Long-lasting cough in an adult German population: incidence, symptoms, and related pathogens.

Studies of the incidence of pertussis in adults have shown that it accounts for only 5-15% cases of prolonged coughing. We assessed the burden of suffering related to prolonged coughing and tried to identify further causative agents. Based on a sentinel study with 35 general practitioners in two German cities (Krefeld, Rostock), with 3,946 patients fulfilling the inclusion criteria, we estimated the incidence of prolonged coughing in adults. In 975 of these outpatients, PCR and/or serology for adenovirus, Bordetella pertussis and B. parapertussis, human metapneumovirus, influenza virus A and rhinovirus, parainfluenza virus, Mycoplasma pneumonia, and respiratory syncytial virus (RSV) were performed. Treatment data were extracted for a subgroup of 138 patients. Descriptive statistics, including Kaplan-Maier curves were generated. Yearly incidence ranged between 1.4 and 2.1% per population in the two cities. Adult patients sought medical attention only after a median of 3 weeks of coughing. Irrespective of smoking and unrelated to the identified pathogens, the median duration of coughing was 6 weeks, with an interquartile range of 4-11 weeks. In 48.3% of patients, possible pathogens were identified, among which adenovirus (15.1%), RSV (7.5%), B. pertussis (5.6%), and influenza viruses (4.0%) were most often found. Symptoms were not indicative of a specific agent and a total of 64% of patients received antibiotics. Prolonged adult coughing requiring medical attention prompts substantial healthcare use. Apart from B. pertussis, a broad range of pathogens was associated with the symptoms. However, patients sought medical attention too late to guide efficacious therapeutic interventions using the diagnostic tests.

Long-term immunogenicity of a single dose of acellular pertussis vaccine in paediatric health-care workers.

OBJECTIVE: Monitor the long-term immunogenicity of a single dose of acellular pertussis vaccine in health-care workers. DESIGN: German health-care workers and child-care workers received a single dose of a monovalent acellular pertussis vaccine (PAC-Mérieux) in an open-label study. Blood samples were taken before (n=261), 4 weeks after (n=246), 1 year (n=187), 2 years (n=53), 3 years (n=134) and 4 years (n=37) after vaccination. IgG- and IgA-anti-pertussis-toxin (PT), IgG- and IgA-anti-filamentous hemagglutinin (FHA), and IgG-anti-pertactin (PRN) were measured by ELISA. RESULTS: Of all subjects, 97.1%, 99.2% and 97.2% had an antibody response to PT, FHA and PRN, respectively. Four weeks after vaccination the median titres of IgG antibodies to PT, FHA and PRN were 314, 785 and 84 EU/l, respectively, and all vaccinees had an immune response to at least one pertussis antigen. IgA-anti-PT and IgA-anti-FHA responses were found in 63.4% and 96.3% of subjects with a median titre of 30 and 196 EU/ml, respectively. The titre of IgG-anti-PT decreased slowly with a median concentration of 76, 71, 71 and 63 EU/ml after 1, 2, 3 and 4 years, respectively. Secondary titre increases were observed in 0.5%, 3.3%, 5.6% and 12.5% of the vaccinees 1, 2, 3, and 4 years after vaccination. CONCLUSION: In German health paediatric care workers long-lasting immune responses with high antibody levels could be induced by a single dose of acellular pertussis vaccine. A renewed contact with B. pertussis antigens resulted in a measurable immune response to PT between 0.5% (1 year p.v.) and 12.5% (4 years p.v.).

Pertussis: not only a disease of childhood.

INTRODUCTION: Pertussis is not just a childhood disease, but a respiratory infection that causes persistent cough in all age groups, from newborns to the elderly. METHODS: The authors performed a selective literature search and reviewed national and international recommendations for treatment and vaccination. RESULTS: Pertussis is found principally in young unvaccinated infants, but school-age children, adolescents, and adults are also affected. Up to 1% of infants contract pertussis, and their respiratory symptoms are often accompanied by apnea. School-age children occasionally display the coughing spasms typical of the disease. Annually, 0.2% to 0.5% of all adolescents and adults are infected and suffer from prolonged, frequently non-paroxysmal coughing. Severe and fatal cases of pertussis occur mainly in newborns and infants, and 25% of affected adults experience complications. Bordetella DNA may be detected by polymerase chain reaction (PCR) for four weeks after symptom onset; except in infants, the sensitivity of this diagnostic technique is low. Although the diagnosis can be confirmed by serological tests, the methods are not well standardized. Treatment with a macrolide prevents the spread of infection, but generally does not alleviate the symptoms. Combination vaccines are the most effective means of prophylaxis. DISCUSSION: Pertussis is usually not included in the differential diagnosis of persistent respiratory symptoms. The considerable burden of disease could be reduced in adults and young infants by vaccinating adults with acellular combination vaccines.