Analysis of the spatial and temporal distribution of malaria in an area of Northern Guatemala with seasonal malaria transmission.

The risk of malaria infection displays spatial and temporal variability that is likely due to interaction between the physical environment and the human population. In this study, we performed a spatial analysis at three different time points, corresponding to three cross-sectional surveys conducted as part of an insecticide-treated bed nets efficacy study, to reveal patterns of malaria incidence distribution in an area of Northern Guatemala characterized by low malaria endemicity. A thorough understanding of the spatial and temporal patterns of malaria distribution is essential for targeted malaria control programs. Two methods, the local Moran's I and the Getis-Ord G*(d), were used for the analysis, providing two different statistical approaches and allowing for a comparison of results. A distance band of 3.5 km was considered to be the most appropriate distance for the analysis of data based on epidemiological and entomological factors. Incidence rates were higher at the first cross-sectional survey conducted prior to the intervention compared to the following two surveys. Clusters or hot spots of malaria incidence exhibited high spatial and temporal variations. Findings from the two statistics were similar, though the G*(d) detected cold spots using a higher distance band (5.5 km). The high spatial and temporal variability in the distribution of clusters of high malaria incidence seems to be consistent with an area of unstable malaria transmission. In such a context, a strong surveillance system and the use of spatial analysis may be crucial for targeted malaria control activities.

Life Chaos and Perceived Social Support Among Methamphetamine-Using Men Who Have Sex With Men Engaging in Transactional Sexual Encounters.

OBJECTIVE: Social support and life chaos have been inversely associated with increased risk of HIV infection. The purpose of this study was to explore among a sample of HIV-negative methamphetamine-using men who have sex with men (MSM) the association between engaging in transactional sex, life chaos, and low social support. METHODS: HIV-negative methamphetamine-using MSM completed an online questionnaire between July and October 2012 about recent substance use and sexual behavior. Bivariate and multivariate tests were used to obtain statistically significant associations between demographic characteristics, engaging in transactional sex, life chaos, and the participants' perception of their social support. RESULTS: Of the 325 participants, 23.7% reported engaging in transactional sex, 45.2% reported high life chaos, and 53.5% reported low perceived social support. Participants who engaged in transactional sex were more likely to have high life chaos than participants who did not (aOR = 1.70, 95% CI = [1.01, 2.84]); transactional sex was not associated with social support. Participants with high life chaos were more out about their sexual orientation (aOR = 2.29, 95% CI = [1.18, 4.42]) and more likely to perceive they had low social support (aOR = 3.78, 95% CI = [2.31, 6.22]) than participants with low life chaos. Non-Latinos perceived they had less social support than Latinos (aOR = 0.48, 95% CI = [0.25, 0.92]). CONCLUSIONS: Methamphetamine-using MSM engaging in transactional sex experience more life chaos than those who do not engage in transactional sex. Outness, perceived social support, and ethnicity are associated with life chaos.

Lost to follow-up: failure to engage children in care in the first three months of diagnosis.

Loss to follow-up (LTFU) is a critical factor in determining clinical outcomes in HIV treatment programs. Identifying modifiable factors of LTFU is fundamental for designing effective patient-retention interventions. We analyzed factors contributing to children LTFU from a treatment program to identify those that can be modified. A case-control study involving 313 children was used to compare the sociodemographic and clinical characteristics of children LTFU (cases) with those remaining in care (controls) at a large pediatric HIV care setting in Botswana. We traced children through caregiver contacts and those we found, we conducted structured interviews with patients' caregivers. Children <5 years were nearly twice as likely as older children to be LTFU (57·8% versus 30·9%, p <0 .01). Approximately half (47·6%, n = 51) of LTFU patients failed to further engage in care after just one clinic visit, as compared to less than 1% (n = 2) in the control group (p < 0.01). Children LTFU were more likely than controls to have advanced disease, greater immunosuppression, and not to be receiving antiretroviral therapy. Among interviewed patient caregivers, psychosocial factors (e.g., stigma, religious beliefs, child rebellion, disclosure of HIV status) were characteristics of patients LTFU, but not of controls. Socioeconomic factors (e.g., lack of transportation, school-related activities, forgetting appointments) were cited predominantly by the controls. Pediatric patients and their caregivers need to be targeted and engaged at their initial clinic visit, with special attention to children <5 years. Possible interventions include providing psychosocial support for issues that deter patients from engaging with The Clinic. Collaboration with community-based organizations focused on reducing stigma may be useful in addressing these complex issues.

Fracture risk assessment in older adults using a combination of selected quantitative computed tomography bone measures: a subanalysis of the Age, Gene/Environment Susceptibility-Reykjavik Study.

Bone mineral density (BMD) and geometric bone measures are individually associated with prevalent osteoporotic fractures. Whether an aggregate of these measures would better associate with fractures has not been examined. We examined relationships between self-reported fractures and selected bone measures acquired by quantitative computerized tomography (QCT), a composite bone score, and QCT-acquired dual-energy X-ray absorptiometry-like total femur BMD in 2110 men and 2682 women in the Age, Gene/Environment Susceptibility-Reykjavik Study. The combined bone score was generated by summing gender-specific Z-scores for 4 QCT measures: vertebral trabecular BMD, femur neck cortical thickness, femur neck trabecular BMD, and femur neck minimal cross-sectional area. Except for the latter measure, lower scores for QCT measures, singly and combined, showed positive (p < 0.05) associations with fractures. Results remained the same in stratified models for participants not taking bone-promoting medication. In women on bone-promoting medication, greater femur neck cortical thickness and trabecular BMD were significantly associated with fracture status. However, the association between fracture and combined bone score was not stronger than the associations between fracture and individual measures or total femur BMD. Thus, the selected measures did not all similarly associate with fracture status and did not appear to have an additive effect on fracture status.

Features of the built environment related to physical activity friendliness and children's obesity and other risk factors.

OBJECTIVES: We investigated the relationships among environmental features of physical activity friendliness, socioeconomic indicators, and prevalence of obesity (BMI status), central adiposity (waist circumference, waist-height ratio), and hypertension. DESIGN AND SAMPLE: The design was cross-sectional; the study was correlational. The sample was 911 kindergarteners through sixth graders from three schools in an urban school district residing in 13 designated neighborhoods. MEASURES: Data from walking environmental community audits, census data for socioeconomic indicators, body mass index, waist circumference, waist-height ratio, and blood pressure were analyzed. A modified Alfonzo's Hierarchy of Walking Needs model was the conceptual framework for environmental features (i.e., accessibility, safety, comfort, and pleasurability) related to physical activity. RESULTS: Accessibility was significantly and negatively correlated with prevalence of obesity and with prevalence of a waist-height ratio >0.50. When neighborhood education was controlled, and when both neighborhood education and poverty were controlled with partial correlational analysis, comfort features of a walking environment were significantly and positively related to prevalence of obesity. When poverty was controlled with partial correlation, accessibility was significantly and negatively correlated with prevalence of waist-height ratio >0.50. CONCLUSIONS: The built environment merits further research to promote physical activity and stem the obesity epidemic in children. Our approach can be a useful framework for future research.

Effectiveness of respondent driven sampling to recruit undocumented Central American immigrant women in Houston, Texas for an HIV behavioral survey.

Respondent driven sampling (RDS) is widely used for HIV behavioral research among sex workers, drug users, and other hidden populations, but has had limited application in immigrant populations in the U.S. In 2010, we used RDS to recruit undocumented Central American immigrant women in Houston, Texas for an HIV behavioral survey. Beginning with three initial participants we recruited 226 women within 16 weeks. Social networks were dense and participants adopted the recruitment system with reasonable ease. Homophily scores indicated moderate within-group preference by country of origin. However, cross-group recruitment was sufficient to achieve a diverse sample that attained equilibrium for all demographic and sexual behavior characteristics. Overall, RDS was easy to implement, attained a large sample in a relatively short period of time, and reached an otherwise hidden population. Our results suggest that RDS is an effective method for recruiting undocumented Latina immigrants for HIV behavioral surveys.

Prevalence of HIV risk behaviors among undocumented Central American immigrant women in Houston, Texas.

Undocumented Central American immigrants in the United States are disproportionately affected by HIV infection. However, epidemiological data on sexual behaviors among undocumented women are sparse and the extent to which behaviors vary by duration of residence in the U.S.is largely unknown. In 2010, we used respondent driven sampling to conduct an HIV behavioral survey among Central American immigrant women residing in Houston, Texas without a valid U.S. visa or residency papers. Here we describe the prevalence of sexual risk behaviors and compare recent (5 years or less in the U.S.) and established immigrants (over 5 years in the U.S.) to elucidate changes in sexual risk behaviors over time. Our data suggest that recent immigrants have less stable sexual partnerships than established immigrants, as they are more likely to have multiple and concurrent sexual partnerships, as well as partnerships of shorter duration.

Implications of the WHO Child Growth Standards in rural Honduras.

OBJECTIVE: The present study analysed the impact of using the 2006 WHO Child Growth Standards ('the WHO standards') compared with the 1977 National Center for Health Statistics (NCHS) international growth reference ('the NCHS reference') on the calculated prevalence of chronic malnutrition in children aged 6·0-59·9 months. DESIGN: Anthropometric data were collected as part of a cross-sectional study exploring the association between household environments and nutritional status of children. Z-scores were computed for height-for-age (HAZ), weight-for-age (WAZ) and weight-for-height (WHZ) using each reference/standard. Results were compared using Bland-Altman plots, percentage agreement, kappa statistics, line graphs and proportion of children in Z-score categories. SETTING: The study was conducted in thirteen rural villages within Honduras's department of Intibucá. SUBJECTS: Children aged 6·0-59·9 months were the focus of the analysis, and households with children in this age range served as the sampling unit for the study. RESULTS: The WHO standards yielded lower means for HAZ and higher means for WAZ and WHZ compared with the NCHS reference. The WHO standards and NCHS reference showed good agreement between Z-score categories, except for HAZ among males aged 24·0-35·9 months and WHZ among males aged >24·0 months. Using the WHO standards resulted in higher proportions of stunting (low HAZ) and overweight (high WHZ) and lower proportions of underweight (low WAZ). The degree of difference among these measures varied by age and gender. CONCLUSIONS: The choice of growth reference/standard employed in nutritional surveys may have important methodological and policy implications. While ostensibly comparable, data on nutritional indicators derived with different growth references/standards must be interpreted cautiously.

Effect of educational level on knowledge and use of breast cancer screening practices in Bangladeshi women.

The Breast Health Global Initiative 2007 emphasized education and cultural values for promoting breast cancer screening in developing countries. This cross-sectional study investigated if educational level and cultural beliefs affect breast cancer screening practices in 152 women 40 years or older in Dhaka, Bangladesh. Women with a higher (>12 years) educational level were more likely to know about breast self-examination (BSE; OR(adj), 95%CI = 22, 6.39-76.76), to know about mammograms (6, 2.49-15.70), and to practice BSE (3, 1.27-6.83) compared with those with a lower educational level. Breast cancer screening practices or knowledge was not affected by perceiving barriers to having mammograms.

Baseline dietary patterns of children enrolled in an urban family weight management study: associations with demographic characteristics.

Objective: To identify dietary patterns (DP) of children enrolled in the Family Weight Management Study (FWMS) and to examine relationship between the identified DP with demographics. Design: We performed a cross-sectional analysis of baseline data from 332 children (BMI ≥85th percentile for age and sex and 7-12 years old) who were enrolled in the FWMS. The Block Kids Food Frequency Questionnaire was used to assess dietary intake. Principal component analysis was conducted to identify DPs. Setting: Participants were recruited from Jacobi Medical Center, Bronx, NY from July 2009 - December 2011. Results: The mean age of the children was 9.3 (±1.7 SD) years; about half were female and 75% self-identified as Hispanic/Latino. The majority of parents/guardians were born outside of the mainland USA and half had less than a high school education. We identified a "pizza-pasta" DP (high loadings of pizza, pasta, red meat, chicken, fries, sweets, processed meat, and sweet breads) and a "snacks-dessert" DP (high loadings of snacks, desserts, soft drinks, and bread and refined grains) but no healthy patterns with high loadings of fruit, vegetables, nuts, and dairy products. The "pizza-pasta" pattern was associated with parents/guardian being born in the mainland USA and having a higher educational level (p < 0.05) whereas the "snack-dessert" pattern was not significantly associated with any of the demographic variables. Conclusion: Our findings suggest that poor DP is common among second-generation immigrant Hispanic/Latino children who are obese/overweight. Future research needs to address how parental education and acculturation status are related to DP to inform future directions for preventing childhood obesity.

Pulsed-field gel electrophoresis for Salmonella infection surveillance, Texas, USA, 2007.

To identify sources of transmission for area clusters, in 2007 the Houston Department of Health and Human Services conducted an 8-month study of enhanced surveillance of Salmonella infection. Protocol included patient interviews and linking the results of interviews to clusters of pulsed-field gel electrophoresis patterns detected by the local PulseNet laboratory.

Emerging disease syndromic surveillance for Hurricane Katrina evacuees seeking shelter in Houston's Astrodome and Reliant Park Complex.

Transmission of infectious diseases became an immediate public health concern when approximately 27,000 New Orleans-area residents evacuated to Houston's Astrodome and Reliant Park Complex following Hurricane Katrina. This article presents a surveillance system that was rapidly developed and implemented for daily tracking of various symptoms in the evacuee population in the Astrodome "megashelter." This system successfully confirmed an outbreak of acute gastroenteritis and became a critical tool in monitoring the course of this outbreak.

Intensive care noise and mean arterial blood pressure in extremely low-birth-weight neonates.

Noise in neonatal intensive care units (NICUs) may impede growth and development for extremely low-birth-weight (ELBW, < 1000 g) newborns. We calculated correlations between NICU sound levels and ELBW neonates' heart rate and arterial blood pressure to evaluate whether this population experiences noise-induced stress. Sound levels inside the incubator, heart rate (HR), and arterial blood pressure recordings were simultaneously collected for eight ELBW neonates for 15 minutes during the first week of life. Cross-correlation functions were calculated for NICU noise, HR, and mean arterial blood pressure (MABP) recordings for each subject. ELBW neonates' HR and MABP were significantly correlated ( R = 0.16 at 2-second lag time), with stronger correlation apparent for higher-birth-weight ELBW newborns (0.22 versus 0.10). Lower-birth-weight newborns responded to increased noise with HR acceleration from 45 to 130 seconds after noise events, and higher-birth-weight infants initially responded with an HR deceleration at 25 to 60 seconds, then HR acceleration ~175 seconds after noise increased. MABP was not as strongly correlated with NICU sound levels, although some correlation coefficients were slightly outside the 95% confidence interval. Higher-birth-weight newborns' more mature neurological systems may be responsible for stronger correlations between HR and MABP. NICU noise influenced newborns' HR, indicating that these infants hear and respond to NICU sounds. ELBW newborns in the first week of life seem to maintain a relatively stable blood pressure in response to moderate NICU sound levels (50 to 60 dBA).

Clinical and laboratory features of neonatal herpes simplex virus infection: a case-control study.

BACKGROUND: Neonatal herpes simplex virus (HSV) infection can cause significant morbidity and mortality but can be difficult to identify, particularly in neonates without vesicular rash. OBJECTIVE: To determine the unique clinical and laboratory features of neonates with and without HSV infection admitted to Texas Children's Hospital during a 14-year period. METHODS: An historic case-control study of all hospitalized neonates with laboratory-confirmed HSV infection and a restricted sample (ratio 1:4) of HSV test-negative hospitalized neonates. Univariate and multivariate analyses were performed to identify clinical and laboratory factors associated with neonatal HSV infection. RESULTS: Forty cases and 160 comparison subjects were identified. The following factors were associated with neonatal HSV infection by univariate analysis: maternal primary HSV infection, maternal fever, vaginal delivery, prematurity, postnatal HSV contact, vesicular rash, hypothermia, lethargy, seizures, severe respiratory distress, hepatosplenomegaly, thrombocytopenia, elevated hepatic enzymes, and cerebrospinal fluid (CSF) pleocyosis and proteinosis. Factors not associated with neonatal HSV infection were fever, total peripheral white blood cell count, and red blood cells in the CSF. For neonates presenting without vesicular rash, maternal fever, respiratory distress requiring mechanical ventilation, and CSF pleocytosis were independently associated with HSV infection. CONCLUSIONS: Inclusion of the newly appreciated features of maternal fever, respiratory distress, and thrombocytopenia might improve the detection of neonatal HSV infection. Clinical and laboratory factors typically associated with neonatal HSV infection were confirmed to be maternal primary HSV infection, vaginal delivery, prematurity, neonatal seizures, vesicular rash, elevated hepatic enzymes, and CSF pleocytosis.

Sexual Behavior Among Young Carers in the Context of a Kenyan Empowerment Program Combining Cash-Transfer, Psychosocial Support, and Entrepreneurship.

This study examined associations between sexual initiation, unprotected sex, and having multiple sex partners in the past year with participation in a three-year empowerment program targeting orphan and vulnerable children (OVC). The Kenya-based program combines community-conditioned cash transfer, psychosocial empowerment, health education, and microenterprise development. Program participants (n = 1,060) were interviewed in a cross-sectional design. Analyses used gender-stratified hierarchical logit models to assess program participation and other potential predictors. Significant predictors of increased female sexual activity included less program exposure, higher age, younger age at most recent parental death, fewer years of schooling, higher food consumption, higher psychological resilience, and lower general self-efficacy. Significant predictors of increased male sexual activity included more program exposure, higher age, better food consumption, not having a living father, and literacy. Findings support a nuanced view of current cash transfer programs, where female sexual activity may be reduced through improved financial status but male sexual activity may increase. Targeting of OVC sexual risk behaviors would likely benefit from being tailored according to associations found in this study. Data suggest involving fathers in sexual education, targeting women who lost a parent at a younger age, and providing social support for female OVC may decrease risk of human immunodeficiency virus (HIV) transmission.

Consenting postpartum women for use of routinely collected biospecimens and/or future biospecimen collection.

The National Children's Study (NCS) Harris County, Texas Study Center participated in the NCS Provider Based Sampling (PBS) substudy of the NCS Vanguard Phase pilot. As part of the hospital-based birth cohort component of the PBS substudy, we conducted a secondary data analysis to evaluate the proportion of postpartum women who consented to future biospecimen collection alone and to both future collection and use of residual birth biospecimens. In phase 1, 32 postpartum women at one hospital were asked to consent only to maternal future biospecimen collection. In phase 2, 40 other postpartum women from the same hospital were asked for an additional consent to use residual clinical biospecimens from the birth event that otherwise would be discarded, including cord blood and maternal blood and urine. Among 103 eligible women, a total of 72 participated. They were 28.3 ± 5.9 years old on average; 58 % were Hispanic; 63 % consented in English, and 37 % in Spanish; 39 % had some college education; 42 % were married; 60 % had an annual family income <$30,000; and 51 % were employed. In phase 1, 59 % consented to future biospecimen collection, and in phase 2, 95 % consented to both future collection and use of at least one residual birth biospecimen, with a difference between phases of 36 % [95 % CI 17-54 %]. Demographic characteristics did not differ among those who did and did not consent. Postpartum women were significantly more likely to grant consent for use of future and residual hospital-obtained biospecimens than future biospecimen collection alone.

Factors associated with general self-efficacy and resilience among youth heads of households in Kenya.

This study assesses resilience and general self-efficacy among Kenyan orphans and vulnerable children (n = 1060) active in a community-based program combining economic household strengthening with psychosocial support. Quantile regression analyses modeled associations between the 25th, 50th, and 75th percentiles of resilience and general self-efficacy and multiple covariates. Program participation positively predicted increased general self-efficacy at all levels. Program participation predicted increased resilience at the 25th percentile but decreased resilience at the 75th percentile. Other significant predictors included economic, educational, sexual behavior and other demographic factors. This study suggests support for an integrated approach to economic and psychosocial empowerment.

Multilevel Provider-Based Sampling for Recruitment of Pregnant Women and Mother-Newborn Dyads.

OBJECTIVE: In 2010, the National Children's Study launched 3 alternative recruitment methods to test possible improvements in efficiency compared with traditional household-based recruitment and participant enrollment. In 2012, a fourth method, provider-based sampling (PBS), tested a probability-based sampling of prenatal provider locations supplemented by a second cohort of neonates born at a convenience sample of maternity hospitals. METHODS: From a sampling frame of 472 prenatal care provider locations and 59 maternity hospitals, 49 provider and 7 hospital locations within or just outside 3 counties participated in study recruitment. During first prenatal care visits or immediately postdelivery at these locations, face-to-face contact was used to screen and recruit eligible women. RESULTS: Of 1450 screened women, 1270 were eligible. Consent rates at prenatal provider locations (62%-74% by county) were similar to those at birth locations (64%-77% by county). During 6 field months, 3 study centers enrolled a total prenatal cohort of 530 women (the majority in the first trimester) and during 2 months enrolled a birth cohort of an additional 320 mother-newborn dyads. As personnel became experienced in the field, the time required to enroll a woman in the prenatal cohort declined from up to 200 hours to 50 to 100 hours per woman recruited. CONCLUSIONS: We demonstrated that PBS was feasible and operationally efficient in recruiting a representative cohort of newborns from 3 diverse US counties. Our findings suggest that PBS is a practical approach to recruit large pregnancy and birth cohorts across the United States.

Parental pregnancy intention and early childhood stunting: findings from Bolivia.

BACKGROUND: This study examined the impact of maternally reported pregnancy intention, differentiating unwanted and mistimed pregnancies, on the prevalence of early childhood stunting. Additionally, it examined the influence of paternal pregnancy intention status. METHODS: Data were collected from a nationally representative sample of women and men interviewed in the 1998 Bolivia Demographic and Health Survey. The sample was restricted to lastborn, singleton children younger than 36 months who had complete anthropometric information. Multivariable logistic regression examined the association between pregnancy intention and stunting. RESULTS: Children from unwanted and mistimed pregnancies comprised 33% and 21% of the sample, respectively. Approximately 29% of the maternally unwanted children were stunted as compared to 19% among intended and 19% among mistimed children. Children 12-35 months (toddlers) from mistimed pregnancies (adjusted prevalence risk ratio [PR(adj)] 1.33, 95% confidence interval [CI]: 1.03-1.72) and unwanted pregnancies (PR(adj) 1.28, 95% CI: 1.04-1.56) were at about a 30% greater risk for stunting than children from intended pregnancies. Infants and toddlers with both parents reporting them as unwanted had an increased risk of being stunted as compared with children both of whose parents intended the pregnancy. No association was found for infants less than 12 months. CONCLUSIONS: Reducing unintended pregnancies in Bolivia may decrease the prevalence of childhood growth stunting. Children born to parents reporting mistimed or unwanted pregnancies should be monitored for growth stunting, and appropriate interventions should be developed. Measurement of paternal pregnancy intention status is valuable in pregnancy intention studies.

Improving efficacy of diabetes management using treatment algorithms in a mainly Hispanic population.

OBJECTIVE: To compare clinical outcomes obtained using treatment algorithms versus standard "usual care" to treat patients with type 2 diabetes in a community setting. RESEARCH DESIGN AND METHODS: An observational group comparison was implemented in three community-based clinics in San Antonio, Texas: 1). a community clinic following treatment algorithms (CC-TA), 2). university clinic following treatment algorithms (UC-TA), and 3). a community clinic following standard "usual care" practices (CC-SC). Three hundred fifty-eight recently diagnosed type 2 diabetic patients (90% Mexican American, from low-income neighborhoods) who were consecutively identified at the three clinics were recruited. Following medical and laboratory evaluation, participants were started on treatment for hyperglycemia, hypertension, and dyslipidemia and followed for 12 months. RESULTS: Decrements in HbA(1c) at 12 months in the CC-TA and UC-TA were 3.1 and 3.3%, respectively, compared to 1.3% in the CC-SC (P < 0.0001). Corresponding decrements in fasting plasma glucose at 12 months were 94 and 99 mg/dl, respectively, versus 38 mg/dl in CC-SC (P < 0.0001). Reductions in total cholesterol, LDL cholesterol, and triglycerides at 12 months were greater in both algorithm-managed clinics compared to standard care-managed clinics (P < 0.0001). In algorithm-managed clinics, there were 30% more documented eye exams and 24% more documented foot exams than in standard care-managed patients. CONCLUSIONS: Adherence to the treatment algorithms improved metabolic outcomes in type 2 diabetic patients to a greater extent than standard care practices. These results have important clinical implications for the treatment of type 2 diabetic patients.