Bordetella is a group of bacteria known to cause respiratory illnesses in various mammals. While some species are primarily associated with animal diseases, several types can infect humans. These infections range from mild respiratory discomfort to severe, prolonged illnesses.
Types of Bordetella Infections in Humans
Bordetella pertussis is the primary cause of whooping cough, a serious Bordetella infection in people. This bacterium specifically targets the respiratory tract, leading to distinct and prolonged coughing episodes. Bordetella parapertussis also causes a similar, but milder, respiratory illness.
Bordetella bronchiseptica is known for causing “kennel cough” in animals. While primarily an animal pathogen, it can be transmitted to humans. Human infections with Bordetella bronchiseptica are most commonly observed in individuals with weakened immune systems. These cases often present with respiratory symptoms.
Symptoms and Disease Progression
Whooping cough, caused by Bordetella pertussis, unfolds in distinct stages. The initial phase, known as the catarrhal stage, often mimics common cold symptoms. Individuals may experience a runny nose, a low-grade fever, and a mild, occasional cough during this period. These early symptoms can last for one to two weeks, making diagnosis challenging.
The illness progresses to the paroxysmal stage, marked by severe, uncontrollable coughing fits. These intense coughing bouts are often followed by a distinctive “whooping” sound as the person struggles to inhale air. Vomiting or exhaustion may occur after these forceful coughs, and this stage can persist for several weeks. The final phase, the convalescent stage, marks a gradual recovery where the frequency and severity of coughing spells slowly decrease over weeks or even months. Vaccinated individuals, adolescents, and adults may experience less severe or atypical symptoms, sometimes presenting as a prolonged cough without the characteristic “whoop.”
Medical Diagnosis and Treatment
Doctors confirm a Bordetella infection primarily through laboratory testing. A common diagnostic method involves collecting a nasopharyngeal swab from the back of the nose and throat. This sample is then analyzed using a polymerase chain reaction (PCR) test, which is highly sensitive in detecting the bacterium’s genetic material. Blood tests may also aid diagnosis, especially if the infection has been present longer.
Once confirmed, the standard treatment involves specific antibiotics, such as azithromycin. These medications are most effective when administered early in the course of the illness, ideally during the initial catarrhal stage, to reduce symptom severity and duration. Antibiotics also prevent the spread of bacteria. Supportive care, including adequate rest and maintaining proper hydration, helps manage symptoms and promotes recovery.
Prevention and High-Risk Groups
Vaccination is the most effective strategy for preventing Bordetella infections, particularly whooping cough. The DTaP vaccine is routinely administered to infants and young children as part of their childhood immunization schedule, providing protection against diphtheria, tetanus, and pertussis. For adolescents and adults, a booster shot called Tdap is recommended to maintain immunity. Pregnant women are also advised to receive the Tdap vaccine, typically in the third trimester, to transfer protective antibodies to their newborns. This strategy, sometimes referred to as “cocooning,” helps protect infants who are too young to be fully vaccinated themselves.
Certain groups face a higher risk of severe disease and complications if infected. Unvaccinated or partially vaccinated infants are particularly vulnerable to serious illness and hospitalization due to their developing immune systems. Older adults, whose immunity may wane over time, also face an increased risk of severe outcomes. Individuals with compromised immune systems, whether due to underlying medical conditions or medications, are additionally susceptible to more severe Bordetella infections.