DTaP and Bordetella Parapertussis
DTaP is a vaccine to prevent pertussis, a potentially fatal illness, in children. Children should receive two or four doses before four years, but no more than five. The ACIP recommends the first dose be given at two years of age. The second dose should be given between 4 and 6 years of age.
The vaccine does not contain live bacteria and is manufactured using inactivated, non-infectious bacterial products. This helps to promote a robust immune response. It has been recommended for postpartum women, adolescents, and pregnant women since 2006. It is also recommended for newborns who cannot receive the vaccine themselves.
The DTaP vaccine has been proven effective in preventing pertussis and diphtheria. However, it is not without risks. It can cause some side effects, including soreness at the site of the shot, fever, loss of appetite, and even convulsions.
Although the rates of pertussis have decreased in recent years, the disease still affects young infants, with 1 in 10 cases occurring in children under one year of age. The disease can be severe and even fatal, especially in children younger than six. It can also spread from infant to infant.
In pregnant women, Tdap vaccination is recommended to be given between 27 and 36 weeks gestation. Because the antibodies from the mother’s immune system will transfer to the fetus, the Tdap vaccine helps protect a pregnant woman and her unborn child from pertussis.
Bordetella parapertussis is a small, Gram-negative bacterium adapted to colonize mammalian respiratory tracts. The resulting disease has symptoms resembling B. pertussis, although it tends to be less severe.
According to recent reports, B parapertussis infections are significantly more common than previously documented. In one study, the relative frequency rates of B parapertussis infections ranged from one percent to 35 percent. In other studies, B parapertussis infections were found in immunized populations, but community-based data were sparse.
The two species of Bordetella parapertussis are closely related but differ in several aspects. Their genomic sequences are highly similar. They have the same O-antigen and lack the pertussis toxin gene. These differences in genomic sequences do not seem to affect the invasiveness of the disease.
While B. parapertussis is often associated with cough, the symptoms are typically milder and may persist for a few days or months. Up to 40 percent of infected individuals are asymptomatic. Only five percent of cases display typical disease symptoms. The typical symptoms include coughing and a whooping sound.
The bacteria that causes the disease is present in both nasal cavities and lungs. Infected persons will develop antibodies against both B. pertussis and B. parapertussis, but the antibodies to B. pertussis will not effectively protect against them.
Bordetella species produce toxins that are thought to play an essential role in the pathogenesis of their diseases. The pertussis toxin is produced by B. pertussis and is responsible for whooping cough and a milder kennel cough syndrome. Bordetella bronchisepticus causes kennel cough and swine rhinitis. Bordetella pertussis also produces the toxins that cause pertussis and parapertussis.
Infections caused by these bacteria have a wide range of host ranges. However, the bacterial genomes of B. bronchiseptica and pertussis are similar and thus may be related. For example, both species have a gene called fimA, which encodes a part of the flagellar operon.
While Bordetella bronchiseptic and pertussis are not epidemic diseases, they can cause respiratory tract infections in children. Moreover, they can affect immune-suppressed individuals. In rare cases, they may cause other conditions such as meningitis, endocarditis, and peritonitis. However, no study has shown direct transmission of these pathogens from guinea pigs to humans.
Mice with the bacterium Bordetella bronchisepticum are susceptible to lethal infection by B. pertussis if they lack neutrophils. In contrast, BALB/c mice with healthy neutrophil counts are not killed by B. bronchiseptica at 5×105 CFU doses.
When mice with Bordetella-free status or infection were compared to mice with the disease, researchers observed that B. bronchiseptica was more active at inducing apoptosis and mediating lysis in J774 cells in the lungs. These findings suggest that B. bronchiseptica may play a role in the onset of pulmonary disease.