Understanding Pertussis

There are between 30 to 50 million cases of pertussis or whooping cough worldwide, causing around 300,000 deaths every year. This makes the disease as one of the leading causes of vaccine-preventable deaths in the world. According to the United States Centers for Disease Control and Prevention, there were almost 26,000 cases of pertussis reported in the country in 2004. 90% of all pertussis cases occur in the underdeveloped and developing world.

Definition

Pertussis is an acute and highly contagious respiratory illness caused by a bacterium. It is also called "whooping cough", derived from the whooping sound of intake breath following a severe hacking cough. The first pertussis outbreaks were recorded in the sixteenth century. Bordetella pertussis, the bacteria that cause the illness, were not isolated until 1906. Its incidence rate has been on the rise since the 1980s.

Causes of pertussis

The bacteria Bordatella pertussis causes whooping. These bacteria work by attaching themselves to the cells found in the respiratory tract that has cilia. When the bacteria interfere with the normal and janitorial functions of the cilia, cellular debris and mucus accumulate, which causes irritation in the respiratory tract. This then increases further mucus production and triggers coughing.

You can be infected if someone infected coughs on you or if you have contact with a contaminated surface upon which the cough droplets landed. Most infants catch pertussis from other children, often a young sibling. Adults can also catch pertussis and infect other adults, children, and infants.

Symptoms of pertussis

In the first stage of pertussis (catarrhal stage), the infected person experiences symptoms of an infection in the upper respiratory system. These include runny nose, low-grade fever, sneezing, or a mild and occasional cough.

The second stage of the infection (the paroxysmal stage) is characterized by bursts of coughing and numerous rapid coughs, a long breathing in after rapid coughs, and vomiting. Also, during an episode, the infected person may turn blue due to lack of oxygen.

Sufferers, especially infants and children, also appear ill and distressed. The third stage is the recovery stage wherein recovery is gradual. The bursts and rapid coughing usually stop after two or three weeks.

Diagnosis

Often, whooping cough is not diagnosed until the symptoms manifest in the second stage. Methods used to diagnose the infection include the culturing of nasopharyngeal swabs on Bordet-Gengou medium, immunofluorescence (DFA), polymerase chain reaction (PCR), and serological methods.

Bordatella pertussis can be recovered from an infected person only during the first three weeks of the onset of the illness. This renders DFA and culturing useless after three weeks.

How to treat pertussis?

Antibiotics directed against the bacteria can effectively reduce the severity of whooping cough when administered in the earliest stage. It can also reduce transmission risk. Antibiotic therapy is recommended for patients who have been infected for not more than 21 days. Trimethoprim/ Sulfamethoxazole, azithromycin (Zithromax), erythromycin, and clarithromycin (Biaxin) are effective in treating pertussis.

How to prevent pertussis?

Whooping cough can be prevented by getting your child fully immunized with the DTaP vaccine. This is the best prevention measure against pertussis. After vaccination, keep your child away from people who are sick, or older children and adults with a cough.