Infectious Disease and Immunizations Flashcards
Vaccine adverse events/side effects
- MMR, varicella zoster, influenza, hepatitis B, meningococcal, and tetanus-containing vaccines are linked to anaphylaxis
- Vaccines injections can cause syncope, fainting, deltoid bursitis, shoulder pain, and loss of shoulder motion
- After MMR, febrile seizures and measles inclusion body encephalitis in immunocompromised children can occur within a year of vaccination
- Varicella zoster vaccine has a causal relationship to some adverse events (Chickenpox rash; pneumonia, meningitis, and hepatitis in children with immunodeficiencies; viral reactivation leading to meningitis or encephalitis)
There is no substantiated evidence of a cause or relationship between vaccines and autism, ADHD, speech/language delays, childhood disintegrative disorder, Asperger syndrome, or Rett syndrome, and type I diabetes
Fever/local reactions within first 24 to 72 hours
General vaccination guidelines
- Doses may be given 4 days prior/later than specified date
- If 2 live virus vaccines are given less than 28 days apart, the vaccine given second should be disregarded; repeat this second vaccine at least four weeks later
- Do not aspirate the syringe before injection
- When multiple vaccines are given on the same extremity, the sites of injection should be at least 1 inch apart
- Use only written, dated records
- Reimmunization of an immune individual is not harmful
- Reduced or divided doses of vaccines should not be given
- In some circumstances, an accelerated schedule is available from the ACIP
- Vaccine failure can occur with improper transport and storage
Contraindications to vaccines
The major vaccine contraindication is anaphylaxis with a prior dose or to a vaccine component
MMR, varicella zoster, influenza, hepatitis B, meningococcal, and tetanus-containing vaccines are linked to anaphylaxis
Anaphylaxis to prior dose, neomycin, polymyxin B, streptomycin - Contraindication to IPV
Pregnancy - Contraindication for HPV
Allergies to vaccines components/yeast - Contraindication for IPV and HepB
Moderate to severe infection - Contraindication for HPV and Hib
History of intussusception or SCID (severe combined immunodeficiency) - Contraindication for RV
CDC vaccine schedule
https://www.cdc.gov/vaccines/schedules/hcp/imz/child-adolescent.html
Inactivated vaccines
DTaP / Tdap
Polio (IPV)
Hib (Most virulent, accounting for pneumonia, bacteremia, meningitis, epiglottitis, septic arthritis, cellulitis, otitis media, purulent pericarditis, and other less common infections, notably in those younger than 4 years of age)
Hepatitis A (two-dose series)
Hepatitis B (premature infant born <2kg, give first dose at 1 month)
HPV (Gardasil-9 given to males and females ages 9-26 years)
Influenza (formulated yearly based on epidemiologic forecasts - annual vaccine starting at 6 months)
Meningococcal
Pneumococcal
Live virus vaccines
An individual with a low T-cell count or a cellular immunodeficiency can be seriously compromised if given a live vaccine
Vaccine timing after reduction or cessation of chemotherapy or administration of an immune globulin varies
- MMR or MMRV
- Measles
- Mumps
- Rubella
- Varicella (localized pain and erythema; may develop maculopapular rash; postexposure prophylaxis should be provided within 10 days of exposure preferably within 96 hours)
- Rotavirus (An estimated 4 out of 5 children are infected with rotavirus before five years old) - is a 2 or 3 dose oral series
- Bacille Calmette-Guerin (BCG) - prevents spread of TB; not commonly used in the US
- Smallpox (Not routinely used in US; reserved for preexposure or postexposure situations)
- FluMist?
Passive immunity
Immunoglobulins
- Reserved for those with immunodeficiencies or who have problems making antibodies
- Given to non-immunized or under-immunized patients exposed to certain infectious diseases
Respiratory Syncytial Virus Prophylaxis - Palivizumab (Synagis)
- Infants born before 29 weeks gestation during RSV season until they are 12 months old
- Children born prematurely at or before 32 weeks who are younger than 2 years old with chronic lung disease (CLD) and who require treatment for their CLD within 6 months of the onset of RSV season; prophylaxis can be given to 2-year-old children with CLD of prematurity who continue to require medical support during the 6 months prior to the onset of RSV season
- Infants up to 12 months old with hemodynamically significant cyanotic or complicated congenital heart disease
- Infants up to 12 months old with neuromuscular disorder or congenital anomalies that compromise clearing of respiratory secretions
Infectious disease clinical findings on physical examination
- Irritability is nonspecific in children
- Stiff/painful neck (meningitis)
- New murmur (endocarditis or rheumatic fever)
- Refusal to walk (deep tissue infection, osteomyelitis, meningitis, or septic arthritis)
- Skin/mucus membrane changes (common in viral illnesses)
Infectious disease diagnostics
CBC:
- WBC: leukocytosis (high WBC) with bacterial infection; leukopenia (low WBC) with viral infection
- Differential: bacterial - increased neutrophil and bands; viral - elevated lymphocyte count
Platelet Count:
- Thrombocytosis (elevated platelets) in active phase of acute infection
CRP:
- Acute-phase reactant; increases in presence of acute inflammation; nonspecific
Procalcitonin:
- Biomarker for differentiating some viral from serious bacterial infections
- Increased in bacteremia; can reflect severity
ESR:
- Acute-phase reactant; nonspecific
- Useful to evaluate therapy when antibiotics used
- Useful in the fever of unknown origin (FUO)
Cultures, stains, antimicrobial susceptibility testing:
- Bacterial, viral, fungal cultures
- Susceptibility to antibiotics on cultures (especially UTI antibiotic choice)
DNA/RNA testing to assess for multiple organisms - PCR: STIs
Immunoserology:
- Detect antibodies to specific infectious organisms
Imaging techniques:
- Diagnosis of infections in bone, sinus, lung, skin, viscera, brain, and heart
- Radiographs, CT, MRI, echocardiography, US
CBC
Elevated WBC (leukocytosis) = bacterial Decreased WBC (leukopenia) = viral
Bacterial = increased neutrophils and elevated bands Viral = elevated lymphocyte counts and/or atypical lymphocyte production
WBC affected by long-term use of certain medications (some can decrease), age, steroid use (can increase), and clinical state (overwhelming sepsis can decrease WBC)
Chronic inflammatory processes can cause decrease in RBCs (anemia)
Platelet Count
Platelets elevated (thrombocytosis) = active phase of acute infection (with elevations in CRP and ESR)
CRP
Increased in the presence of acute inflammation and specific pathogens
Normal = 0.0 - 0.05 mg/dL
Sepsis is much less likely to occur with CRP <10 mg/L
Serial CRPs 24-48 hours after onset of symptoms is recommended
Can help monitor body’s response to treatment
Inflammatory processes (maternal and perinatal factors, trauma, rheumatologic diseases, and oncologic diseases) can elevate CRP
Persistent elevations of CRP = treatment failure and conditions such as adiposity, use of birth control pills, and pregnancy
Procalcitonin
Biomarker that differentiates certain viral infections from serious bacterial infection
Increased in children with bacteremia and reflect the severity of illness
Higher sensitivity and specificity than CRP for predicting pyelonephritis, pneumonia, early-onset sepsis in premature infants, bacterial infection in febrile neutropenic children with cancer, diarrhea associated hemolytic-uremic syndrome, bacterial causes of acute hepatic disease, bacterial versus aseptic meningitis, and various diseases or conditions that involve inflammatory processes
ESR
Measure of inflammation and reflects RBCs settling faster when acute phase proteins (such as fibrinogen) are present in serum than when they are not
Useful in evaluating fever of unknown origin (FUO) and like CRP, can be used to monitor therapy response
Low sedimentation rate (<10 mm/h) = Unlikely in bacterial infection as the cause of prolonged unexplained fever
Viral infections = mean ESR around 22 mm/h
Exception: adenovirus = values higher than 30 mm/h
ESR > 50 mm/h = warrants further evaluation
Respiratory Bacteria and Viruses
-BACTERIA: Hib Neisseria meningitides Group A Strep Streptococcus pneumonia Mycobacterium TB Kingella kingae
- VIRUSES: Adenovirus Coronavirus Influenza A and B Measles Mumps Varicella-zoster Metapneumovirus Parainfluenza Parvovirus B19 Respiratory syncytial virus (RSV) Rhinovirus
Fecal-oral Bacteria and Viruses
-BACTERIA: Campylobacter jejuni Salmonella spp. Shigella spp. Clostridium difficile Aeromonas Plesiomonas E. coli
- VIRUSES: Enteroviruses (genus Klebsiella) Hepatitis A virus Rotavirus Calicivirus Astrovirus Norovirus (Norwalk) Enteric adenovirus
Person-to-person via SKIN CONTACT with bacteria and viruses
-BACTERIA:
Group A strep (GAS)
Staphylococcus aureus
-VIRUSES:
Herpes simplex
Varicella-zoster
Molluscum contagiosum
Contact with blood, urine, or saliva
-VIRUSES: Cytomegalovirus (CMV) Hepatitis B and C Herpes simplex Human immunodeficiency virus (HIV)
Enteroviruses (non-polio)
- Most common cause of aseptic meningitis
- Coxsackievirus B?
- Hand-foot-mouth, herpangina, acute hemorrhagic conjunctivitis
- Primary invasion through G.I. tract
- Transmitted via respiratory route
- Transplacental transmission can occur
Hx: Mild URI; nonspecific febrile illness >3 days; onset within two weeks after delivery
PE:
- Skin: macular, maculopapular, urticarial, vesicular, petechial
- Herpangina (Sudden onset of my fever; vesicular lesions on oropharynx and palate)
- Acute lymphonodular pharyngitis
- Hand-foot-mouth disease (vesicles)
- Aseptic meningitis (fever, stiff neck, headache)
- Pleurodynia (sudden occurrence of lancinating chest pain or abdominal pain attacks)
- Orchitis (similar to mumps)
- Myocarditis/pericarditis (mild to severe)
- Respiratory - wheezing, asthma exacerbation, apnea, distress
Dx: PCR highly sensitive; cultures from throat, stool, CSF, and blood
Diff Dx: viral/bacterial causes
Management: supportive care
Enteroviruses (poliomyelitis)
Asymptomatic illness to severe CNS involvement
Fecal-oral/respiratory transmission
Nonspecific febrile illness, aseptic meningitis, paralytic symptoms
Dx: Viral culture from stool/throat (two samples 24 hours apart)
Management is supportive
Hepatitis A Virus
Causes primary infection in liver
Person-to-person; fecal-oral transmission
Only 30% are symptomatic (Allows for rapid spread)
Clinical findings:
- Preicteric phase - acute febrile illness, malaise, nausea, anorexia, vomiting, digestive complaints, RUQ pain
- Icteric phase - jaundice, dark urine, clay-colored stools, feel sick, poor weight gain an infants
- Complete recovery in 1 to 2 months; occasional relapses up to six months
Dx: serologic testing
Management, complications, prevention:
- Supportive care and good hand hygiene
- Immunoglobulin or HAV vaccine within two weeks of exposure
- Good personal hygiene; safe drinking water
- Routine HAV vaccine
