WHOOPING COUGH

 

 

 

 INTRODUCTION:

Whooping cough — or pertussis — is an infection of the respiratory system caused by the bacterium Bordetella pertussis (or B. pertussis). It's characterized by severe coughing spells that end in a "whooping" sound when the person breathes in. Before a vaccine was available, pertussis killed 5,000 to 10,000 people in the United States each year. Now, the pertussis vaccine has reduced the annual number of deaths to less than 30.
But in recent years, the number of cases has started to rise. By 2004, the number of whooping cough cases spiked past 25,000, the highest level it's been since the 1950s. It's mainly affected infants younger than 6 months old before they're adequately protected by immunizations, and kids 11 to 18 years old whose immunity has faded.

Whooping coughis another name for pertussis, an infection of the airways caused by the bacteria Bordetella pertussis. Kids with pertussis will have spells of back-to-back coughs without breathing in between. At the end of the coughing, they'll take a deep breath in that makes a "whooping" sound. Other symptoms of pertussis are a runny nose, sneezing, mild cough, and a low-grade fever.
Although pertussis can happen at any age, it's most severe in infants under 1 year old who did not get the pertussis vaccine. Pertussis is very contagious, so your child should get the pertussis shot at 2 months, 4 months, 6 months, 15 months, and 4-6 years of age. This shot is given as part of the DTaP vaccine (diphtheria, tetanus, acellular pertussis).
The Tdap vaccine (which is similar to DTaP but with lower concentrations of diphtheria and tetanus toxoid for adults) is given to children at 11-12 years and once again in adulthood as a part of one of the tetanus boosters. Adults are recommended to receive this pertussis vaccine since immunity to pertussis lessens over time. By protecting yourself against pertussis, you are also protecting your kids from getting it.
Since pertussis is very contagious, it can spread from person to person through tiny drops of fluid in the air coming from the nose or mouth when people sneeze, cough, or laugh. Others can become infected by inhaling the drops or getting the drops on their hands and then touching their mouths or noses.

What is whooping cough? What is the history of whooping cough?

The disease is named for the characteristic sound produced when affected individuals attempt to inhale; the whoop originates from the inflammation and swelling of the laryngeal structures that vibrate when there is a rapid inflow of air during inspiration. The first outbreaks of whooping cough were described in the 16th century. The bacterium responsible for the infection, Bordetella pertussis, was not identified until 1906. In the prevaccination era (during the 1920s and 30s), there were over 250,000 cases of whooping cough per year in the U.S., with up to 9,000 deaths. In the 1940s, the pertussis vaccine, combined with diphtheria and tetanus toxoids (DTP), was introduced. By 1976, the incidence of whooping cough in the U.S. had decreased by over 99%.
During the 1980s, however, the incidence of whooping cough began to increase and has risen steadily, with epidemics typically occurring every three to five years in the U.S. In the last epidemic, which occurred in 2005, 25,616 cases were reported according to the U.S. Centers for Disease Control and Prevention (CDC). In 2008, over 13,000 cases of whooping cough were reported in the U.S., resulting in 18 deaths.
In 2010, a pertussis epidemic was declared in California. The California Department of Public Health warned in June 2010 that the state was on pace to suffer the most illnesses and deaths due to whooping cough in the past 50 years. In the previous epidemic of 2005, California recorded 3,182 cases and eight deaths.
Unimmunized or incompletely immunized young infants  are particularly vulnerable to the infection and its complications, which can include pneumonia and seizures.

Can whooping cough be prevented with a vaccine?

Whooping cough commonly affects infants and young children  but can be prevented by immunization with pertussis vaccine. Pertussis vaccine is most commonly given in combination with the vaccines for diphtheria and tetanus (Pertussis is the "P" in the DTaP combination inoculation routinely given to children, and the "p" in the Tdap vaccine administered to adolescents and adults.) Since immunity from the pertussis vaccine wears off with time, many teenager sand adults get whooping cough.
For maximum protection against pertussis, children need five DTaP shots. The first three vaccinations are given at 2, 4, and 6 months of age. The fourth vaccination is given between 15 and 18 months of age, and a fifth is given when a child enters school, at 4-6 years of age. Preteens going to the doctor for their regular checkup at 11 or 12 years of age should get a dose of the Tdap booster, and adults who didn't get Tdap as a preteen or teen should get one dose of Tdap. The easiest way for adults to ensure immunity is to get the Tdap vaccine instead of their next regular tetanus booster. (The Td shot is recommended every 10 years.)
To protect their infants, most pregnant women who were not previously vaccinated with Tdap should get one dose of Tdap postpartum before leaving the hospital or birthing center. Getting vaccinated with Tdap is especially important for mothers and families with new infants as well as all people caring for newborns. Women planning pregnancy may also choose to get vaccinated with Tdap prior to becoming pregnant.
In some cases, pregnant women may desire vaccination with the Tdap vaccine or may be at risk for acquiring whooping cough. Although the U.S. CDC states that pregnancy is not a contraindication for receiving the Tdap vaccine, data on the safety of the vaccine in pregnant women are limited. The tetanus and diphtheria (Td) components of the vaccine are considered safe for pregnant women. If the Tdap vaccine is given in pregnancy, the CDC recommends that it be given in the second or third trimester. Pregnant women should consult their health-care provider for a discussion their individual situation regarding the pertussis vaccine.

What are whooping cough symptoms, signs, and stages?

The first stage of whooping cough is known as the catarrhal stage. In the catarrhal stage, which typically lasts from one to two weeks, an infected person has symptoms characteristic of an upper respiratory infection, including

• runny nose,
• sneezing,
• low-grade fever,
• mild, occasional cough, similar to the common cold.

The cough gradually becomes more severe, and after one to two weeks, the second stage begins. It is during the second stage (the paroxysmal stage) that the diagnosis of whooping cough usually is suspected. The following characteristics describe the second stage:

• There are bursts (paroxysms) of coughing, or numerous rapid coughs, apparently due to difficulty expelling thick mucus from the airways in the lungs. Bursts of coughing increase in frequency during the first one to two weeks, remain constant for two to three weeks, and then gradually begin to decrease in frequency.
• At the end of the bursts of rapid coughs, a long inspiratory effort (breathing in) is usually accompanied by a characteristic high-pitched "whoop" sound.
• During an attack, the individual may become cyanotic (turn blue) from lack of oxygen.
• Children and young infants appear especially ill and distressed.
• Vomiting (referred to by doctors as post-tussive vomiting) and exhaustion commonly follow the episodes of coughing.
• The person usually appears normal between episodes.
• Paroxysmal attacks occur more frequently at night, with an average of 15-24 attacks per 24 hours.
• The paroxysmal stage usually lasts from one to six weeks but may persist for up to 10 weeks.
• Infants under 6 months of age may not have the strength to have a whoop, but they do have paroxysms of coughing. 

The first symptoms of whooping cough are similar to those of a common cold:

• runny nose
• sneezing
• mild cough
• low-grade fever

After about 1 to 2 weeks, the dry, irritating cough evolves into coughing spells. During a coughing spell, which can last for more than a minute, the child may turn red or purple. At the end of a spell, the child may make a characteristic whooping sound when breathing in or may vomit. Between spells, the child usually feels well.
Although it's likely that infants and younger children who become infected with B. pertussis will develop the characteristic coughing episodes with their accompanying whoop, not everyone will. However, sometimes infants don't cough or whoop as older kids do. They may look as if they're gasping for air with a reddened face and may actually stop breathing for a few seconds during particularly bad spells.
Adults and adolescents with whooping cough may have milder or atypical symptoms, such as a prolonged cough without the coughing spells or the whoop.

The third stage of whooping cough is the recovery or convalescent stage. In the convalescent stage, recovery is gradual. The cough becomes less paroxysmal and usually disappears over two to three weeks; however, paroxysms often recur with subsequent respiratory infections for many months.

How is whooping cough transmitted?

Whooping cough is highly contagious and is spread among people by direct contact with fluids from the nose or mouth of infected people. People contaminate their hands with respiratory secretions from an infected person and then touch their own mouth or nose. In addition, small bacteria-containing droplets of mucus from the nose or lungs enter the air during coughing or sneezing. People can become infected by breathing in these drops.

• The infection is transferred through airborne droplets when an infected person coughs. Anyone who has not been vaccinated is highly likely to contract the disease just by spending time in the same room as an infected person.
• Anyone who has been vaccinated or has suffered from whooping cough will have a degree of immunity to the disease. They may contract a mild case some years later but this will not develop into a full-blown attack.
• The incubation period - the time between contracting the infection and the appearance of the main symptoms - can vary from 5 to 15 days or even longer.
• Whooping cough is infectious from the first sneezes and throughout the course of the disease, which can last for up to eight weeks. This is a much longer period than with other children's diseases.

Can adults get whooping cough?

Although whooping cough is considered to be an illness of childhood, adults may also develop the disease. The illness usually is milder in adults than in children, but the duration of the paroxysmal cough is just as long as in children. The characteristic whoop that occurs after paroxysmal bouts of coughing is recognized in only 20%-40% of adults with whooping cough.
Because immunity from the pertussis vaccine decreases over time but does not necessarily disappear, adults who do become infected may have retained a partial degree of immunity against the infection that results in a milder illness. Whooping cough in adults is more common than usually appreciated, accounting for up to 7% of adult illnesses that cause coughing each year. Infected adults are a reservoir (source) of infection for children, so it is particularly important that all family members and caregivers of young infants be properly vaccinated.

How is whooping cough diagnosed?

When a patient has the typical symptoms of whooping cough, the diagnosis can be made from the clinical history. However, the disease and its symptoms, including its severity, can vary among affected individuals. In cases in which the diagnosis is not certain or a doctor wants to confirm the diagnosis, laboratory tests can be carried out. Culture of the bacterium Bordetella pertussis from nasal secretions can establish the diagnosis. Another test that has been used to successfully identify the bacterium and diagnose whooping cough is the polymerase chain reaction (PCR) test that can identify genetic material from the bacterium in nasal secretions.

What is the treatment for whooping cough?

Antibiotics directed against Bordetella pertussis can be effective in reducing the severity of whooping cough when administered early in the course of the disease. Antibiotic therapy can also help reduce the risk of transmission of the bacterium to other household members as well as to others who may come into contact with an infected person. Unfortunately, most people with whooping cough are diagnosed later with the condition in the second (paroxysmal) stage of the disease. Treatment with antibiotics is recommended for anyone who has had the disease for less than three to four weeks. Azithromycin (Zithromax), clarithromycin (Biaxin), erythromycin (E-Mycin, Eryc, Ery-Tab, PCE, Pediazole, Ilosone), and trimethoprim andsulfamethoxazole (Bactrim, Septra) are antibiotics which have been shown to be effective in treating whooping cough. It is unclear whether antibiotics have any benefit for people who have been ill with whooping cough for longer than three to four weeks, although antibiotic therapy still is often considered for this group. There is no proven effective treatment for the paroxysms of coughing that accompany whooping cough.
Antibiotics also are routinely administered to people who have had close contact with an infected person, regardless of their vaccination status.

What are possible complications of whooping cough?

The most common complication and the cause of most whooping cough-related deaths is secondary bacterial pneumonia. (Secondary bacterial pneumonia is bacterial pneumonia that follows another infection of the lung, be it viral or bacterial. Secondary pneumonia is caused by a different virus or bacterium than the original infection.) Young infants are at highest risk for whooping cough and also for its associated complications, including secondary pneumonia. Other possible complications of whooping cough, particularly in infants less than 6 months of age, include seizures, encephalopathy (abnormal function of the brain due to decreased oxygen delivery to the brain caused by the episodes of coughing), reactive airway disease (asthma), dehydration, hearing loss, and malnutrition.
Data indicate that secondary pneumonia occurs in about one out of every 20 infants with whooping cough, and one out of 100 affected infants develop convulsions.
Whooping cough can cause serious illness and even death in young children; 10 children died from the infection in 2007. From 2004-2005, 66 deaths due to whooping cough were reported to the CDC, and 56 of these were children under 3 months of age. In 2008, 18 deaths due to whooping cough were reported in the U.S. Most deaths from whooping cough have occurred in children who have not been vaccinated or who are too young to have received the vaccine.

How does the doctor make the diagnosis?

The diagnosis is usually made from the symptoms and the history of contact with a person suffering from whooping cough.
In case of doubt, the doctor can take swabs from the nose and throat for analysis and have the results in about five days.
In older children and adults with whooping cough, the symptoms are often far milder and the condition is often not diagnosed.
The diagnosis can also be made from blood tests, but these are often avoided in young children owing to their invasive nature.
A new enhanced surveillance test for pertussis was launched by the Health Protection Agency in 2007.
The test involves taking a specimen by brushing along the gumline with a saliva-collecting device. It’s used to estimate antibody levels directed against a toxin produced by the bacterium and is suitable for assisting in the diagnosis of those patients who have been coughing for more than two weeks and are suspected of having whooping cough.

Where can people find more information about whooping cough (pertussis)?

A recording of the classic "whooping" sounds of whooping cough can be heard at the web site for the Utah Department of Public Health.
For immunization information on whooping cough for children, adolescents, and adults, please visit the following areas.

• Immunizations (Vaccination) for Adolescents and Adults
• Immunizations (Vaccinations) for Infants and Children

Whooping Cough (Pertussis) At A Glance

• Whooping cough (pertussis) is an acute, highly contagious respiratory infection that is caused by the bacterium Bordetella pertussis.
• Whooping cough commonly affects infants and young children but can be prevented by immunization with pertussis vaccine.
• Adults may develop whooping cough as their immunity from childhood vaccines wears off over time.
• Clinical symptoms occur in three stages; the characteristic bursts of coughing are observed in the second, or paroxysmal, stage.
• Antibiotics can help reduce the severity of the disease when administered early in the course of the disease.
• Secondary bacterial pneumonia is the most common complication of whooping cough.

How does one prevent the infection?

• Just as significant as vaccination is the need to prevent infection spreading, especially to small children. This is especially important for children in nursery school.
• If there are infected children in childcare, other infants under the age of one year should not be admitted unless they have had whooping cough or have been vaccinated against it twice, with a period of four weeks between vaccinations.
• If the children are more than one year old they may be admitted even if they have not had the disease themselves or been vaccinated. But the parents must be informed of the danger of infection.
• If whooping cough occurs at home, no special measures are necessary.