Whooping Cough (Pertussis) Facts
Whooping cough is an infectious bacterial illness that affects the respiratory passages. First described in the 1640s, whooping cough is so named because spasms of coughing are punctuated by a characteristic "whoop" sound when the child inhales deeply after a coughing spell.
- Whooping cough is one of the most common vaccine-preventable diseases among children younger than 5 years of age in the United States. It is also known as pertussis -- the "P" in the familiar DTaP combination inoculation routinely given to children and the "p" in Tdap given to adolescents and adults.
- Despite the widespread use of vaccines, whooping cough has made a comeback in recent years. According to the U.S. Centers for Disease Control and Prevention (CDC), prior to the introduction of the pertussis vaccine, there were an average of 175,000 cases of whooping cough each year. This dropped off to fewer than 3,000 cases per year in the 1980s. There has been a recent resurgence in the U.S., with a total of 48,277 cases of pertussis reported in 2012, 24,231 cases in 2013, and 32,971 cases in 2014.
- The World Health Organization estimates there were 195,000 deaths from whooping cough worldwide in 2008 and 139,382 reported deaths in 2011, making this easy-to-prevent disease one of the leading causes of illness and death.
- The prevalence of whooping cough in infants and children is increasing. Most deaths from pertussis occur among infants under 3 months of age. The incidence rate of pertussis among infants is greater than all other age groups. The second highest rates of whooping cough are seen in children 7 to 10 years of age.
- A pertussis epidemic arose in June 2014 in California, and as of November 26, 2014, 9,935 cases of pertussis were reported to the California Department of Public Health.
- States that reported pertussis epidemics in 2012 include Washington (4,783 reported cases), Vermont (632 reported cases), Minnesota (4,433 reported cases), Wisconsin (5,923 reported cases), and Colorado (1,510 cases).
What causes whooping cough?
Whooping cough is caused by the bacteria Bordetella pertussis. Humans are the only known reservoir for these bacteria. (That means it can only thrive and multiply in humans.)
- Whooping cough is spread by contact with droplets coughed out by someone with the disease or by contact with recently contaminated hard surfaces upon which the droplets landed. The bacteria thrive in the respiratory passages where they produce toxins that damage the tiny hairs (cilia) that are needed to remove particulate matter and cellular debris that are normally introduced into the airways with each breath. This results in an increased inflammation of the respiratory passages and the typical dry cough which is the hallmark of the infection. Whooping cough is contagious from seven days after exposure to the bacteria and up to three weeks after the onset of coughing spasms. The most contagious time is during the first stage of the illness.
- Initially thought to be a disease of childhood, studies have shown that adults are susceptible to whooping cough and account for up to 25% of cases. The disease tends to be milder in adults and adolescents -- a persistent cough much like an upper respiratory infection or cold. Because of this fine distinction, the diagnosis of whooping cough is frequently missed in that population and thus allows the bacteria to spread to more susceptible infants and children.
- Whooping cough is highly contagious. Between 75%-100% of unimmunized household contacts of a person with pertussis will develop the disease. Even among fully immunized and naturally immunized people living in the same household, there have been reports of undetectable infection following extreme exposure.
Whooping Cough and Pertussis
Is Whooping Cough Contagious?
Pertussis Is Highly Contagious
Bordetella pertussis is considered an atypical bacterium that does not enter the bloodstream. It stays in the upper airways and interferes with the body's ability to clear airway secretions by infecting the cells needed for this function. It spreads easily from person to person and can often be mistaken for the common cold in the early phases of infection.
What are the symptoms and signs of whooping cough?
The course of whooping cough is divided into three stages.
- The first stage of whooping cough is the catarrhal (runny nose) stage. This phase typically lasts for one to two weeks. Symptoms during this phase resemble that of an upper respiratory illness: runny nose, nasal congestion, sneezing, and occasional cough. A low-grade fever may be present in some cases. It is only during this stage that progression of whooping cough can be halted by antibiotics.
- The second stage of whooping cough is the paroxysmal stage. The duration of this phase is highly variable, lasting from one to 10 weeks. It is characterized by intense and drawn out bouts of coughing. The attacks tend to be more frequent at night, with an average of 15 attacks in a 24-hour period. Often a "whoop" can be heard caused by the gasping person inhaling between coughs. (Barking coughs usually indicate a viral infection and are not indicative of whooping cough). Newborn babies and infants, in particular, may appear to stop breathing and perhaps turn blue during the coughing spasms. Vomiting or choking is also common during this stage as well.
- The third stage of whooping cough is the convalescent stage. This can last for weeks or months and is characterized by a chronic cough that becomes less paroxysmal (fewer sudden outbursts of coughing) in nature.
When should I seek medical care for whooping cough?
When to call the doctor
- If you suspect you or your child has whooping cough
- If your child has been exposed to someone with whooping cough, regardless of whether the child has received immunization shots
- If your child has a fever that cannot be controlled with over-the-counter medication
- If your child is unable to keep solids and liquids down (vomits)
When to go to the hospital
- If your child stops breathing, call 911 emergency services and begin CPR.
- If your child turns blue during a coughing spell
- Go to a hospital's emergency department if someone with whooping cough shows these symptoms:
- Inability to tolerate liquids (vomiting)
- Uncontrolled fever even with anti-fever medications
- Signs of respiratory distress including rapid breathing and turning blue
- Signs of dehydration, including weight loss, dry mucous membranes, or decreased urine output
How is whooping cough diagnosed?
The best way to diagnose whooping cough is by confirming the presence of the specific disease-causing bacteria Bordetella pertussis in mucus taken from the nose and throat.
- Because the growth of the bacteria is inhibited by cotton, swabs made from special material, either calcium alginate or Dacron, must be used in obtaining the sample. Studies have shown that cultures are more likely to be positive if the sample is collected during the first stage of the illness or early in the second. The likelihood for isolating the organism (and confirming the diagnosis) declines with any delay in specimen collection beyond the first three weeks of illness. A culture for Bordetella pertussis is usually negative after five days of treatment with antibiotics.
- Other laboratory methods used to diagnose pertussis infection such as serologic testing and PCR are available in certain labs. Neither method has been shown to be more specific than culture isolation of the organism.
- A complete blood count (CBC) may be performed.
Self-Care at Home for Whooping Cough
Because younger children are at higher risk to develop a severe case of whooping cough than adults, many may be admitted to the hospital.
For children and adults who do not require hospitalization, here are some tips to manage the disease at home after a doctor has diagnosed whooping cough.
- Isolate the person as much as possible (for example, a separate bedroom) until he or she has received five days of antibiotics. If possible, everyone who comes into contact with the sick person should wear a surgical mask to cover their face. Sometimes close contacts of an individual diagnosed with whooping cough may be prescribed antibiotics to prevent transmission of the bacteria.
- Practice good hand washing. Whooping cough bacteria can be transmitted through contact with contaminated inanimate objects such as dishes.
- Drink plenty of fluids, including water, juices, soups, and eat fruits to prevent dehydration.
- Eat small, frequent meals to decrease the amount of vomiting.
- Use a cool-mist vaporizer to help loosen secretions and soothe the cough.
- Keep the home environment free from irritants that can trigger coughing, such as smoke, aerosols, and fumes.
- Monitor a sick child for signs of dehydration, such as dry lips and tongue, dry skin, decrease in the amount of urine or wet diapers, and crying without producing tears. Report any signs of dehydration to your doctor immediately.
- Do not give cough medications or other home remedies unless otherwise instructed by your doctor.
Whooping Cough Treatment
Antibiotics are used to lessen the severity of whooping cough and make the person taking them noncontagious. Antibiotics are most effective if given early in the first phase of the illness.
The Sanford Guide to Antimicrobial Therapy recommends the following antibiotic treatments: a
five-day course of azithromycin, a seven-day course of clarithromycin, or a 14-day course of either erythromycin or
- Some strains of whooping cough are resistant to certain antibiotics. Symptoms
may worsen if this is the case.
- In addition to treating the adult or child who has whooping cough, everyone in the household should be treated prophylactically with antibiotics.
- All close contacts younger than 7 years of age who have not completed their primary vaccinations (including the DTaP to prevent pertussis) should complete this series with the minimum time between shots.
- Close contacts younger than 7 years of age who have completed their primary series but have not received a booster of DTaP within
three years of exposure should be given the booster dose.
- Exposed adults should be vaccinated with Tdap (see the "Prevention" section below).
- Anyone with whooping cough should be isolated for five days after starting antibiotics or until
three weeks after the onset of the coughing spasms if the person has not received antibiotic treatment.
Whooping Cough Follow-up
Schools and day-care facilities should be notified of whooping cough illnesses. Children who later develop a cough should be evaluated by their doctors. Children younger than 7 years of age who attend the school or day care and are behind in their vaccinations should receive them.
- School-wide treatment with antibiotics is not currently recommended.
- Children with mild cases of whooping cough may return to school or day care after receiving antibiotics for at least five days.
Whooping Cough Prevention (Pertussis Vaccine)
- Risk factors for getting whooping cough include exposure to an infected person's cough or sneeze or touching surfaces used by an infected person. Both frequent hand washing and the use of masks will help lessen the likelihood that the bacteria will spread to other members of a household where someone has whooping cough. Also avoid touching your nose or mouth and introducing the bacteria you may have picked up during outbreaks.
- For children, follow the recommended vaccine schedule for the DTaP (diphtheria, tetanus, pertussis) inoculations. Shots are given at the ages of 2 months, 4 months, 6 months, 15-18 months, and 4-6 years of age for full immunity, according to the American Academy of Pediatrics; however, vaccine immunity generally wanes after six to 10 years and does not result in permanent immunity, which is why a pertussis booster shot is needed.
- In 2005, the U.S. government approved Tdap, the first pertussis booster shot for children 10-18 years of age. The Advisory Committee on Immunization Practices (ACIP) of the Centers for Disease Control recommends one dose of Tdap in place of one Td booster.
- For adults 19 and older, the ACIP recommends a single dose of Tdap.
- If you have never received a dose of Tdap, one dose of Tdap should replace one dose of Td for booster immunization if the most recent tetanus toxoid-containing vaccine was received at least 10 years earlier.
- Adults over 19 years of age in close contact with, or anticipating contact with, infants aged 12 months or younger or with pregnant women, who have not previously received Tdap should receive a dose of Tdap; an interval as short as two years since the most recent Td is suggested.
- Health-care personnel in settings with direct patient contact who have not previously received Tdap should receive a dose of Tdap; an interval as short as two years since the most recent Td is recommended.
- The CDC recommends pregnant women receive Tdap before pregnancy. Recommendations in 2011 from the CDC add that pregnant women who have not been previously vaccinated with Tdap should get one dose of Tdap during the third trimester or late second trimester -- or immediately postpartum, before leaving the hospital or birthing center.
- The vaccine side effects are mild but can include tenderness, redness, or a lump at the site of the injection, and fever.
What is the prognosis for whooping cough?
Complications of whooping cough are most commonly seen in children younger than 1 year of age, with an increased risk of severe whooping cough in premature infants.
- Between 1999-2003, 17,000 children under 2 years of age diagnosed with whooping cough required hospitalization.
- More than half of infants younger than 1 year of age who get the disease must be hospitalized.
- In 2012, 18 deaths due to whooping cough were reported by the CDC; the majority of them were infants under 3 months of age.
- Bacterial pneumonia is the most common complication of whooping cough. It is also the most common cause of pertussis-related deaths. The CDC estimates about one in five infants with pertussis get pneumonia (lung infection).
- Other complications include bluish skin from lack of oxygen, collapse of a lung, sinusitis, otitis media (ear infection), dehydration, nosebleed, bruising, hernias, retinal detachment, rectal prolapse, seizures, diseases of the brain, and failure to thrive.