Pneumococcal carriage and disease in adults in England 2011-2019: the importance of adults as a reservoir for pneumococcus in communities.

BACKGROUND: Pneumococcal carriage in children has been extensively studied, but carriage in healthy adults and its relationship to invasive pneumococcal disease (IPD) is less understood. METHODS: Nasal wash samples from adults without close contact with young children (Liverpool, UK), 2011-2019, were cultured, and culture-negative samples tested by PCR. Pneumococcal carriage in adults 18-44 years was compared with carriage among PCV-vaccinated children 13-48 months (nasopharyngeal swabs, Thames Valley, UK) and IPD data for England for the same ages for 2014-2019. Age-group specific serotype invasiveness was calculated and used with national IPD data to estimate carriage serotype distributions for adults aged 65+ years. RESULTS: In total 98 isolates (97 carriers) were identified from 1,631 adults aged 18+ years (age and sex standardized carriage prevalence 6.4%), with only three identified solely by PCR. Despite different carriage and IPD serotype distributions between adults and children, serotype invasiveness was highly correlated (R=0.9). Serotypes 3, 37 and 8 represented a higher proportion of adult carriage than expected from direct low-level transmission from children to adults. The predicted carriage serotype distributions for 65+ years aligned more closely with the carriage serotype distribution for young adults than young children. CONCLUSIONS: The nasal wash technique is highly sensitive; additional benefit of PCR is limited. Comparison of carriage serotype distributions suggests some serotypes may be circulating preferentially within these specific young adults. Our data suggest that for some serotypes carried by adults 65+ years, other adults may be an important reservoir for transmission. Age groups such as older children should also be considered.

The public health value of vaccines beyond efficacy: methods, measures and outcomes.

BACKGROUND: Assessments of vaccine efficacy and safety capture only the minimum information needed for regulatory approval, rather than the full public health value of vaccines. Vaccine efficacy provides a measure of proportionate disease reduction, is usually limited to etiologically confirmed disease, and focuses on the direct protection of the vaccinated individual. Herein, we propose a broader scope of methods, measures and outcomes to evaluate the effectiveness and public health impact to be considered for evidence-informed policymaking in both pre- and post-licensure stages. DISCUSSION: Pre-licensure: Regulatory concerns dictate an individually randomised clinical trial. However, some circumstances (such as the West African Ebola epidemic) may require novel designs that could be considered valid for licensure by regulatory agencies. In addition, protocol-defined analytic plans for these studies should include clinical as well as etiologically confirmed endpoints (e.g. all cause hospitalisations, pneumonias, acute gastroenteritis and others as appropriate to the vaccine target), and should include vaccine-preventable disease incidence and 'number needed to vaccinate' as outcomes. Post-licensure: There is a central role for phase IV cluster randomised clinical trials that allows for estimation of population-level vaccine impact, including indirect, total and overall effects. Dynamic models should be prioritised over static models as the constant force of infection assumed in static models will usually underestimate the effectiveness and cost-effectiveness of the immunisation programme by underestimating indirect effects. The economic impact of vaccinations should incorporate health and non-health benefits of vaccination in both the vaccinated and unvaccinated populations, thus allowing for estimation of the net social value of vaccination. CONCLUSIONS: The full benefits of vaccination reach beyond direct prevention of etiologically confirmed disease and often extend across the life course of a vaccinated person, prevent outcomes in the wider community, stabilise health systems, promote health equity, and benefit local and national economies. The degree to which vaccinations provide broad public health benefits is stronger than for other preventive and curative interventions.

Evaluation of chest radiography, lytA real-time PCR, and other routine tests for diagnosis of community-acquired pneumonia and estimation of possible attributable fraction of pneumococcus in northern Togo.

Streptococcus pneumoniae (Spn) is a leading cause of community-acquired pneumonia (CAP), yet existing diagnostic tools remain inadequate. We aimed to evaluate laboratory and radiological methods for detecting pneumococcal aetiology in CAP patients and to estimate Spn prevalence in this group. All-aged patients hospitalized with clinically defined CAP in northern Togo were enrolled during 2010-2013. Latent class analysis pooled results of semi-automated blood culture (SABC), whole blood lytA real-time polymerase chain reaction (rt-PCR), serum C-reactive protein (CRP), and chest radiography (CXR) and categorized patients as likely pneumococcal or non-pneumococcal CAP. We enrolled 1684 patients; 1501 had results for all tests. CXR, SABC, lytA rt-PCR and CRP >71·2 mg/l had sensitivities of 94% [95% confidence interval (CI) 87-100], 13% (95% CI 10-16), 17% (95% CI 14-21) and 78% (95% CI 75-80), and specificities of 88% (95% CI 84-93), 100% (95% CI 99-100), 97% (95% CI 96-99) and 77% (95% CI 75-79), respectively. Pneumococcal attributable proportion was 34% (95% CI 32-37), increasing with age and in men. We estimated that Spn caused one third of CAP. Whole blood lytA rt-PCR was more sensitive than SABC; both had low sensitivity and high specificity. Conversely CXR was highly sensitive and reasonably specific; it could be a useful tool for epidemiological studies aiming to define Spn pneumonia incidence across all ages.

Maternal influenza and birth outcomes: systematic review of comparative studies.

BACKGROUND: Although pregnant women are considered at high risk for severe influenza disease, comparative studies of maternal influenza and birth outcomes have not been comprehensively summarised. OBJECTIVE: To review comparative studies evaluating maternal influenza disease and birth outcomes. SEARCH STRATEGY: We searched bibliographic databases from inception to December 2014. SELECTION CRITERIA: Studies of preterm birth, small-for-gestational-age (SGA) birth or fetal death, comparing women with and without clinical influenza illness or laboratory-confirmed influenza infection during pregnancy. DATA COLLECTION AND ANALYSIS: Two reviewers independently abstracted data and assessed study quality. MAIN RESULTS: Heterogeneity across 16 studies reporting preterm birth precluded meta-analysis. In a subgroup of the highest-quality studies, two reported significantly increased preterm birth (risk ratios (RR) from 2.4 to 4.0) following severe 2009 pandemic H1N1 (pH1N1) influenza illness, whereas those assessing mild-to-moderate pH1N1 or seasonal influenza found no association. Five studies of SGA birth showed no discernible patterns with respect to influenza disease severity (pooled odds ratio 1.24; 95% CI 0.96-1.59). Two fetal death studies were of sufficient quality and size to permit meaningful interpretation. Both reported an increased risk of fetal death following maternal pH1N1 disease (RR 1.9 for mild-to-moderate disease and 4.2 for severe disease). CONCLUSIONS: Comparative studies of preterm birth, SGA birth and fetal death following maternal influenza disease are limited in number and quality. An association between severe pH1N1 disease and preterm birth and fetal death was reported by several studies; however, these limited data do not permit firm conclusions on the magnitude of any association. TWEETABLE ABSTRACT: Comparative studies are limited in quality but suggest severe pandemic H1N1 influenza increases preterm birth.

Improving influenza surveillance in sub-Saharan Africa.

PROBLEM: Little is known about the burden of influenza in sub-Saharan Africa. Routine influenza surveillance is key to getting a better understanding of the impact of acute respiratory infections on sub-Saharan African populations. APPROACH: A project known as Strengthening Influenza Sentinel Surveillance in Africa (SISA) was launched in Angola, Cameroon, Ghana, Nigeria, Rwanda, Senegal, Sierra Leone and Zambia to help improve influenza sentinel surveillance, including both epidemiological and virological data collection, and to develop routine national, regional and international reporting mechanisms. These countries received technical support through remote supervision and onsite visits. Consultants worked closely with health ministries, the World Health Organization, national influenza laboratories and other stakeholders involved in influenza surveillance. LOCAL SETTING: Influenza surveillance systems in the target countries were in different stages of development when SISA was launched. Senegal, for instance, had conducted virological surveillance for years, whereas Sierra Leone had no surveillance activity at all. RELEVANT CHANGES: Working documents such as national surveillance protocols and procedures were developed or updated and training for sentinel site staff and data managers was organized. LESSONS LEARNT: Targeted support to countries can help them strengthen national influenza surveillance, but long-term sustainability can only be achieved with external funding and strong national government leadership.

Identification of Streptococcus pneumoniae in hospital-acquired pneumonia in adults.

Hospital-acquired pneumonia (HAP) is often more severe and life-threatening than community-acquired pneumonia (CAP). The role of Streptococcus pneumoniae in CAP is well-understood, but its role in HAP is unclear. The objective of this study was to summarize the available literature on the prevalence of S. pneumoniae in HAP episodes. We searched MEDLINE for peer-reviewed articles on the microbiology of HAP in individuals aged ≥18 years, published between 2008 and 2018. We calculated pooled estimates of the prevalence of S. pneumoniae in episodes of HAP using a random-effects, inverse-variance-weighted meta-analysis. Forty-seven of 1908 articles met the inclusion criteria. Bacterial specimen isolation techniques for microbiologically defined HAP episodes included bronchoalveolar lavage, protective specimen brush, tracheobronchial aspirate and sputum, as well as blood culture. Culture was performed in all studies; five studies also used urine antigen detection (5/47; 10.6%). S. pneumoniae was identified in 5.1% (95% confidence interval (CI): 3.8-6.6%) of microbiologically defined HAP episodes (N = 20), with 5.4% (95% CI: 4.3-6.7%, N = 29) in ventilator-associated HAP and 6.0% (95% CI: 4.1-8.8%, N = 6) in non-ventilator-associated HAP. S. pneumoniae was identified in 5.3% (95% CI: 4.5-6.3%) of HAP occurring in the intensive care unit (ICU, N = 41) and in 5.6% (95% CI: 3.3-9.5%, N = 5) outside the ICU. A higher proportion of early-onset HAP (10.3%; 95% CI: 8.3-12.8%, N = 16) identified S. pneumoniae as compared with late-onset HAP (3.3%; 95% CI: 2.5-4.4%, N = 16). In conclusion, S. pneumoniae was identified by culture in 5.1% of microbiologically defined HAP episodes. The importance of HAP as part of the disease burden caused by S. pneumoniae merits further research.

Updated recommendations of the International Dengue Initiative expert group for CYD-TDV vaccine implementation in Latin America.

Dengue disease represents a large and growing global threat to public health, causing a significant burden to health systems of endemic countries. For countries considering vaccination as part of their Integrated Management Strategy for Prevention and Control of Dengue, the World Health Organization currently recommends the first licensed dengue vaccine, CYD-TDV for: individuals aged 9 years or above from populations with high transmission rates, based on either seroprevalence criteria or pre-vaccination screening strategies, and for persons with confirmed prior exposure to infection in moderate to lower transmission settings. This paper describes the main conclusions of the Sixth Meeting of the International Dengue Initiative (IDI) held in June 2018, following release of a new product label by the manufacturer, updated WHO-SAGE recommendations, additional scientific evidence on vaccine performance, and reports of experiences by implementing countries. Considerations were made regarding the need for improving the quality of epidemiological and surveillance data in the region to help define the convenience of either of the two vaccination strategies recommended by WHO-SAGE. Extensive discussion was dedicated to the pros and cons of implementing either of such strategies in Latin America. Although, in general, a seroprevalence-based approach was preferred in high transmission settings, when cost-effectivity is favorable pre-vaccination screening is a convenient alternative. Cost-effectiveness evaluations can assist with the decisions by public health authorities of whether to introduce a vaccine. Where implemented, vaccine introduction should be part of a public health strategy that includes the participation of multiple sectors of society, incorporating input from scientific societies, ministries of heath, and civil society, while ensuring a robust communication program.

Evaluation of the Pastorex meningitis kit for the rapid identification of Neisseria meningitidis serogroups A and W135.

The recent emergence of Neisseria meningitidis W135 as a cause of epidemic bacterial meningitis and the availability of a trivalent ACW135 vaccine have created a need for accurate and timely meningococcal serogroup determination for organization of epidemic vaccine response. The sensitivity and specificity of the Pastorex meningitis kit (Bio-Rad) to identify serogroups A and W135 in the African meningitis belt was assessed using PCR testing as the gold standard. The sensitivity and specificity for serogroups A and W135 were 87 and 85%, respectively, while the specificities were 93 and 97%. The positive and negative likelihood ratios for A were 12 and 0.14 and for W135 were 33 and 0.16. The positive and negative predictive values, computed to simulate an epidemic of meningococcal meningitis with an estimated 70% prevalence of N. meningitidis among suspected cases, were 97% and 75% for A and 99% and 73% for W135. In remote locations of the African meningitis belt, latex agglutination is the only currently available test that can rapidly determine meningococcal serogroup. This study showed that latex agglutination performs well and could be used during the epidemic season to determine appropriate vaccine response.

Streptococcus pneumoniae serotype 1 burden in the African meningitis belt: exploration of functionality in specific antibodies.

Streptococcus pneumoniae serotype 1 (Sp1) constitutes an important cause of seasonal endemic meningitis in all age groups in the African meningitis belt. Despite a higher meningitis incidence, the Burkinabé population has an Sp1-specific antibody seroprevalence similar to that reported in the United Kingdom (UK). We aimed to establish whether the opsonophagocytic activity (OPA) of pneumococcal IgG naturally present in Burkina Faso differs from that seen in individuals in the UK and to compare the OPAs generated by natural and vaccine-induced immunity. Samples collected from pneumococcal vaccine-naive Burkinabé and UK subjects were matched for age (1 to 39 years) and anti-Sp1 IgG level, analyzed for OPA to 3 S. pneumoniae serotypes (1, 5, and 19A), and compared to postvaccine samples. Furthermore, the Burkinabé samples were assessed for IgG avidity and serotype-specific IgM concentrations. One hundred sixty-nine matched serum samples from both populations were selected. A greater proportion of Burkinabé subjects aged 1 to 19 years had functional Sp1 activity (OPA ≥ 8) compared to UK subjects (12% versus 2%, P < 0.001); however, the proportions were similar among adults (9%). The correlation between Sp1 IgG concentration and OPA was good (P < 0.001), but many individuals had nonfunctional IgG, which was not related to avidity. While the Sp1 IgM concentrations correlated with OPA, not all of the function in serum samples with low IgG could be attributed to IgM. Finally, vaccine-induced Sp1-specific IgG was more functional than equivalent amounts of naturally occurring IgG. In conclusion, despite a substantially higher pneumococcal meningitis incidence, no decreased functional immunity to Sp1 could be evidenced in the Burkinabé population compared to that in the population from the UK. Furthermore, the naturally induced antibodies were less functional than vaccine-induced antibodies.

Impact of the Hajj on pneumococcal transmission.

Over two million Muslim pilgrims assemble annually in Mecca and Medina, Saudi Arabia, to complete the Hajj. The large number of people in a crowded environment increases the potential for pneumococcal carriage amplification. We evaluated pneumococcal carriage prevalence with four cross-sectional studies conducted at beginning-Hajj (Mecca) and end-Hajj (Mina) during 2011 and 2012. A questionnaire was administered and a nasopharyngeal swab was collected. The swab was tested for pneumococcus, serotype and antibiotic resistance. A total of 3203 subjects (1590 at beginning-Hajj and 1613 at end-Hajj) originating from 18 countries in Africa or Asia were enrolled. The overall pneumococcal carriage prevalence was 6.0%. There was an increase in carriage between beginning-Hajj and end-Hajj cohorts for: overall carriage (4.4% versus 7.5%, prevalence ratio (PR) 1.7, 95% CI 1.3-2.3), and carriage of 23-valent pneumococcal polysaccharide vaccine serotypes (2.3% versus 4.1%, PR 1.8, 95% CI 1.2-2.7), 13-valent pneumococcal conjugate vaccine (PCV) serotypes (1.1% versus 3.6%, PR 3.2, 95% CI 1.9-5.6), 10-valent PCV serotypes (0.6% versus 1.6%, PR 2.6, 95% CI 1.2-5.3), antibiotic non-susceptible isolates (2.5% versus 6.1%, PR 2.5, 95% CI 1.7-3.6) and multiple non-susceptible isolates (0.6% versus 2.2%, PR 3.8, 95% CI 1.8-7.9). Fifty-two different serotypes were identified, most commonly serotypes 3 (17%), 19F (5%) and 34 (5%). These results suggest that the Hajj may increase pneumococcal carriage-particularly conjugate vaccine serotypes and antibiotic non-susceptible strains, although the exact mechanism remains unknown. The Hajj may therefore provide a mechanism for the global distribution of pneumococci.

The contribution of infectious diseases to infant mortality in Alaska.

BACKGROUND: Based on death certificates to determine cause of death, current research suggests that infectious diseases are less important causes of infant mortality than in the past. METHODS: To determine the contribution of infectious diseases to infant mortality and the sensitivity of death certificates for identifying infectious disease causes of death, we examined information from multiple sources for a population-based sample of infant deaths that occurred in Alaska during 1992 through 1994. RESULTS: We collected information for 181 of 272 reported infant deaths and identified 48 infants for whom an infection was a primary (n = 15), contributing (n = 12) or suspected (n = 21) cause of death (infectious disease-related infant mortality rate, 2.2/1000 live births). Of these 48 deaths 27 were associated with a maternal peripartum infection and 15 were associated with a postneonatal respiratory tract infection. A specific organism was identified for 15 of 29 infants who died during the neonatal period and for 5 of 19 infants who died during the postneonatal period (including 2 with coagulase-negative Staphylococcus and the rest with a variety of other organisms). Death certificates identified an infectious disease as a primary or contributing cause of death for 19 infants (sensitivity, 40%) and reported a specific organism for 4 infants. CONCLUSIONS: Infectious diseases caused or contributed to a high proportion of infant mortality in Alaska during 1992 through 1994. Death certificates had poor sensitivity for identifying infectious disease-related infant deaths.

Risk factors for invasive disease caused by Streptococcus pneumoniae among Alaska native children younger than two years of age.

Streptococcus pneumoniae causes a significant amount of illness and death from pneumonia, bacteremia and meningitis among children < 2 years of age. No currently available effective vaccine exists to prevent pneumococcal disease in this age group. To identify modifiable risk factors we conducted a retrospective case-control study of 29 Alaska Native residents of Bethel, AK, < 2 years of age who had invasive pneumococcal illness from 1983 to 1992 and 85 controls matched for race, city of residence and date of birth. Data were collected through reviews of medical records and telephone interviews. In matched univariate analysis the following variables were associated with illness at P < or = 0.25 and were included in the multivariate model: at least one prior episode of pneumonia; at least one prior hospitalization; group child care center attendance; at least one tobacco smoker in the household; at least one tobacco chewer in the household; and lack of breast-feeding. Using a conditional multiple logistic regression analysis, we found that group child care center attendance (odds ratio, 98.6; 95% confidence interval, 5.1 to 1920.6) and the presence in the household of at least one person who chewed tobacco (odds ratio, 20.6; 95% confidence interval, 1.4 to 294.5) were independently associated with illness while breast-feeding was protective (odds ratio, 0.1; 95% confidence interval, 0.0 to 1.0). These data suggest that breast-feeding may prevent invasive pneumococcal disease and that strategies for decreasing risks should target children in group child care settings. Further studies are needed to evaluate the interaction of tobacco and pneumococcal illness.

A population-based survey of Haemophilus influenzae type b nasopharyngeal carriage prevalence in Lombok Island, Indonesia.

BACKGROUND: The Haemophilus influenzae type b (Hib) nasopharyngeal carriage prevalence and invasive disease incidence rates are unknown in Indonesia; consequently Hib vaccine is not included in the routine vaccine schedule. METHODS: To determine carriage prevalence we conducted a population-based, island-wide prospective study of a systematic sample of 484 children 0 to 2 years of age in Lombok, Indonesia. We conducted a risk factor questionnaire and determined serotypes and antibiotic sensitivity patterns. RESULTS: We identified 155 H. influenzae isolates, of which 22 were type b and 12 were encapsulated but not type b. The age- and population-weighted Hib carriage prevalence, adjusted for the sampling design, was 4.6% (95% confidence interval, 3.7 to 5.5%). Children younger than 6 months of age had a carriage prevalence less than one-half that of older children, and carriage varied within the four administrative regions of the island; otherwise no risk factors for Hib carriage were identified. All Hib specimens were sensitive to ampicillin and 20 (91%) were sensitive to chloramphenicol. CONCLUSIONS: The Hib carriage prevalence in Lombok is similar to that found in developed countries before vaccine introduction. This suggests that further studies should proceed to determine whether Lombok has invasive disease rates as high as those that justified vaccine introduction in developed countries.

Risk factors for nasopharyngeal carriage of resistant Streptococcus pneumoniae and detection of a multiply resistant clone among children living in the Yukon-Kuskokwim Delta region of Alaska.

BACKGROUND: Children < 2 years old living in the Yukon-Kuskokwim Delta (YKD) region of Alaska have one of the highest pneumococcal bacteremia rates of in the world. METHODS: To determine the prevalence of and risk factors for infection with intermediate or resistant Streptococcus pneumoniae in the YKD, we cultured nasopharyngeal secretions of healthy children < or = 5 years old, reviewed their hospital records and administered questionnaires to accompanying parents. RESULTS: Of 185 children evaluated we obtained 95 pneumococcal isolates; drug susceptibility patterns and serotyping results were available for 92. Of these, 33 (36%) were intermediate or resistant to at least one drug class tested; 27 isolates were intermediate (minimum inhibitory concentration 0.1 to 1.0 mg/l) and none were resistant to penicillin. Compared with other isolates, capsular serotype 6B isolates were more likely to be intermediate or resistant to at least one drug (relative risk, 5.3; P < 0.001) and to more than one drug (relative risk, 17.0; P < 0.001). The majority of 6B isolates had identical pneumococcal surface protein A patterns. Carriage of intermediate or resistant pneumococcus was associated with age < 2 years (relative risk, 3.0; P < 0.001) but not with antibiotic use or other evaluated risk factors. CONCLUSIONS: Young age but not antibiotic use was associated with carriage of intermediate or resistant S. pneumoniae in the YKD region of Alaska. Much of the intermediate or resistant pneumococcus in the YKD may have resulted from the proliferation of a single capsular serotype 6B clone.

Incidence rates, clinical features, and case identification of pediatric tuberculosis in Alaska.

SETTING: The population of Alaska. OBJECTIVE: To determine incidence rates, clinical features, and source of case identification for pediatric tuberculosis in Alaska. DESIGN: A state-wide, population-based, retrospective analysis of all cases of tuberculosis among children 0 to 14 years of age reported to the Alaska Division of Public Health during 1987-1994. RESULTS: Seventy children with tuberculous disease were identified for an incidence rate of 5.8/100000/year. Compared to whites, Alaska Natives (relative risk [RR], 65; 95% confidence interval [CI], 20 to 207) and people of other races (RR, 21; 95% CI, 5.6 to 79) had an increased risk of tuberculosis. Clinical features did not differ by race. Twenty-three of 45 persons with at least one specimen collected had a positive culture result, including three with isoniazid-resistant strains. While most cases were identified through contact investigations, 23% were identified through required school screening. CONCLUSION: Alaska has a high rate of pediatric tuberculosis, with non-white race identified as a risk factor. Required school screening proved useful for case identification.

Hypertension and identification of toxin in human urine and serum following a cluster of mussel-associated paralytic shellfish poisoning outbreaks.

Following four outbreaks of paralytic shellfish poisoning on Kodiak Island, Alaska, during 1994, medical records of ill persons were reviewed and interviews were conducted. Urine and serum specimens were analyzed at three independent laboratories using four different saxitoxin binding assays. High-performance liquid chromatography was used to determine the presence of specific toxin congeners. Among 11 ill persons, three required mechanical ventilation and one died. Mean peak systolic and diastolic blood pressure measurements were 172 (range 128-247) and 102 (range 78-165) mmHg, respectively, and blood pressure measurements corresponded with ingested toxin dose. All four different laboratory methodologies detected toxin in serum at 2.8-47 nM during acute illness and toxin in urine at 65-372 nM after acute symptom resolution. The composition of specific paralytic shellfish poisons differed between mussels and human biological specimens, suggesting that human metabolism of toxins had occurred. The results of this study indicate that saxitoxin analogues may cause severe hypertension. In addition, we demonstrate that saxitoxins can be detected in human biological specimens, that nanomolar serum toxin levels may cause serious illness and that human metabolism of toxin may occur. Clearance of paralytic shellfish poisons from serum was evident within 24 hr and urine was identified as a major route of toxin excretion in humans.

A cost-effectiveness evaluation of newborn hemoglobinopathy screening from the perspective of state health care systems.

OBJECTIVE: To determine the most cost-effective strategy for newborn hemoglobinopathy screening from the perspective of state health care systems. STUDY DESIGN: Using Alaska as an example, we used decision analysis to compare a policy of no screening to universal or targeted screening with selective follow-up only of infants who are homozygous or compound heterozygous for an abnormal hemoglobin variant and to universal or targeted screening with complete follow-up, including follow-up of infants with clinically insignificant traits. Probabilities and costs were varied over values that might be expected for other states. RESULTS: Among the selective follow-up options, targeted screening would be the most cost-effective strategy for Alaska at a cost of $206,192 per death averted; by contrast, universal screening would prevent 50% more deaths at an incremental cost of $2,040,000 per death averted. Universal would be more cost-effective than targeted screening for several scenarios expected to occur in other states, including a high sickle cell disease prevalence, a low screening test cost, and a high cost per screen associated with racial targeting. Among the complete follow-up options, both targeted and universal screening would cost at least $200,000 per death averted over the range of all variables tested during sensitivity analysis; the incremental cost of universal versus targeted screening would be at least $600,000 per death averted. CONCLUSIONS: Our data suggest each state should determine the most cost-effective option based on state-specific values for sickle cell disease prevalence, test costs and racial targeting costs.

Experience of violence among teenage mothers in Alaska.

PURPOSE: To quantify the experience of violence before, during, and after pregnancy among teenage mothers compared to older mothers and to identify the proportion of births to teenagers that result from statutory rape. METHODS: We analyzed data collected during 1991-1994 from the Alaska Pregnancy Risk Assessment Monitoring System (PRAMS), a population-based, stratified sample survey of 200 of the approximately 900 Alaska resident women each month who have delivered a live infant. RESULTS: Compared to new mothers at least 20 years of age, mothers < 18 and 18-19 years of age were approximately twice as likely to report having experienced violence during pregnancy (10% vs. 4%) and were two to three times as likely to have experienced violence after pregnancy (10% and 6%, respectively, vs. 3%). When controlling for potentially confounding factors, however, age was associated with the experience of violence only for mothers < 18 years after pregnancy. The percentage of women who reported experiencing violence each week increased following pregnancy for mothers of all ages. At least 38.9% and up to 66.2% of all births to unmarried teenagers younger than 16 years of age resulted from second-degree statutory rape. CONCLUSIONS: Teenage mothers are more likely to experience violence during and after their pregnancy than older women and for women of all ages the risk increases after pregnancy. Nearly half of the births to the youngest teenagers result from second-degree statutory rape.

PIP: Data collected in 1991-94 as part of the Alaska Pregnancy Risk Assessment Monitoring System were used to assess the experience of violence before, during, and after pregnancy among teenage mothers compared with older mothers and to identify the proportion of births to teenagers that result from statutory rape. A total of 7178 new mothers 13-45 years of age were included in this population-based data set. 9.7% of mothers under 18 years of age and 9.4% of those 18-19 years old reported having experienced domestic violence during pregnancy compared with 3.8% of mothers at least 20 years of age; violence after pregnancy was reported by 10%, 6%, and 2.9% of mothers, respectively. When potentially confounding factors (marital status, an unplanned pregnancy, enrollment in a medical assistance program) were controlled, however, age was associated with the experience of violence only for mothers under 18 years of age after pregnancy. The percentage of women who reported domestic violence each week increased after pregnancy for mothers of all ages. 66.2% of all births to unmarried teens under 16 years of age for which the age of the father was recorded resulted from second-degree statutory rape. Pediatricians and family practitioners should be aware of the increased risk of violence that occurs after pregnancy, especially in teen mothers. Recommended are violence prevention and intervention programs at school-based clinics, increased public awareness of the extent and consequences of violence against women, and identification of the specific reasons that teenage mothers experience an increased risk of violence.

Temporal trends and geographic patterns of teen suicide in Alaska, 1979-1993.

The author analyzed death certificate and U.S. census data to document trends in suicide rates among Alaskans 14-19 years of age. During 1979-1993, Alaskan teenagers had a suicide rate of 31.5 per 100,000 persons per year. Suicide rates varied up to sixfold by race, gender, and local census area of residence; in particular, Alaska Native males had one of the highest documented suicide rates in the world. Suicide rates increased two- to threefold during the study period for persons less than 18 years of age, while remaining stable for older teenagers. Within census areas, suicide rates correlated inversely with the percentage of all households headed by a married couple.

Age- and cause-specific childhood mortality in Lombok, Indonesia, as a factor for determining the appropriateness of introducing Haemophilus influenzae type b and pneumococcal vaccines.

Using age and cause-specific childhood mortality in Lombok, Indonesia, as a factor for determining the appropriateness of introducing Haemophilus influenzae type b (Hib) and pneumococcal vaccines, the study describes a cross-sectional, hamlet-level mortality survey in 40 of 305 villages in Lombok Island, Indonesia. Causes of death were assessed with a standardized verbal-autopsy questionnaire. One thousand four hundred ninety-nine births and 141 deaths occurring among children aged less than 2 years were identified, with 43% of deaths occurring during the first 2 months of life. The infant mortality rate was 89 (95% CI: 75, 104) per 1,000 live-births. All mortality rates are reported per 1,000 live-births. To examine children whose deaths could potentially have been prevented through vaccination with Hib or pneumococcal vaccine, deaths due to acute respiratory infection (ARI) and central nervous system (CNS) infections among children, aged 2-23 months, were analyzed. ARI and CNS infections caused 58% (mortality rate: 31 per 1,000 live-births; 95% CI: 23, 41) and 17% (mortality rate: 9 per 1,000 live-births; 95% CI: 5, 16), respectively, of all deaths within this age group. Between the ages of 2 and 23 months, 5% of all babies born alive died of ARI, and another 1% died of CNS infections. Our results indicate that current efforts to reduce childhood mortality should focus on reducing ARI and meningitis. These efforts should include evaluating the impact of Hib and pneumococcal vaccines within the routine Expanded Programme on Immunization system.