measles virus case study
TRANSCRIPT
Measles: Case StudyHiro LandazuriKarla GonzalezJonathan Chen
Case
• An 18 yr old freshman complained of a cough, runny nose, and conjunctivitis. The physician in the campus health center noticed small white lesions inside the patient’s mouth. The next day, a confluent red rash covered his face and neck.
Overview
• Rubeola• Paramyxovirus -
Morbillivirus• Negative-sense
ssRNA• F (fusion) protein/H
(hemoagglutanin) protein
http://www.cdc.gov/vaccines/vpd-vac/measles/photos.htm
Overview
• Systemic infection– Respiratory transmission– Primary site of infection =
nasopharynx• Primary viremia (2-3 days
post exposure)• Secondary viremia (5-7 days
post exposure)
http://www.homehealth-uk.com/image_01/image/throatdiagram.gif
Physical Diagnosis
• The 3 C’s– Cough, coryza,
conjunctivitis• Koplik’s spots• MV rash
– Maculopapular• Macule – red lesion
flushing• Papule – raised red lesion
dermatlas.med.jhmi.edu
Koplik’s Spots
Conjunctivitis
MV rashhttp://en.wikipedia.org/wiki/Conjunctivitis
http://www.cdc.gov/vaccines/vpd-vac/measles/photos.htm
Laboratory Diagnosis
• Isolation of MV from clinical specimen
• Serodiagnosis
– IgM ab (ELISA)
– IgG ab• ELISA, HI, Indirect flourescent ab test,
microneutralization, plaque reduction neutralization, complement fixation
Complement Fixation AssayPositive Negative
http://web.indstate.edu/thcme/PSP/labtests/complementfix.htm
Treatment
• No treatment• Supportive Care Only
– Tylenol, Non-steroidal anti-inflammatory drugs like Advil, Aspirin, Motrin etc.
– Isolation– Vitamin K– Hydration– Post-exposure Prophylaxis
• Antibiotics for serious complications (rare)Melissa Burnett, MD, Measles, Rubeola, EMedicine from WebMD, http://www.emedicine.com/derm/topic259.htm (Oct. 29, 2007).
When was this patient contagious?
• Course of the infection– Incubation 7-14 days– Initial symptoms immediately following incubation:
cough, coryza, conjunctivitis, fever – Koplik’s spots 2-3 days after initial symptoms– Rash appears 4-5 days after the initial symptoms
• Infection communicable four days before his rash appeared to four days afterMayoClinic.com Tools for Healthier Lives, Measles, http://www.mayoclinic.com/print/measles/DS00331/DSECTION=all&METHOD=print (Oct. 29, 2007).
Melissa Burnett, MD, Measles, Rubeola, EMedicine from WebMD, http://www.emedicine.com/derm/topic259.htm (Oct. 29, 2007).
Why is this disease not common in the United States?
• the United States is a developed country– most children are immunized with MMR (Measles Mumps
Rubella) vaccination– required proof of MMR immunization
• the Measles Initiative is working on standard global immunization for measles
Several possible reasons for patient’s susceptibility to measles at 18 years of age.
• if the patient did not receive MMR vaccinations– allergic reaction to component of MMR
• recent studies have shown no direct correlation
– poor healthcare• undeveloped countries without required MMR
– linking of MMR and autism• studies lacked substantial scientific evidence
• if patient did receive MMR vaccinations– may not have developed immunity
• either way, patient was susceptible to measles and was exposed via– traveling– dorms/college campus