[6-26-2017 As I reviewed all the resources in this post, and in the earlier post,
This tragic YouTube video, Losing a Baby to Whooping Cough: One Woman’s Story (4:12), is important to watch.
In the video, the mother states “my cough was just getting worse since labor. After we were home she [the newborn] was fine for the first week. And then during the second week she started to sneeze a little bit. . . . ” And the mother started googling stuff and pertussis caught her eye. “And I [the mother] was coughing pretty bad at this point but she [the newborn] wasn’t coughing – she just sneezed a few times.” And the mother was very worried that it was pertussis. And around two weeks of age [I think] the mother took the newborn to the walk-in clinic. “At that point she wasn’t really sick, she was just sneezing. And about four days later she was getting blue around the eyes. She wasn’t really keeping food down. And we took her to the emergency department” where her oxygen saturation was found to be low and her course deteriorated over days.
And what follows are some resources on the diagnosis and treatment of pertussis.
Mayo Clinic’s Recognizing and Treating Whooping Cough video (1:51) and
Mayo Clinic’s Infant girl with whooping cough video (2:23).
Then review the excellent brief review of pertussis in children is found in COMBATING THE PERSISTENT COUGH, Audio-Digest Family Practice Volume 62, Issue 16 April 28, 2014: Cough: Pharmacologic and Nonpharmacologic Remedies – Michael D. Shepherd, MD; Pertussis in Children: The 100-Day Cough – Ellen Laves, MD (link is to summary lecture notes).
Dr. Laves makes the following points:
The incubation period is about three weeks.
There are three phases of pertussis infection.
The first is the catarrhal phase which lasts from 0 to two weeks and is characterized by cough, mild fever, and rhinorrhea. It is only during this phase that treatment with azithromycin shortens the course. These children are frequently diagnosed with a URI or with acute otitis media.
The second phase is the paroxysmal phase which lasts from one to six weeks and is characterized by paroxysms of cough. Treatment in this phase does not change the course but renders the patient less infectious.
The third phase where the cough gradually resolves can last from weeks to months.
Complications can include autonomic instability (apnea and bradycardia), poor feeding, dehydration, emesis, pneumonia, respiratory distress and failure, and death. Other complications are intracranial hemorrhage, pneumothorax, and seizures.
Approximately 90% or more of the serious complications occur in infants from 0 to 3 months of age. ______________________________________________________________
See Pertussis Testing Video: Collecting a Nasopharyngeal Aspirate Clinical Specimen (4:14) from the CDC.
Watch the CDC’s Dr. Sema Mandal’s excellent video, Pertussis Diagnosis: Avoid the Pitfalls of PCR (5:14) . She recommends use of nasal pharyngeal aspirates rather than using nasal pharyngeal swaps.
She states that “Proper specimen collection is critical. Specimens for PCR testing should be obtained from the posterior nasopharynx by aspiration or swabbing. Throat swabs and anterior nasal swabs are not recommended because they have unacceptably low rates of DNA recovery. Swab tips should be polyester, such as Dacron®, rayon, or nylon-flocked. Cotton-tipped or calcium alginate swabs are not acceptable, because the residues present in these materials inhibit PCR assays. If feasible, nasopharyngeal (NP) aspirates that flush the posterior nasopharynx with a saline wash are preferred over swabs. Aspiration results in a larger quantity of bacterial DNA in the sample.” _______________________________________________________________
A brief FAQs, Pertussis Information for Clinicians, is available from the The Children’s Hospital of Philadelphia.
The CDC Pertussis Home Page is a portal to all the information a clinician will need.
The test of choice to diagnose Bordetella Pertussis is the Bordetella Pertussis PCR test.
See the Centers for Disease Control and Prevention resource, Best Practices for Health Care Professionals on the use of Polymerase Chain Reaction (PCR) for Diagnosing Pertussis, for guidance. Here is some information from that page:
Testing Patients with Signs and Symptoms of Pertussis
Early signs and symptoms of pertussis are often non-specific, making it difficult to determine clinically who has pertussis in the earliest stages. However, only patients with signs and symptoms consistent with pertussis should be tested by PCR to confirm the diagnosis. Testing asymptomatic persons should be avoided as it increases the likelihood of obtaining falsely-positive results. Asymptomatic close contacts of confirmed cases should not be tested and testing of contacts should not be used for post-exposure prophylaxis decisions.
Optimal Timing for PCR Testing for Pertussis
PCR has optimal sensitivity during the first 3 weeks of cough when bacterial DNA is still present in the nasopharynx. After the fourth week of cough, the amount of bacterial DNA rapidly diminishes, which increases the risk of obtaining falsely-negative results. For more information, consult diagnostic testing for pertussis, including the use of serology for late diagnosis.
PCR testing following antibiotic therapy also can result in falsely-negative findings. The exact duration of positivity following antibiotic use is not well understood, but PCR testing after 5 days of antibiotic use is unlikely to be of benefit and is generally not recommended.
Optimal Specimen Collection for PCR Testing for Pertussis
Specimens for PCR testing should be obtained by aspiration or swabbing the posterior nasopharynx. Throat swabs and anterior nasal swabs have unacceptably low rates of DNA recovery and should not be used for pertussis diagnosis. The swab tips may be polyester (such as Dacron®), rayon, or nylon-flocked. Cotton-tipped or calcium alginate swabs are not acceptable as residues present in these materials inhibit PCR assays. If feasible, nasopharyngeal (NP) aspirates that flush the posterior nasopharynx with a saline wash are preferred over swabs because this method results in a larger quantity of bacterial DNA in the sample.