Pertussis Awareness And Prevention W. Michael Brown, MD, FAAP Director of Pediatrics Associate Director Family Medicine Residency Bayfront Medical Center St. Petersburg, Florida

Pertussis Awareness and Prevention: Objectives Increase awareness and prevention of pertussis in the United States Educate health care professionals on epidemiology and diagnosis of pertussis Discuss importance of pertussis immunization Discuss important strategies for improving control of pertussis The objectives of this program, as stated in the above slide, are to: 1) Increase awareness and prevention of pertussis in the United States; 2) Educate health care professionals on the epidemiology and diagnosis of pertussis; 3) Discuss the importance of pertussis immunization, and to review efficacy and safety data of pertussis vaccines; and 4) Discuss the implementation of important strategies for improving control of pertussis.

PERTUSSIS (WHOOPING COUGH) Acute respiratory tract infection by Bordetella pertussis highly communicable 80% secondary attack rates among susceptible persons Significant morbidity and mortality in infants Milder nonspecific upper respiratory tract infection in adolescents and adults Difficult to diagnose Referred to by the Chinese as “the cough of 100 days” Pertussis, or whooping cough, is a highly contagious acute respiratory infection caused by Bordetella pertussis, a gram-negative aerobic bacillus. It is one of the most highly communicable of all infectious diseases, easily transmitted from one person to another via coughed aerosolized droplets. The disease may occur at any age, but it manifests most severely in infants and young children, in whom it is potentially life-threatening. In adults and adolescents, pertussis is relatively mild; the only symptoms may be those of a minor, nonspecific upper respiratory tract infection, or there may be no symptoms whatsoever. Diagnosis is thus difficult in this age group. Infected adults and adolescents with mild disease constitute the reservoir for infection in infants and young children. Edwards KM, Decker MD, Mortimer EA Jr. Pertussis vaccine. In: Plotkin SA, Orenstein WA, eds. Vaccines. Philadelphia, PA: WB Saunders; 1999:293-344. Scott PT, Clark JB, Miser WF. Pertussis: an update on primary prevention and outbreak control. Am Fam Physician. 1997;56:1121-1128.

Prolonged Cough Illness in Adolescents and Adults Due to Bordetella Pertussis Source Locale Year(s) % of cough illnesses Jackson et al Seattle 1983-87 15% Robertson et al New S Wales 1985-86 26% Mink et al Los Angeles 1986-89 Schmitt-Grohé et al Germany 1992-94 32% Wright et al Nashville 21% Wirsing v Köenig et al 31% Rosenthal et al Chicago 1993-94 Jansen et al San Diego 17% Nennig et al San Francisco 1994-95 12% Strebel et al Minn-St Paul 1995-96 13% Birbeback et al Denmark 1995-97 Vicent et al Korea 1997-98 50% Gilberg et al Paris 1999 52% [Note: New slide provided by S. Barone]

Pertussis Disease Manifestations Incubation period -- 7 - 10 days (range 4 - 21) Stages Catarrhal: runny nose, sneezing, low-grade fever, mild cough Paroxysmal: severe spasms of cough, thick mucus, whoops, vomiting, exhaustion Convalescent: gradual recovery with less frequent & less severe coughing Photograph courtesy of the WHO

Why Is Pertussis Increasing? Ascertainment…awareness and better diagnostic tests Incomplete immunization of children Variable vaccine efficacy Waning immunity ~ 15 years after active disease ~ 5-10 years after vaccination Under diagnosis, especially in adolescents and adults Lack of an adolescent/adult booster vaccine UNTIL NOW

DECLINE IN VACCINE-PREVENTABLE DISEASE Disease Maximum Cases % cases in 2003 change _____________________________________________________________________________________ Diphtheria 296,939 in 1921 1 99.99% Tetanus 1,560 in 1923 20 98.5% Pertussis 265,269 in 1934 11647 92.1% Measles 894,134 in 1941 56 99.98% Paralytic polio 21,269 in 1952 0 100% 3,100 died _______________________ _____________________________________________________________ Mumps 152,209 in 1968 231 99.80% Rubella 57,686 in 1969 7 99.9% HIB 20,000 prior to 1985 259 98.7% From Centers for Disease Control and Prevention. MMWR 2004

Efficacy of Acellular Pertussis Vaccines Randomized, Blinded Trials* Study Vaccine Efficacy (%) (Confidence Interval)† (WHO)† Stockholm Gustafsson L et al. N Engl J Med. 1996;334:349-355. DAPTACEL™ 85 (81-89) Connaught DTP 48 (37-58) Italy Greco D et al. N Engl J Med. 1996;334(6):341-348. Infanrix® 84 (76-89) 36 (14-52) *Shows results for vaccines available in the United States for 3-dose infant immunization series; effects of any booster dose are not included. †The definition closest to the standard WHO case definition (Edwards KM et al. In: Plotkin SA et al, eds. Vaccines. 1999;293-344).

Reported Pertussis Cases by Year United States, 1922 – 2000 300 Routine pertussis immunization begins 250 200 Cases (Thousands) 150 100 50 1922 1930 1940 1950 1960 1970 1980 1990 2000 Year Source: CDC. Pertussis --- United States, 1997--2000. MMWR 2002;51:73-76.

The Growing Disease Reservoir Increases Exposure to Pertussis 26,000 25,827 24,000 22,000 25,827 122% 20,000 18,000 All Patients 16,000 Children  4 yrs. of age 14,000 11,647 11,647 12,000 9,771 10,000 7,867 5,795 8000 7,580 73% 5,795 3,355 5,137 6000 7,288 4,570 4000 1,730 3,355 2000 1980 1990 1995 1999 2000 2001 2002 2003 2004

Reports of Pertussis in the U.S. Average Number of Cases / Year 1990-1993 1994-1996 1997-2000 2001-2003 3500 552% 490% 3000 2500 Average Number of Cases / Year 2000 1500 1000 500 <1 yr 1-4 yrs 5-9 yrs 10-19 yrs 20+ yrs Centers for Disease Control and Prevention. MMWR. 2002;51:73-76; Güriş et al. Clin Infect Dis. 1999;28:1230-1237. National Immunization Program, Bacterial Vaccine Preventable Diseases Branch. Pertussis Surveillance Report, August 6, 2004

…there are between ~800,000 and 3 …there are between ~800,000 and 3.3 million cases per year in the United States.

Estimated Duration of Immunity After Infection or Vaccination Source of Immunity Duration Reference Natural infection 15 years Wirsing Von Konig, 1995 Whole-cell vaccine UK 6 years Jenkinson, 1988 Finland 6 years He, 1994 Germany > 6 years Lugauer, 2002 Acellular vaccine Italy 6 years Salmaso, 2001 Germany > 6 years Lugauer, 2002 Wirsing Von Konig et al. Lancet ID 2002:2:774-750

Consequences of Waning Immunity Increased transmission of pertussis disease to unimmunized and underimmunized infants and children1 Considerable pertussis-related morbidity and economic cost in families2 Increased incidence of pertussis disease among adolescents and adults1,3 Key Point: Adults and adolescents who are not reimmunized are not only susceptible to infection but also pose a significant risk to close contacts of all ages, including infants who are too young to be vaccinated. Notes: Individuals who do become infected can then serve as a reservoir of infection for other susceptible people, including the unimmunized and underimmunized infants most at risk for severe illness.1 Pertussis disease is also associated with considerable morbidity and economic cost in families,2 which will undoubtedly increase with the incidence of the disease. Since the immunity afforded by vaccines gradually decreases after vaccination,1 and adolescents and adults in the United States generally do not receive a pertussis booster, it is possible the incidence of pertussis disease in these age groups may continue to increase.1,3 References: Edwards KM, Decker MD, Mortimer EA Jr. Pertussis vaccine. In: Plotkin SA, Orenstein WA, eds. Vaccines. Philadelphia, PA; 1999:293-344. 2. Lee LH, Pichichero ME. Cost of illness due to Bordetella pertussis in families. Arch Fam Med. 2000;9:989-996. 3. Centers for Disease Control and Prevention. Pertussis—United States, 1997-2000. MMWR. 2002;51:73-76. 1. Edwards KM et al. In: Plotkin SA et al, eds. Vaccines. 1999;293-344. 2. Lee LH et al. Arch Fam Med. 2000;9:989-996. 3. Centers for Disease Control and Prevention. MMWR. 2002;51:73-76.

Reported Pertussis Cases Are the Tip of the Iceberg Nationwide, an estimated 12% of pertussis cases are actually reported Underreporting may be greatest among adolescents and adults Reported Atypical forms Not Reported Key Point: Pertussis is highly underreported—only 12% of cases are actually reported. It is likely that underreporting may be greatest among adults and adolescents. Notes: One study estimated that nationwide, only 12% of pertussis cases are actually reported. [Güriş 1999, pg 1235, col 2, para 1, line 1] Due to a lack of typical pertussis symptoms such as whoop, underreporting may be higher among adolescents and adults than for young children. [Güriş 1999, pg 1235, col 2, para 1, lines 2-4] Therefore, the reported cases form the tip of the iceberg. The majority of cases are not reported due to various reasons, such as atypical forms, wide disease variability, underconsultation, underdiagnosis, low physician awareness, and inconsistency in case definitions. Reference: Güriş D et al. Changing epidemiology of pertussis in the United States: increasing reported incidence among adolescents and adults, 1990-1996. Clin Infect Dis. 1999;28:1230. Wide disease variability Under- reporting Underconsultation Underdiagnosis Low physician awareness Inconsistent case definitions Güriş et al. Clin Infect Dis. 1999;28:1230. 16

Pertussis Cases Reported in 2002 Each Dot Represents One Case The total number of cases and incidence rate for each state represent provisional numbers, which may change as states report more cases for 2002 Source: Bacterial Vaccine Preventable Diseases Branch, National Immunization Program, CDC. Sharp demarcation at state borders illustrates inconsistent reporting.

75% Of Suspected Sources For Infant Pertussis Cases Were Family Members Other 25% Mom 32% 20% Other Adults Grandparent 8% Dad 15% Sibling 20% 47% Mom or Dad 33% Other Children Bisgard, K. et al. Ped Infect Dis J. 2004;23:985-989.

The Cycle of Pertussis Susceptibility Promotes Transmission & Disease Unvaccinated or partially vaccinated infants: Susceptible Break the Pertussis Cycle: Vaccinate Reduce morbidity in all age groups Reduce reservoir of Pertussis disease Prevent transmission of Pertussis disease between adolescents and adults, and from adolescents and adults to infants Primary vaccination: Protected Susceptible adolescents and adults: Reservoir of B pertussis Booster vaccination: Prolonged protection No additional booster: Immunity wanes Supported by multiple publications. See notes

Pertussis: Clinical Presentation In Infants

Severe vs Mild Pertussis More common in infants Occurs in nonimmune individuals Paroxysmal cough (>21 days’ duration) with heavy inspiration (whoops) accompanied by vomiting and gagging Characteristic symptoms (eg, whoop) often absent1 An important mechanism of transmission to infants Estimated to represent 21% to 26% of acute cough illness in adults2,3 Often unrecognized, underdiagnosed 1. Scott PT et al. Am Fam Physician. 1997;56:1121-1128. 2. Strebel P. Infect Med. 1996;13:S33-S41. 3. Edwards KM et al. In: Plotkin SA et al, eds. Vaccines. 1999;293-344. * World Health Organization (WHO) definition.

Common Clinical Manifestations of Adolescent-Adult Pertussis Cough 97%  3 weeks, 52%  9 weeks Paroxysms  3 weeks in 73% Whoop in 69% Post-tussive emesis in 65% Teens missed average 5 days of school; Adults missed average 7 days of work Average 14 days of disrupted sleep De Serres et al. J Infect Dis. 2000;182:174–9.

PERTUSSIS DEATHS BY AGE, UNITED STATES (1980-1999)

Pertussis Complications By Age

Diagnostic Laboratory Findings In Pertussis Marked lymphocytosis with leukocyte counts often exceeding 50,000 cells/mm3 Generally afebrile with no elevation of ESR or other acute phase reactions CXR with a “shaggy heart” produced by bilateral perihilar infiltrates, edema, and atelectasis Culture of posterior NP swab may take 2 weeks, but negative cultures are common especially after 4 weeks of illness Direct immunofluorescent assay of NP secretions had variable sensitivity and low specificity Serologic tests to measure immunglobin antibody to pertusis toxin (IgG, IgM, IgA). DNA by PCR of NP secretions is the most sensitive and rapid test but may not always be available *Most cases of Pertussis are diagnosed clinically!

Period Of Communicability Of Pertussis -2 -1 1 2 3 4 5 6 7 8 9 10 11 12 Weeks of cough Catarrhal stage Paroxysmal stage Convalescent stage Cough onset Period of communicability Persons with pertussis are most infectious during the catarrhal period starting as early as one day of cough Some individuals, such as infants who remain culture-positive for several weeks, may be infectious for a longer period

Diagnostic Laboratory Findings in Pertussis Positive Culture Catarrhal Paroxysmal Stage Convalescent 50 Lymphocyte Count (thousands) 30 10 1-2 2-5 5-12+ Time After Onset of Symptoms (weeks) Adapted from Mortimer EA. In: Krugman’s Infectious Diseases of Children. 10th ed. Mosby Year Book, Inc; 1998:335-349.

The best site to obtain an appropriate clinical specimen is the posterior nasopharynx, either by aspiration of nasopharyngeal secretions or by insertion of a swab applicator into the posterior nasopharynx.1 Samples taken from nasal discharge or by swabbing the throat and tonsils are inadequate.2 Polymerase chain reaction (PCR) is emerging as the diagnostic method of choice on the basis of studies showing it to be more specific and sensitive than culture.3,4 Serologic testing is not standardized and because of a lack of association between antibody levels and immunity to pertussis, results are difficult to interpret.3,4 Direct fluorescent antibody (DFA) can yield rapid results but has disadvantages of variable sensitivity and specificity.1 References: 1. CDC. Epidemiology and prevention of vaccine-preventable diseases (The Pink Book), 7th ed. US Department of Health and Human Services. 2002:75-88. Available at www.cdc.gov/nip/publications/pink/pert.pdf. Accessed March 13, 2005. 2. Murphy T, Bisgard K, Sanden G. VPD Surveillance Manual, 2000. Chapter 2. Diagnosis and laboratory methods. June 2000;2-1-2-15. 3. Chia JH, Su LH, Lin PY, et al. Comparison of multiplex polymerase chain reaction, culture, and serology for the diagnosis of Bordetella pertussis infection [abstract]. Chang Gung Med J. 2004;27(6):408-415. 4. Wright SW. Pertussis infection in adults. South Med J. 1998;91(8):702-708.

Serology 3 weeks or longer IFA never Diagnosis Culture 1-3 weeks cough PCR 1-4 Serology 3 weeks or longer IFA never

TREAMENT OF PERTUSSIS Infants younger than 6 months generally require hospitalization Antibiotic Therapy: Erythromycin 40 to 50 mg/kg/day given QID x 14 days Azythromycin 10 to 12 mg/kg/day given Qday X 5 days Clarithromycin 15 to 20 mg/kg/day given BID X 7 days Bactrim or Septra 8 mg TMP/ 40 mg SMX per kg per day in two divided doses for 14 days if allergic to macrolides *Treatment with antibiotics does not effect duration or severity of clinical course Cough suppressants MMWR Jan. 2005 Pertussis is most common among infants less than a year old, but anyone can get this disease. Pertussis can be hard to diagnose in very young infants, teens and adults because their symptoms often look like a cold with a nagging cough. However many different forums provide an avenue for transmission: Adolescents acquiring pertussis from community and household contacts School age or daycare children transmitting pertussis back to adults The disease ranges from asymptomatic to severe however adolescents and adults with pertussis are more likely to have milder illness (I.e. and illness resembling and upper respiratory infection or acute cough illness without paroxysms, whoop, or post-tussive vomiting).1 Adults and adolescents can then transmit pertussis to their young infants who are at the highest risk of morbidity and mortality. 1 Cherry JD. Epidemiological, clinical, and laboratory aspects of pertussis in adults. Clin Inf Dis 1999; 28 (Suppl 2): S112-7.

Antigenic Components of B pertussis FIM Pertussis toxin (PT), also known as “lymphocytosis-promoting factor” (systemic action) Filamentous hemagglutinin (FHA) Pertactin (PRN) or 69 kD* protein Fimbrial agglutinogens (FIM) (1-4 serotypes) FHA PT PRN *kD = kilodalton. Edwards KM et al. In: Plotkin SA et al, eds. Vaccines. 1999;293-344.

Diphtheria, Tetanus, and Acellular Pertussis Vaccines Currently licensed in US Tripedia® Infanrix®* Daptacel™ Boostrix™ Adacel® Indicated Age Group Infants/ Children† Adolescents‡ (10-18 years) Adults/ Adolescents‡ (11-64 years) Antigenic Components§ PT (µg) FHA (µg) PRN (µg) FIM 2 + 3 (µg) D (Lf) T (Lf) 23.4 23.4 — — 6.7 5 25 25 8 — 25 10 10 5 3 5 15 5 8 8 2.5 — 2.5 5 2.5 5 3 5 2 5

Comparison of Tdap Vaccines Adacel Boostrix Company Sanofi GSK Age 11-64 10-18 Efficacy 21d 85% 84% 7d 78% 71% Components 4 (fimbrae) 3 Diphtheria LF 2 2.5

The Adacel Program in Newfoundland Replaced Td in 1999 school year Adacel delivered in a Grade 9 (14 year olds) school-based program Approximately 25,000 doses given by June 2004

Incidence of Pertussis in Newfoundland, 1993-2003 70 60 Introduction of adolescent dTaP5 50 40 Incidence per 100,000 Population 30 **** Pertussis outbreak confined to persons not immunized with dTaP5 20 10 **** 1993 94 95 96 97 98 99 2000 01 02 03 Time Periods CCDR Notifiable Disease Annual Summaries

Pertussis Incidence and Vaccine Use, 1993 – 2004 Canada’s Northwest Territories Switch to Pentacel Adacel begun 12 10 8 Average Yearly Cases / 10,000 6 4 2 1993-1996 1997-2000 2001-2002 2003-2004 Time Periods Kandola, K. Abstract in Can J Infect Dis Med Microbiol. 2004;15:351. Manuscript in preparation.

United States Licensure Trial: Summary of Immunogenicity Key point: Seroprotection rates for diphtheria and tetanus were comparable with the Tdap and Td vaccines. Notes: This slide presents seroprotection achieved one month post vaccination with the Tdap and Td vaccines in adolescents and adults in a pivotal US trial. Td 506 was a Phase 3, multicenter, randomized, double-blind trial conducted in the United States in adolescents (11-17 years) and adults (18-64 years) comparing the safety and immunogenicity of Tdap (Adacel™) and Td. In adolescents, the diphtheria seroprotection rates were equal99.8% with Tdap and Td; as were the tetanus seroprotection rates which were 100%. In adults, the diphtheria seroprotection rates were 94.1% and 95.1% with Tdap and Td, respectively. The tetanus seroprotection rates were 100% and 99.8% with Tdap and Td, respectively. For diphtheria, the seroprotection rates among adults increased equally by 50% with both vaccines. Among adolescents they increased by 38% and 41% with Tdap and Td, respectively. For tetanus, the seroprotection rates among adults increased by 2.7% and 4.1% with Tdap and Td, respectively. Among adolescents they increased by 0.4% and 0.8% with Tdap and Td, respectively. Reference: Data on file, Td 506 Aventis Pasteur Limited, Toronto, Canada. Pre Post Diphtheria Tetanus Data reported for sera collected one month after vaccination. Data on file, Td 506, Aventis Pasteur Limited, Toronto, Canada.

United States Licensure Trial: Summary of Solicited Systemic Reactions Key Point: The incidence of systemic adverse reactions was comparable following Tdap and Td vaccine administration. For both Tdap and Td vaccines, headache is the most common reaction reported among adults and adolescents. Notes: This slide presents the most common systemic adverse events observed after Tdap and Td vaccine administration in adolescents and adults in a large scale US safety and immunogenicity trial (Td506). This trial was a Phase 3, multicenter, randomized, double-blind trial conducted in the United States in adolescents (11-17 years) and adults (18-64 years) comparing the safety and immunogenicity of Tdap (Adacel™) vs Td. The adverse events observed with Tdap were comparable to those observed with Td vaccine. The most common systemic reaction, among both adolescents and adults was headache, with an incidence of 44% for Tdap and 40% for Td in adolescents. Other common systemic reactions included fever, body ache/weakness, tiredness, sore/swollen joint, and chills. Severe systemic reactions were uncommon: the most common, headache, was reported in 1.96% of adolescents and 2.77% of adults in Tdap vaccine recipients. Severe occurrences of all other systemic reactions occurred in <2.00% of adolescents and <2.37% of adults in Tdap recipients. Reference: Data on file, Td 506, Aventis Pasteur Limited, Toronto, Canada. Fever Headache GeneralizedBody Ache Tiredness Sore Joints Chills Data collected from days 0-14. Data on file, Td 506, Aventis Pasteur Limited, Toronto, Canada.

United States Licensure Trial: Summary of Solicited Local Reactions Adolescents = 11-17 years. Adults = 18-64 years. Key point: The incidence of local adverse events in the first 3 days after vaccination is similar between Tdap and Td vaccines for both adults and adolescents, and these reactions were well-tolerated. Notes: This trial was a Phase 3, multicenter, randomized, double-blind trial conducted in the United States in adolescents (11-17 years) and adults (18-64 years), comparing the safety and immunogenicity of Tdap (Adacel) vs Td. Localized reactions of pain, swelling, and redness or erythema are common adverse reactions observed at the injection site for both Tdap and Td vaccine recipients and were comparable with both vaccines. For both age groups, local pain was the most common reaction. The incidence of any pain was slightly higher in adolescents receiving Tdap than Td (78% vs 71%); this difference is due to a slight increase in reports of mild pain among Tdap recipients. Comparable rates of local pain were reported in adults receiving Tdap and Td vaccines. Overall Tdap vaccine was well-tolerated in both adolescents and adults; injection site erythema, swelling, and pain were brief in duration and tended to be of mild or moderate intensity. Reports of severe local reactions were uncommon. The severity data is as follows: Severe erythema in adolescents: Tdap vs Td (6.04% vs 5.34%); in adults: Tdap vs Td ( 6.18% vs 4.81%). Severe swelling in adolescents: Tdap vs Td (6.38% vs 5.46%); in adults: Tdap vs Td (5.77% vs 5.53%). Severe pain in Adolescents: Tdap vs Td (1.45% vs 0.64%), in adults: Tdap vs Td (1.12% vs 0.89%). Reference: Data on file, Td 506, Aventis Pasteur Limited, Toronto, Canada. Severe Erythema* Erythema Severe Swelling* Swelling Severe Local Pain† Local Pain No significant difference was observed between Tdap and Td recipients for any safety parameters measured with the exception of pain in adolescents which was marginally more frequent in Tdap recipients. Data collected from days 0-3. *≥35 mm; †Severe local pain: incapacitating, unable to perform usual activities, may have/or required medical care or absenteeism. Data on file, Td 506, Aventis Pasteur Limited, Toronto, Canada.

Adequacy, Efficacy, & Safety Data for Tdap Vaccines Age Indications: Adacel 11- 64 years, Boostrix 10-18 years Both vaccines met all agreed non-inferiority criteria For Diphtheria and Tetanus antigens, at least as immunogenic as US – licensed Td vaccines Pertussis booster response induced an immune response at least as immunogenic as Daptacel and Infanrix Can be used concomitantly with other vaccines Safety profile comparable to US-licensed Td Vaccine

FDA Vaccine Advisory Committee Unanimous vote March 2005 Adacel safe and effective age 11-64 years of age Boostrix safe and effective 10-18 years of age Licensure… May, June 2005 CDC ACIP July 2005 11-12 yr Universal Immunization, catch up 5 yrs from last Td Oct 2005 Universal Adult Immunization,10 yrs from Td

Rationale for Vaccinating Adolescents and Adults: Bordetella Pertussis Reservoirs Adolescents and Adults Are Primary Sources for Infant Transmission Health Care Providers Most hospital outbreaks of pertussis disease involve transmission from health care workers to pediatric patients1 Adults/Parents In Chicago, young mothers with a cough >7 days were shown to be a significant source of pertussis disease transmission to their young infants2 Grandparents In 15% of families, an adult patient was identified as the source of infection for other household members. Fifteen percent of these adults were grandparents or great-grandparents of an affected child3 Adolescents/Siblings For 27% of infants hospitalized with pertussis disease in London between 1998 and 2000, an older, fully vaccinated sibling was the source of infection4 Key Point: Identification and vaccination of the adult B pertussis reservoirs, such as healthcare providers, parents, grandparents, and siblings are essential to preventing the transmission of the disease to infants. Young infants are at highest risk for severe complications from pertussis as they are too young to be immunized. Certain adolescent and adult population groups who serve as pertussis reservoirs should be vaccinated. Health care workers: Most hospital outbreaks of pertussis disease involve transmission from health care workers to pediatric patients.1 [Sheretz 2001, pg 1, col 1, para 3, lines 6-10] Adults/parents: A study assessing risk factors for pertussis among young infants during a pertussis outbreak in Chicago in 1993 found that young mothers with cough >7 days were shown to be a significant source of pertussis disease transmission to their young children.2 [Izurieta 1996, pg 503, abstract, lines 11-13] Grandparents: A 2-year study assessing the symptoms and complications of pertussis in adults showed that in 15% of cases, an adult was the source of infection for other household members. Fifteen percent of these adults were grandparents or great-grandparents of the affected child.3 [Postels-Multani 1995, pg 140, col 2, para 5, lines 5-6; pg 141, col 1, para 1, lines 5-7] Adolescents/siblings: For 27% of infants hospitalized with pertussis disease in London between 1998 to 2000, an older, fully vaccinated sibling was the source of infection.4 [Crowcroft 2003, pg 802, abstract, para 3, lines 8-9] References: 1. Sherertz RJ, Bassetti S, Bassetti-Wyss B. “Cloud” health-care workers. Emerg Infect Dis. 2001;7:241-244. 2. Izurieta HS, Kenyon TA, Strebel PM et al. Risk factors for pertussis in young infants during an outbreak in Chicago in 1993. Clin Infect Dis. 1996;22:503-507. 3. Postels-Multani S, Schmitt HJ, Wirsing von Konig CH, et al. Symptoms and complications of pertussis in adults. Infection. 1995;23:139-142. 4. Crowcroft NS, Booy T, Harrison T et al. Arch Dis Child. 2003;88:802-806. 1. Sheretz et al. Emerg Infect Dis. 2001;7:241-244. 2. Izurieta et al. Clin Infect Dis. 1996;22:503-507. 3. Postels-Multani et al. Infection. 1995;23:139-142. 4. Crowcroft et al. Arch Dis Child. 2003;88:802-806.

Recommendations of the ACIP (CDC) for the use of Tdap vaccines: Advisory Committee On Immunization Practices (ACIP) Recommendations For Tdap Vaccine In Adolescents Recommendations of the ACIP (CDC) for the use of Tdap vaccines: Adolescents 11 to 12 years of age be given Tdap in place of the Td booster currently being used Tdap vaccine should be given to adolescents 13 to 18 years who missed the 11 to 12 year dose of Td Adolescents 11 to 18 years of age who have already been vaccinated with Td are encouraged to receive a dose of Tdap to further protect against pertussis Adolescents can and should receive Tdap and the meningococcal conjugate vaccine (menactra) at the same visit

ACIP Recommendations for Tdap Vaccine Use in Adults Adults who have not received a Td immunization during the last 10 years should receive a single dose of Tdap Vaccine Those not previously given Tdap vaccine may be given Tdap vaccine at shorter intervals (< 10 years) following last Td immunizations in settings of wound management and increased risk (including pertussis outbreaks and contact with infants Adults who anticipate having close contact with infants (ie: parents, healthcare workers and daycare workers) should receive a single dose of Tdap vaccine to protect against pertussis if they have not received Tdap vaccine. Ideally these adults should receive Tdap vaccine at least one month before beginning close contact with infants

Other ACIP Recommendations for Adult Tdap Use Women should receive Tdap vaccine immediately post partum if not previously immunized Women are encouraged to receive Tdap vaccine before conception Tdap vaccine is encouraged over Td vaccine in the wound care setting for those who have not previously received Tdap vaccine Pregnancy is not a contraindication to Tdap and may be considered in the 2nd and 3rd trimester

ACIP Recommendations for Tdap Use In Healthcare Workers There are 8-10 million workers employed in hospital and ambulatory settings. The risk of contracting pertussis from healthcare workers is nearly 2 times greater than the general population. For each decade the immunization of healthcare workers could prevent as many as 100, 000 cases of pertussis and save up to $151 million in direct and indirect costs. Therefore it is recommended that all healthcare workers and anyone who works in a healthcare setting receive Tdap.

Strategies to Control Pertussis… Improve immunization coverage Ensure immunization of all appropriate infants Prevent mild disease Improve surveillance and reporting Implement Tdap vaccines for adolescents and adults Eliminate reservoirs of infection in general population Reduce transmission to vulnerable infants

SUMMARY Epidemiology of pertussis disease has changed with the spectrum of illness shifting to a milder form in all age groups B. pertussis infections in the adolescent and adult populations are common and endemic accounting for more of the disease seen today Immunity after natural infection or vaccinations is not life long and wanes rapidly after 5 – 8 years Pertussis acounts for up to 25% of acute cough illnesses in the adolescent and adult populations The adolescent and adult populations serve as a major resevoir of disease transmission to the young infant population Immunizing the infant population on time and implementing a booster vaccine program in the adolescent and adult populations will have the greatest impact on decreasing the amount of disease seen

…a universal program of adolescent and adult boosters would decrease the circulation of B pertussis… and possibly could lead to the elimination of the organism…

Questions