Infectious Disease Flashcards
What are the risk factors for Hib meningitis?
Partially immunized Unimmunized New to Canada Immunosuppressed Immune-incompetent
Who is at risk for listeria meningitis?
Age (neonate)
immunocompromised
brainstem symptoms as initial presentation
Drug of choice for GBS infection?
Penicillin
What are the contraindications to an LP?
Coagulopathy
Cutaneous lesion at proposed puncture site
Signs of herniation
Unstable pt
What are your empiric Abx choices for meningitis >1 mo and why?
What Abx do you add if worried about listeria?
Ceftriaxone 100mg/kg/day div q12
(Or cefotaxime 300 mg/kg/day div q6h)
Vanco 60 mg/kg/day div q6h
- ceftriaxone bc some strep pneumo and n menin are penicillin resistant
- vanco bc a small portion of strep pneumo is resistant to 3rd gen cephalo
Ampicillin 300mg/kg/day div q4-6h
What is the drug of choice for close contacts of pt with meningococcal disease or Hib?
Rifampin
When do we give steroids for meningitis and why?
Hib
Shown to decrease hearing loss
-some experts say if suspect bacterial etiology start iV steroids within 30mins of antibiotics and continue q6h (total 2 days doe strep pneumo and Hib)
In which cases of meningitis should you do a repeat LP?
Gram negatives (eg E. coli) at 24 to 48h HSV meningitis (near end of 21 day course)
How long do we treat meningitis due to: A) strep pneumo B) Hib C) n meningitides D) GBS
A) 10-14 days
B) 7-10 days
C) 5-7 days
D) 14-21 days
What are the main bugs for kids with meningitis >1 month?
H flu type b (rare…now more non typable)
N meningitides
Strep pneumo
GBS and E. coli if child is
How is C. diff spread and what is the incubation period from time of exposure?
Fecal-oral
2-3 days
What are risk factors for C diff infection?
Duration of hospital stay Older age Exposure to multiple Abx classes Chemotherapy Immunosuppression Hypogammaglobulonemia GI surgery
What are the important pathophysiological features of C diff?
Heat resistance of spores
Acid resistance of spores
Toxin production (A enterotoxin, B cytotoxin)
What are the diagnostic criteria for C diff?
Presence of symptoms (usually diarrhea) PLUS stool test positive for toxin OR scope showing pseudomembranous colitis
Which populations are most likely to have complications from c diff?
Neutropenic oncology kids
Stem cell transplant recipients
Infants with hirschsprungs
IBD pts
What tests are commonly used for dx of C diff?
- Enzyme immunoassay (EIA) for glutamate dehydrogenase
- EIA for toxins A and B
- Cell cytotoxic assay
What is the treatment for mild, mod, severe, severe/complicated c diff?
Mild - stop Abx
Mod - stop Abx, metronidazole PO 30 mg/kg/day div q6h x 10-14 days
Severe - stop Abx, vanco PO 40 mg/kg/day div q6h x 10-14 days
Severe/complic - stop Abx, Vanco PO PLUS IV flagyl 30/mg/kg/day q6h x 10-14 days
How do we treat first and second recurrences of c diff?
First recurrence- same as initial
Second - Vanco PO wih tapered or pulsed regimen
*there may be a role for probiotics in preventing recurrences
How recently should a pt have had Abx in order to include c diff in the differential?
Within the past 12 wks
What is the worst manifestation of pseudomembranous colitis?
Toxic megacolon
What groups are at risk for invasive meningococcal disease?
- Anatomical or functional asplenia
- Primary antibody deficiency disorders
- Complement, properdin or factor d def
- Travelers to areas where meningococcal risk is high
- Lab personnel with exposure to meningococcus
- The military
What are the 2 types of meningococcal vaccines, what strains do they cover and what age should they be given?
Meningococcal serogroup C conjugate (MCV-C)
- serogroup C
- all infants age 12 months (even if had doses before age 1 yr they need a dose at 12 mo)
- high risk kids can start with doses at 2 and 4 months
- adolescent booster if don’t get quadrivalent
Quadrivalent Meningococcal conjugate (MCV-4) -Types A, C, Y, W-135 -booster in adolescence -kids >2 yrs at increased risk for meningococcal disease
What is the most common cause/strain of meningococcal infection in Canada and why don’t we vaccinate against it?
Meningococcal serogroup B
(Esp in kids under 5 yrs)
-polysaccharide of serogroup B is poorly immunogenic in humans so hard to dev a vaccine
-vaccine came out last year against it (bactero) but not publicly funded yet
Does having a primary rsv infection confer protective immunity?
No. Reinfections continue into adulthood
What are nonpharmacologic ways to prevent spread of RSV to high risk children?
Good hand hygiene at home
Limit contact with kids/adults with URTI symptoms
Which high risk groups should get palivizumab?
CLD of prematurity age
What lab testing do you do to see if pt is immune to varicella with natural disease? After vaccine?
IgG to VZV for natural disease
No commercially available testing for ppl who have received vaccine (reference labs can do gpELISA and FAMA test)
Define primary and secondary vaccine failure
Primary - after vaccine given, a protective immune response does not develop
Secondary - waning immunity
What are the limitations of single dose varicella vaccine?
- case numbers have plateaued
- shift in median age of disease onset (adolescents and adults have more severe complications)
- waning immunity over time
What is most common adverse event with varicella vaccine?
Pain and redness at injection site
CPS recommends 2 doses of varicella vaccine for kids 1-12yrs. When should the first and second dose be given?
first dose: Btwn 12 and 18 months
- second dose:
- age 4-6 yrs
- > 3 months after the first dose (> 1 month apart for kids over 12 yrs)
What specific at risk population should be screened for varicella immunity and what should you do if they are not immune?
Pregnant women
When no longer pregnant then give vaccine (ok to give if breastfeeding)
What is acceptable to consider someone immune to varicella?
- IgG to VZV (natural disease)
- documentation of 2 doses of vaccine (do NOT do serology)
- lab confirmation of varicella or herpes zoster from a lesion
- previous dx of varicella or herpes zoster by a HCP
What are the benefits of home IV therapy?
Improved quality of life
Lower healthcare cost
What are the indications for home IV therapy?
- Infections req prolonged IV Abx (eg bone and soft tissue, endocarditis post stabilization, cmv, fungal)
- hemophilia for factors
- palliative care
- chemo
- immune deficiencies
- anti inflammatory mediators
What is the most common complication of home IV therapy?
Mechanical (eg. IV insertion, dislodgement, thrombosis, occlusion)
What infrastructure do you need in place to do home IV therapy?
Home IV therapy team
Facilities to insert vascular access devices
Available infusion pumps and equipment
Protocols
Who should be on the IV home therapy team?
Physician Primary care provider Infusion nurse specialist Home care Ppl with skills in vascular access Pharmacist SW, specialists prn
*pt should be seen at least once a week by RN or MD
What are some patient and family factors to consider when doing home IV therapy?
Willing to participate
Understand importance of compliance
Require adjustments to schedules and sports/activities
Understand benefits/risks
Can learn skills needs reliably
Understand economic implications (may not be entirely covered)
Have schedule flexibility
Able to rapidly communicate with IV team
Adequate housing conditions
Safe home environment (eg no substance abuse)
What are antibiotic factors important in home IV therapy?
Can be given in programmable electronic pump
Stable at room temperature at least 24h
Stable in fridge at least one week
What are the types of vascular access devices for home IV therapy?
PIV Midline catheter PICC Tunneled line (broviac or Hickman) Port
What monitoring is required for pts on home IV therapy?
Ongoing evaluation of illness being treated
Evaluation of vascular access site
Compliance
Monitor for adverse drug effects +- drug levels
What are the benefits of a harmonized immunization schedule for Canada?
- safer and equal access across Canada
- larger bulk purchase of vaccines
- educational information simplified
- new programs introduced in organized fashion
- HCP do not need to learn a new schedule if they move provinces
How is rotavirus transmitted? What is its incubation period? Main symptoms? Avg # of days to resolve? What age do we commonly see infection?
Transmission: Fecal-oral and fomites Incubation: 1-5 days Main Sx: vomiting, fever then diarrhea Days to resolution: 3-8 days Age: less than 5 years, more severe in kids
If mortality from rotavirus is rare why do we recommend a vaccine?
Significant health care resource use associated with rota infections.
How do we diagnose rotavirus?
antigen detection in stool by enzyme immunoassay
What was the reason of recall for the previously licensed Rotavirus vaccine RotaShield?
increased association with intussusception
When should a child be vaccinated against rotavirus? How many doses and by when should it be complete?
Two approved vaccines either 2 or 3 doses depending on the brand.
Vaccine must start at 6 to 14+6 weeks of age and completed by age 8 months.
**can be given with other vaccines
Do shed the virus with vaccine administration.
What are the contraindications to the rotavirus vaccines (RotaTeq and Rotarix)?
- hypersensitivity to vaccine or any of its components
- history of intussusception
- known or suspected immunodeficiency
Should kids who have had rotavirus infection get the vaccinations?
Yes b/c infection only provides partial immunity but they must be in the recommended age range.
What is the pathophysiology of AOM?
Eustachian tube dysfunction and obstruction:
1) viral infection causes obstruction of eustachian tube
2) impaired mucociliary clearance (mucus trapped in middle ear)
3) resorption of gasses causes pressure differential and vacuum which pulls bacteria from nasopharynx into middle ear
What are the risk factors for AOM?
MAJOR
- young age
- daycare attendance
OTHER
- orofacial abnormalities
- household crowding
- exosure to cigarette smoke
- prematurity
- not being breastfed
- immunodeficiency
- positive family history
- first nations/aboriginal
What are the diagnostic criteria for AOM?
1) Signs of middle ear effusion
- immobile TM, +/- opacification/loss of bony landmarks/ruptured with fluid
2) Signs of middle ear inflammation
- bulging and discoloured TM
3) Symtpoms
- irritability, acute ear pain
What are the main bugs that cause AOM?
Streptococcus penumoniae
Hemophilus influenzae
Moraxella catarrhalis
For who can you use the watchful waiting approach in AOM? (48 to 72h)
- older than 6 months
- no immunodeficiency, chronic heart/lung condition, T21, orofacial abnormality, or hx of complicated OM (suppurative complications or chronic perf)
- illness not severe (temp is
What are the biggest complications of AOM we worry about?
mastoiditis
meningitis
intracranial abscess
Strep pneumo has increasing abc resistance, what are the RF for abx-resistent Strep pneumo for AOM?
- age 4h per week with at least 2 unrelated kids)
- frequent AOM
- recent abx use
- failed initial abx treatment
What is first line tx for AOM?
First line if have a type 1 run (anaphylaxis or urticaria to amoxil)?
First line if non-type 1 run to amoxil?
First line:
Amoxicillin 75-90 mg/kg/day
Type 1 rxn to amoxil:
Clarithromycin or Azithromycin
non-Type 1 rxn to amoxil:
2nd generation cephalosporin (eg cefuroxime)
If symptoms of AOM do not improve by 2 days, what abx should you change to?
Amox/Clav 90 mg/kg/day of amoxil component bid x 10 days
OR
Ceftriaxone 50 mg/kg/day IV OD x 3 days
How long should you treat AOM?
5 days for most
10 days if:
-age
What reduces a child’s risk of AOM?
Hand washing Exclusive breastfeeding until age 3 months Not using pacifiers before age 3 years Limiting daycare Not smoking
What is the incubation period for varicella-zoster virus?
How long before the rash appears are you contagious?
How is varicella transmitted?
Incubation: 10-21 days (avg 14-16 days)
Infectivity: 24-96 hrs before rash onset
Respiratory (as per CPS) but is airborne
When should a child with chickenpox return to school/daycare?
When well enough to participate normally in all activities.
Does not matter the state of the rash
How long should hospitals keep their varicella patients in isolation?
8 to 21 days from the time of contact with the infected person
How are head lice spread and how do you diagnosis a head lice infestation?
Spread through head-to-head contact
(they do not hop or fly!)
Must detect a living louse (a nit does not count!), best method is using a fine toothed comb.
How long can adult head lice and nymphs (babies) survive away from the human host?
3 days
How do you treat head lice?
Does itching post treatment mean reinfestation?
Topical insecticides (2 applications 7-10 days apart) e.g. permethrin or pyrethrin -is a new non-insecticidal product
NO! can be due to irritation from treatment, must have live louse to diagnose reinfestation
1) How long should kids stay out of school with a head lice infestation?
2) What does that mean for other kids in the class?
3) What do you do with household contacts and household items?
1) Do not need to be excluded (including if have nits).
2) Inform parents about active head lice case in the class and how to check for it.
3) wash items in contact with the head in hot water (66 degrees C) and then the dryer for 15 minutes or store in occlusive plastic bag x 2 weeks; check household contacts for live louse
For which of the following chronic infections can kids be excluded from daycare?
A) hep b
B) hep c
C) hiv
None
How is hep b transmitted? Under what circumstances would a bite potentially result in transmission?
Transmitted via mucous membranes or open skin lesions with blood, saliva, or genital secretions from an infected person
-only if there is a break in the skin is there a potential for transmission
Under what circumstances is post exposure prophylaxis indicated for hep b after a bite?
- kid with hep b bites another kid and breaks the skin
- kid who is not infected who bites a kid with hep b if the blood from bthe kid who was bitten comes in contact with the biter’s oral mucosa
Are parents of hiv positive kids required to report the hiv status to the child care personnel?
Nope
Under what circumstances is post exposure prophylaxis indicates for hiv after a bite in daycare?
Very rarely Bc transmission via saliva is very low. Only give in consultation with Peds ID.
What specific treatment can be offered after a bite at daycare involving a kid with hep c?
None. No prophylaxis currently available.
Need serology at 6 months
What information should be given to parents prophylactically about bites at daycare?
If bite with significant blood exposure occurs parents of both kids will need to be informed of the incident and may be referred for medical evaluation.
Under what circumstances can a kid with hep b be excluded from daycare?
If frequent aggressive biter
Assessed on individual basis by kids doctor and public health
What are measures to decrease biting at daycare? (8 answers)
- avoid stressful situations and conflicts
- provide small group, age appropriate activities
- observe how, when and why a kid bites to guide management
- pay attention to the victim first
- firm statements to biter that behaviour is inappropriate
- direct biter to appropriate activities
- positive reinforcement of appropriate activities
- collaboration with family
What can be done as prophylaxis at a daycare for hep b?
All staff should be immunized
Parents should be encouraged to have their kids vaccinated
Can offer it to kids without revealing the identity of the infected kid.
What do you do when a bite happens at daycare if skin not broken? Broken?
Not broken
- clean with soap and water
- apply cold compress
Broken skin
- allow to bleed gently, don’t squeeze
- Clean with soap and water
- apply mild antiseptic
- write official report
- report bite to public health
- parents of both kids should be notified
- review and update tetanus status
- consider if need prophylactic antibiotics
Under what circumstances should prophylactic antibiotics be used for a bite in daycare?
Moderate or severe tissue damage
Deep puncture
Bites to face, hand, foot, genitals
What is post exposure prophylaxis for hep b?
Hep b immunoglobulin (0.6ml/kg IM) and hep b vaccine if kid involved is incompletely immunized or non immune
If hep b status of one (or both) of the kids is unknown and bite breaks the skin, give hep b vaccine
- -> need f/u to complete hep b series
- -> hep b serology at 6 months if known hep b exposure
How quickly should post exposure prophylaxis be given after a bite involving hiv positive kid?
Within a few hours of the exposure
Not indicated if more than 72 hrs have passed
What are the major risk factors for seropositivity of Hep C in pregnant women? (4)
Current or past IVDU
Dating an IVDU
Blood transfusion before 1990/fr developing country
Recipient of organ or tissue transplant from unscreened donors
What is the definition of chronic Hep C infection?
Acute phase is usually subclinical
active viral replication for more than 6 months
*some kids have had spontaneous clearance of Hep C infection after 6 months
What is the most common lab finding and physical finding for Hep C in kids?
intermittent/chronically elevated aminotrasferase
heptomegaly
What are the risk factors of increased risk of transmission of Hep C from infected mum to baby? (4)
high maternal viral titre
elevated ALT in year before pregnancy
maternal cirrhosis
HIV coinfection (if on antiretrovirals this risk may be eliminated)
How does vertical transmission of Hep C occur?
intrauterine AND intrapartum
NOT via breastmilk (should breastfeed unless bleeding nipples)
What can be done to prevent vertical transmission of Hep C? What is the transmission rate?
nothing
5%
What body fluids are the major source of transmission for Hep c?
blood
No known risk from saliva, urine or stool
When should Hep C serology be done in a newborn born to a hep C positive mum and why?
- age 12-18 months, repeat at 18 months if done prior and was positive
- minimum age is 2 months but not recommended routinely (only if ++parental anxiety or concern re: loss to f/u)
- b/c before that get passive maternal antibodies
What is your management of a child with Hep C RNA positive as an infant?
Repeat HCV RNA and ALTs q6months (to see if will become chronic or have spontaneous clearance)
What are the longterm sequelae of chronic hep c infection for kids?
Liver disease
hepatocellular carcinoma
How would you interpret the following of a baby born to Hep C positive mum >18 months?
+HCV antibody
HCV RNA PCR not detected
Clearance of Hep C virus (occurs in 25%)
How would you interpret the following of a baby born to Hep C positive mum >6 months?
+HCV antibody
HCV RNA PCR detected >6 months
Chronic Hep C infection
How would you interpret the following of a baby born to Hep C positive mum at any age?
+HCV antibodies
HCV RNA PCR detected
Acute Hep C infection
What are risk factors for transmission of bugs in the outpatient peds setting? (6)
- kids who can’t handle their secretions well
- diarrhea in diapers/incontinent
- open wounds/lesions
- organisms that can survive on inanimate objects for long periods of time
- crowded waiting rooms
- being immunocompromised
What bugs are transmitted via the airborne route?
Measles
TB
Varicella
What precautions do you use for meningitis?
Droplet
What precautions do you need for influenza?
Droplet + Contact
b/c can survive on surfaces
What is the difference between droplet and airborne?
Droplet - large droplets that do not stay suspended in the air, must wear mask within 2m of the patient
Airborne - small droplets that stay suspended in the air and can be dispersed over large areas, N95 and negative pressure rooms
How often do hard toys need to be washed at a Dr’s office and how?
q1-2weeks
cleaning and soaking for 1 h in bleach solution (1:100 dilution)
Name some measures in office design to minimize spread of infection?
- ventilation with at least 6 exchanges per hour
- no carpets
- handwashing sinks with adjacent soap and paper towel
- signs about coughing into a tissue or your sleeve
Under what conditions should a kid not wait in the waiting room at the doctors office?
- immunocompromised
- ideally those with contagious illnesses (fever, diarrhea, vomiting, cough, open skin lesions)
- anyone with suspected airborne illness (measles, TB, varicella)
What are the moments of hand hygiene?
before contact with patient
after contact with body fluids
before invasive procedures
after contact with patient
What do you use in the Dr’s office to clean spills of bloody body fluid?
bleach 1:10 to 1:100 dilution
wear gloves
How long does it take for the air to be free of aerosolized particles from an airborne illness? aka how long til the examining room can be used again?
70 minutes
What special precautions do you need to use for patients with antibiotic resistant organisms (e.g MRSA, VRE)?
Routine practices
Emphasis on hand hygiene
What vaccine immunity should you check of the personnel who work at a Dr’s office?
Immunity to:
- MMR
- varicella
- Hep B
- Polio
- one dose of acellular pertussis as an adult
Should have negative documented TST
How long should personnel at Dr’s office avoid direct care of high risk patients if have URTI?
until symptoms resolve
How long should personnel at Dr’s office avoid direct care of high risk patients if have Hep A?
until one week after onset of jaundice
How long should personnel at Dr’s office avoid direct care of high risk patients if have conjunctivitis?
until exudate resolves
How long should personnel at Dr’s office avoid office of high risk patients if have Rubella?
until 7 days after onset of rash
What are 5 factors that are important for a screening program?
- sensitivity and specificity of the diagnostic test
- acceptability and feasibility of the diagnostic test (easy to administer)
- benefit of early detection
- disadvantages of testing
- prevalence of disease
How do you diagnose HIV infection?
1) screening with enzyme immunoassay
2) confirmatory test with western blot **only done for HIV-1 in Canada
- must do pre and post test counselling
What is the window period for HIV infection? (from infection to detectable antibodies)
4-6 weeks
How do you interpret an indeterminate western blot for HIV?
- early infection
- infection with HIV-2 (b/c we only test for HIV-1)
- waning maternal antibodies in an infant
- false positive
Which pregnant women should be screened for HIV?
all of them
How does vertical transmission of HIV occur?
- time of delivery
- via breastmilk (9% risk of transmission per year of breast-feeding)
- avoid breastfeeding even if on antiretrovirals
What is the major risk factor for perinatal transmission of HIV?
maternal viral load
How should a baby of an HIV-positive mum be delivered?
-c-section or vaginal delivery if viral load
If a women is HIV positive and pregnant should she be on antiretrovirals?
Yes (benefits outweigh the risk of toxicity in utero)
What is the perinatal transmission rate of HIV if no interventions are taken?
25%
What is the management of an infant born to an HIV positive mother?
Refer to ID
needs AZT and possibly combo therapy
Why do we give 2 doses of the rubella vaccine?
Failure of one dose of vaccine is as high as 10%
What can we do to minimize congenital rubella syndrome?
- screen women in pregnancy and if not immune give them the vaccine post partum
- screen newcomers to Canada
What are the manifestations of congenital rubella syndrome in an infant?
microcephaly cataracts glaucoma pigmentary retinopathy hearing impairment PDA HSM thrombocytopenia radiolucent bone densities
What testing should you do for patients with illnesses compatible with rubella or measles?
IgM (rubella and measles) IgG serology (look for a 4-four increase in the titre) and/or virus detection
When can rubella vaccine be given to a pregnant woman?
28 days after delivery
- breastfeeding is NOT a contraindication
- contraindicated if have immune deficiency
What are the complications of rubella vaccine for postpartum women?
transient acute arthritis or arthralgia
Define: biocide sterilant disinfectant sanitizer fungicide
- Biocide: synthetic/semisynthetic agents that kill living cells above certain concentrations
- Sterilants: kills all forms of microbial life
- Disinfectant: eliminate infectious pathogenic bacteria
- Sanitizer: reduce microbial contaminants
- Fungicides: destroy fungi on inanimate surfaces
What are the pros and cons of alcohol-based antiseptics in the household?
- need 60-95% alcohol
- denatures proteins
- good against rota, adeno, rhino, hep A, poliovirus
- less active against bacterial spores, some non enveloped viruses and protozoan oocysts
What are the pros and cons of chlorhexidine in the household?
- active against gram-positive bacteria, less against gram-neg and fungi
- not sporicidal
- acts against enveloped viruses (HSV, HIV, CMV, flu)
- not as good against non enveloped viruses (rota, adeno, enter)
What are the pros and cons of triclosan in the household?
- incorporated into soaps
- 0.2-2% concentrations have antimicrobial activity
- often bacteriostatic
- better against gram-pos
- reasonable activity against mycobacteria and candida
What are the pros and cons of quaternary ammonium compounds in the household?
- mainly bacteriostatic and fungistatic
- more active against gram-pos
- less common against gram-neg bacilli
What are mechanisms microorganisms have developed to be resistant?
- enzymatic inhibition
- membrane impermeability
- efflux pumps
- alterations of ribosomal target
- alteration of cell wall precursor target
- alteration of alteration of target enzymes
- overproduction of target enzymes
- auxotrophs that bypass inhibited steps
What are important aspects for hygiene of the skin at home?
- mild, plain soaps are best
- no data to support bathing with antimicrobial products
- antiseptic hand products if close contact with neonates, old ppl, immunocompromised ppl
How long should you wash your hands for to prevent spread of respiratory viruses?
15-20 seconds
How should you handle diarrhea and vomiting at home?
- frequent handwashing, esp after diaper change
- disinfect contaminated surfaces with chlorine bleach-based cleaners
- if there is a spill clean with 1 part bleach to 9 parts water and let sit for 20 mins
How should you clean toys at home?
-if machine washable put them in the dishwasher
What are CPS recommendations for antimicrobial product use in the home?
Does not recommend their use
What are the CPS recommendations for egg-allergic patients and the flu vaccine?
All egg-allergic its should be vaccinated with a full dose of the INactivated vaccine, unless previous documented anaphylactic rxn to flu shot
(live attenuated not yet studied). Do NOT need skin testing or split doses.
Why don’t we give flu vaccines to kids
variable immune response and vaccine effectiveness unclear
What are the benefits of immunizing pregnant women against the flu?
- clinically effective
- safe
- cost effective
- lower maternal and infant flu-related hospitalizations
- decreased preterm and SGA newborns
What congenital anomalies are you at increased risk for if you get influenza during the 1st trimester?
- neural tube defects
- hydrocephaly
- CHD
- cleft lip
- digestive system defects
- limb reduction defects
Which flu vaccine should be given to pregnant women?
Trivalent inactivated vaccine
Which adolescents should be screened for STIs females and males?
Females: all who are sexually active or victims of abuse
Males: (at least one of)
- history of sex with someone with an STI
- personal hx of STI
- being a patient of an STI clinic previously
- new sexual partner or >2 partners in the past year
- IVDU or other drugs esp if assoc with sex
- usafe sex practices
- anonymous sex partnering
- sex workers/their clients
- street involvement/homelessness
- time in a detention facility
- experience of sexual assault/abuse
What is the most common symptom of rectal and pharyngeal gonococcal infections?
-often asymptomatic
When and how do you test for chlamydia?
WHEN TO TEST
- if have risk factors
- q6 months after infection if RF persists
- 3-4 weeks post tx if prepurbertal or if post pubertal and compliance uncertain or is pregnant
HOW TO TEST
- NAAT (nucleic acid amplification test) via first-catch void (can’t have voided in 2 hrs prior), vaginal, endocervical or urethral specimens
- need culture of cervix or urethra for medico-legal purposes
When and how do you test for gonorrhoea?
WHEN TO TEST
- risk factors
- 6 months after infection
- test of cure at 3-7 days if prepubertal or if use 2nd line tx, adolescent is pregnant, previous tx failure, pharyngeal infection, high re-exposure risk or symptoms persist
HOW TO TEST
- NAAT via first catch void, urethral and cervical samples
- should do Cx if possible b/c increasing abx resistance
- do Cx if:
- sexual abuse of child is suspected
- sexual assault cases
- tx failure presumed
- Pelvic inflammatory disease
- symptomatic MSM
- suspect acquired infection overseas or area with known resistance
When and how do you test for syphilis?
WHEN TO TEST
- if pregnant (ideally early on and at delivery)
- repeat RPR after treatment at 1, 3, 6 and 12 months post tx
- repeat RPR at 12 and 24 months in latent cases
HOW TO TEST
- Enzyme immunoassays is the best, if is positive need a second confirmatory test
- Rapid plasma reagin (RPR) but can be falsely negative early on
How do you treat gonococcal infection in children and youth?
If over 9 years use max adult doses
Cefritaxone 50mg/kg IM (max 250mg) PLUS Azithro 20 mg/kg (max 1g) PO x1
OR
Cefixime 8mg/kg PO bid x 2 doses (max 400 mg per dose or 800mg x1 if >9 years) PLUS Azithro
- *if pharyngeal do not use Cefixime, use Ceftriaxone PLUS Azithro
- **Always tx for both gonorrhoea and chlamydia even if test negative for chlamydia
Name some primary (3) and secondary (2) prevention strategies for STIs?
PRIMARY
- vaccinate against Hep B and HPV
- condom use
- behavioural change
SECONDARY
- partner notification
- tx and screening for STIs in asymptomatic young adults
What bacteria causes Lyme disease?
Borrelia burgdorferi
How is Lyme transmitted?
- via black-legged ticks (Ixodes scapulars and Ixodes pacific us) that live on mice, rodents, small mammals, birds, white-tailed deer, humans
- ticks can’t jump/fly
- wait on tall grass and attach when a host brushes past them
- immature ticks (nymphs) cause the most infections due to small size so ppl don’t see them
What is the peak incidence for lyme?
kids 5-9 yrs and adults 55-59 yrs
How long does a tick feed on its host?
5 days or more
After how long of being attached are you likely to get Lyme?
if remove within 24-36h of its feeding you are likely to prevent lyme disease
What do you need to do if a patient is dx with lyme disease?
Need to report it to public health
What are the clinical manifestations of lyme disease?
EARLY LOCALIZED
- erythema migrans (rash at site of tick bite…bullseye) usually after 7-14 days after the bite, macule or papule that expands centrifugally can have central clearing, can be flat or raise, usually >5cm diameter; usually painless, not pruritic; resolves in 4 wks
- can get fever, malaise, h/a, myalgia, arthralgia, neck stiffness
- can also have no rash
EARLY DISSEMINATED
- multiple EM lesions (usually several weeks after the bite, secondary annular erythematous lesions but smaller than the primary) - represents spirochetemia
- acute neurological signs (facial nerve palsy, papilledema, lymphocytic meningitis)
- lyme carditis (rare in kids)
LATE DISEASE
- rare if treated with abx
- pauciarticular arthritis affecting large joints (esp knees); can be weeks to months after tick bite, can happen without hx of earlier illness
- peripheral neuropathy and CNS manifestations
How do you diagnose early localized lyme? early disseminated and late disease?
EARLY LOCALIZED
- clinically + hx of potential tick exposure in area where there are suspected black-legged ticks
- antibodies often not detectable in first 4 weeks of infection
- all clinical manifestations of possible lyme (except EM) need lab confirmation
EARLY DISSEMINATED AND LATE DISEASE
- ELISA screening test then confirmatory Western blot
- most affected ppl have antibodies against B burgdorferi
- some ppl treated early with abx for early Lyme will never develop antibodies –> they are cured :)
- if have lyme meningitis intrathecal IgM or IgG might be helpful
How do you treat lyme disease?
Doxycycline if >8 yrs 4mg/kg/day divided bid
Amoxil if
What is the natural course of lyme arthritis?
- 1/3 have resideual synovitis and joint swelling which almost always resolves
- if persistent or recurrent joint swelling after tx then tx for another 4 wks
- if arthritis ongoing then consult an expert
What is the Jarisch-Herxheimer reaction in lyme disease? How do you treat it?
-fever, h/a, myalgia and an aggravated clinical picture lasting
What is post-treatment lyme disease syndrome and how common is it? How do you treat it?
- 10-20% of pts
- lingering fatigue, joint and muscle aches that last longer than 6 months
- NO benefits in giving long-term abx treatments
How do you remove a tick?
- fine-tipped tweezers
- pull upward with steady, even pressure
- do not twist or jerk
- if mouthpart breaks off and you cannot remove it easily, leave it in the skin
- clean the bit and hands with alcohol, iodine or soap and water
- keep the tick and bring to medical appointment if develop symptoms
How can we prevent lyme disease?
- landscaping
- 20-30% deet or icaridin repellents on clothes and exposed skin
- do full body check daily for ticks
- shower/bathe within 2 hrs of being outdoors
Should you treat a pt who has been exposed to a tick?
No consensus
Some say give a single dose of doxy if >8yrs within 72 hrs
Consider this if in a known endemic area
-no data for recommending amoxil to younger kids
What is the pathophysiology of acute otitis externa (aka swimmer’s ear)?
1) impaired local defense mechanisms due to prolonged ear canal wetness
2) desquamation causing microscopic fissures
3) entry of infecting organisms
What are risk factors for acute otitis externa?
- swimming
- trauma
- foreign body
- hearing aid
- certain dermatologic conditions
- chronic otorrhea
- wearing tight head scarves
- being immunocompromised
How does acute otitis externa present in terms of symptoms?
- otalgia
- itching
- fullness
- may have hearing loss
- ear canal pain when chewing
What is the distinguishing physical exam sign classic for acute otitis externa?
- tenderness of tragus when pushed
- tenderness of pinna when pulled