Pertussis, commonly known as whooping cough, is a highly contagious respiratory illness caused by the bacterium Bordetella pertussis. This infection targets the lining of the respiratory tract, leading to severe, often prolonged coughing fits. Understanding the specific way this bacterium moves from person to person is necessary to implement the correct infection control measures and prevent its spread.
Understanding Pertussis Transmission
Pertussis is primarily transmitted through respiratory droplets produced when an infected individual coughs, sneezes, or talks. This differs from true airborne transmission, which involves smaller particles that remain suspended in the air for extended periods and travel long distances. Droplets are larger and heavier, causing them to fall quickly out of the air within a short range.
The violent and frequent coughing fits characteristic of whooping cough make the infected person highly effective at projecting these droplets, meaning transmission generally requires close, face-to-face contact. The infectious period begins with the onset of initial cold-like symptoms and can last for up to three weeks if the infection is left untreated.
Because the droplets do not stay suspended, the risk of transmission drops significantly beyond three to six feet. This short-range spread dictates the required safety measures.
Implementing Droplet Precautions
The classification of Pertussis as a droplet-transmitted disease dictates the use of Droplet Precautions, which are utilized in addition to standard hygiene practices. A standard surgical mask is the personal protective equipment recommended for individuals who must be within the close-contact zone of an infected person.
In clinical settings, healthcare personnel should wear a surgical mask when entering the patient’s room. The infected individual should be placed in a single-patient room to limit exposure. Isolation is maintained until the patient has received a full five days of antibiotic treatment, as the medication quickly reduces the bacterial load and halts contagiousness.
Maintaining physical distance is an effective precaution in both clinical and home environments. Minimizing face-to-face contact and keeping a distance greater than three feet helps prevent droplets from reaching another person’s eyes, nose, or mouth. Respiratory hygiene, such as covering coughs and sneezes, and frequent handwashing are important supporting actions.
Prevention Through Immunization
Vaccination remains the most effective long-term strategy for preventing pertussis. The vaccine is administered as a combination product that also protects against diphtheria and tetanus. For infants and younger children, the DTaP vaccine involves a five-dose series beginning at two months of age.
Adolescents and adults receive a different formulation called Tdap, typically given as a single booster dose around 11 or 12 years of age. A single dose of Tdap is also recommended during each pregnancy, preferably between the 27th and 36th weeks of gestation. This timing allows the mother to build protective antibodies that are transferred to the fetus, offering the newborn temporary protection during the first months of life.
This maternal vaccination strategy is a form of “cocooning,” which aims to protect infants too young to complete their primary DTaP series. Close contacts of a newborn, such as fathers, grandparents, and caregivers, should also ensure they are up to date on their Tdap vaccine. Maintaining vaccination coverage across all age groups reduces the severity of illness and the overall community transmission rate.