It is a highly infectious bacterial disease involving the respiratory tract. It is caused by a bacterium Bordetella pertussis or Bordetella Parapertussis that is found in the mouth, nose and throat of an infected person. Symptoms usually appear after 7 to 10 days after infection, but may also appear up to 21 days later. Initially, symptoms resemble those of a common cold, including sneezing, runny nose, low-grade fever and a mild cough.
Within two weeks, the cough becomes more severe and is characterised by episodes of numerous rapid coughs, followed by a crowing or high-pitched whoop. These episodes frequently end with the expulsion of a thick, clear mucous, often followed by vomiting. They initially occur at night and then become more frequent during the day and may recur for one to two months. In young infants the typical 'whoop' may never develop, and the coughing fits may be followed by brief periods when breathing stops.
After this phase, the coughing fits become less frequent and less severe, and the infant gradually gets better although this can take up to three months. Adolescents, adults, or partially immunised children generally have milder or atypical symptoms, so in these groups, in addition to very young infants, pertussis might be more difficult to diagnose.
Supportive care following hospital admission is especially important for very young infants or older children with severe disease. Antibiotic therapy is the treatment of choice for pertussis. However, in order to be effective, treatment must begin early in the course of disease, preferably within two weeks of onset.
Antibiotic treatment can eradicate the bacteria from the nose and throat and limits the risk of it being passed on to others. Complications of pertussis include pneumonia, middle ear infection, loss of appetite, dehydration, seizures, brain disorders, hernias, rib fractures, rectal prolapse, episodes of cessation of breathing.
Severe cases can lead to death. Infants may look as if they're gasping for air with a reddened face and may actually stop breathing this is called apnea for a few seconds during very bad spells. Adults and teens may have milder or different symptoms, such as a prolonged cough rather than coughing spells or coughing without the whoop.
Pertussis is highly contagious. The bacteria spread from person to person through tiny drops of fluid from an infected person's nose or mouth.
These may become airborne when the person sneezes, coughs, or laughs. Others then can become infected by inhaling the drops or getting the drops on their hands and then touching their mouths or noses. Infected people are most contagious during the earliest stages of the illness for up to about 2 weeks after the cough begins.
Antibiotics shorten the period of contagiousness to 5 days following the start of antibiotic treatment. Whooping cough can be prevented with the pertussis vaccine , which is part of the DTaP diphtheria, tetanus, acellular pertussis immunization.
DTaP immunizations are routinely given in five doses before a child's sixth birthday. For additional protection in case immunity fades, experts recommend that kids ages get a booster shot of the new combination vaccine called Tdap , ideally when they're 11 or 12 years old. The Tdap vaccine is similar to DTaP but with lower concentrations of diphtheria and tetanus toxoid. It also should be given to adults who did not receive it as preteens or teens.
The vaccine is also recommended for all pregnant women during the second half of each pregnancy, regardless of whether or not they had the vaccine before, or when it was last given.
Getting the vaccine is especially important for people who are in close contact with infants, because babies can develop severe and potentially life-threatening complications from whooping cough. An adult's immunity to whooping cough lessens over time, so getting vaccinated and protecting yourself against the infection also helps protect your infant or child from getting it.
As is the case with all immunization schedules, there are important exceptions and special circumstances. Before the vaccine was developed, whooping cough was considered a childhood disease. Now whooping cough primarily affects children too young to have completed the full course of vaccinations and teenagers and adults whose immunity has faded. Deaths associated with whooping cough are rare but most commonly occur in infants.
That's why it's so important for pregnant women — and other people who will have close contact with an infant — to be vaccinated against whooping cough. Once you become infected with whooping cough, it takes about seven to 10 days for signs and symptoms to appear, though it can sometimes take longer. They're usually mild at first and resemble those of a common cold:. After a week or two, signs and symptoms worsen.
Thick mucus accumulates inside your airways, causing uncontrollable coughing. Severe and prolonged coughing attacks may:. However, many people don't develop the characteristic whoop. Sometimes, a persistent hacking cough is the only sign that an adolescent or adult has whooping cough. Infants may not cough at all. Instead, they may struggle to breathe, or they may even temporarily stop breathing. Whooping cough is caused by a type of bacteria called Bordetella pertussis. In , the largest peak in recent years, states reported 48, cases of pertussis.
During pertussis outbreaks, the primary goal is to protect babies from getting sick and dying from pertussis. A second goal is to protect people of all other ages from getting pertussis. Pertussis outbreaks can be difficult to identify and manage , and cases of pertussis may go unreported. Other respiratory pathogens often cause symptoms similar to pertussis. Also, pertussis co-circulates with other pathogens bacterial and viral at times.
Healthcare professionals commonly use polymerase chain reaction PCR tests to diagnose pertussis. PCR tests vary in their ability to correctly show who does not have pertussis specificity. This is important because if a test has a high specificity and someone tests positive, then it is very likely they actually have the disease. Since PCR tests vary in specificity, CDC recommends getting confirmation with culture a lab test where the bacteria are grown for at least one suspected case any time there is suspicion of a pertussis outbreak.
False pseudo outbreaks of pertussis have resulted because of false positive test results with PCR.
0コメント