CH 40 Infections: Viral & Rickettsial Flashcards
Polio
asymptomatic in 90-95%, caused by underlying immune deficiency or partial immunization
Polio signs and symptoms
fever, myalgia, sore throat, headache for 2-6 days that progress to loss of reflexes and flaccid paralysis with sensation remaining intact. May have symptom free days followed by recurrent fever and signs of aseptic meningitis (HA, stiff neck,nuchal rigidity, nausea). Mild cases resolve completely. Paralysis is usually asymmetrical and usually more proximal. Bulbar involvement affects speech, swallowing, cardiac function, and may cause death. Bladder distention and marked constipation. Paralysis resolves when temp normalizes. improvement of muscle paralysis within 6 months
Polio labs
CSF may show lymphocytic pleocytosis and a normal glucose with mildly elevated protein. Easy to differentiate in cell culture. more easily isolated in throat and stool following infection. use PCR
Polio Complications
result of permanent destruction of anterior horn cells and paralysis. Resp (usually causes death), pharyngeal, bladder, bowel malfunction are most critical. Limbs injured during infection (from IM injection, trauma, excessive prior use) are more likely to have provocation paralysis
encephalitis
common severe manifestation of many infections spread by insects.
encephalitis signs and symptoms/diagnosis
fever and headache, diagnosed made clinically during recognized outbreaks and is confirmed with by virus specific serology
encephalitis prevention
control of mosquito vectors and precautions with proper clothing and insect repellents to minimize bites and tick bites.. Exclude herpes encephalitis
West nile virus
flavivirus, most important arbovirus infection in US.
West nile virus
fever, headache, retroorbital pain, nausea, vomiting, lymphadenopathy and a maculopapular rash. More common in those over 50 but may develop in kids.
West nile virus complications
meningitis or encephalitis.
West nile encephalitis in kids (signs and symptoms)
polio like acute flaccid paralysis, movement disorders (parkinsonism, tremor, and myoclonus), brainstem symptoms, polyneuropathy, optic neuritis, muscle weakness, facial palsy, and hyporeflexia. slow recovery
West nile encephalitis diagnosis
best made by detecting IgM antibody (enzyme immunoassay) to the virus in CSF. Will present by 5-6 days after onset using PCR. Antibody rise in serum is also used.
West nile encephalitis treatment
supportive, antivirals and immunoglobulins are being studied. be careful as it can be spread by donated organs, blood, breast milk, and across placenta
Colorado tick fever
endemic in high plains and mountains of central and northern rocky mountains and northern pacific coast of US. Reservoirs are squirrels and chipmunks
Colorado tick fever signs and symptoms
incubation period of 3- 4 days (14 day max). fever begins suddenly with chills, lethargy, headache, ocular pain, myalgia, abdominal pain, nausea and vomiting. may have conjunctivitis. lasts 7-10 days and several patients have biphasic fever (afebrile days in midst of illness)
Colorado tick fever labs
leukopenia, decreased platelets. tested with ELISA using seroconversion. Fluorescent antibody staining will detect virus infected erythrocytes during illness and for weeks after recovery.
Colorado tick fever complications
Meningoencephalitis , cardiac and pulmonary issues
Colorado tick fever prevention and treatment
avoid endemic areas and avoid tick bites. Supportive therapy. Don’s use pain meds that modify platelet function
mumps
paramyxovirus spread by resp route and attacks all unprotected children. Infectious from 2 days prior to and 5 days after onset of parotitis. Incubation of- days
mumps signs and symptoms
fever, severe HA, aches, anorexia, parotid gland swelling, Salivary gland disease (parotid stimulation with sour foods is painful and orifice of Stensen duct may be red and swollen, secretions may be yellow), meningoencephalitis, pancreatitis (epigastric abdominal pain), orchitis, oophoritis (usually unilateral tenderness and swelling), thyroiditis, mastitis, arthritis, presternal edema
mumps labs
leukocyte is normal, mildly elevated protein, slightly decreased glucose. Viral culture or PCR test of saliva, throat, urine, spinal fluid may be positive for one week after onset. Diagnosis with positive IgM antibody and ELISA
mumps complications
nerve deafness (usually unilateral) resulting in inability to hear high tones. Adueductal stenosis and hydrocephalus, myocarditis, transverse myelitis, facial paralysis
mumps treatment
supportive, includes provision of fluids, analgesics, scrotal support for orchitis (corticosteroids)
rabies
acute progressive CNS viral zoonotic infection. Dogs and cats most responsible. History of animal bite 10 days to 1 year previously
rabies signs and symptoms
most occur 3-12 weeks of exposure and may have vague symptoms. Paresthesia at bite site, non specific anxiety, excitabilty, or depression follows then muscle spasms, drooling, hydrophobia, delerium, lethargy. Pharygeal spasms from swallowing or air blown in the face. Seizures, fever, cranial nerve palsies, coma, and death follow within 7-14 days
rabies labs
leukocytosis, CSF usually normal. Cerebral imaging ang EEG not diagnostic. Test brain tissue of animal for antigen. Excreted in saliva of infected humans.
rabies prevention
vaccination, rabies immunoglobulin and diploid cell vaccine
rabies treatment
survival is rare, early diagnosis is important for survival
Rocky Mountain spotted fever
most severe Rickettsia rickettsii. reservoirs: dogs and rodents and large mammals.
Rocky Mountain spotted fever signs and symptoms
incubation period 3-12 days, high fever, abrupt onset, myalgia, severe and persistent HA (retroorbital), toxicity, photophobia, vomiting, abdominal pain, and diarrhea. rash on palms, soles, and extremities (face is spared).
Rocky Mountain spotted fever labs
thrombocytopenia, hyponatremia, early mild leukopenia, proteinuria, mildly abnormal liver function tests, hypoalbuminemia, hematuria, CFS pleocytosis. Diagnosed with indirect fluorescent or latex agglutination antibody methods
Rocky Mountain spotted fever treatment
must be started early. Doxycycline for 10 days
Rocky Mountain spotted fever complications
death resulting from vasculitis, persistent neuro deficits
Q Fever
coxiella burnetil is transmitted by inhalation. Sources: birth tissues and excreta of domestic animals and some rodents
Q Fever signs and symptoms
self limited flu like syndrome (chills, fevere, severe HA, abrupt onset myalgia), abdominal pain, vomiting, chest pain, dry cough, hepatosplenomegaly
Q Fever labs
leukopenia with left shift, elevated aminotransferase and y glutamyl transferase. Diagnosis with four fold rise or single high titer in ELISA.
Q Fever imaging
segemental infiltrates if there is pneumonitis
Q Fever treatment
lasts 1-2 weeks without therapy. treat with doxycyline for 10-4 days. Quinolones also effective.
Q Fever complications
chronic dz: myocarditis, grabulomatous hepatitis, meningoencephalits, endocarditis
