infectious diseae Flashcards
Infectious agent in Lyme disease
Borrelia burgdorferi (Bb), a spirochete, is the causative agent that is carried and transmitted to humans by infected species of deer ticks.
3 Cs o Measles
Cough, coryza, conjunctivitis
first signs of the illness and lasts 4 to 5 days: URI symptoms including a cough, runny nose due to inflammation of the nasal membranes (coryza), and conjunctivitis (the “three C’s” of measles).
-low to moderate fever and Koplik spots (an enanthem found on the oral mucosa opposite the lower molars that are small bluish-white spots on an erythematous background)
-maculopapular rash first appearing behind the ears and on the forehead, moving progressively downward to engulf the entire body, generally appears on the third or fourth day of the illness, and lasts about 1 week.
PPD and vaccinations
Measles vaccination may temporarily suppress tuberculin reactivity. The MMR vaccine may be given after (or even on the same day as) the PPD test. However, since MMR was already administered in this scenario, PPD should be postponed for the next 28 days (4 to 6 weeks). The effects of other live vaccines on PPD is unknown.
influenza symptoms
cough, headache, and sore throat is often an indicator of influenza infection in children. In addition, a sudden onset of high fever is common, as well as chills, coryza, vertigo, and pain in the back and extremities. The cough presents as a dry hacking cough, resembling pertussis.
Acute Rheumatic fever: Jones criteria
The Jones criteria are a set of guidelines used to diagnose acute rheumatic fever, requiring evidence of a recent group A streptococcal infection and either two major manifestations or one major and two minor manifestations of the disease.
Acute Rheumatic Fever
ARF is a nonsuppurative complication following a sequela of streptococcal infection, typically 2 to 3 weeks after group A streptococcal (GAS) pharyngitis. It results in an autoimmune inflammatory process involving the joints (polyarthritis), heart (rheumatic heart disease), CNS ( Sydenham chorea) and subcutaneous tissue (subcutaneous nodules and erythema marginatum). It most commonly presents between the ages of five and 15 years old. Long-term effects on tissues are generally mild except for the damage done to cardiac valves, leaving fibrosis and scarring that results in rheumatic heart disease.
Major manifestations include:
Carditis ( pancarditis, valves, pericardium, myocardium)
Polyarthritis (migratory and painful)
Chorea (uncoordinated jerking movements of face, hands, feet)
Erythema marginatum (nonpruritic rash involving pink rings on torso and limbs)
Subcutaneous nodules
Minor manifestations include:
Clinical fever, polyarthralgia
Laboratory elevated acute phase reactants (ESR or leukocyte count)
Aseptic meningitis findings on CSF and sx
most common cause is viral (not bacterial) infection. Up to 90% of cases are caused by enteroviruses and arboviruses. Symptoms vary, but headache and fever are predominating symptoms. Nuchal rigidity. +kernig
Again, CSF findings include increased lymphocytes, normal glucose concentration, normal or slightly elevated protein, and negative bacterial antigen tests.
Pertussis
B. pertussis generally follows a three-stage pattern:
Catarrhal stage: 1-2 weeks with nonspecific complaints and manifestations of the common cold including low-grade fever, mild but worsening cough, coryza, sneezing. This is the most contagious stage.
Paroxysmal stage: 2-4 weeks with absent or minimal fever, persistent paroxysmal cough ending with an inspiratory whoop, worse at night, with vomiting, cyanosis, sweating, and exhaustion present (especially after coughing)
Convalescent phase: 3 weeks to 6 months; paroxysms become less frequent and less distressing, although the cough may become louder.
Pertussis (whooping cough) is mainly a clinical diagnosis, but a prolonged course of cough along with leukocytosis (not leukopenia) with a marked lymphocytosis supports the diagnosis. Pertussis is known as the “100-day cough” in China.
Polymerase chain reaction (PCR) is the primary diagnostic test used in most commercial and state laboratories for confirmation. Chest x-rays are most often normal or have nonspecific findings, and a majority of cases occur in children younger than 5 years old.
Congenital Rubella
Congenital rubella can be devastating, especially if the mother is infected with the virus in the first trimester.
Physical exam of the infant can reveal an array of potential complications, including cataracts or glaucoma, microphthalmia, hearing loss, intellectual disability, and petechial and purpuric eruptions known as, “blueberry muffin” skin lesions. Congenital heart diseases associated with this condition are pulmonary artery stenosis, PDA, TOF, VSD, and rarely coarctation of the aorta.
Congenital rubella can be associated with thrombocytopenia (not polycythemia vera), and radiolucent (not sclerotic) bone disease.
treatment of Bacterial meningitis <1 mos
Any infant under 1 month of age with a documented fever should undergo laboratory evaluation for sepsis, including blood for complete blood count (CBC) with differential, platelet count and culture, as well as urine for analysis and culture (if infant >72 hours old). CSF is often obtained for protein, glucose, cell count, and culture.
The child should also be admitted for observation until culture results are obtained, or the source of the fever is found and treated. GBS (group B streptococcus) is the leading cause of sepsis in infants from birth to 3 months old. Management includes initiation of antibiotic therapy with a penicillin (usually ampicillin) and an aminoglycoside, often gentamicin, until GBS has been differentiated from other pathogens such as E. coli or Listeria sepsis or other organisms.
AOM causative organisms
S. pneumoniae continues to be the most common bacteria responsible for AOM.
H. influenza is the most common cause of bilateral otitis media, severe inflammation of the tympanic membrane, and otitis-conjunctivitis syndrome.
Rifampin use
Oral rifampin or ciprofloxacin are the antimicrobials of choice for infants and children when treating prophylactically for N. meningitis.
meningococcemia
Blood born bacterial infection with Neisseria Meningitidis
non blanching petechial rash on trunk and lower extremities, purpura, fever, extreme lethargy, ill appearing
-requires immediate attention and antibiotics
-chemoprophylaxis with exposed contacts with Rifampin or Cipro
Treatment of Varicella Zoster VIrus
In typical cases that involve otherwise healthy individuals, treatment is supportive and includes management of itching with antihistamines, acetaminophen for fever, and antistaphylococcal penicillin or cephalosporins for bacterial superinfections.
Intravenous acyclovir is efficacious for IMMUNOCOMPROMISED individuals and for those with severe disease. Oral acyclovir is expensive and is not routinely recommended for most children.
In addition, varicella immune globulin (VZIG) is indicated for high-risk individuals (immunosuppressed, immunocompromised, those with malignancies) within 10 days of exposure, or as soon as possible, because it is not effective after the disease progresses).
community-acquire pneumonia treatment
2mos-3 mos
3mos plus
2 months to 3 months old: If chlamydia is suspected, treat with oral azithromycin for 5 days or erythromycin base or ethyl succinate for 14 days. Hospital admission may be needed depending on clinical presentation.
3 months to 18 years old: Amoxicillin 90 mg/kg/day, divided every 12 hours for 10 days is recommended. If there is a history of non- type I hypersensitivity reaction to penicillin, a second- or third-generation cephalosporin (e.g., cednifir) can be used. If a history of type I hypersensitivity reaction is present, clindamycin can be used.
Hantavirus Pulmonary syndrome
virus carried by rodents and deer mice, feces, saliva, urine aerosolized. Spring and summer months. diagnosed with ELIZA IgG and IgM antibodies. Symptoms: hypotension, pulmonary edema, fever, leukocytosis, thrombocytopenia, proteinuria, hematuria due to hypoxemia/hypotension
rocket mountain spotted fever diagnosis
IHC staining (immunohistochemical staining)
Rickettsial infections cause and diagnosis
arthropod vectors (i.e., fleas, lice, mites, or ticks) during feeding
IHC most available rapid. Most conclusive is Immunofluorescent assay (IFA)
Gonococcal conjunctivitis treatment
IM ceftriaxone given once
if there are extraoccular manifestations: 7 day course of. IM or IV ceftriaxone
Chlamydial conjunctivitis
Systemic azythromycin or erythromycin
