Tag: vaccination

Measles in 2025: What Patients and Providers Need to Know

On By Dr. Scott RennieIn Infectious DiseaseLeave a comment

The 2025 measles outbreak was one of the most concerning we’d seen in more than a decade. As of March 2025, Texas alone had reported almost 200 confirmed cases, the highest in years. Other states, including New Mexico, Georgia, Kentucky, New Jersey, New York, Pennsylvania, Rhode Island, Washington, California, and Florida, were seeing rising numbers too. Most of those infected were younger than 19, and 95 percent had either not been vaccinated or had an unknown vaccine status. Roughly one in five patients had needed hospitalization by that point. Tragically, one unvaccinated child in Texas had died.

Lower vaccination rates in some communities made it easier for the virus to spread at the time. Clinicians need to stay alert regardless: a cough, fever, and rash in an area with known cases should still raise immediate suspicion for measles.

What Measles Is

Measles is caused by the measles virus, part of the Morbillivirus family. It’s a single-stranded RNA virus that first infects the respiratory tract, then spreads throughout the body.

How It Spreads

The virus is extremely contagious. When someone coughs or sneezes, droplets can hang in the air for up to two hours, and touching a contaminated surface, then your eyes, nose, or mouth, can spread it just as easily.

If someone is exposed and not immune, nine out of ten will get sick. People with measles can spread the virus four days before the rash starts and four days after. That’s one reason outbreaks move so quickly.

The infectiousness of a virus is often measured by R0. For measles, in an unvaccinated community, R0 runs between 12 and 18, meaning one person can spread it to 12 to 18 others, a transmission rate high enough that public health teams treat a single confirmed case as urgent rather than waiting to see if it spreads further. Get 95 percent of a community vaccinated and R0 drops to about 1, which usually stops an outbreak in its tracks.

Symptoms

The illness follows a predictable pattern. Fever first. Then the rash.

About 7 to 21 days after exposure, early symptoms show up: high fever, cough, runny nose, red and watery eyes. Two or three days later, tiny white spots called Koplik spots can appear inside the mouth. By days 3 to 5 of illness, a red rash spreads from the face and hairline down the body, sometimes raised in the center, often with the fever spiking again at the same time.

Why It’s Serious

Complications are common. Pneumonia is the leading cause of death from measles. About one in a thousand people develops encephalitis, or brain inflammation, which can cause seizures or permanent damage. Severe diarrhea can cause dehydration. In rare cases, blindness or hearing loss occur.

There’s also a delayed complication called subacute sclerosing panencephalitis, a chronic infection of the central nervous system that shows up 6 to 8 years after measles. Symptoms include weakness, tremors, difficulty walking, and eventually coma. It is progressive and untreatable.

Infants, pregnant patients, and people with weak immune systems are at highest risk.

Diagnosis and Treatment

Diagnosis is usually confirmed by blood testing for IgM antibodies, which indicate recent infection. Respiratory swabs from the nose and throat can also detect measles RNA by PCR testing. Sometimes urine is tested as well.

There is no direct antiviral therapy. Treatment is supportive: keeping patients hydrated, managing fever and discomfort with acetaminophen or ibuprofen, and in children, supplementing with vitamin A. The virus lowers vitamin A levels in the body, and supplementing helps reduce the risk of severe complications.

What To Do if Someone Gets Measles

Isolation is critical. A patient should stay isolated for at least four days after the rash appears. Family and close contacts should be alerted. Post-exposure prophylaxis is an option for people who are unvaccinated or whose immunity is uncertain. The MMR vaccine may help if given within 72 hours of exposure. If that’s not possible, immune globulin (IVIG) within 6 days is another option, though the two should not be given together.

Complications need close monitoring. Breathing trouble, high fever that does not improve, or neurological symptoms should trigger immediate medical evaluation.

Prevention

The MMR vaccine is the most effective protection we have. Two doses run about 97 percent effective. Children should get their first dose at 12 to 15 months and the second between ages 4 and 6. Adults without immunity should receive at least one dose, and during outbreaks, infants as young as 6 months may be vaccinated early.

Vaccination protects the person who gets it. It also protects those who can’t get vaccinated themselves, including babies too young for the series and patients with immune conditions that rule out live vaccines. Stopping an outbreak for good takes at least 95 percent community coverage.

Closing

The 2025 measles outbreak showed how quickly this virus can return when vaccination coverage drops. Recognizing symptoms early, isolating cases, and vaccinating remain the keys to controlling it. As healthcare providers, we need to keep talking with patients about the value of the MMR vaccine and stay proactive about reporting and diagnosing cases.

For more information, visit the CDC’s measles page.

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Scott Rennie, D.O.
Board Certified in Obesity Medicine and Family Medicine

This blog is for educational purposes only and does not constitute individual medical advice. Always consult your own physician before making changes to your health, medications, or treatment plan.

Sources

Is Pertussis Contagious? Symptoms and Treatment Explained

On By Dr. Scott RennieIn Infectious DiseaseLeave a comment

Pertussis, or whooping cough, made a comeback in 2024. Outbreaks were reported in different regions around the world, and the United States was no exception, with cases rising for several years running despite decades of vaccination effort, and in 2024 there were more than 35,000 reported cases, higher than what we’d typically seen over the prior decade. Some of that traces to waning vaccine immunity, incomplete vaccine schedules, and vaccine hesitancy. Schools were a particular hotspot, especially among older children and adolescents who had missed boosters.

This isn’t a new story. In the early 20th century, pertussis was one of the leading causes of death in children. In the 1920s and 1930s, hundreds of thousands of cases occurred every year in the U.S., and fatality rates in infants sometimes reached 5 to 10 percent. Families often saw multiple children get sick at the same time. Hospitals had few tools to help. No antibiotics. No vaccines. Isolation was the only real measure available, and it wasn’t enough.

The arrival of the first whole-cell vaccine in the 1940s changed the picture, and by the 1950s and 60s, pertussis cases had dropped by more than 90 percent. It went from a routine killer to something most doctors rarely saw. But the drop didn’t mean it disappeared; over time, as immunity fades and vaccine uptake slips, the disease resurfaces.

What Pertussis Does in the Body

The cause is Bordetella pertussis, a gram-negative bacterium discovered in 1906. It attaches to the airway lining using adhesion proteins and releases toxins that damage the respiratory tract and disrupt the immune response. Pertussis toxin, adenylate cyclase toxin, and tracheal cytotoxin are some of the key players, and together they paralyze cilia, create thick mucus, and inflame the airways. That’s what sets up the violent coughing fits and the difficulty clearing secretions.

The incubation period is usually 5 to 10 days but can stretch out to 3 weeks, and transmission is mainly through droplets when people cough, sneeze, or talk, though it can also spread indirectly through contaminated surfaces.

The Course of Illness

Pertussis has three stages. The first, the catarrhal stage, looks a lot like a cold. Patients may have mild cough, runny nose, and low-grade fever. But this is also the most contagious stage, and infants in this stage can suddenly stop breathing or develop pneumonia.

After one to two weeks, the paroxysmal stage begins, the coughing fits severe, sometimes so prolonged that patients vomit or become exhausted. The classic “whoop” happens when the patient forcefully inhales after running out of breath. This stage can last weeks.

Finally comes the convalescent stage. Symptoms ease, but the cough may linger for months, and infants are at the highest risk of complications throughout, including pneumonia, seizures, and encephalopathy.

How Long People Are Contagious

Without treatment, a person with pertussis can remain infectious for weeks, often up to three weeks into the paroxysmal stage. With antibiotics, contagiousness drops significantly after five days of therapy.

Diagnosing Pertussis

Clinical suspicion is usually the first step. The cough pattern and exposure history often give it away. PCR testing is the most rapid and sensitive diagnostic method now, while culture is still considered the gold standard, though rarely used because it takes longer and needs special media. Serology may help later in the illness.

Treatment and Timing

Macrolides like azithromycin are first-line treatment, with trimethoprim-sulfamethoxazole an option if macrolides can’t be used. Antibiotics are most effective early, ideally in the catarrhal stage, but they’re still useful later to limit spread.

The CDC recommends treating patients within three weeks of cough onset if they’re over a year old, within six weeks for infants under one, and also within six weeks for pregnant women close to delivery. Supportive care, hydration, rest, and monitoring, is especially important for infants, who may need hospitalization.

Post-Exposure Prophylaxis

Preventing spread matters just as much as treating active cases, and giving antibiotics to close contacts can stop the chain. This is particularly recommended for infants under 12 months, pregnant women in their third trimester, and household members or healthcare workers exposed to confirmed cases. Timing matters: post-exposure prophylaxis should start within 21 days of exposure.

Prevention and Vaccination

Vaccination is still the strongest defense. The childhood DTaP series provides good protection early on, though immunity fades over time. About 98 percent of children are immune one year after their last DTaP dose, but that drops to around 70 percent five years later. That’s why boosters are needed.

The Tdap booster is given at 11 or 12 years of age, again in adulthood every 10 years, and during each pregnancy between 27 and 36 weeks. Protection from Tdap is estimated at about 73 percent in the first year and 34 percent after four years. This waning immunity is a major factor in outbreaks.

Public health responses focus on quick recognition, isolation of cases, prophylaxis for contacts, and community education, and mask use, hand hygiene, and cleaning surfaces all help reduce spread.

Why Vigilance Matters

Pertussis is not a disease of the past. It’s resurging in part because immunity doesn’t last forever, and physicians need to recognize it early and treat aggressively, while patients and families need to keep vaccination schedules up to date. When that doesn’t happen, infants and medically fragile patients pay the highest price.

—

Scott Rennie, D.O.
Board Certified in Obesity Medicine and Family Medicine

This blog is for educational purposes only and does not constitute individual medical advice. Always consult your own physician before making changes to your health, medications, or treatment plan.

Sources

  • Centers for Disease Control and Prevention. Pertussis (Whooping Cough). https://www.cdc.gov/pertussis
  • Cherry JD. The science and fiction of the “resurgence” of pertussis. Pediatrics. 2003;112(2):405-406. PMID 12897292.
  • American Academy of Pediatrics. Red Book: 2021–2024 Report of the Committee on Infectious Diseases.
  • Clark TA. Changing pertussis epidemiology: Everything old is new again. J Infect Dis. 2014;209(7):978-981. PMID 24626532.