Pertussis is a highly contagious acute respiratory disease caused by the bacteria Bordetella pertussis. This disease has 3 stages: catarrhal, paroxysmal, and convalescent. The symptoms of the catarrhal stage are mild and may go unnoticed. The paroxysmal stage of Pertussis is characterized by episodes of coughing with a distinctive "whooping" sound when breathing in (inspiration). This characteristic cough gives the disease its common name, Whooping Cough. During the convalescent stage, episodes of coughing are less frequent and symptoms improve. The incidence of Pertussis has diminished greatly with widespread use of the DPT vaccine (Diphtheria Pertussis Tetanus), but in certain areas of the United States outbreaks have occurred periodically in recent years.
Pertussis is a highly contagious disease that typically lasts for approximately 6 to 10 weeks. The symptoms are more severe in infants or in individuals who have never been immunized against the disease. There are three recognized stages of the disease: catarrhal, paroxysmal, and convalescent.
The incubation period for Pertussis is 7 to 10 days. During the first or catarrhal stage of the disease, the symptoms are mild and may go unnoticed or be confused with the common cold or influenza. Symptoms may include a general feeling of ill health (malaise), a runny nose (rhinorrhea), sneezing, and/or tearing of the eyes (lacrimation). Some affected people may experience a slight elevation in temperature (low-grade fever). Toward the end of this phase, a cough develops that becomes increasingly more persistent, especially at night.
The paroxysmal stage of Pertussis is characterized by recurring intense episodes of coughing. An episode or “paroxysm” consists of a series of coughs in rapid succession with increasing intensity. The last cough in the series is followed by a large inspiration that produces a characteristic “whoop” sound. During these coughing episodes, affected individuals find it difficult to draw air into the lungs (inspiration) between coughs. Typically, people with Pertussis cough up (expectorate) large amounts of thick mucus, which may cause vomiting (post-pertussis emesis). Other symptoms during an attack may include bulging eyes, prominent veins in the neck, protrusion of the tongue, and/or excessive salivation. Aspiration of mucous into the lungs may cause bacterial pneumonia. Infections of the middle ear (otitis media) may also occur during this stage of the disease.
The convalescent stage of Pertussis begins approximately 4 weeks after onset of the disease. Episodes of coughing become less frequent and not as severe. Slow recovery begins during this phase of the disease. Occasionally episodes of coughing may recur for months.
The coughing associated with Pertussis may cause a sudden increase in the pressure within the blood vessels of the nose and/or eyes. This may lead to nosebleeds (epistaxis) and the appearance of red blood vessels in the white of the eyes (scleral hemorrhage). Other more severe complications may include seizures, a collapsed lung (atelectasis), abnormal enlargement and destruction of the bronchi and bronchial tubes (bronchiectasis), the escape of air from the lungs into the surrounding soft tissues (subcutaneous emphysema), and/or a hernia in the area of the groin (inguinal hernia). Bacterial superinfection and, in rare cases, acute inflammation of the brain (encephalitis) may also occur.
Pertussis is an infectious disease caused by the gram-negative coccobacillus, Bordetella pertussis. Pertussis is a highly contagious disease via droplets in the air from the respiratory tract of infected individuals. Transmission occurs during the catarrhal stage and during the first 2 to 3 weeks of the paroxysmal phase.
Pertussis occurs most frequently and severely in young children. Adolescents and adults tend to experience much less severe symptoms, and sometimes the disease may not even be recognized as Pertussis. For reasons that are not fully understood, slightly more females than males are affected.
Pertussis occurs in all geographic locations throughout the world. There is no seasonal pattern to outbreaks of the disease. The World Health Organization (WHO) has estimated that 60 million cases of Pertussis occur worldwide each year. Approximately 500,000 to 1,000,000 individuals develop life-threatening complications because of Pertussis.
The Pertussis vaccine (DPT vaccination) has been in widespread use since the late 1940s. Since that time, the incidence of Pertussis has fallen dramatically from 250,000 cases per year in the United States. Recently, the CDC reported that pertussis affected about 1,900 infants per year between 1994 and 1996. However, the Pertussis vaccine is not 100 percent effective in preventing the disease. In widespread outbreaks of Pertussis, individuals’ susceptibility to this infection increases with the amount of time that has elapsed since their last immunization. The Centers for Disease Control (CDC) in Atlanta, GA suggest that the small risk of severe reactions associated with the DPT vaccine is negligible when compared to the possible severity of the disease itself. The risk of serious complications is estimated to be 1 in 100,000 to 300,000 for the vaccine as opposed to 1 in 9,500 for the disease itself. The American Academy of Pediatrics has reported near epidemic local outbreaks of Pertussis in at least 10 geographic areas in the United States during recent years. In most of these areas, parents have not permitted immunization of their children against Pertussis because of the possible complications of vaccine.
The diagnosis of Pertussis may be confirmed by isolating the organism Bordetella pertussis from the sputum of an affected individual. These sputum samples are best obtained using a cotton swab that is placed through the nose into the rear portion of the throat (posterior pharynx). The paroxysmal phase of Pertussis is associated with very high levels of white cells in the blood (i.e., lymphocytosis).
The most important treatment for Pertussis is prevention. The DPT vaccine is provided to infants and although there may be some discomfort from the injection, it is generally safe and effective. There may be extremely rare but serious adverse reactions in some children. These should be immediately brought to the attention of a physician when they begin to appear.
An acellular vaccine, which is made with part of the bacterium that causes Pertussis rather than the whole bacterium, is available for vaccination of infants. Known as Tripedia, the vaccine is manufactured by Connaught Laboratories. It is hoped that this acellular vaccine will produce fewer side effects (e.g., fever, seizures, etc.) than cellular vaccines.
Adverse reactions have been associated with the Diphtheria Pertussis Tetanus (DPT) vaccination and the risk for these reactions increases with age. In most circumstances, vaccination is not recommended for children over the age of seven years. Adverse reactions may be local or systemic. Local reactions may include pain, skin redness (erythema), and/or swelling. Elevated temperature is a common systemic reaction to the pertussis vaccine. In some rare cases, a fever of over 104.9F degrees has been reported. Other very rare complications have included seizures, shock, and severe hypersensitivity reactions (anaphylaxis). The most severe complication of the DPT vaccination is the very rare occurrence of brain inflammation (encephalopathy). (For more information on these allergic reactions, choose “Anaphylaxis” as your search term in the Rare Disease Database.)
A new combined vaccine, known as Certiva, for diphtheria, tetanus, and acellular pertussis (DTaP) has been approved by the Food and Drug Administration (FDA) as a preventative measure against these illnesses. For more information, contact:
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The treatment of Pertussis involves the administration of antibiotic drugs that help to clear the bacteria from the throat of affected individuals, usually within three to four days. By the fourth day of treatment, the disease is no longer contagious. Erythromycin is the antibiotic drug of choice and is routinely given because it halts transmission of the disease to others. A course of antibiotic therapy may also be prescribed to those individuals who have been in close contact with affected individuals, especially children. The combination of trimethoprim-sulfamethoxazole is an alternative antibiotic therapy that is given to those who cannot tolerate erythromycin.
Recently, the Centers for Disease Control (CDC) reported that erythromycin may caus. pyloric stenosis, a severe stomach disorder, in some babies. Pyloric stenosis blocks digestion and causes projectile vomiting. However, while CDC urges physicians and parents to be aware of this potentially serious side-effect, it does not recommend that physicians stop prescribing erythromycin for Pertussis.
Seriously ill infants with Pertussis should be kept in a dark and quiet room. They should be disturbed as little as possible to help prevent frequent episodes of severe coughing. Close attention should be paid to the nutritional needs of the infant, since poor nutrition can contribute significantly to complications. Small meals should be given as frequently as possible. Expectorant cough mixtures, cough suppressants, and sedatives are of little value and should be used cautiously or not at all.
Hospitalization may be recommended for seriously ill infants with Pertussis. Parenteral fluid (IV) therapy may be required to replace salt and water loss if vomiting is severe. Careful suctioning of the throat may become necessary to clear excessive mucous secretions. When suctioning is not able to clear the airway, a surgical procedure may be performed to create a temporary opening into the throat (tracheostomy). A tube is then inserted into this opening, through which oxygen is supplied to the lungs. Oxygen may also be administered to affected infants if their skin and mucous membranes have a bluish discoloration (cyanotic) after the removal of secretions from the throat. This type of intensive supportive care may be lifesaving in very severe cases of Pertussis.
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