ID Board Review

May 1, 2009

If it’s in ORANGE, it’s in PREP

2 day old infant presents with respiratory distress and fever of 101.

Which bugs should we be concerned about in the newborn period? E. coli GBS Listeria Coag. negative Staph (Staph epidermis)

What is the typical antibiotic therapy? Ampicillin + Gentamicin

Listeria Gram positive rod -- Listeria monocytogenes Common cause of neonatal sepsis Mode of transmission

Food borne (unpasteurized milk, soft cheeses, hot dogs, deli meats, undercooked poultry, unwashed raw vegetables)

Transplacental / Ascending (fecal/vaginal carrier) Clinical

Neonatal Early onset—Asymptomatic, Preterm, PNA, Septicemia,

Rash (erythematous granulomatous/papular) Late onset (after 1st wk) – meningitis

Immunocompromised – Meningitis, Parenchymal brain infection

Treatment: Ampicillin +/- Gentamicin

Group B Strep Mode of transmission

Maternal-fetus, contact GI/GU colonization

Clinical Early onset (0 - 6 days)

Sepsis, PNA, Meningitis (<10%) Late onset (7d - 3mos)

Occult bacteremia, meningitis, osteomyelitis, cellulitis Lab Diagnosis

Culture of blood, CSF, other fluid Most rapid method: Antigen detection

Treatment Ampicillin + Gentamicin GBS identified -- PCN G

GBS & Pregnancy When do we screen mothers for GBS?

35-37 WGA What are the risk factors for neonatal infection?

< 37 WGA PROM > 18 hrs Intrapartum fever Chorioamnionitis GBS UTI during pregnancy Previous infant w/invasive GBS disease

Prophylaxis Who, What, When, Where, How?????

GBS IAP

Vaginal & Rectal GBS cultures at 35-37 WGA

IAP Indicated What is the IAP?

Previous infant with invasive GBS

PCN G IV or Ampicillin Q4hrs until delivery

Adequate treatment 2 doses at least 4 hrs prior to delivery

GBS bacteriuria

Positive GBS (unless planned C/S w/o labor or ROM)

Unknown GBS and < 37 WGA PROM > 18 hrs Intrapartum fever

H. influenzae type B (Hib) Clinical

Before Hib vaccine, most common cause of bacterial meningitis

Since vaccine (1988), invasive disease has decreased by 99% in children < 5 yrs

Infection now occurs in un-/under- immunized or young PNA Sepsis / Occult Bacteremia Meningitis Epiglottitis OM Septic Arthritis Cellulitis Pericarditis

FYI Nontypeable strains cause infxn of respiratory tract Conjunctivitis, OM, sinusitis, PNA

Mode of transmission Inhalation of droplets, contact, neonatal

HIB Lab diagnosis

Culture of fluid (chocolate agar), CSF Latex DO serotyping

Treatment URI/OM/Sinusitis – Amoxil, Augmentin Invasive/Meningitis/Epiglottitis – Rocephin,

Claforan Prophylaxis??

Drug of choice – Rifampin +/- vaccine When / Who?

All household contacts if child < 4 who is un- / incompletely immunized, < 12 mos old child, IC child

Nursery / Daycares if > / = 2 cases within 60 days

7-month-old girl comes to see you because of runny nose and an occasional cough for most of the past week.

Nobody else in the home is sick except for the grandmother………

Mee Maw has had a severe cough for the past 2 weeks. In fact, the coughing fits were so violent that she would pass out.

What should you suspect? What do you want to do about this infant’s cold? Who should receive Ab prophylaxis?

WHOOPING COUGH

Pertussis (aka Whooping Cough) Adults are major reservoir Immunity not lifelong Mode of transmission

Close contact with aerosolized droplets Clinical manifestations

Catarrhal: 1- 2 weeks URI symptoms Paroxysmal: 2 - 6 weeks Cough increases in severity

Paroxysmal attacks Cough + gagging, cyanosis, post-tussive emesis, apnea Followed by whoop (forced inspiratory effort)

Convalescent: wks – mos Cough decreases Most contagious: catarrhal stage and first 2 weeks after

onset of cough Disease in infants

May have only cough w/associated apnea, cyanosis, feeding difficulties, tachypnea

More likely to have complications PNA, apnea, FTT, seizures, death

Whoooooopin’ Cough Lab diagnosis

Direct Fluorescent Antibody (DFA) Low sensitivity

PCR assay Gold standard: Culture

Treatment Does not alter the disease course, but decrease patient

infectivity Azithromycin x 5 d Alternatives: clarithromycin x 7d, erythromycin x 14 d, Bactrim

x 14 d

Prevention Droplet Precautions Antibiotic prophyalxis for close contacts No school/daycare until treated x 5 days

Diphtheria Clinical

Membranous nasopharyngitis or obstructive laryngotracheitis Rare: cutaneous, vaginal, conjunctival, otic infection,

myocarditis, peripheral neuropathies Transmission – respiratory droplets and/or contact Toxin mediated illness

Exotoxin A & B Treatment

Equine antitoxin (1o therapy) Erythromycin or PCNG to

Stop toxin production, eradicate C diptheriae, prevent transmission

Vaccination prevents disease (only effective control measure)

Working in a refugee camp when a mother brings in her 8 day old boy

States irritable x 2 days Now loud noises appear to cause him pain,

evidenced by muscle tightening and back arching causing his head to nearly touch his feet

On exam, you note dried packing on his umbilical cord, which is the local custom

MMMMM, VERY WEIRD……. WHAT DO YOU THINK IS GOING ON?

Tetanus Clostridium tetani Clinical

Gradual onset of trismus , severe muscle spasms Can be localized, cephalic (CN), or generalized Exacerbated by external stimuli (noise)

Toxin mediated illness Neurotoxin in a contaminated wound ** Poor umbilical cord care

Treatment Tetanus Ig, wound management, Metronidazole or PCN

G x 10-14 d Vaccination prevents disease (only effective control

measure)

Dirty Wound, Clean Wound… Dirty wounds:

Contaminated with dirt, feces, soil, or saliva; puncture wounds, crush and avulsion injury, burns, or devitalized tissue

So what to do?

Which toxoid to use?? < 7 yrs: DTaP > 7 yrs: Adult Td Adolescent (>11yr): Tdap if not previously immunized

Vaccine status Clean Wound Dirty Wound

Td or TDaP Td or TDaP TIG

Incomplete/ Unknown

Yes Yes Yes

>/= 3

No(less than 10

yrs)

No(less than 5

yrs)

No

4 mos old female presents to clinic with poor feeding and constipation

Any thoughts??? On exam, note hypotonia (greatest in UE)

Ok, so what do we have? Other symptoms that may be present? What is the usual mode of acquistion?

Botulism Botulinum toxin …… Method of action???

Blocks release of acetylcholine into synapse

Characteristics of botulism Acute, afebrile, symmetric, descending flaccid

paralysis 3 Types:

Food borne – ingestion of preformed toxin Wound – systemic spread Infantile -- ingestion of spores intestinal colonization

Suspect in infant < 6 mos w/ constipation, listlessness, loss of facial expression, poor feeding, weak cry, decreased gag reflex, hypotonia (“floppy”), ptosis

Floppy baby eating honey….. Lab diagnosis of infantile botulism

C. botulinum in stool Treatment

Primarily supportive care Antitoxin NO Antibiotics – lysis of spores / release of more

toxin NOT GOOD

NO HONEY <12 MOS!!!!! AND NO….. BULGING CANS

7 yr old girl is hospitalized after acute onset of fever, rapid development of hypotension, diffuse erythema of the skin, rapidly accelerating renal failure, and multi-organ involvement

What is the diagnosis? Due to what bacteria?

Group A Strep Streptococcus pyogenes Mode of transmission: Contact Clinical

Upper respiratory tract Acute pharyngitis & Scarlet Fever Serous rhinitis, OM, sinusitis, RPA, peritonsillar abscess,

cervical adenitis Skin

Impetigo, Erysipelas, Perianal cellulitis, Pyoderma Other

PNA, endocarditis, septic arthritis, cellulitis, necrotizing fasciitis, osteomyelitis, TSS

Treatment of choice PCN G IM or PCN V PO Marcolides for allergic patients

Return to School 24 hrs after treatment

GAS Nonsuppurative Sequelae (What?!?!) Rheumatic Fever

Follows pharyngitis NOT skin infections THE REASON WE TREAT JONES + Documented Strep infection (ASO)

Joints – Migratory polyarthritis -- Carditis (new murmur) Nodules – subcutaneous Erythema marginatum Sydenham chroea

What are the minor criteria??? Fever Arthralgia Elevated ESR/CRP Prolonged PR interval

Those Sequelae (cont…) Glomerulonephritis

Can follow pharyngitis (1-2 wks) or skin infection (3-6 wks)

Clinical Hematuria (RBC cast in urine) Proteinuria Edema HTN

Low C3

Streptococcus pneumonia Clinical

AOM, sinusitis, CA PNA, conjunctivitis, periorbital cellulitis osteomyelitis, endo-/peri- carditis, soft tissue infxn Before PCV7, most common cause of AOM

Most common cause of meningitis in children (along with meningococci)

Mode of transmission Contact (respiratory droplets

Treatment PCN G, Rocephin, Claforan, Vancomycin

What are we dealing with????

Treatment of MRSA Severe/Invasive: Vancomycin +/- Gentamicin +/- Rifampin Skin/soft tissue: Bactrim, Clindamycin PNA/Septic arthritis/osteomyelitis: Clindamycin

26 week old preterm infant has developed a line-associated Staph epidermidis sepsis

Does anyone know the most effective antibiotic regimen for this infant??? Ampicillin Ampicillin + Gentamicin Ceftriaxone Oxacillin + Gentamicin Vancomycin + Rifampin

Staphylococcus epidermidis Coagulase negative Staph Lab tests

Gram stain & culture (look at susceptibilities) DO NOT ASSUME CONTAMINATE in neonates, IC, prosthetic

device/hardware…….REPEAT & START EMPIRIC ABTX Clinical syndromes

If not a contaminate Health care associated infections #1 cause of VP shunt infections (ventriculitis) Infection of implanted hardware, catheters, shunts,

prosthetic devices Endocarditis, PD cath peritonitis, UTIs, Osteomyelitis

Sepsis in preterm infants, sepsis/bacteremia in IC children Treatment

Lots of resistance: Methicillin, Ceftriaxone, Clindamycin, Macrolides

Empiric treatment – Vancomycin +/- Rifampin or Gentamicin, Cipro

Remove foreign body

14 yo old male presents with fever, palpable purpuric rash, generalized fatigue…

What should we suspect?

What is our treatment?

Isolation?

Neisseria meningitidis Clinical syndromes

Meningococcemia and/or Meningitis Rapid onset of fever/chills, malaise, maculopap./petechial rash Waterhouse Friderichsen Syndrome – fulminant disease

Sequelae – hearing loss, neuro deficits, digit/limb amputation

Lab diagnosis Presumptive – gram negative diplococci sterile fluid Confirmed – isolation/culture from sterile site or clinical

(petechial/purpuric lesions + clinical illness) Treatment

PCN G Alternatives: Rocephin, Claforan, Ampicillin

Isolation: Droplet Prophylaxis

Close contacts Rifampin (children); Rifampin, Rocephin, Cipro (Adults)

2 yo old female with ALL has developed enterococcal bacteremia.

You begin treatment with vancomycin She remains febrile after 48 hrs of vancomycin

therapy

What should you be concerned about? What do you need to check?

Dealing with Vancomycin Resistant Enterococcus

What is the most effective treatment? A. Ampicillin B. Cipro C. Linezolid D. Ticarcillin

E. Vanc

Enterococcus Enterococcus faecalis & Enterococcus faecium Clinical

UTI, bacteremia, endocarditis, meningitis, device associated infections, intra-abdominal abscess, peritonitis

Treatment Ampicillin / Vancomycin +/- Gentamicin **Don’t forget resistance patterns Check

susceptibilities VRE (Vancomycin resistant) strains, ampicillin, &

cephalosporins VRE present treat with Linezolid

THAT’S ALL FOR ME!!!!!