Seroprevalence of Pertussis Toxin Antibody in Manisa Province of Turkey, After Six Years Implementation of Acellular Pertussis Vaccine

Abstract

Vaccination is the most effective way of preventing pertussis disease. Turkey commenced a routine infant immunization program using whole cell (wP) pertussis vaccine in 1968. Immunization accelerated in 1985 after participation of Turkey in the Expanded Programme on Immunization initiated by the World Health Organization. Acellular vaccine (aP) replaced wP in 2008 and a booster was added to age 6 in 2010. The immunization programme was successful in reducing the morbidity rate from 20.58 per 100.000 in 1970 to the lowest level of 0.01 per 100.000 in 2009. However, reduction of vaccine-induced protection and reduced natural boosting of circulating Bordetella pertussis are likely to increase the susceptibility of the population. As a result, morbidity rate increased from 0.09 per 100.000 to 0.41 per 100.000 in 2015 compared to the previous year. The aim of this epidemiological study was to determine the seroprevalence of pertussis toxin (PT) antibodies among healthy people and its association with various social determinants in Manisa province in Turkey, 6 years after aP replaced wP vaccine. The study was conducted as a cross-sectional study with a sample of 1250 people that was randomly selected from the over 2 years of age population in Manisa in 2014. Seroprevalence of PT antibody was determined as the dependent variable of the study. Independent variables of the study were; gender, age, migration in the last 5 years, occupational class, perceived income, house ownership, number of people per room, annually per capita equivalent income. The presence of anti-PT IgG was detected by quantitatively using a commercially available ELISA kit. The antibody levels were categorized into groups according to pertussis infection or vaccination immune response status. The groups consisted of undetectable (< 5 IU/ml), mid-range (5-< 62.5 IU/ml: more than one year previously), high (62.5-< 125: with in 12 months) and very high (≥ 125 IU/ml: with in 6 months) antibody levels. The test results with ≥ 5 IU/ml were defined as seropositive. Level > 100 IU/ml detected among adolescent and adult participants indicated acute or recently recovered pertussis infection. Chi-square test was used to evaluate association between social determinants and pertussis seropositivity. The seroprevalence of the whole study population was 58.1% (95% CI 55.32-60.79) and no association was found with any of the social determinants. The highest seroprevalence was found among 2-9 age group (68.3%) followed by 70-79 age group (63.5%). The lowest seroprevalence was found among 20-29 age group (50.9%) followed by 10-19 age group (51.6%). When seropositivity levels according to ages were compared, it was found that there was a decrease one year after the first vaccination at 2nd, 4th and 6th months and the booster at the 6th year, with a lowest rate (19%) in 11 year-old. The highest seropositivity (77.3%) with a level of >100 IU/ml (13.6%) were detected at age 15 among all adolescent and adult participants. Adding an adolescent booster to immunization schedu...

Recommending immunizations to adolescents in Turkey: a study of the knowledge, attitude, and practices of physicians

“…27 In another study of patients between 2 and 80 years old, anti-PT IgG antibodies were found to be lowest at 11 years old and highest at 15 years old. 28 The authors suggested that the high levels of anti-PT IgG antibodies detected in 15-year-olds were due to pertussis infection. 28 In another study, Bordetella pertussis positivity was found in 19.8% of children who had a cough for more than two weeks between the ages of 7 and 18.…”

“…28 The authors suggested that the high levels of anti-PT IgG antibodies detected in 15-year-olds were due to pertussis infection. 28 In another study, Bordetella pertussis positivity was found in 19.8% of children who had a cough for more than two weeks between the ages of 7 and 18. 29 The results of the present study indicate that physicians do not have sufficient knowledge of Tdap immunization for adolescents.…”

Retrospective analysis of serologic test requests in the diagnosis of viral hepatitis: Inappropriate test requests and cost

“…Özbek et al found that 14% for anti-HAV total and 18% for anti-HBc total were unnecessarily repeated tests between May 2002 and May 2005 at Dokuz Eylül University. [11] Özbek examined unnecessary test requests from hepatitis B vaccinated patients between 2007 to 2009 and found that 24.6% of anti-HBs positive patients had repeat tests and 12.9% of other parameters (HBsAg, anti-HBc, anti-HBc IgM, HBeAg, anti-HBe) were unnecessarily requested. [5] In their study evaluating inappropriate test rerequests for HbsAg, anti-HCV, and antihuman immunodeficiency virus antibody tests performed at Sakarya University Training and Research Hospital between January 2009 and December 2013, Demiray et al found a re-request rate of 20.2% and a financial loss of 6489 US dollars.…”

“…[11] Özbek examined unnecessary test requests from hepatitis B vaccinated patients between 2007 to 2009 and found that 24.6% of anti-HBs positive patients had repeat tests and 12.9% of other parameters (HBsAg, anti-HBc, anti-HBc IgM, HBeAg, anti-HBe) were unnecessarily requested. [5] In their study evaluating inappropriate test rerequests for HbsAg, anti-HCV, and antihuman immunodeficiency virus antibody tests performed at Sakarya University Training and Research Hospital between January 2009 and December 2013, Demiray et al found a re-request rate of 20.2% and a financial loss of 6489 US dollars. [12] Genç et al found that the total number of unnecessary HBV serologic tests performed at Dumlupınar University between 2011 to 2013 was 3.01%.…”

“…[2,3] The tests used in the diagnosis and treatment follow-up of these infections constitute a significant portion of the workload and cost in the serology laboratory. [4][5][6] The markers used in the routine serologic diagnosis of hepatitis A, B, and C are anti-HAV total, anti-HAV immunoglobulin M (IgM), hepatitis B surface antigen (HBsAg), anti-hepatitis B surface antibody (anti-HBs), hepatitis B core antigen antibody (anti-HBc) IgM, anti-HBc immunoglobulin G (IgG), hepatitis B e antigen (HBeAg), anti-hepatitis B e antibody (anti-HBe), and anti-HCV. Anti-HAV total positivity is detected in people who have had hepatitis A infection or who have been vaccinated, while the patient's exposure to HBV is indicated by anti-HBc IgG positivity and negative in vaccinated people.…”