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Pertussis diagnosis and treatment

Video transcript

before we talk about how to diagnose pertussis also called whooping cough let's review the timeline of the stages that occur during the bacterial infection from the time the first common cold symptoms occur - about two weeks the bacteria that causes pertussis is in the upper respiratory tract it's thriving and it's causing damage and inflammation in the Airways and in about two weeks this damage is significant enough to cause mutable din Airways and it triggers a coughing fit with woopy when breathing in and vomiting after fits at the same time the body's finally been able to make antibodies specific for pertussis which tied the bacteria for destruction by the immune system so that means that about eight weeks into the infection the immune systems been able to clear the infection and the damage in the inflammation the Airways can begin to heal over the next four weeks which means that symptoms will slowly go away now the timeline is important because there's a few ways to diagnose pertussis but which ways used depends heavily on the stage of the infection the gold standard test for diagnosing pertussis can only be done in the first two weeks of the symptoms when the bacteria is still alive so let's mark off the two weeks and write in that the test is a swab and to test a patient healthcare worker would take protective cautions wear a gown gloves and mask to prevent being infected and then swab the back of the patient's nasal pharynx with the polyester Dacron tip swab then it's brought back to the lab and if pertussis is present it'll multiply and grow like I'm drawing here within seven to eight days and positive results are really accurate but negative results don't rule out an infections occurred because the sample may not have been taken during the correct stage or with the right technique so this test is often used in combination with another test that confirms results a polymerase chain reaction can be performed any time up to four weeks it's often just abbreviated and called a PCR so PC R and it can be done on the same swab sample because it tests only for the presence of the pertussis DNA if pertussis DNA is present the PCR will make millions of copies of a specific portion and these copies can be detected in lab to confirm a pertussis infection now because the DNA can come from live or dead bacteria testing is possible up to four weeks when the bacteria is mostly dead and the results are fast and they take about one to two days but they can sometimes give positive results that are actually false if the sample is contaminated so that's why it's typically done in combination with growing pertussis in the lab and finally I want to include one last test that exists because it's the only one that can be performed from weeks two to twelve which is pretty late into the course of the disease it's serology in this test detects antibody levels in the blood here are some pertussis bacteria in about two weeks the body starts producing these antibodies that are specific to tagged pertussis for destruction by the immune system so because anybody levels are at their highest between weeks two and eight when the body's in the middle of fighting pertussis this is an ideal time to have the serology tests done but since antibody levels will slowly taper off once the infection is cleared they can still be detected all the way to the twelfth week one of the technical challenges with this test is that if a person's recently been vaccinated anybody levels in the blood will be high and this will give positive test results even if a natural infection hasn't occurred for this reason and a few other technical challenges the test isn't widely available and it's not a preferred diagnostic tool but it's something to keep in mind because it's being developed and fine-tuned for general use now that we've covered the lab tests let's talk about how clinical diagnosis of pertussis can be made if for two weeks or longer a patients experiencing coughing fits looping or vomiting after coughing without any other known cause pertussis can be diagnosed and while I drew this line during the second stage when the symptoms would normally develop a diagnosis can be made earlier and in less time if it's known a person has been exposed to a person with a pertussis diagnosis and let's say a person is diagnosed with pertussis what do we do next well let's slide this up and let's say a patient's diagnosed with pertussis early in the first two weeks of the initial symptoms during this time macrolide antibiotics can be prescribed to make future symptoms more mild but the antibiotics won't be useful after this time because remember past this point the damage and the inflammation from the infections already occurred and it'll still lead to the symptoms and the other stages but if an uninfected person has been exposed to a person with a protest diagnosis they can begin taking antibiotics immediately during the seven to ten day incubation period and by doing this the antibiotics will help prevent the damage in the inflammation and make symptoms more mild if they occur at all but really mostly the treatment for pertussis is managing the symptoms so for the cough a patient can use the humidifier to hydrate the mucus to make it easier to cough up and a patient would benefit from avoiding activities that might trigger additional coughing so avoid running dusty locations things like that but we don't want to eliminate the cough all together because it's still needed to help remove the mucus from the airways so over-the-counter cough suppressants are not recommended plenty of rest is a good idea though to save up energy for the tiring coughing that's when they do come and to prepare for the vomiting which commonly occurs after coughing fits patients just pay attention to proper nutrition by staying hydrated and eating small frequent meals in infants younger than 1 year old who tend to have severe symptoms this may mean they need some extra help at the hospital through IV hydration and passing a tube down their throat to their stomach to get food in if a patient starts having trouble breathing administering oxygen may be necessary symptoms of trouble breathing or respiratory distress are low oxygen an increased heart and breathing rate and finally patients should be monitored for the development of additional respiratory infections in addition to pertussis because pertussis infections cause mucus to build in the lungs and it creates this perfect environment for other bacteria to survive and thrive so monitoring for this can be done with chest x-rays since pertussis is not typically visible on x-rays what other infections may appear as white areas and the lungs that would normally be black