under the microscope
under the microscope
By Priya Dhagat , MS , MLS ( ASCP ) CM , CIC
Pertussis : Pathogenesis and Prevention
• As of Oct . 26 , 2024 , the Centers for Disease Control and Prevention ( CDC ) has reported
20,791 cases
of pertussis ( year to date ), which is five times as many cases compared to the same time in 2023 .
• Numerous factors may be contributing to this rise , such as :
• Increased circulation of the bacteria
• Genetic changes to the bacteria
• Waning immunity from previous vaccination
• Decreased vaccination rates
Pertussis , also known as whooping cough , has made national news due to a surge in cases across the country . Numerous states , including Pennsylvania , New Mexico , Colorado , and Arizona , have reported a stark increase in cases over the past few weeks . As of Oct . 26 , 2024 , the Centers for Disease Control and Prevention ( CDC ) has reported 20,791 cases of pertussis ( year to date ), which is five times as many cases compared to the same time in 2023 . Numerous factors may be contributing to this rise , such as increased circulation of the bacteria , genetic changes to the bacteria , waning immunity from previous vaccination , and decreased vaccination rates .
Once known as the “ the cough of 100 days ,” pertussis dates back to 1578 and was a major cause of infant morbidity and mortality . The bacteria Bordetella pertussis was discovered to be the cause of disease in 1906 and a vaccine was developed a few decades later in the 1940s . Before vaccination was introduced in the 1940s , more than 200,000 cases of pertussis occurred annually compared to approximately 10,000 annual cases pre-pandemic .
Pertussis is an exclusively human disease with no animal reservoirs . Transmission occurs via contact with respiratory , oral , or nasal secretions from an infected person or contaminated objects . The incubation period is between seven to 10 days on average with a range of four to 21 days . After colonizing the mucous membranes in the respiratory tract , the bacteria attach to cilia ( hair-like extensions on respiratory epithelial cells that are essential to clear mucous and other pulmonary secretions ) and release numerous toxins . Some of these toxins damage or paralyze the cilia , preventing mucous to be cleared and leading to swelling of the airway and continuous coughing in effort to clear the mucous .
Clinical course is divided into three stages : ( 1 ) catarrhal , ( 2 ) paroxysmal , and ( 3 ) convalescent . The catarrhal stage is characterized by common cold symptoms , such as runny nose , sneezing , and the occasional cough . This is the most contagious this stage since symptoms are similar to other upper respiratory infections and may be less severe in adults than in children and infants which could lead to delayed recognition . The cough progresses to the paroxysmal stage after one to two weeks , becoming severe with uncontrolled and rapid coughing bursts – called paroxysms – due to the difficulty in removing mucous from the respiratory tract . The characteristic high-pitched “ whoop ” noise occurs at the end of the paroxysm when gasping for air . Vomiting and exhaustion typically follow after the paroxysm . The paroxysmal stage usually lasts one to six weeks but may persist for up to 10 weeks . People
Pertussis is an exclusively human disease with no animal reservoirs . Transmission occurs via contact with respiratory , oral , or nasal secretions from an infected person or contaminated objects ."
are infectious from catarrhal stage through the third week of paroxysms . Recovery is gradual during the convalescent stage which lasts for one to three weeks . The cough becomes less paroxysmal and disappears in two to three weeks . Pneumonia is the most common and frequent complication , but other complications include sinusitis , otitis media , viral and bacterial superinfections , apnea , and hypoxia , and neurologic complications . In adolescents and adults , coughing can become so severe that rib fractures , hernias , syncope , and urinary incontinence may occur .
In healthcare settings , unprotected close contact with an infectious person or contact with their secretions may be considered an exposure to pertussis . Patients should ideally be placed in a single room and droplet and standard precautions should be followed until five days after effective antibiotic therapy . Hand hygiene and thorough environmental cleaning and disinfection are essential . Because vaccinated healthcare personnel may still be at risk for pertussis infection , post-exposure prophylaxis should be considered . With the rise in cases , it is imperative to remember that pertussis is a vaccine-preventable disease . Per the CDC , children should receive five doses of the DTaP given at 2 , 4 , and 6 months , with booster doses given at 15 to 18 months and between 4 to 6 years old . Adolescents should receive a Tdap booster at 11 to 12 years old to maintain protection . Pregnant women should get a dose of Tdap during every pregnancy , preferably during the early part of the third trimester . Read more here : Chapter 16 : Pertussis | Pink Book | CDC Pertussis | Infection Control | CDC
Priya Dhagat , MS , MLS ( ASCP ) CM , CIC , is an infection preventionist and the associate director of the system-wide Special Pathogens Program within the Department of Emergency Management at New York City Health + Hospitals , overseeing special pathogen preparedness and response efforts across New York City Health + Hospitals frontline healthcare facilities . Additionally , she supports and offers subject matter expertise for infection prevention topics for the National Emerging Special Pathogens Training and Education Center ( NETEC ).
8 • www . healthcarehygienemagazine . com • november 2024