Seroprevalence of Bordetella pertussis among a nationally representative sample of Iranian pediatric population: The childhood and adolescence surveillance and prevention of adult noncommunicable disease-V study

Sero-Epidemiological Study of Bordetella pertussis Infection in the Italian General Population

A multicenter study was conducted to estimate the prevalence of pertussis IgG antibodies (anti-PTx) in the Italian population. Serum samples (4154) collected in the years 2019−2020 from subjects aged 6 to 90 years were tested. The anti-PTx IgG levels were determined by ELISA test. The limit of detection was 5 IU/mL (International Units per milliliter); values ≥ 40 IU/mL and ≥100 IU/mL indicate an infection that has occurred in recent years and a recent infection (occurred during the last year), respectively. The mean concentration of anti-PTx IgG antibodies in the tested samples was 13 IU/mL; 1.0% of subjects had a titer ≥ 100 IU/mL, 5.3% a titer between 40 and 100 IU/mL, and 38.9% a titer < 5 IU/mL. The mean antibody concentration was significantly higher in males than in females. The age group 25−39 years had the lowest percentage of negative subjects (36.9%) and the highest prevalence of subjects with antibody titers ≥ 100 IU/mL (1.3%). In the age group ≥ 65 years, the prevalence of subjects with titers between 40 and 100 IU/mL (6.7%) and the percentage of negative subjects (44.8%) was higher than in the other age groups. The results highlight the possible role of adolescents and adults in the transmission of B. pertussis.

Pertussis Prevalence in Adult Population in Greece: A Seroprevalence Nationwide Study

The reported cases of pertussis vary considerably globally. In the present nationwide study, we aimed to record the Bordetella pertussis prevalence in Greece by measuring serum IgG specific antibody levels to pertussis toxin (anti-PT IgG). General practitioners and laboratories participated in this study from 12 regions of Greece. A geographically stratified sampling plan based on regional units (NUTS level 2) was applied in order to produce a representative sample, taking into consideration age group (30−39, 40−49, 50−59, 60−69, 70−79 and 80+) and sex. In total, 1169 subjects participated in the study. The percentage of participants with anti-PT IgG antibodies higher than 50 IU/mL was 3.7%. The levels of anti-PT IgG antibodies of total sample ranged between 1.46 IU/mL to 126.60 IU/mL, with mean 17.74 IU/mL and standard deviation 14.03 U/mL (p-value < 0.001). The total seroprevalence of Greek regions for pertussis disease varied significantly among prefectures. The region with the highest seroprevalence was Peloponnese 21.3%, followed by the region of Central Greece 15.3%. The proportion of adults who have pertussis specific antibodies <50 IU/mL has been >90%, suggesting that a large number of adults may be vulnerable to infection of pertussis despite well-established vaccination programs in Greece. Despite the fact that vaccination reduced the number of reported pertussis cases in the last decades in Greece, our seroprevalence study may indicate that the herd immunity level among Greek adults is suboptimal.