Epidemiology of Spotted Fever Group and Typhus Group Rickettsial Infection in the Amazon Basin of Peru

A seroprevalence study for IgG antibodies against spotted fever group (SFGR) and typhus group (TGR) Rickettsia among humans and domestic pets was conducted in the city of Iquitos, located in the Amazon basin of Peru. Of 1,195 human sera analyzed, 521 (43.6%) and 123 (10.3%) were positive for SFGR and TGR antibodies, respectively. District of residence and participant age were associated with antibody positivity for both groups, whereas rodent sightings in the home were associated with TGR antibody positivity. Of the 71 canines tested, 42 (59.2%) were positive for SFGR antibodies, and two (2.8%) were positive for TGR antibodies; one active SFGR infection was detected by polymerase chain reaction. An uncharacterized SFGR species was detected in 95.9% (71/74) of Ctenocephalides felis pools collected from domestic pets. These data suggest that rickettsial transmission is widespread in Iquitos. Rickettsia species should be further explored as potential causes of acute febrile illnesses in the region.     

Decreased necrotizing fasciitis capacity caused by a single nucleotide mutation that alters a multiple gene virulence axis

Single-nucleotide changes are the most common cause of natural genetic variation among members of the same species, but there is remarkably little information bearing on how they alter bacterial virulence. We recently discovered a single-nucleotide mutation in the group A Streptococcus genome that is epidemiologically associated with decreased human necrotizing fasciitis (“flesh-eating disease”). Working from this clinical observation, we find that wild-type mtsR function is required for group A Streptococcus to cause necrotizing fasciitis in mice and nonhuman primates. Expression microarray analysis revealed that mtsR inactivation results in overexpression of PrsA, a chaperonin involved in posttranslational maturation of SpeB, an extracellular cysteine protease. Isogenic mutant strains that overexpress prsA or lack speB had decreased secreted protease activity in vivo and recapitulated the necrotizing fasciitis-negative phenotype of the ΔmtsR mutant strain in mice and monkeys. mtsR inactivation results in increased PrsA expression, which in turn causes decreased SpeB secreted protease activity and reduced necrotizing fasciitis capacity. Thus, a naturally occurring single-nucleotide mutation dramatically alters virulence by dysregulating a multiple gene virulence axis. Our discovery has broad implications for the confluence of population genomics and molecular pathogenesis research.     

Peer Reviewed: HPV Vaccine Attitudes and Practices Among Primary Care Providers in Appalachian Pennsylvania

Introduction

The incidence of cervical cancer in Appalachia exceeds the national rate; rural Appalachian women are at especially high risk. We assessed the attitudes and practices related to human papillomavirus vaccination among providers in primary care practices in a contiguous 5-county area of Appalachian Pennsylvania.

Methods

In December 2006 and May 2007, all family medicine, pediatric, and gynecology practices (n = 65) in the study area were surveyed by 2 faxed survey instruments.

Results

Of the 65 practices, 55 completed the first survey instrument. Of these 55, 44 offered the vaccine to their patients. Forty of the 44 practices offered it to girls and women aged 9 to 26 years, and 11 were willing to accept referrals from other practices for vaccination. The average reported charge for each of the 3 required injections was $150. Of the 55 practices that responded to the first survey instrument, 49 responded to the second survey instrument, 46 of which recommended the vaccine to their patients.

Conclusion

The prevalence of offering the vaccine against human papillomavirus was high in this area of Appalachian Pennsylvania. Future interventions may focus on community education because the vaccine is available from most providers.     

Toward Understanding Suicide Among Youths: Results From the White Mountain Apache Tribally Mandated Suicide Surveillance System, 2001�C2006

Objectives. We examined suicide and suicide attempt rates, patterns, and risk factors among White Mountain Apache youths (aged < 25 years) from 2001 to 2006 as the first phase of a community-based participatory research process to design and evaluate suicide prevention interventions.Methods. Apache paraprofessionals gathered data as part of a tribally mandated suicide surveillance system. We compared findings to other North American populations.Results. Between 2001 and 2006, 61% of Apache suicides occurred among youths younger than 25 years. Annual rates among those aged 15 to 24 years were highest: 128.5 per 100 000, 13 times the US all-races rate and 7 times the American Indian and Alaska Native rate. The annual suicide attempt incidence rate in this age group was 3.5%. The male-to-female ratio was 5:1 for suicide and approximately 1:1 for suicide attempts. Hanging was the most common suicide method, and third most common attempt method. The most frequently cited attempt precipitants were family or intimate partner conflict.Conclusions. An innovative tribal surveillance system identified high suicide and attempt rates and unique patterns and risk factors of suicidal behavior among Apache youths. Findings are guiding targeted suicide prevention programs.Suicide is the third leading cause of death among US youths aged 10 to 24 years,¹ and suicide attempts are a major source of adolescent morbidity in the United States. As behavioral scientists have increasingly recognized youths'' suicide behavior as an important and preventable public health problem, Healthy People 2010 has set specific objectives to reduce suicide and suicide attempt rates among youths. Past evidence supports the premise that youth suicide can be prevented by addressing risk factors and promoting early identification, referral, and treatment of mental and substance use disorders. However, risk factors vary across races, ethnic groups, and regions, necessitating targeted formative research and community-specific prevention approaches.²It is well-documented that American Indians and Alaska Natives have the highest rates of suicide of all US races.³ American Indian and Alaska Native (AIAN) suicides occur predominantly among youths ( < 25 years), in contrast to the US general population, in which deaths from suicide are concentrated among the elderly ( ≥ 65 years).⁴ Further, there is significant variability in suicide rates among youths across tribes and rural versus urban AIAN populations. Among the 1.3 million American Indians and Alaska Natives residing on or near rural reservation lands tracked by the Indian Health Service, the average rate of suicide per 100 000 is 20.2, with a range of 7.7 (Nashville area) to 45.9 (Alaska area).⁵ In comparison, for all 4.1 million American Indians and Alaska Natives identified by the US Census, the suicide rate is 11.7.⁶ Because urban AIAN residents compose approximately 60% of the US Census AIAN population,⁷ the lower overall census suicide rate indicates that rural reservation suicide rates are higher than urban AIAN suicide rates.To date, little reservation-specific information on suicide behavior or related risk factors exists to explain differences in rates across AIAN communities and in comparison with other US populations. Developing the means to collect and analyze local tribal data is key to discerning unique risk factors that are driving local and national disparities in suicide among AIAN youths, and to the public health mission of reducing suicide among youths across the United States and the world.There are approximately 15 500 White Mountain Apache (Apache) tribal members who reside on the 1.6 million acre Fort Apache Reservation in east-central Arizona. More than half (54%) of the tribal members are younger than 25 years, compared with approximately 35% of the US all-races population.⁸ In 2001, a cluster of suicides among youths on the Apache reservation led the Tribal Council to enact a resolution to mandate tribal members and community providers to report all suicidal behavior (ideation, attempts, and deaths) to a central data registry. The resulting surveillance system is the first of its kind, gathering data from both community-based and clinical settings.In 2004, as part of the Johns Hopkins Center for American Indian Health, we partnered with the Apaches to conduct a community-based participatory research (CBPR) project that included formalizing the mandated reporting process, transferring the registry system to an electronic format, analyzing quarterly trends, and engaging community leaders in interpreting surveillance data to inform prevention strategies. Because of the contentious history of research in tribal communities, CBPR methodologies are essential to ensuring a culturally sensitive interpretation of findings and culturally relevant interventions.⁹ A CBPR approach is particularly important in the complex area of mental health because explanatory models for cause and treatment of mental illness can vary widely across tribal and nontribal cultures.¹⁰We describe the Apache suicide behavior surveillance system, report patterns of Apache youths'' suicide and suicide attempts between 2001 and 2006, and compare those rates with those of other tribal and North American populations. We discuss the relevance of the paraprofessional-administered surveillance system and its findings to public health prevention of suicide behavior among youths.     

Noise Levels Associated With New York City's Mass Transit Systems

Objectives. We measured noise levels associated with various forms of mass transit and compared them to exposure guidelines designed to protect against noise-induced hearing loss.Methods. We used noise dosimetry to measure time-integrated noise levels in a representative sample of New York City mass transit systems (subways, buses, ferries, tramway, and commuter railways) aboard transit vehicles and at vehicle boarding platforms or terminals during June and July 2007.Results. Of the transit types evaluated, subway cars and platforms had the highest associated equivalent continuous average (L_eq) and maximum noise levels. All transit types had L_eq levels appreciably above 70 A-weighted decibels, the threshold at which noise-induced hearing loss is considered possible.Conclusions. Mass transit noise exposure has the potential to exceed limits recommended by the World Health Organization and the US Environmental Protection Agency and thus cause noise-induced hearing loss among riders of all forms of mass transit given sufficient exposure durations. Environmental noise–control efforts in mass transit and, in cases in which controls are infeasible, the use of personal hearing protection would benefit the ridership''s hearing health.For the first time in history, more than half of the world''s population lives in cities, and it is projected that more than two thirds of the population will live in cities by 2030.¹ An important factor supporting the growth and viability of urban centers is mass transportation, which is rapidly expanding to keep pace with increasing demand. For example, in 2004 there were 95 subway systems worldwide; today there are 167, a 76% increase in only 5 years.² Although there are well-documented environmental and public health benefits associated with mass transit, interest in the health and safety effects of mass transit on urban communities is increasing.^3–5 A particular concern is the potential for mass transit to result in excessive exposure to noise.Noise exposure is a function of 2 main factors: (1) the frequency-weighted exposure level, measured in A-weighted decibels (dBA), and (2) the exposure duration. The causal association between chronic exposure to excessive noise and permanent, irreversible, noise-induced hearing loss (NIHL) is well known, as are the adverse social, psychological, and occupational effects associated with the condition. Nonauditory adverse health effects have also been reported,^6–8 and recent research suggests that excessive noise exposure may be linked to hypertension and ischemic heart disease, disruptions in stress hormones, and sleep disorders.^9–12There are no comprehensive national or international surveillance programs for hearing loss. Worldwide, more than 250 million people are estimated to suffer from hearing loss, of which at least 30 million cases represent NIHL.¹³ In the United States alone, between 3 to 10 million people are estimated to have NIHL.¹⁴ Hearing loss from all causes ranks among the top 10 most common serious health problems worldwide, and NIHL is the leading occupational disease in industrialized nations.^14,15 The limited data available suggest not only that NIHL prevalence and incidence rates are extraordinarily high but also that the associated costs are enormous.^16,17 Importantly, even though US occupational exposure regulations have been in place for decades, rates of NIHL-related workers'' compensation cases remain high. Therefore, nonoccupational sources of exposure are coming under scrutiny, including mass transit.The size of the population exposed to mass transit noise is of considerable magnitude. The US mass transit network, with an infrastructure encompassing subways, buses, commuter and light rail, ferry boats, trolleys, and tramways, is the largest in the world, with 9.7 billion passenger rides in 2006.¹⁸ There are 14 subway systems in the United States, with a combined daily ridership in excess of 10 million people.^19–21 Five of the US systems are more than 75 years old, and the largest, the New York City subway system, with over 4 million riders per weekday,²² is more than 100 years old. These older systems were designed before noise-control technologies were available. Worldwide, there are 2 subway systems with even greater ridership rates: Tokyo''s is the largest at 2.6 billion passenger rides per year, and Moscow''s is the second largest with 2.5 billion.^23,24In a recent sound-level pilot survey on subways,³ we noted levels that potentially exceeded the community exposure limits initially recommended by the US Environmental Protection Agency (EPA) in 1974 and confirmed by the World Health Organization (WHO) in 1998. WHO and EPA recommended daily allowable exposure times are 24 hours at 70 dBA, 8 hours at 75 dBA, 2.7 hours at 80 dBA, 0.9 hours at 85 dBA, and 0.3 hours at 90 dBA. Chronic exposures that exceed these allowable combinations of duration and noise level are expected to produce NIHL in some members of the exposed population.^25,26The amount of NIHL anticipated to result from specific noise-exposure levels can be predicted with a model published by the International Organization for Standardization.²⁷ This model allows users to estimate the amount of NIHL expected to result from chronic 8-hour equivalent continuous average (L_eq) noise exposures between 75 and 100 dBA or 24-hour L_eq exposures between 70 and 95 dBA. The model permits the estimation of median values of expected NIHL as well as values for the 0.05 to 0.95 fractiles among an exposed population for given exposure levels and durations. Based on the WHO and EPA recommendations, chronic exposure to 80.3 dBA for more than 160 minutes per day may be expected to produce hearing loss in some exposed individuals, and a 90.2-dBA level likewise may cause hearing loss with just 18 minutes of exposure per day.Few data involving dosimetry measurements of noise exposures associated with mass transit have been reported previously. In a study of the daily noise exposures experienced by 32 people in Madrid, Spain, Diaz et al.²⁸ measured noise levels associated with a variety of self-reported transportation exposures with noise dosimeters. Zheng et al.²⁹ conducted 24-hour noise dosimetry on 221 residents of Beijing, China, and assessed the noise levels associated with self-reported activities, including commuting. Nearly all other studies that have evaluated noise levels associated with subway equipment are decades old and based on sound level measurements rather than dosimetry. In 1931, Stanton conducted an unpublished noise-level survey of the New York City subways,³⁰ and in 1971, Harris and Aitken³¹ reported levels measured on specific New York City train line platforms and cars. A small sound level survey on a subway system in India was also recently reported.³²Our current study expanded on our pilot study of subway noise and assessed average noise levels on a variety of types of mass transit to further evaluate noise exposure among transit riders.     

Community-Based Services for Homeless Adults Experiencing Concurrent Mental Health and Substance Use Disorders: A Realist Approach to Synthesizing Evidence

Consultations with community-based service providers in Toronto identified a lack of strong research evidence about successful community-based interventions that address the needs of homeless clients experiencing concurrent mental health and substance use disorders. We undertook a collaborative research effort between academic-based and community-based partners to conduct a systematic evidence synthesis drawing heavily from Pawson’s realist review methodology to focus on both whether programs are successful and why and how they lead to improved outcomes. We examined scholarly and nonscholarly literature to explore program approaches and program elements that lead to improvements in mental health and substance use disorders among homeless individuals with concurrent disorders (CD). Information related to program contexts, elements, and successes and failures were extracted and further supplemented by key informant interviews and author communication regarding reviewed published studies. From the ten programs that we reviewed, we identified six important and promising program strategies that reduce mental health and, to a far lesser degree, substance use problems: client choice in treatment decision-making, positive interpersonal relationships between client and provider, assertive community treatment approaches, providing supportive housing, providing supports for instrumental needs, and nonrestrictive program approaches. These promising program strategies function, in part, by promoting and supporting autonomy among homeless adults experiencing CD. Our realist informed review is a useful methodology for synthesizing complex programming information on community-based interventions.     

One-year health-related quality of life outcomes in weight loss trial participants: comparison of three measures

Background  

The literature on changes in health-related quality of life (HRQOL) in weight loss studies is inconsistent, and few studies use more than one type of measure. The purpose of the current study was to compare one-year changes in HRQOL as a function of weight change using three different measures: a weight-related measure (Impact of Weight on Quality of Life-Lite [IWQOL-Lite)]) and two generic measures (SF-36; EQ-5D).     

Performance-based or self-report measures of physical function: which should be used in clinical trials of hip fracture patients?

Latham NK, Mehta V, Nguyen AM, Jette AM, Olarsch S, Papanicolaou D, Chandler J. Performance-based or self-report measures of physical function: which should be used in clinical trials of hip fracture patients?

Objectives

To assess the validity, sensitivity to change, and responsiveness of 3 self-report and 4 performance-based measures of physical function: activity measure for postacute care (AM-PAC) Physical Mobility and Personal Care scales, the Medical Outcomes Study 36-Item Short Form Health Survey Physical Function scale (SF-36 PF), the Physical Functional Performance test (PFP-10), the Short Physical Performance Battery (SPPB), a 4-meter gait speed, and the six-minute walk test (6MWT).

Design

A prospective observational study of patients after a hip fracture. Assessments were performed at baseline and 12 weeks postenrollment.

Setting

Inpatient and outpatient rehabilitation facilities in Norway, the United Kingdom, Sweden, Israel, Germany, the United States, Denmark, and Spain.

Participants

A sample of study participants (N=108) who had a hip fracture.

Interventions

Not applicable.

Main Outcome Measures

Assessments of validity (known-groups, concurrent, construct, and predictive), sensitivity to change (effect size, standardized response mean [SRM], SE of measure, minimal detectable change (MDC), and responsiveness (optimal operating cut-points and area under the curve) between baseline and 12-week follow-up.

Results

All physical function measures achieved comparably acceptable levels of validity. Odds ratios in predicting patient Global Assessment of Improvement at 12 weeks were as follows: AM-PAC Physical Mobility scale, 5.3; AM-PAC Personal Care scale, 3.6; SF-36 PF, 4.3; SPPB, 2.0; PFP-10, 2.5; gait speed, 1.9; and 6MWT, 2.4. Effect sizes and SRM exceeded 1 SD for all 7 measures. Percent of patients who exceeded the MDC₉₀ at week 12 were as follows: AM-PAC Physical Mobility scale, 90%; AM-PAC Personal Care scale, 74%; SF-36 PF, 66%; SPPB, 36%; PFP-10, 75%; gait speed, 69%; and 6MWT, 75%. When evaluating responsiveness using the area under receiver operating curves for each measure, all measures had acceptable responsiveness, and no pattern emerged of superior responsiveness depending on the type of measure used.

Conclusions

Findings reveal that the validity, sensitivity, and responsiveness of self-report measures of physical function are comparable to performance-based measures in a sample of patients followed after fracturing a hip. From a psychometric perspective, either type of functional measure would be suitable for use in clinical trials where improvement in function is an endpoint of interest. The selection of the most appropriate type of functional measure as the primary endpoint for a clinical trial will depend on other factors, such as the measure's feasibility or the strength of the association between the hypothesized mechanism of action of the study intervention and a functional outcome measure.     

The effects of music preference and exercise intensity on psychological variables

The purpose of this study was to examine the effects of music preference and exercise intensity on exercise enjoyment, perceived exertion (RPE), and attentional focus. Participants were assigned to 1 of 3 music preference conditions (most preferred, least preferred, or no music) and walked/ran on a treadmill at 1 of 3 exercise intensities (low, moderate, or high) for 20 minutes. Measures of exercise enjoyment, RPE, and attentional focus (association, dissociation, distress) were taken. A 3 x 3 ANOVA on enjoyment revealed that when participants paid attention to the music, music accounted for roughly 5% of the variance in exercise enjoyment (p = .04). Results of a 3 (music) x 3 (intensity) repeated measures ANOVA on RPE showed a main effect of intensity (p < .001) but no main effect for music and no interaction effect. A 3 x 3 ANOVA on attentional focus revealed that those in the high intensity condition reported the greatest association (p < .001) and distress (p < .001). Although not significant, on average, participants in the most preferred music condition reported the highest levels of dissociation.     

Dectin-1 Fc targeting of aspergillus fumigatus beta-glucans augments innate defense against invasive pulmonary aspergillosis

Invasive pulmonary aspergillosis (IPA) has significantly increased over the last decade. Here, a fusion protein consisting of the Dectin-1 extracellular domain linked to the Fc portion of murine immunoglobulin G1 augmented alveolar macrophage killing of Aspergillus fumigatus and shifted mortality associated with IPA via attenuation of A. fumigatus growth in the lung.