under the microscope
under the microscope
By Rodney E . Rohde , PhD , MS , SM ( ASCP ) CM , SVCM , MBCM , FACSc
Measles Once Again ?
Measles is caused by the measles virus , a single-stranded , negative-sense , enveloped RNA virus of the genus Morbillivirus within the family Paramyxoviridae . Unfortunately , a resurgence of this dangerous virus is occurring in pockets of states around the country . It is a highly contagious , vaccine-preventable infectious disease . For most countries , the recommendation is that children be immunized against measles at 12 months , generally as part of a three-part MMR vaccine ( measles , mumps , and rubella ). Waiting until an infant is 12 months old is necessary due to their immune system not adequately responding to the vaccine due to immaturity . Further , children between the ages of four and five are given a second dose of the to increase rates of immunity .
Due to these ongoing public health concerns , the CDC has asked that before one is going to travel internationally , to make sure you ’ re protected against measles . The best way to protect yourself and others from measles is via vaccination . You should plan to be fully vaccinated at least two weeks prior to departure .”
U . S . Measles Outbreak
According to the Centers for Disease Control and Prevention ( CDC ), as of March 22 , 2024 , a total of at least 58 cases were reported by 17 jurisdictions : Arizona , California , Florida , Georgia , Illinois , Indiana , Louisiana , Maryland , Michigan , Minnesota , Missouri , New Jersey , New York City , Ohio , Pennsylvania , Virginia , and Washington . Measles was declared eliminated from the United States in 2000 which means the disease is no longer constantly present in this country . If a measles outbreak continues for a year or more , the U . S . could lose its measles elimination status . Healthcare officials should be aware of possible measles cases .
Measles cases usually occur when unvaccinated or under vaccinated citizens from the United States travel abroad and then transmit the infection ( disease ) to other individuals who are not vaccinated or have no immunity to measles . During this most recent outbreak over the past several weeks , the increased number of imported measles cases is mirroring the rise in global cases of measles and the growing global threat from this dangerous pathogen .
Due to these ongoing public health concerns , the CDC has asked that before one is going to travel internationally , to make sure you ’ re protected against measles . The best way to protect yourself and others from measles is via vaccination . You should plan to be fully vaccinated at least two weeks prior to departure . However , even if your trip is less than two weeks away and you ’ re not protected against measles , you should still get a dose of the measles-mumps-rubella ( MMR ) vaccine . The MMR vaccine protects against all three diseases .
● Two doses of MMR vaccine provide 97 percent protection against measles .
● One dose provides 93 percent protection .
Transmission As an airborne agent , the virus spreads easily from one person to the next through the coughs and sneezes of infected people . Measles resides in the nose and throat mucus of an infected person , so it is perfectly positioned to spread to others via respiratory droplets . If other people breathe the contaminated air or touch the infected surface , then touch their eyes , noses , or mouths , they can become infected .
The CDC states that measles is so contagious that if one person has it , up to 9 out of 10 people around him or her will also become infected without protection . An infected individual can transmit measles to others from four days prior through four days post time of the typical rash appearance . The viability of measles for up to two hours in an airspace after an infected person leaves an area is possible . The virus poses a threat to those who are pregnant and not immunized for the developing fetus .
Humans are the sole reservoir of the virus ; animals do not get or spread measles . Interestingly and important , this characteristic makes measles theoretically an obvious pathogen for eradication via vaccination much like that of smallpox .
Signs and Symptoms Symptoms from an infection usually appear one to two weeks after virus contact and usually include high fever , cough , runny nose , and watery eyes . Measles rash appears three to five days after the first symptoms . This isn ’ t a typical rash , and it can be dangerous , especially for babies and young children . Classic symptoms include a four-day fever ( the four Ds ) and the 3 Cs — cough , coryza ( head cold , fever , sneezing ), and conjunctivitis ( red eyes )— along with a maculopapular rash .
Koplik spots , which appear as tiny white spots , may appear inside the mouth two to three days after symptoms begin . Then , three to five days after symptoms begin , a rash breaks out . It usually begins as on the face as flat red spots just on the hairline and spread downward to the neck , trunk , arms , legs , and feet . One may see small , raised bumps on top of the flat red spots and the spots may coalesce as they spread . Finally , one ’ s fever can spike to 104 degrees Fahrenheit with the rash appearing .
Measles can be serious . Children younger than 5 years of age and adults older than 20 years of age are more likely to suffer from complications . These complications may be rare but in the case of subacute sclerosing panencephalitis ( SSPE ), a fatal disease of the central nervous system that results from a measles virus infection acquired earlier in life can occur .
If one suspects a measles infection , a physician should be consulted . Laboratory diagnosis of measles can be done with confirmation of positive measles IgM antibodies or detection of measles virus RNA from throat , nasal or urine specimen by using the reverse transcription polymerase chain reaction ( RT-PCR ) assay . RT-PCR is particularly useful to confirm inconclusive IgM antibody results .
For more information on this infection , see Measles [ Rubeola ] via the CDC .
Rodney E . Rohde , PhD , MS , SM ( ASCP ) CM , SVCM , MBCM , FACSc , is the Regents ’ Professor , Texas State University System ; University Distinguished Chair & Professor , Clinical Laboratory Science ( CLS ); TEDx Speaker & Global Fellow – Global Citizenship Alliance ; Texas State Honorary Professor of International Studies ; Associate Director , Translational Health Research Initiative ; Past President , Texas Association for CLS .
8 • www . healthcarehygienemagazine . com • april 2024