Assessment of carriage of Haemophilus influenzae type a after a case of invasive disease.
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Carrier State↗
Biomedical subjects
Jay C Butler
Publications and source records attributed to Jay C Butler.
Indirect effect of conjugate vaccine on adult carriage of Streptococcus pneumoniae: an explanation of trends in invasive pneumococcal disease.
BACKGROUND: Use of heptavalent protein-polysaccharide pneumococcal conjugate vaccine (PCV7) has been associated with decreases in PCV7-type invasive pneumococcal disease and nasopharyngeal (NP) carriage in children. Vaccine use has also indirectly decreased the rate of invasive disease in adults, presumably through decreased transmission of pneumococci from vaccinated children to adults. METHODS: We conducted NP carriage surveys in 8 villages in Alaska in 1998-2004. Streptococcus pneumoniae isolates were characterized by serotype and antimicrobial susceptibility. We analyzed trends in serotype distribution, antibiotic resistance, and factors associated with adult carriage of PCV7-serotype pneumococci before and after the introduction of PCV7 in 2001. RESULTS: We collected 15,598 NP swabs; overall, 52% of adults living in the villages surveyed participated in the colonization study. The proportion of adult carriers with PCV7-type pneumococcal carriage decreased from 28% of carriers in 1998-2000 to 4.5% of carriers in 2004 (P<.0001). Among adults, the proportion of colonizing isolates that were resistant to penicillin decreased from 13% in 1998-2000 to 6% in 2004 (P=.05), whereas the percentage of isolates with intermediate susceptibility to penicillin increased from 12% in 1998-2000 to 19% in 2004 (P<.01). Adults were more likely to carry PCV7-type pneumococci if they lived with a child <5 years old or if they lived with a child who had not been age-appropriately vaccinated with PCV7. CONCLUSIONS: Pediatric vaccination with PCV7 has resulted in decreased PCV7-type pneumococcal carriage among adults and helps to explain recent decreases in the rate of PCV7-type invasive pneumococcal disease among adults.
Adolescent↗
Immunogenicity and reactogenicity to Haemophilus influenzae type B (Hib) conjugate vaccine among rural Alaska adults.
BACKGROUND: Despite routine vaccination and declining disease rates, Haemophilus influenzae type b (Hib) invasive disease still occurs in rural Alaska. Colonization studies indicate persistent transmission of Hib among village residents, including adults. As part of a project to eliminate Hib carriage in three rural villages, we evaluated a cohort of Alaska adults for antibody response and reactogenicity to a single dose of Hib conjugate vaccine (HbOC). METHODS: 75 previously unvaccinated, randomly-selected adults in one village received a single dose of HbOC vaccine and completed a side-effects diary. Sera and oropharyngeal specimens were collected at baseline, two months and one year. RESULTS: No participants were colonized with Hib or reported serious side-effects. At baseline, 97% of adults had IgG anti-PRP concentrations > or = 0.15 microg/mL, 69% > or = 1 microg/mL, and 28% > or = 5 microg/mL. Two months post-vaccination, 100% of participants had concentrations > or = 0.15 microg/mL, 93% > or = 1 microg/mL, and 86% > or = 5 microg/mL. After 1 year, 98% had IgG anti-PRP concentrations > or = 0.15 microg/mL, 86% > or = 1 microg/mL, and 67% > or = 5 microg/mL. GMCs were 1.9, 33.3 and 8.4 microg/mL at baseline, 2 months and 1 year post-vaccine, respectively (p < 0.01). Serum bactericidal activity increased from a baseline geometric mean titer of 2,205 to 8,349 two months post vaccination and declined to 1102 after one year. CONCLUSIONS: HbOC vaccine was immunogenic and well-tolerated among Alaskan adults. Nearly 90% of the adults developed an antibody level associated with protection against Hib colonization which persisted for 1 year in 67% of participants.
Adult↗
Relationship between IgE and specific aeroallergen sensitivity in Alaskan native children.
BACKGROUND: The relationship between atopic disease and serum IgE levels varies among populations and geographic regions. The close association of atopy with IgE may not occur in subarctic populations as it does in developed countries in temperate climates. OBJECTIVE: To evaluate the relationship between total and specific IgE concentrations and clinical atopy in 5- to 8-year-old Alaskan native children. METHODS: Medical record reviews, interviews, physical examinations, serum IgE measurements, and radioallergosorbent testing (RAST) were performed. RESULTS: The IgE geometric mean was 122.1 IU/mL. Fifty-eight percent of patients had IgE levels greater than 70 IU/mL, and 17% had levels greater than 1,000 IU/mL; 14% had RAST values greater than 0.35 kU/L. Both IgE levels greater than 70 IU/mL and greater than 1,000 IU/mL were associated with RAST values greater than 0.35 IU/L (P = .004) and early wheezing (P = .005) but not with current wheezing, asthma, eczema, or a history of allergies. A RAST value greater than 3.51 kU/L was associated with eczema (P = .04) but not with allergies or wheezing. Children with current wheezing were more likely to have allergies (P = .03) but not eczema, an IgE level greater than 70 IU/mL, or a positive RAST value. Children hospitalized with respiratory syncytial virus (RSV) were not more likely than controls to have current wheezing. CONCLUSIONS: Elevated serum IgE concentrations, including levels greater than 1,000 IU/mL, are common among Alaskan native children; positive RAST reactions to aeroallergens are not. The IgE levels do not relate to wheezing, eczema, a history of allergies, or past hospitalization for RSV infection but likely reflect infections other than RSV and environmental factors in subarctic indigenous populations.
Alaska↗
Decline in respiratory syncytial virus hospitalizations in a region with high hospitalization rates and prolonged season.
BACKGROUND: During 1993 to 1996, Alaska Native infants <1 year of age from the Yukon Kuskokwim (YK) Delta in Alaska experienced a respiratory syncytial virus (RSV) hospitalization rate 5 times the U.S. general infant population rate. We describe trends in lower respiratory tract infection (LRTI) and RSV hospitalizations in YK children from 1994 to 2004. METHODS: We abstracted hospital dates, RSV test results and clinical information from the hospital records for YK children <3 years of age hospitalized between July 1994 and June 2004. RESULTS: : The RSV hospitalization rate in YK Delta children <1 year of age decreased from 178 per 1000 infants per year (1994-1997) to 104 per 1000 infants per year (2001-2004) (P < 0.001), and the RSV hospitalization rate for premature infants decreased from 317 to 123 per 1000 infants per year (P < 0.001). The risk reduction for RSV hospitalization was greater in premature (relative risk, 0.39) than in term infants (relative risk, 0.60; P = 0.04). The rate of non-RSV LRTI hospitalizations increased from 153 to 215 per 1000 infants per year (P < 0.001). The median RSV season length was 30.5 weeks. Pneumonia was diagnosed in more than half of RSV admissions. CONCLUSIONS: In YK infants, the RSV hospitalization rate decreased by one-third between 1994 and 2004; however, the overall LRTI hospitalization rate did not change. The median RSV season was twice as long as for the U.S. population. Palivizumab prophylaxis may be responsible for the larger decrease in the RSV hospitalization rate among premature infants; however, the 2001-2004 RSV hospitalization rate among YK infants remained 3 times higher than the U.S. infant rate.
Alaska↗
Immunologic response to Haemophilus influenzae type b (Hib) conjugate vaccine and risk factors for carriage among Hib carriers and noncarriers in Southwestern Alaska.
Continued Haemophilus influenzae type b (Hib) carriage in rural Alaska contributes to the ongoing risk of invasive disease. Community-wide Hib carriage surveys were conducted in three villages in southwestern Alaska. Sixteen carriers and 32 age- and village-matched controls were enrolled and were vaccinated with Hib oligosaccharide-CRM(197) conjugate vaccine. Serum immunoglobulin G (IgG) concentration, antibody avidity, and serum bactericidal activity (SBA) were measured prior to Hib vaccination and 2 and 12 months after vaccination. We identified no demographic or behavioral factors associated with Hib colonization. Prior to vaccination, Hib carriers had a higher IgG geometric mean concentration than controls did (8.2 versus 1.6 microg/ml; P < 0.001) and a higher SBA geometric mean titer (7,132 versus 1,235; P = 0.006). Both groups responded to vaccination with increased IgG and SBA. These data illustrate the role of Hib colonization as an immunizing event and show that Hib carriers in communities with ongoing transmission have no evidence of reduced immune responsiveness that may have put them at risk for colonization.
Adolescent↗
The Alaska Haemophilus influenzae type b experience: lessons in controlling a vaccine-preventable disease.
OBJECTIVE: Before 1991, Alaska Native children experienced one of the highest rates of invasive Haemophilus influenzae type b disease. H influenzae type b vaccine has led to a near-elimination of invasive H influenzae type b disease in the United States. We describe challenges encountered in controlling H influenzae type b disease in Alaska and update the current status of H influenzae disease and carriage in Alaska as lessons to other populations. PATIENTS AND METHODS: We reviewed data from statewide H influenzae disease surveillance conducted during 1980-2004. Vaccine coverage data were based on audits from tribal facilities and the National Immunization Survey. H influenzae type b colonization data were based on 6 carriage studies. RESULTS: After universal infant vaccination in 1991, H influenzae type b disease among Alaska Native and non-Native children < 5 years of age decreased by 94% and 96%, respectively. After a 1996 change in H influenzae type b vaccine from polyribosylribitol phosphate-outer membrane protein conjugate vaccine to H influenzae type b oligosaccharide-CRM197 vaccine, the incidence of H influenzae type b disease increased in rural Alaska Natives from 19.8 to 91.1 cases per 100000 per year < 5 years of age. During 2001-2004, with use of polyribosylribitol phosphate-outer membrane protein conjugate vaccine, the rate of H influenzae type b disease in Alaska Native and non-Native children aged < 5 years decreased to 5.4 and 0 per 100000 per year, respectively. In postvaccine studies, H influenzae type b carriage has decreased in Alaska Native children < 5 years of age. CONCLUSIONS: H influenzae type b vaccination has resulted in a dramatic decrease in invasive H influenzae type b disease in Alaska; however, despite high rates of H influenzae type b vaccine coverage, H influenzae type b disease rates among rural Alaska Native children < 5 years of age remain higher than the rates among non-Native Alaska and other US children. Equity in disease rates may not be achieved in indigenous populations with the current vaccines unless other environmental and household factors contributing to disease transmission are addressed.
Alaska↗
Closer to home: local care improves compliance with RSV prophylaxis in high-risk infants.
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Alaska↗
Impact of heptavalent pneumococcal conjugate vaccine on invasive disease, antimicrobial resistance and colonization in Alaska Natives: progress towards elimination of a health disparity.
We evaluated invasive pneumococcal disease (IPD), antimicrobial resistance and nasopharyngeal colonization before and after introduction of pneumococcal conjugate vaccine (PCV7) in Alaska Natives (AN), a population with high IPD rates. We obtained IPD rates from population-based surveillance. Colonization was determined from annual surveys among rural AN of all ages and from urban children. After vaccine introduction, vaccine-type IPD rates declined by 91% among AN children <2 years, by 80% among non-Natives <2 years, and by 40% for adults of all races (P<0.001 each). IPD decreased for isolates resistant to penicillin, erythromycin and cotrimoxazole (P<0.001 each). Vaccine-type colonization decreased among rural and urban children <5 years and among rural adults (P<0.001 each). PCV7 vaccine has eliminated a longstanding disparity of vaccine-type IPD for AN children. Decreased vaccine-type colonization and IPD in adults demonstrate indirect vaccine effects.
Adolescent↗
The changing landscape of epidemic bacterial meningitis in Africa: new opportunities for prevention.
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Africa↗
Reactions after 3 or more doses of pneumococcal polysaccharide vaccine in adults in Alaska.
BACKGROUND: Following vaccination with 23-valent pneumococcal polysaccharide vaccine (PPV), pneumococcal antibody levels decline to prevaccination levels within 6-10 years. The Advisory Committee on Immunization Practices does not recommend routine revaccination because data on the safety and effectiveness of additional doses are insufficient. METHODS: To determine whether medically attended adverse events occur more frequently after the third dose of PPV than after the first or second dose, we performed a retrospective review of medical records from a computer database for health care facilities that serve more than one-half of the Alaska Native population. All persons who had received > or = 3 PPV doses (n = 179) were included in the review, as were a randomly selected comparison group of 181 persons who had received 1 or 2 doses. RESULTS: Only 1 (0.55%) of 179 persons who had received > or = 3 PPV doses and 4 (2.76%) of 181 persons in the comparison group had a medically attended adverse event, and no severe adverse events were recorded. CONCLUSION: We found no difference in the risk of medically attended adverse events following > or = 3 doses of PPV, compared with 1 or 2 doses.
Adult↗
Nature abhors vacuum, but public health is loving it: the sustained decrease in the rate of invasive Haemophilus influenzae disease.
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Child↗
Outbreak of invasive Haemophilus influenzae serotype a disease.
Haemophilus influenzae serotype a is a rare cause of invasive disease. We report 5 cases of invasive H. influenzae type a that occurred in 3 infants living in a remote region of Alaska during the last 6 months of 2003. H. influenzae type a isolates from this outbreak were closely related as determined by pulsed field gel electrophoresis. Continued surveillance is necessary to monitor trends in H. influenzae invasive disease.
Alaska↗
Persistence of antibody to hepatitis B and protection from disease among Alaska natives immunized at birth.
BACKGROUND: Alaska Native (AN) children were at high risk of acquiring hepatitis B virus (HBV) infection before vaccination began in 1983. We evaluated the long-term protection from hepatitis B (HB) vaccination among AN children immunized when infants. METHODS: During 1984-1995, we recruited a convenience sample of AN children who had received a three dose series of HB vaccine starting at birth and had serum antibody to hepatitis B (anti-HBs) concentrations of >/= 10 mIU/mL at 7-26 months of age. We evaluated anti-HBs concentrations and the presence of anti-HBc in participants' sera every other year up to age 16 years. Anti-HB core antigen (anti-HBc)-positive specimens were tested for hepatitis B surface antigen and for HBV DNA. RESULTS: We followed 334 children for 3151 person-years (median, 10 years per child) with 1610 specimens collected. Anti-HBs concentrations dropped rapidly among all participants. Among children 2, 5 and 10 years of age, 37 of 79 (47%), 33 of 176 (19%) and 8 of 95 (8%), respectively, had anti-HBs concentrations of >/= 10 mIU/mL. Receipt of recombinant vaccine was significantly associated with a more rapid antibody decline (P < 0.001). Six (1.8%) children acquired anti-HBc, 3 of whom had definite breakthrough infections (at least 2 consecutive anti-HBc-positive specimens or at least 1 anti-HBc-positive specimen and HBV DNA detection by PCR). None of these children had detectable hepatitis B surface antigen, and none had symptoms of hepatitis. CONCLUSIONS: Anti-HBs concentrations declined over time among AN infants successfully immunized with HB vaccine starting at birth. Transient anti-HBc appeared in a small percentage of children; however, none developed clinical signs of hepatitis or chronic HBV infection.
Age Factors↗
Evaluation of a volunteer sample in nasopharyngeal colonization surveys for Streptococcus pneumoniae in rural Alaska.
OBJECTIVE: To compare characteristics of persons in rural northern communities who participated in a study on antimicrobial use and drug-resistant Streptococcus pneumoniae (SP) to those who did not participate. STUDY DESIGN: The original study (1998--2000) was a community-based, controlled intervention trial designed to determine the penicillin susceptibility of nasopharyngeal SP isolates in relation to community-wide use of antibiotics. The study continued after 2000, in a subset of the original communities, to prospectively evaluate the impact of the heptavalent pneumococcal conjugate vaccine on the carriage of SP. The results presented here are an analysis of the first five years of data. METHODS: We conducted annual surveys (1998--2002) for nasopharyngeal colonization of SP using a volunteer sample of residents in rural communities. Medical chart reviews for health clinic visitation and antibiotic use were completed for all village residents. RESULTS: Participants were younger (22.8 vs. 28.4 years), had more health clinic utilization (3.3 vs. 2.4 visits) and received more antibiotics (1.0 vs. 0.6 courses) than non-participants. Differences between participants and non-participants were similar across all years of the study. CONCLUSIONS: Our study provides further empirical evidence that selection bias should be considered when designing studies. However, a volunteer sample provided internal consistency for comparison of our main study outcomes across time.
Adolescent↗
Potential impacts of climate change on infectious diseases in the Arctic.
Climate change could cause changes in the incidence of infectious diseases in Arctic regions. Higher ambient temperatures in the Arctic may result in an increase in some temperature sensitive foodborne diseases such as gastroenteritis, paralytic shellfish poisoning and botulism. An increase in mean temperature may also influence the incidence of infectious diseases of animals that are spread to humans (zoonoses) by changing the population and range of animal hosts and insect vectors. An increase in flooding events may result in outbreaks of waterborne infection, such as Giardia lamblia or Cryptospordium parvum. A change in rodent and fox populations may result in an increase in rabies or echinococcosis. Temperature and humidity influence the distribution and density of many arthropod vectors which in turn may influence the incidence and northern range of vectorborne diseases such as West Nile virus. Recommendations include: the strenghtening of public health systems, disease surveillance coordinated with climate monitoring, and research into the detection, prevention, control and treatment of temperature-sensitive infectious diseases.
Animals↗
Impact of a conjugate vaccine on community-wide carriage of nonsusceptible Streptococcus pneumoniae in Alaska.
BACKGROUND: Streptococcus pneumoniae is a leading cause of invasive bacterial disease and pneumonia among children. Antimicrobial resistance among pneumococci has increased in recent years and complicates treatment. The introduction of heptavalent pneumococcal conjugate vaccine (PCV7) could reduce acquisition of antimicrobial-resistant pneumococci. METHODS: We obtained 1350 nasopharyngeal swabs for culture from 1275 children aged 3-59 months presenting at 3 clinics in Anchorage, Alaska, during the winters of 2000, 2001, and 2002, as PCV7 was being introduced into the routine immunization schedule. We recorded the frequency of use of antibiotics as well as the dates of doses of PCV7 for enrolled children. We used multivariate logistic regression modeling to identify independent risk factors for overall carriage of pneumococci and carriage of PCV7-type pneumococci, cotrimoxazole-nonsusceptible (COT-NS) pneumococci, or penicillin-nonsusceptible (PCN-NS) pneumococci. RESULTS: The proportion of children who were up-to-date for age, with respect to PCV7 vaccination, increased from 0% in 2000 to 55% in 2002. Carriage of PCV7-type pneumococci decreased by 43% (P<.0001). Risk of carriage of PCV7-type pneumococci was lower in 2002 than in 2000, independent of vaccination status, suggesting an indirect effect of vaccination. Carriage of COT-NS, but not PCN-NS, pneumococci also decreased (38%; P=.02), not only among vaccinated children but also among unvaccinated children without recent use of antibiotics. CONCLUSIONS: Introduction of PCV7 into the routine infant immunization schedule in a community with a high prevalence of antimicrobial-resistant pneumococci appears to reduce transmission of PCV7 vaccine serotypes and COT-NS pneumococci but has no impact on overall carriage of pneumococci or carriage of PCN-NS pneumococci.
Alaska↗
Temporal and geographic stability of the serogroup-specific invasive disease potential of Streptococcus pneumoniae in children.
A meta-analysis study design was used to analyze 7 data sets of invasive and carriage pneumococcal isolates recovered from children, to determine whether invasive disease potential differs for each serotype and, if so, whether it has changed over time or differs geographically. Serotype- and serogroup-specific odds ratios (ORs) were calculated for each study and as a pooled estimate, with use of serotype 14 as the reference group. ORs varied widely: the serotypes with the highest ORs (1, 5, and 7) were 60-fold more invasive than those with the lowest ORs (3, 6A, and 15). There was a significant inverse correlation between invasive disease and carriage prevalence for the serotypes that we considered, which implies that the most invasive serotypes and serogroups were the least commonly carried and that the most frequently carried were the least likely to cause invasive disease. There was no evidence of any temporal change or major geographical differences in serotype- or serogroup-specific invasive disease potential.
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