clean catch) is considered significant.
- Significant colony counts are:
- Clean void: >100,000 CFU/ml
- Catheter specimen: >50,000 CFU/mL
- Suprapubic aspiration: any growth or uropathogen
- Significant colony counts are:
- Tx:
- Empiric antibiotic choices usually cover the most common causes of UTI in this age group (eg E coli, Klebsiella, gram negatives) and can typically be given orally, such as amoxicillin/clavulanate or cefixime (oral 3rd generation).
- Routine UTI: TMP/SMX for 3 days in adolescents/adults and longer in those younger (7-14 days)
- TMP-SMX is contraindicated in infants <2mo age. Sulfonamides displace bilirubin from albumin-binding sites, leading to increases in bilirubin plasma levels.
- Nitrofurantoin should not be used in febrile UTI in young children bc it does not have adequate kidney tissue penetration.
- CDC recommends ciprofloxacin for 2nd line therapy of UTI and pyelonephritis in children 1-17 years of age.
- Consider ciprofloxacin if Pseudomonas is an issue.
- For community-acquired UTIs with extended-spectrum beta-lactamase (ESBL)-producing E coli, a carbapenem is the DOC.
- Routine UTI: TMP/SMX for 3 days in adolescents/adults and longer in those younger (7-14 days)
- Empiric antibiotic choices usually cover the most common causes of UTI in this age group (eg E coli, Klebsiella, gram negatives) and can typically be given orally, such as amoxicillin/clavulanate or cefixime (oral 3rd generation).
- Tx of pregnant pts:
- Tx asymptomatic bacteriuria in pregnant pts (⅓ of those who go untreated go on to pyelonephritis).
- Pregnancy-safe antibiotics to use for pyelonephritis are ampicillin, aminoglycosides, cephalosporins, and TMP/SMX; but do not give TMP/SMX in late pregnancy or to early nursing mothers bc it might cause kernicterus in the infant. Also do not use tetracycline/doxycycline or quinolones.
- Always admit pregnant pts with pyelonephritis and tx with 3rd generation cephalosporin, IV ampicillin and gentamicin, or TMP/SMX (except in late pregnancy)
21
Q
High fever (>____ ) with no source
- Males
- Circumcised: Get UA/UCx if less than __mo
- Uncircumcised: Get UA/UCx if less than __mo
- Females
- Get UA/UCx if less than __yo
A
High fever (>39) with no source
- Males
- Circumcised: Get UA/UCx if <6mo
- Uncircumcised: Get UA/UCx if <12mo
- Females
- Get UA/UCx if <2yo
22
Q
Indications for renal US
- 1) less than __ mo with 1st febrile UTI
- 2) Recurrent febrile UTIs
- 3) UTI in a child of any age with ___
- 4) Children who do not respond to appropriate abx tx
A
Indications for renal US
- 1) <24 mo with 1st febrile UTI
- 2) Recurrent febrile UTIs
- 3) UTI in a child of any age with family hx of renal or urologic dx, HTN, or poor growth
- 4) Children who do not respond to appropriate abx tx
23
Q
VCUG indications
- 1) Febrile UTI less than __mo
- 2) __ febrile UTIs __mo-__yo
- 3) Febrile UTI for __mo-__yo with __
- 4) __US
- 5) Prenatal US with __
A
VCUG indications
- 1) Febrile UTI <2mo
- 2) 2 febrile UTIs 2mo-2yo
- 3) Febrile UTI for 2mo-2yo with family hx of renal abnormalities or abnormal renal US
- 4) Abnormal US
- 5) Prenatal US with severe hydronephrosis
24
Q
Osteomyelitis
- Most common: _____. Then group A strep.
- In neonates, ___, ___, and ____ are most common.
- Group B strep: Common in neonates <3 months
- ___: Common in neonates less than __mo: ___, ___, ____
- Kingella kingae in young children __-__mo
- Puncture wound or IV drug user: __
- Sickle cell: ___
- Any child with bone pain in the absence of obvious trauma should raise suspicion for osteomyelitis, particularly if there are elevated inflammatory markers (CRP, ESR) and/or constitutional symptoms
- Dx:
- 1st line imaging: ____. May take 10-14 days after onset of illness
- ____ is preferred for definitive radiology
- Definitive diagnosis: bone aspirate to culture
- Tx:
- <3mo: ___ and ____
- > 3mo: ____ or ____
- Duration typically ___ weeks
A
Osteomyelitis
- Most common: S aureus. Then group A strep.
- In neonates, S aureus, GBS, and gram negatives are most common.
- Group B strep: Common in neonates <3 months
- E coli: Common in neonates <3 months
- > 6yo: Staph aureus, group A strep, Pseudomonas
- Kingella kingae in young children 6-36mo
- Puncture wound or IV drug user: Pseudomonas
- Sickle cell: Salmonella
- Any child with bone pain in the absence of obvious trauma should raise suspicion for osteomyelitis, particularly if there are elevated inflammatory markers (CRP, ESR) and/or constitutional symptoms
- Dx:
- 1st line imaging: Plain radiograph. May take 10-14 days after onset of illness
- MRI is preferred for definitive radiology
- Definitive diagnosis: bone aspirate to culture
- Tx:
- <3mo: Vancomycin and cefotaxime
- > 3mo: Vancomycin or cilndamycin
- Duration typically 3-6 weeks
25
Q
Septic Arthritis
- Critical diagnosis that cannot be missed and is a true medical emergency. Missed septic arthritis leads to severe destruction of the infected joint.
- _____ is most common cause
- In neonates, GBS (usually late-onset disease) and gram negatives are implicated
- In children <5yo, S aureus, S pyogenes, and S pneumoniae are the most common
- In >5yo, S pneumoniae diminishes as a cause.
- Do not forget Neisseria gonorrhoeae in the sexually active adolescent, esp if menstruating.
- Consider Salmonella septic arthritis in pts with Sickle cell disease or other hemoglobinopathies.
- Neonates are more difficult to diagnose bc of the immature inflammatory and immune responses present. Therefore, neonates may present with only vague symptoms and may be lacking fever or obvious joint involvement, although pseudoparalysis (refusal to move an affected joint) is common.
- Maneuvers that twist the pelvis, such as the FABER test, are painful in pts with septic arthritis of the sacroiliac joint.
- Perform the FABER test (aka Patrick test “figure of 4” test) by inducing flexion of the hip and knee, with abduction and external rotation of the hip, in such a way that the ankle of the ipsilateral leg lies atop the opposite knee in a figure of 4 configuration.
- Dx:
- Those pts with ____, ____, ____, and ___ can be classified as being highly likely to have septic arthritis, with a chance of >96% rather than transient synovitis.
- Do _______ quickly to discern the diagnosis and send the fluid for gram stain, culture, and cell count.
- WBC count >50,000/uL is common with mostly PMNs.
- K. kingae is difficult to isolate on typical culture media (negative synovial fluid culture), but PCR assays can improve the diagnostic yield.
- Also, obtain ____
- _____of the joint is helpful in discerning the presence of fluid. MRI can also detect any accompanying osteomyelitis.
- Tx: Prompt Ortho consult for decompression
- <3mo: ____ and ____
- > 3mo: ____ or ____
A
Septic Arthritis
- Critical diagnosis that cannot be missed and is a true medical emergency. Missed septic arthritis leads to severe destruction of the infected joint.
- Staph aureus is most common cause
- In neonates, GBS (usually late-onset disease) and gram negatives are implicated
- In children <5yo, S aureus, S pyogenes, and S pneumoniae are the most common
- In >5yo, S pneumoniae diminishes as a cause.
- Do not forget Neisseria gonorrhoeae in the sexually active adolescent, esp if menstruating.
- Consider Salmonella septic arthritis in pts with Sickle cell disease or other hemoglobinopathies.
- Neonates are more difficult to diagnose bc of the immature inflammatory and immune responses present. Therefore, neonates may present with only vague symptoms and may be lacking fever or obvious joint involvement, although pseudoparalysis (refusal to move an affected joint) is common.
- Maneuvers that twist the pelvis, such as the FABER test, are painful in pts with septic arthritis of the sacroiliac joint.
- Perform the FABER test (aka Patrick test “figure of 4” test) by inducing flexion of the hip and knee, with abduction and external rotation of the hip, in such a way that the ankle of the ipsilateral leg lies atop the opposite knee in a figure of 4 configuration.
- Dx:
- Those pts with refusal to bear weight, fever >38.5 (101.3), ESR >40mm/h, and WBC >12,000/uL can be classified as being highly likely to have septic arthritis, with a chance of >96% rather than transient synovitis.
- Do joint aspiration quickly to discern the diagnosis and send the fluid for gram stain, culture, and cell count.
- WBC count >50,000/uL is common with mostly PMNs.
- K. kingae is difficult to isolate on typical culture media (negative synovial fluid culture), but PCR assays can improve the diagnostic yield.
- Also, obtain blood cultures
- MRI or US of the joint is helpful in discerning the presence of fluid. MRI can also detect any accompanying osteomyelitis.
- Tx: Prompt Ortho consult for decompression
- <3mo: Vancomycin and cefotaxime
- > 3mo: Vancomycin or cilndamycin
26
Q
Kingella kingae
- Gram ____.
- Increasingly recognized as a cause of osteoarticular infections in pediatrics, such as osteomyelitis, septic arthritis, and tenosynovitis.
- Indolent organism seen in patients age __-___ months.
- Pt: More subacute presentation
- Entire disease course is more subacute than other causes of septic arthritis.
- Afebrile presentation is classic for Kingella
- Entire disease course is more subacute than other causes of septic arthritis.
- K. kingae is difficult to isolate on typical culture media (negative synovial fluid culture), but PCR assays can improve the diagnostic yield.
- Tx: Beta-lactam antibiotics; Penicillin, Amp-sulbactam or cephalosporin
A
Kingella kingae
- Gram negative.
- Increasingly recognized as a cause of osteoarticular infections in pediatrics, such as osteomyelitis, septic arthritis, and tenosynovitis.
- Indolent organism seen in patients age 6-36 months.
- Pt: More subacute presentation
- Entire disease course is more subacute than other causes of septic arthritis.
- Afebrile presentation is classic for Kingella
- Entire disease course is more subacute than other causes of septic arthritis.
- K. kingae is difficult to isolate on typical culture media (negative synovial fluid culture), but PCR assays can improve the diagnostic yield.
- Tx: Beta-lactam antibiotics; Penicillin, Amp-sulbactam or cephalosporin
27
Q
Reactive arthritis
- Inflammatory arthritis associated with prior infection at a site other than the affected joint, most commonly associated with _____.
- 1-4 weeks after GI/GU/URI infection
- Pt: Triad of ____, ____, ___
- Synovial fluid is typically _____ (No microorganisms are present) with signs of inflammation including elevated leukocyte counts.
- Due to fever and the severity of the systemic symptoms, reactive arthritis can present like septic arthritis, requiring you to aspirate joint fluid.
- Tx: ___
A
Reactive arthritis
- Inflammatory arthritis associated with prior infection at a site other than the affected joint, most commonly associated with GI or GU.
- 1-4 weeks after GI/GU/URI infection
- Pt: Triad of urethritis, conjunctivitis, arthritis (can’t pee, can’t see, can’t climb a tree)
- Synovial fluid is typically sterile (No microorganisms are present) with signs of inflammation including elevated leukocyte counts.
- Due to fever and the severity of the systemic symptoms, reactive arthritis can present like septic arthritis, requiring you to aspirate joint fluid.
- Tx: NSAIDs
28
Q
Sore throat + eye infection (pharyngoconjunctival fever) = _____
A
Sore throat + eye infection (pharyngoconjunctival fever) = Adenovirus
29
Q
Sore throat + eye infection (pharyngoconjunctival fever) = _____
A
Sore throat + eye infection (pharyngoconjunctival fever) = Adenovirus
30
Q
Human Metapneumovirus
- Enveloped, ___-stranded, ___-sense ___ virus
- In a pt presenting with ___ and ____, human metapneumovirus is the likely etiology.
- Tx: Supportive.
A
Human Metapneumovirus
- Enveloped, SINGLE-stranded, NEGATIVE-sense RNA virus
- In a pt presenting with bronchiolitis and acute otitis media, human metapneumovirus is the likely etiology.
- Tx: Supportive.
31
Q
Influenza Virus
- Begins with sudden onset of nonspecific systemic symptoms including fever, malaise, and myalgias.
- Most common complication of influenza is otitis media
- ____ is approved for treatment of influenza A and B viruses in individuals >__ weeks of age and prophylaxis of influenza A and B viruses in individuals >1 yo.
- _____ is approved for the prophylaxis of influenza in individuals >___ years and the treatment of influenza in individuals >7 years. It is a dry powder administered by oral inhalation. It is not recommended for pts with a hx of _____.
- This mechanism has been linked to bronchospasm in patients with asthma as well as in individuals without airway disease.
- Antiviral tx is recommended as early as possible, even > ___ hours duration of illness, for patients who are:
- 1) Hospitalized with presumed influenza
- 2) Confirmed or suspected influenza who have severe, complicated, or progressive illness
- 3) Influenza infection of any severity in children at high risk for complications
- 4) Any otherwise healthy child with influenza infection for whom a decrease in duration of clinical symptoms is felt to be warranted by his or her provider
- High Risk patients who are at increased risk of complications and need treatment:
- Children less than ___ years of age - especially those less than ___ yo.
- Children with chronic disease: pulmonary diseases (asthma, chronic lung disease), cardiovascular (except HTN alone), chronic renal disease, hepatic, hematological (including sickle cell disease), immunosuppressive disorders, HIV, metabolic disorders (including diabetes mellitus), conditions requiring long-term aspirin use, or neurologic/neurodevelopment conditions (cerebral palsy, epilepsy, stroke, intellectual disability, moderate-severe developmental delay, muscular dystrophy, spinal cord injury)
- People less than 19yo who are receiving long-term aspirin or salicylate-containing medications (rheumatoid arthritis, Kawasaki disease) due to risk of Reye syndrome
- Adults >65yo
- People with immunosuppression (by medications or by HIV infection)
- Women who are pregnant or postpartum within 2 weeks
- American Indians/Alaska Natives
- People who are extremely obese (BMI >40)
- Residents of nursing homes and other chronic care facilities
A
Influenza Virus
- Begins with sudden onset of nonspecific systemic symptoms including fever, malaise, and myalgias.
- Most common complication of influenza is otitis media
- Oseltamivir (Tamiflu) is approved for treatment of influenza A and B viruses in individuals >2 weeks of age and prophylaxis of influenza A and B viruses in individuals >1 yo.
- Zanamivir (Relenza) is approved for the prophylaxis of influenza in individuals >5 years and the treatment of influenza in individuals >7 years. It is a dry powder administered by oral inhalation. It is not recommended for pts with a hx of wheezing or underlying chronic respiratory disease.
- This mechanism has been linked to bronchospasm in patients with asthma as well as in individuals without airway disease.
- Antiviral tx is recommended as early as possible, even > 48 hours duration of illness, for patients who are:
- 1) Hospitalized with presumed influenza
- 2) Confirmed or suspected influenza who have severe, complicated, or progressive illness
- 3) Influenza infection of any severity in children at high risk for complications
- 4) Any otherwise healthy child with influenza infection for whom a decrease in duration of clinical symptoms is felt to be warranted by his or her provider
- High Risk patients who are at increased risk of complications and need treatment:
- Children <5 years of age - especially those <2yo.
- Children with chronic disease: pulmonary diseases (asthma, chronic lung disease), cardiovascular (except HTN alone), chronic renal disease, hepatic, hematological (including sickle cell disease), immunosuppressive disorders, HIV, metabolic disorders (including diabetes mellitus), conditions requiring long-term aspirin use, or neurologic/neurodevelopment conditions (cerebral palsy, epilepsy, stroke, intellectual disability, moderate-severe developmental delay, muscular dystrophy, spinal cord injury)
- People <19yo who are receiving long-term aspirin or salicylate-containing medications (rheumatoid arthritis, Kawasaki disease) due to risk of Reye syndrome
- Adults >65yo
- People with immunosuppression (by medications or by HIV infection)
- Women who are pregnant or postpartum within 2 weeks
- American Indians/Alaska Natives
- People who are extremely obese (BMI >40)
- Residents of nursing homes and other chronic care facilities
32
Q
Staph aureus
- Can cause several toxin-mediated syndromes (toxic shock syndrome, staph scalded skin syndrome, staph food poisoning)
- Staph aureus is the most common cause of food poisoning in the US. Typical incubation period is 2-4 hours; this short incubation period distinguishes from other organisms
- MRSA: ______ is DOC
- Newer agents (off label): Linezolid, daptomycin, ceftaroline, tigecycline
A
Staph aureus
- Can cause several toxin-mediated syndromes (toxic shock syndrome, staph scalded skin syndrome, staph food poisoning)
- Staph aureus is the most common cause of food poisoning in the US. Typical incubation period is 2-4 hours; this short incubation period distinguishes from other organisms
- MRSA: Vancomycin is DOC
- Newer agents (off label): Linezolid, daptomycin, ceftaroline, tigecycline
33
Q
Coagulase negative staph (CONS): S epidermis, S saprophyticus
- S epidermidis: Usually methicillin resistant.
- It is the most common cause of both ____bacteremia and ___ bacteremia occurring when any foreign material is left in the body (eg prosthetics, including heart valves, joint, VP shunts)
- Common “contaminant” of blood. If isolated in a child without underlying prosthetic device is usually a contaminant
- Tx: ____ +/- gentamicin (serious infections) +/- rifampin
- S saprophytic:
- ___ in adolescent females
- Tx:___, ____, cephalothin
A
Coagulase negative staph (CONS): S epidermis, S saprophyticus
- S epidermidis: Usually methicillin resistant.
- It is the most common cause of both catheter-related bacteremia and post-op bacteremia occurring when any foreign material is left in the body (eg prosthetics, including heart valves, joint, VP shunts)
- Common “contaminant” of blood. If isolated in a child without underlying prosthetic device is usually a contaminant
- Tx: Vancomycin +/- gentamicin (serious infections) +/- rifampin
- S saprophytic:
- UTIs in adolescent females
- Tx: TMP/SMX, nitrofurantoin, cephalothin
34
Q
____ are the most common cause of endocarditis in children
A
Viridans streptococci are the most common cause of endocarditis in children
35
Q
Strep pyogenes (group __ strep)
Strep pharyngitis
- Do not test or give treatment if less than ____ yo
- Tx:
- IM ____ (bicillin) once ____ U for less than ___kg or ___ U for >__kg
- PO amoxicillin 50mg/kg daily for 10 days
- If penicillin allergic, use cephalexin, cefadroxile, or cephalosporin for 10 days
- If allergic to PCN and cephalosporins, use macrolide (erythromycin, azithromycin) over clindamycin
- To eradicate carrier state: clindamycin
- Complications:
- ____ Can be prevented if abx given within ___ days after onset of symptoms. Occurs only after ___
- Poststrep glomerulonephritis: Occurs regardless of therapy and regardless of source (pharynx (10 days) or skin (21 days))
- Paradise criteria for tonsillectomy:
- > __ in the preceding year, or
- > ___ in each of the preceding 2 years, or
- > __ in each of the preceding 3 years
A
Strep pyogenes (group A strep)
Strep pharyngitis
- Do not test or give treatment if <3 yo
- Tx:
- IM Penicillin G benzathine (bicillin) once 600,000 U for <27kg or 1.2 million U for >27kg
- PO amoxicillin 50mg/kg daily for 10 days
- If penicillin allergic, use cephalexin, cefadroxile, or cephalosporin for 10 days
- If allergic to PCN and cephalosporins, use macrolide (erythromycin, azithromycin) over clindamycin
- To eradicate carrier state: clindamycin
- Complications:
- Rheumatic fever: Can be prevented if abx given within 9 days after onset of symptoms. Occurs only after pharyngitis
- Poststrep glomerulonephritis: Occurs regardless of therapy and regardless of source (pharynx (10 days) or skin (21 days))
- Paradise criteria for tonsillectomy:
- > 7 in the preceding year, or
- > 5 in each of the preceding 2 years, or
- > 3 in each of the preceding 3 years
36
Q
Enterococcus (E faecalis, E faecium)
- Gram ____ in short-medium chains
- 3 main types of infections: UTI, abdominal infection, bacteremia/sepsis
- Tx:
- Ampicillin/vancomycin + gentamicin
- For VRE: Linezolid or daptomycin
- Resistant to cephalosporin
A
Enterococcus (E faecalis, E faecium)
- Gram positive in short-medium chains
- 3 main types of infections: UTI, abdominal infection, bacteremia/sepsis
- Tx:
- Ampicillin/vancomycin + gentamicin
- For VRE: Linezolid or daptomycin
- Resistant to cephalosporin
37
Q
Listeria
- Direct contact with milk products (goat cheese), deli meats, hot dogs, tofu, vegetables
- Granulomatosis infantisepticum: Amnionitis, pneumonia, septicemia, erythematous rash with papules
- Be aware of a neonate for whom the lab has identified an organism from blood or CSF as ______. Remember: Listeria is a gram+ rod and can mimic the appearance of diphtheroids.
- Tx:
- Mild-moderate: _____
- Serious/resistance: PCN/ampicillin + aminoglycoside
- Listeria meningitis: High-dose PCN/ampicillin + aminoglycoside
A
Listeria
- Direct contact with milk products (goat cheese), deli meats, hot dogs, tofu, vegetables
- Granulomatosis infantisepticum: Amnionitis, pneumonia, septicemia, erythematous rash with papules
- Be aware of a neonate for whom the lab has identified an organism from blood or CSF as diphtheroids. Remember: Listeria is a gram+ rod and can mimic the appearance of diphtheroids.
- Tx:
- Mild-moderate: ampicillin
- Serious/resistance: PCN/ampicillin + aminoglycoside
- Listeria meningitis: High-dose PCN/ampicillin + aminoglycoside
38
Q
Corynebacterium diphtheriae
- Respiratory distress, cutaneous disease, or asymptomatic carriage
- Tonsillar diphtheria:
- Incubation of 1-10 days, then
- Sore throat, hoarseness, ____ fever (rarely >39.4)
- After 2-3 days, grey-white pharyngeal pseudomembrane
- In severe disease, cervical lymphadenopathy lead to marked edema of neck, creating “______”
- Toxin-medicated effects: ______ (strong predictor for mortality), QTc prolongation, ST-T wave changes, 1st degree heart block
- Concomitant ____ and ____changes (vs strep pyogenes with onset of rheumatic fever a few weeks after tonsillitis)
- Tx:
- Specific equine _____.
- Also give close contacts _____ to render noncontagious and to stop production of toxin.
- Give close contacts prophylaxis with oral erythromycin or IM PCN
A
Corynebacterium diphtheriae
- Respiratory distress, cutaneous disease, or asymptomatic carriage
- Tonsillar diphtheria:
- Incubation of 1-10 days, then
- Sore throat, hoarseness, LOW fever (rarely >39.4)
- After 2-3 days, grey-white pharyngeal pseudomembrane
- In severe disease, cervical lymphadenopathy lead to marked edema of neck, creating “bull neck”
- Toxin-medicated effects: Myocarditis (strong predictor for mortality), QTc prolongation, ST-T wave changes, 1st degree heart block
- Concomitant tonsillitis and ECG changes (vs strep pyogenes with onset of rheumatic fever a few weeks after tonsillitis)
- Tx:
- Specific equine antitoxin.
- Also give close contacts erythromycin to render noncontagious and to stop production of toxin.
- Give close contacts prophylaxis with oral erythromycin or IM PCN
39
Q
Bacillus Anthracis
- Large encapsulate spore-forming gram+ rod
- 3 types: Cutaneous, GI, Inhalation (Woolsorter’s disease)
- Cutaneous: Pain____ pruritic papule, then over 7 days evolving into a pain____ black eschar with nonpitting, painless induration and swelling
- Tx:
- Cutaneous: ___ or ___ or ___ for 7-10 days
- Inhalation and GI: 2-drug (eg ___ + ___)
- CNS: 3-drug (___, ___, ____)
A
Bacillus Anthracis
- Large encapsulate spore-forming gram+ rod
- 3 types: Cutaneous, GI, Inhalation (Woolsorter’s disease)
- Cutaneous: PainLESS pruritic papule, then over 7 days evolving into a painLESS black eschar with nonpitting, painless induration and swelling
- Tx:
- Cutaneous: Amoxicillin or ciprofloxacin or doxycycline for 7-10 days
- Inhalation and GI: 2-drug (eg ciprofloxacin + clindamycin)
- CNS: 3-drug (ciprofloxacin, meropenem, linezolid)
40
Q
Clostridium: Infant botulism
- Spores are typically found in honey, corn syrup, or more commonly presumed inhalation of spores from environmental dust/soil, particularly in rural or farm areas where soil is disturbed. Outbreaks have appeared with carrot juice and cheese sauce. Highest rates are in Alaska and are due to ingestion of fermented fish.
- Pt:
- Starts with prodrome of ____, then weakness and hypotonia
- Lack of ______ reflex (in contrast to SMA in which pupils are unaffected and tongue has fasciculations). Oculobulbar weakness resulting in ___. Absent gag reflex
- Poor feeding, weak cry, difficulty swallowing, facial droop, and diminished cough, gag, swallow
- Later poor head control, diminished DTR
- _____ paralysis
- ____ failure (can occur without respiratory distress)
- Starts with prodrome of ____, then weakness and hypotonia
- Dx: Gold standard is to detect ____ botulinum spores or toxins in the feces
- Tx: Give ___: Equine serum botulism antitoxin for pts >1yo, and human botulism immunoglobulin for pts <1yo.
A
Clostridium: Infant botulism
- Spores are typically found in honey, corn syrup, or more commonly presumed inhalation of spores from environmental dust/soil, particularly in rural or farm areas where soil is disturbed. Outbreaks have appeared with carrot juice and cheese sauce. Highest rates are in Alaska and are due to ingestion of fermented fish.
- Pt:
- Starts with prodrome of constipation, then weakness and hypotonia
- Lack of pupillary reflex (in contrast to SMA in which pupils are unaffected and tongue has fasciculations). Oculobulbar weakness resulting in ptosis. Absent gag reflex
- Poor feeding, weak cry, difficulty swallowing, facial droop, and diminished cough, gag, swallow
- Later poor head control, diminished DTR
- Descending paralysis
- Respiratory failure (can occur without respiratory distress)
- Starts with prodrome of constipation, then weakness and hypotonia
- Dx: Gold standard is to detect stool botulinum spores or toxins in the feces
- Tx: Give antitoxin:Equine serum botulism antitoxin for pts >1yo, and human botulism immunoglobulin for pts <1yo.
41
Q
Clostridium perfringes:
- Food poisoning
- ___ can be caused by it
- Acute tx: High dose___
A
Clostridium perfringes:
- Food poisoning
- Gas gangrene can be caused by it
- Acute tx: High dose PCN G
42
Q
Clostridium tetani:
- Usually by 24h into the illness, there is marked ___
- Tx: _____ for 10-14 days preferred. ____acceptable
A
Clostridium tetani:
- Usually by 24h into the illness, there is marked trismus
- Tx: Metronidazole for 10-14 days preferred. PCN G acceptable
43
Q
Nocardia
- Only weakly ___
- Gram ___
- Beaded, branching, filamentous
- Usually starts as a ____ infection in immunocompromised children - occasionally causing a ____ lesion
- Can cause ___ abscesses and chronic neutrophilic meningitis
- Tx:
- High-dose _____ or ___.
- In severely ill patients, add combinations of drugs, including amikacin + ceftriaxone or amikacin + imipenem.
- 6-12 weeks for immunocompetent
- 6-12 mo for immunocompromised
A
Nocardia
- Only weakly acid fast
- Gram positive
- Beaded, branching, filamentous
- Usually starts as a lung infection in immunocompromised children - occasionally causing a thin-walled cavity lesion
- Can cause brain abscesses and chronic neutrophilic meningitis
- Tx:
- High-dose sulfonamides or TMP/SMX.
- In severely ill patients, add combinations of drugs, including amikacin + ceftriaxone or amikacin + imipenem.
- 6-12 weeks for immunocompetent
- 6-12 mo for immunocompromised
44
Q
Actinomyces
- Gram ____, filamentous, branching, anaerobic organisms
- Most common presentation: _____ involvement caused by a dental infection or trauma
- In infections of normally sterile sites, the presence of characteristically _____ granules that are actually clusters of organisms and inflammatory debris is typical
- Tx: ____ is 1st choice
A
Actinomyces
- Gram positive, filamentous, branching, anaerobic organisms
- Most common presentation: Cervicofacial involvement caused by a dental infection or trauma
- In infections of normally sterile sites, the presence of characteristically yellow “sulfur” granules that are actually clusters of organisms and inflammatory debris is typical
- Tx: PCN is 1st choice
45
Q
Neisseria Meningitidis
- Tx: 3rd generation cephalosporin ____
- Recurrent meningococcal infections should prompt evaluation for ____ deficiencies. Screen with total hemolytic complement activity assay
- Ppx: With ____ for 2 days, ___ x1 (DOC in exposed pregnant woman), ___ 500mg once in adults
- Ideally within ___ hours for:
- ______: Kissing, sharing toothbrushes or eating utensils, mouth-to-mouth resuscitation, intubation, or suctioning <24h after initiation of antimicrobial therapy
- ___ contacts within previous __ days
- Slept in same dwelling within ____
- _____ members
- Passengers directly next to index case (within 3 feet) during flights >__h within __ week of symptom onset or less than 24h after start of antibiotics
- Ideally within ___ hours for:
A
Neisseria Meningitidis
- Tx: 3rd generation cephalosporin ceftriaxone
- Recurrent meningococcal infections should prompt evaluation for complement deficiencies. Screen with total hemolytic complement activity assay
- Ppx: With Rifampin for 2 days, ceftriaxone x1 (DOC in exposed pregnant woman), ciprofloxacin 500mg once in adults
- Ideally within 24 hours for:
- Direct exposure to patient’s oral secretions: Kissing, sharing toothbrushes or eating utensils, mouth-to-mouth resuscitation, intubation, or suctioning <24h after initiation of antimicrobial therapy
- Child care/preschool contacts within previous 7 days
- Slept in same dwelling within previous 7 days
- Household members
- Passengers directly next to index case (within 3 feet) during flights >8h within 1 week of symptom onset or <24h after start of antibiotics
- Ideally within 24 hours for:
46
Q
Bordetella pertussis
- 3 stages of infection:
- 1) C___ (1-__ weeks): Rhinorrhea, cough, +/- fever
- 2) P__ (_-__ weeks): Cough with paroxysms, inspiratory wheeze/whoop
- 3) C___ Resolve gradually. Typically 6-10 weeks
- Complications: seizures, encephalopathy
- Labs: _____-predominant _____
- Dx: ______ testing in most appropriate in earliest stages. ____ is gold standard
- Tx:
- less than __mo: ____ (less likely to cause pyloric stenosis)
- ___mo: Any _____- azithromycin or clarithromycin or erythromycin. If allergic, TMP/SMX
- Chemoprophylaxis (same meds) for _____
- Return to daycare when ___ day treatment is completed OR if not treated, ___ days after onset of symptoms
A
Bordetella pertussis
- 3 stages of infection:
- 1) Catarral (1-2 weeks): Rhinorrhea, cough, +/- fever
- 2) Paroxysmal (2-6 weeks): Cough with paroxysms, inspiratory wheeze/whoop
- 3) Convalescent: Resolve gradually. Typically 6-10 weeks
- Complications: seizures, encephalopathy
- Labs: Lymphocyte-predominant leukocytosis
- Dx: Nasal PCR testing in most appropriate in earliest stages. Nasophyarngeal culture is gold standard
- Tx:
- <1mo: Azithromycin (less likely to cause pyloric stenosis)
- > 1mo: Any macrolide- azithromycin or clarithromycin or erythromycin. If allergic, TMP/SMX
- Chemoprophylaxis (same meds) for household contacts
- Return to daycare when 5 day treatment is completed OR if not treated, 21 days after onset of symptoms
47
Q
Pseudomonas Aeruginosa
- Consider in osteochondritis/osteomyelitis of the foot following a nail-puncture wound (esp if through a tennis shoe), endocarditis in IV drug abusers, bacteremia in burn pts, chronic suppurative otitis media, and otitis externa
- In immunocompromised hosts, might see cutaneous _______ (round, indurated, painless pustular/bullous/nodular black lesion with central ulceration with gray-black eschar surrounded by erythematous halo)
- Tx: __, ___, ___, aminoglycosides, ____ (only oral option), imipenem, meropenem
A
Pseudomonas Aeruginosa
- Consider in osteochondritis/osteomyelitis of the foot following a nail-puncture wound (esp if through a tennis shoe), endocarditis in IV drug abusers, bacteremia in burn pts, chronic suppurative otitis media, and otitis externa
- In immunocompromised hosts, might see cutaneous ecthyma gangrenosum (round, indurated, painless pustular/bullous/nodular black lesion with central ulceration with gray-black eschar surrounded by erythematous halo)
- Tx: Pip-tazo, ceftazidime, cefepime, aminoglycosides, fluoroquinolones (only oral option), imipenem, meropenem
48
Q
Salmonella
- Gram ___ ___
A
Salmonella
- Gram negative bacilli
49
Q
Nontyphoidal Salmonella
- Risk factor is milk bottles prepared in the same sink that family uses to wash raw chicken
- Food borne (chicken, milk, eggs, produce, peanut butter). Main reservoirs are animals (birds, mammals, reptiles, amphibians)
- Pt: Enteritis
- Treatment __________
- However, give antibiotics for salmonella diarrhea in less than ___ mo and older children with ___
- Treat invasive infections with ___ until susceptibilities are known. TMP/SMX, ciprofloxacin
- However, give antibiotics for salmonella diarrhea in less than ___ mo and older children with ___
- A child or staff member with nontyphoidal Salmonella enteritis should be excluded from a child care center only if symptomatic.
A
Nontyphoidal Salmonella
- Risk factor is milk bottles prepared in the same sink that family uses to wash raw chicken
- Food borne (chicken, milk, eggs, produce, peanut butter). Main reservoirs are animals (birds, mammals, reptiles, amphibians)
- Pt: Enteritis
- Treatment generally not recommended. Antibiotics can prolong salmonella infection (HIV/AIDS, agammaglobulinemia, malignancy, Crohn’s)
- However, give antibiotics for salmonella diarrhea in <3mo and older children with immunocompromising conditions
- Treat invasive infections with 3rd generation cephalosporin until susceptibilities are known. TMP/SMX, ciprofloxacin
- However, give antibiotics for salmonella diarrhea in <3mo and older children with immunocompromising conditions
- A child or staff member with nontyphoidal Salmonella enteritis should be excluded from a child care center only if symptomatic.
50
Q
Salmonella Typhi (Typhoid fever) - Humans are carriers/source. Tend to seed in \_\_\_\_\_.
- Pt: ____ rising slowly (accompanied by relative _____ is classic!), constitutional symptoms, and abdominal pain.
- Classic “______” form on the trunk a week after the fever starts
- Typhoid fever must be considered in the differential in any traveler returning from a resource-limited country
- Labs: Commonly leukopenia
- Dx: Blood, bone marrow, or bile culture. Stool often negative
- Tx: ______ is 1st line. Ampicillin, Bactrim, quinolones
- Typhoid vaccine should be offered to patients traveling to endemic regions
A
Salmonella Typhi (Typhoid fever) - Humans are carriers/source. Tend to seed in gallstones.
- Pt: Fever rising slowly (accompanied by relative bradycardia is classic!), constitutional symptoms, and abdominal pain.
- Classic “rose spots” form on the trunk a week after the fever starts
- Typhoid fever must be considered in the differential in any traveler returning from a resource-limited country
- Labs: Commonly leukopenia
- Dx: Blood, bone marrow, or bile culture. Stool often negative
- Tx: Ceftriaxone is 1st line. Ampicillin, Bactrim, quinolones
- Typhoid vaccine should be offered to patients traveling to endemic regions
51
Q
Shigella
- Gram negative bacilli
- Highest incidence occurs in child care centers, among people living in crowded conditions or institutions, and among people living on Native American reservations.
- _____ transmission plays a key role (unlike Salmonella). Shigella can infect with 10-100 organisms (compared to thousands-millions for Salmonella)
- Pt:
- Diarrhea is typically water and voluminous and can progress to dysentery within hours or days - frequent small stools with mucus or blood accompanied by lower abdominal cramps and tenesmus.
- Shigella can also cause vulvovaginitis with bloody or serosanguineous vaginal discharge. _____ + _____ = Shigella
- ____ occur with increased frequency in Shigella infection in young children; seizures are the most common neurologic symptom.
- Classic scenario is an infant presenting with high fever and new-onset _____ who, while performing the LP, has a _____
- Complications: _____ (5-8%),
- Generous leukocytosis and associated bandemia is common with this infection.
- Tx:
- Most clinical infections are self-limited (48-72 hours) and do not require tx.
- While mild cases do not require antimicrobial therapy, tx is recommended for severe disease (ie hypovolemic shock from increased losses) or immunocompromised individuals.
- Empiric abx tx options for severe dx in children include ____ or _____ (or ciprofloxacin in adults >18yo) for 5 days.
A
Shigella
- Gram negative bacilli
- Highest incidence occurs in child care centers, among people living in crowded conditions or institutions, and among people living on Native American reservations.
- Person-to-person transmission plays a key role (unlike Salmonella). Shigella can infect with 10-100 organisms (compared to thousands-millions for Salmonella)
- Pt:
- Diarrhea is typically water and voluminous and can progress to dysentery within hours or days - frequent small stools with mucus or blood accompanied by lower abdominal cramps and tenesmus.
- Shigella can also cause vulvovaginitis with bloody or serosanguineous vaginal discharge. GI symptoms + vaginal symptoms = Shigella
- Seizures occur with increased frequency in Shigella infection in young children; seizures are the most common neurologic symptom.
- Classic scenario is an infant presenting with high fever and new-onset seizure who, while performing the LP, has a large bloody stool!
- Complications: Rectal prolapse (5-8%),
- Generous leukocytosis and associated bandemia is common with this infection.
- Tx:
- Most clinical infections are self-limited (48-72 hours) and do not require tx.
- While mild cases do not require antimicrobial therapy, tx is recommended for severe disease (ie hypovolemic shock from increased losses) or immunocompromised individuals.
- Empiric abx tx options for severe dx in children include azithromycin or ceftriaxone (or ciprofloxacin in adults >18yo) for 5 days.
52
Q
Haemophilus influenzae
- For meningitis: Prior to or concurrent with initiation of antibiotics, use _____ 0.5mg/kg/day divided q6h for 2-4 days to decease the incidence of ___ and ____
- For pneumonia: _____ is DOC
Chemoprophylaxis is important for those exposed to invasive strains of H influenzae.
- Ppx: With \_\_\_ daily for \_\_ days
- All household members if household has
- \_\_\_\_ OR
- \_\_\_\_
- \_\_\_\_contacts when have had >=\_\_ pts with invasive Hib disease within \_\_ days
- For index pt tx with regimen other than cefotaxime or ceftriaxone
- <2yo OR
- Lives in household with child <3yo who is under immunized or immunocompromised
A
Haemophilus influenzae
- For meningitis: Prior to or concurrent with initiation of antibiotics, use dexamethasone 0.5mg/kg/day divided q6h for 2-4 days to decease the incidence of hearing loss and neurologic sequelae.
- For pneumonia: Amoxicillin is DOC
Chemoprophylaxis is important for those exposed to invasive strains of H influenzae.
- Ppx: With rifampin daily for 4 days
- All household members if household has
- At least 1 contact <4yo incompletely immunized OR
- Immunocompromised regardless of immunization
- Preschool and child care center contacts when have had >2 pts with invasive Hib disease within 60 days
- For index pt tx with regimen other than cefotaxime or ceftriaxone
- <2yo OR
- Lives in household with child <3yo who is under immunized or immunocompromised
53
Q
Yersinia
- Reservoir is wild rodents. Transmitted by fleas or direct contact
- Infected from ingestion of contaminated food or water, especially undercooked or raw ____, and contact with animals.
- Has been associated with preparation of chitterlings (chitins),
- Pt: Febrile illness with lymphadenopathy (usually inguinal)
- 1) Fever and diarrhea (often bloody in children). 20% report ____.
- ____ may be an important diagnostic clue for the diarrhea’s etiology as this is not associated with other acute bacterial diarrheas
- Duration of diarrhea is typically longer than the usual acute gastroenteritis, sometimes persisting up to 3 weeks.
- 2) Older children and adults may develop ______: RLQ pain, and elevated WBC, without evidence of appendicitis on imaging
- 1) Fever and diarrhea (often bloody in children). 20% report ____.
- Postinfectious complications: _____ and _____
- Dx: Culture or serology
- Tx:_______
- No evidence that abx are of any benefit. Supportive care: Encourage oral fluids
- Treatment is only indicated for _____
- A ___, ____ (if >8years), and___ would be oral drugs of choice. IV therapy would include 3rd gen cephalosporin (ceftriaxone or a fluoroquinolone) plus gentamicin.
- Gentamicin or streptomycin
A
Yersinia
- Reservoir is wild rodents. Transmitted by fleas or direct contact
- Infected from ingestion of contaminated food or water, especially undercooked or raw pork, and contact with animals.
- Has been associated with preparation of chitterlings (chitins),
- Pt: Febrile illness with lymphadenopathy (usually inguinal)
- 1) Fever and diarrhea (often bloody in children). 20% report pharyngitis.
- Pharyngitis may be an important diagnostic clue for the diarrhea’s etiology as this is not associated with other acute bacterial diarrheas
- Duration of diarrhea is typically longer than the usual acute gastroenteritis, sometimes persisting up to 3 weeks.
- 2) Older children and adults may develop pseudoappendicitis: RLQ pain, and elevated WBC, without evidence of appendicitis on imaging
- 1) Fever and diarrhea (often bloody in children). 20% report pharyngitis.
- Postinfectious complications: Reactive arthritis and erythema nodosum
- Dx: Culture or serology
- Tx:
- No evidence that abx are of any benefit. Supportive care: Encourage oral fluids
- Treatment is only indicated for pts with septicemia or those who are immunocompromised.
- A fluoroquinolone, doxycycline (if >8years), and TMP-SMX would be oral drugs of choice. IV therapy would include 3rd gen cephalosporin (ceftriaxone or a fluoroquinolone) plus gentamicin.
- Gentamicin or streptomycin
54
Q
Legionella pneumophila
- Found in water
- Pt: Multisystem disease is the clue (diarrhea, CNS, renal, pneumonia). Similar to and often confused with Mycoplasma pneumoniae.
- Triad of ____, ____, ____
- CXR looks worse than exam indicates
- Dx: ____ immunoassay to detect Legionella antigen
- Tx: ___ or ____
A
Legionella pneumophila
- Found in water
- Pt: Multisystem disease is the clue (diarrhea, CNS, renal, pneumonia). Similar to and often confused with Mycoplasma pneumoniae.
- Triad of pneumonia, diarrhea, CNS symptoms (headache, delirium, and confusion)
- CXR looks worse than exam indicates
- Dx: Urine immunoassay to detect Legionella antigen
- Tx: Azithromycin or quinolones
55
Q
Klebsiella
- DOC: _____. Most are resistant to ampicillin
A
Klebsiella
- DOC: Meropenem. Most are resistant to ampicillin
56
Q
Brucella
- Pt: Undulant fever, weight loss, night sweats
- Check for brucella in a _____ workup. It should be considered in any child with ______, esp if there is a hx of contact with farm animals or travel to an endemic region.
- Tx:
- > 8yo: _____ for 6 weeks + ____ for 2 weeks OR doxycycline + rifampin for 6 weeks
A
Brucella
- Pt: Undulant fever, weight loss, night sweats
- Check for brucella in a fever of unknown workup. It should be considered in any child with prolonged fever without an obvious source, esp if there is a hx of contact with farm animals or travel to an endemic region.
- Tx:
- > 8yo: Doxycycline for 6 weeks + aminoglycoside for 2 weeks OR doxycycline + rifampin for 6 weeks
57
Q
Francisella Tularensis (Tularemia, rabbit fever) - Classic scenario is someone who handles \_\_\_\_
- Pt: _____ form (myalgia, arthralgia, irregular ulcer with surrounding erythema)
- Dx: Clinical. Confirm with serologic testing.
- Differential includes plague, which occurs mostly in desert Southwest
- Tx: ______ for 10 days. Alternative is doxycycline.
A
Francisella Tularensis (Tularemia, rabbit fever) - Classic scenario is someone who handles rabbits
- Pt: Ulceroglandular form (myalgia, arthralgia, irregular ulcer with surrounding erythema)
- Dx: Clinical. Confirm with serologic testing.
- Differential includes plague, which occurs mostly in desert Southwest
- Tx: Gentamicin or streptomycin for 10 days. Alternative is doxycycline.
58
Q
Bartonella Henselae
- Can cause cat scratch disease
- Transmission is from flea to cat to human
- Pt: >3 weeks of chronic tender regional ________, often in absence of systemic sx
- Enlarged erythematous node (site of inoculation)
- Less common: ____ oculoglandular syndrome (conjunctivitis with preauricular adenopathy)
- Hepatosplenic CSD: Hepatomegaly, splenomegaly, micro abscesses in liver/spleen
- Dx:
- Clinical
- PCR and serology (antibodies) to confirm
- Rarely, FNA/tissue biopsy of lymph nodes to show necrotizing granulomas and see bacilli on Warthin Starry silver stain
- Tx:____
- Some recommend _ days of oral ___ to speed up recovery
A
Bartonella Henselae
- Can cause cat scratch disease
- Transmission is from flea to cat to human
- Pt: >3 weeks of chronic tender regional lymphadenopathy/lymphadenitis, often in absence of systemic sx
- Enlarged erythematous node (site of inoculation)
- Less common: Parinaud oculoglandular syndrome (conjunctivitis with preauricular adenopathy)
- Hepatosplenic CSD: Hepatomegaly, splenomegaly, micro abscesses in liver/spleen
- Dx:
- Clinical
- PCR and serology (antibodies) to confirm
- Rarely, FNA/tissue biopsy of lymph nodes to show necrotizing granulomas and see bacilli on Warthin Starry silver stain
- Tx: Self-limited
- Some recommend 5 days of oral azithromycin to speed up recovery
59
Q
Pasteurella
- Best known for causing infection in ______
- Pt: rapidly progressing cellulitis within 24 hours of bite, often with fever and regional lymphadenopathy
- Tx: _____
- Give for all cat bites and only dogs bites that are infected, involve critical area (eg face), or are deep wounds
A
Pasteurella
- Best known for causing infection in cat or dog bites
- Pt: rapidly progressing cellulitis within 24 hours of bite, often with fever and regional lymphadenopathy
- Tx: Amoxicillin/Clavulanate
- Give for all cat bites and only dogs bites that are infected, involve critical area (eg face), or are deep wounds
60
Q
Helicobacter Pylori
- Pt: Dyspepsia - epigastric pain worse with eating
- Alarm features: Anorexia, weight loss, recurrent vomiting, reported GI bleeding.
- Dx:
- Without alarm symptoms: ____ or _____ in patients
- With alarm symptoms: _____
- _____ tests cannot distinguish past from current infection
A
Helicobacter Pylori
- Pt: Dyspepsia - epigastric pain worse with eating
- Alarm features: Anorexia, weight loss, recurrent vomiting, reported GI bleeding.
- Dx:
- Without alarm symptoms: Urea breath test or H pylori stool antigen in patients
- With alarm symptoms: Upper endoscopy with biopsies
- Serologic tests cannot distinguish past from current infection
