M. Margaret Weigel

The Household Food Insecurity and Health Outcomes of U.S.-Mexico Border Migrant and Seasonal Farmworkers

Emerging evidence suggests chronic household food insecurity has an adverse effect on health. This study examined the prevalence, predictors and health outcomes associated with food insecurity in 100 migrant and seasonal farmworker (MSFW) households living on the U.S.–Mexico border. Data were collected using the U.S. Food Security Scale, California Agricultural Worker’s Health Survey, and objective anthropometric, clinical and biochemical indicators. Food insecurity affected 82% of households; 49% also had hunger. Household food insecurity was predicted by the presence of minor children in the home and low maternal education. Food insecure households were more likely to have at least one member affected by symptoms of depression (deprimido), nervios (an ethnospecific condition), learning disorders, and symptoms suggestive of gastrointestinal infection. Although not directly associated with food insecurity, adult obesity, central body adiposity, elevated blood pressure, and blood lipid and glucose disturbances were common. These findings highlight the significant food security and health challenges faced by border area MSFW families.

Field Trial of a Vaccine against New World Cutaneous Leishmaniasis in an At-Risk Child Population: Safety, Immunogenicity, and Efficacy during the First 12 Months of Follow-Up

The safety, immunogenicity, and efficacy of a vaccine against cutaneous leishmaniasis in rural Ecuadorian children was assessed in a randomized, controlled, double-blinded study. Vaccine group subjects received 2 intradermal doses of a whole, killed promastigote vaccine cocktail plus bacille Calmette-Guérin (BCG) adjuvant. Control subjects got 2 doses of BCG only. The subjects who received both vaccination doses, 438 in the vaccine group (79.3%) and 406 in the control group (83.4%), were followed for 12 months. No serious adverse side effects were identified in either group. Significantly more vaccine group subjects than controls converted to a positive Montenegro skin test (85.1% vs. 20.1%; chi2 = 279; P < .001). The incidence of cutaneous leishmaniasis was significantly reduced in the vaccine compared with the control group (2.1% vs. 7.6%; chi2 = 8.95; P < .003). The protective efficacy of the vaccine was 72.9% (95% confidence interval = 36.1%-88.5%).

The epidemiology of cutaneous leishmaniasis in subtropical Ecuador

An epidemiologic survey (n=466) was conducted in an area of subtropical rainforest in north‐west Ecuador with the following objectives: (1) to determine the prevalence of cutaneous leishmaniasis (CL), (2) to identify the Leishmania species causing human disease, (3) to investigate the major clinical manifestations of leishmaniasis, (4) to study cellular and humoral immune response indicators associated with disease status and (5) to identify risk factors for CL. Fourteen per cent of subjects had parasitologically confirmed CL; 33% had evidence of prior disease. However, 17.2% of subjects with a negative CL clinical history presented with a positive Montenegro skin test (MST), indicating the possibility of subclinical infection. The species isolated from subject lesions were L. guyanensis (63%), L. panamensis (33%), and L. brazilensis (4%). Mean specific anti‐Leishmania IgG and IgM OD serum levels were highest in subjects diagnosed with current CL, followed by those with prior CL, and were lowest in healthy subjects, respectively (0.56±0.27 vs 0.33±0.2 vs 0.22±0.14; F‐ratio=74; P<0.00001) and (665±270 vs 481±220 vs 301±128.5; F‐ratio=37; P<0.00001). Likewise, subjects with present CL had measurably higher MST reactions (13±6.7 mm) than those with prior CL (10.9±7.8 mm) or healthy individuals (2.4±2.5 mm; F‐ratio=106; P<0.00001). Serum concentrations of IgG were predicted by lesion number (t=2.5; P=0.018), size (t=3.7; P=0.0006), and duration (t=3.5; P=0.0013). Furthermore, the MST induration size increased as a function of lesion number (t=3.0; P=0.005) and size (t=3.4; P=0.022). Subject age and sex did not predict serum IgG or IgM concentrations or MST reactions in the 3 disease groups. Although no sex differences were found with respect to clinical characteristics, children 12 years of age were almost 3 times more likely to have CL lesions or scars located on the face and head area compared to adults (OR=2.75; 95% CI=1.4–5.6, P=0.004). The risk factors associated with disease included age under 5 years (AOR=1.5; 95% CI=0.48–2.35), male gender in adults (AOR=2.8; 95% CI=1.1–7.8), and wood and/or cane exterior house walls (AOR=1.8; 95% CI=1.4–2.5). In contrast, electric home lighting was associated with decreased risk (AOR=0.7; 95% CI=0.4–2.3). The results suggest that it may be possible to modify a portion of the risk of CL by making changes in the housing environment which may help to reduce the amount of human–vector contact.

Is the nausea and vomiting of early pregnancy really feto-protective?

Abstract Background: Health care providers and popular press articles frequently advise women that nausea and vomiting of early pregnancy (NVP) portends a favorable fetal outcome. Aim: To investigate the claim that NVP protects against adverse fetal outcomes and improves placental and fetal growth. Methods: Data were collected on a prospective cohort of 849 Ecuadorian prenatal patients beginning in early gestation until postpartum. A questionnaire collected information on NVP and other maternal characteristics. Fetal outcomes and placental characteristics were examined using anthropometry and physical examination. Multivariate statistical methods controlled for potential confounders. Results: Women with nausea only (AOR=0.45; 95% CI=0.22–0.94) or nausea with vomiting (AOR=0.66; 95% CI=0.46–0.99) had significantly decreased miscarriage risk although the strength of the protection appeared less than that reported for other populations. NVP was not associated with low birth weight, preterm delivery, congenital anomaly, or other outcomes excepting slightly increased mean infant thigh skinfold (P=0.024), mid-upper arm circumference (P=0.049), and placental weight (P=0.034). Conclusions: The data did not support the common belief that NVP protects against multiple adverse outcomes. Placental weight was slightly increased in women with NVP but this difference was not reflected in higher birth weights or other types of fetal growth except of marginally increased limb fat.

Food aversions and cravings during early pregnancy: Association with nausea and vomiting

The prospective cohort study examined whether Ecuadorian women with early pregnancy nausea and vomiting (NVP) are more likely to develop food aversions and cravings, and if so, whether the specific foods identified as aversive or craved are the same as those predicted by the popular maternal-embryo protection hypothesis (MEPH). Consistent with MEPH predictions, women with NVP were more likely to report increased odor sensitivity and aversions for some predicted “toxic” foods and more likely to crave fruits. However, other hypothesis predictions were not supported. The relationship of food aversions and cravings with NVP appears more complicated than that explained by the MEPH.

Field Trial of a Vaccine against New World Cutaneous Leishmaniasis in an At-Risk Child Population: How Long Does Protection Last?

During 12 months of follow-up in a randomized double-blind controlled field study, a killed whole-promastigote vaccine cocktail plus bacille Calmette-Guérin (BCG) adjuvant significantly reduced the incidence of cutaneous leishmaniasis (CL) in Ecuadorian children, compared with BCG alone. To determine how much longer protection might continue, the study was reblinded to permit 48 additional months of follow-up. During months 13-18, CL incidence remained lower in the vaccine group, compared with that in the control group (5.9% vs. 13.8%; chi2=8.8; P=.003), with vaccine efficacy calculated at 56.5% (95% confidence interval, 18.7%-76.7%); however, during months 24-60, no significant between-group differences were detected. Periodic administration of boosters may be necessary to maintain whole-parasite-vaccine protection against New World CL.

The meaning and consequences of tuberculosis for an at-risk urban group in Ecuador

OBJECTIVE To explore knowledge, beliefs, perceptions, and attitudes about tuberculosis (TB) in a high-risk group in Ecuador. This included signs and symptoms, causation, transmission, treatment, treatment adherence, impact on lifestyle and role functioning, and stigma. METHODS A convenience sample of 212 adults undergoing diagnostic TB testing at a public health facility in Quito, Ecuador, was recruited for the study. Data were collected from subjects during face-to-face interviews using a structured instrument containing closed and openended questions. Descriptive and bivariate statistics were used for quantitative analyses; content analysis was used to analyze qualitative data. RESULTS Most subjects were familiar with TB and some of its characteristics and treatment aspects. However, many also held misconceptions or lacked key knowledge which could adversely affect early diagnosis and treatment and adherence to treatment, and thereby allow the disease to spread. Subject education was the single most important predictor of knowledge, beliefs, perceptions, and attitudes followed by gender, age, and prior disease experience. The subjects linked TB to multiple adverse health, economic, psychological, and social consequences, including stigma. Although none knew if they had TB when interviewed, many reported feeling stigmatized just by being tested. The subjects identified a strong need for formal educational opportunities to learn about TB prevention and control but had little access to these. CONCLUSIONS The study findings highlight a need for enhanced population access to TB education. Health education and social marketing directed toward increasing TB knowledge and changing perceptions and attitudes could ultimately contribute to improved early diagnosis, treatment adherence, prevention, and decreased stigma. This could be accomplished providing that the public health infrastructure is adequate to meet demands.

Adjunctive micronutrient supplementation for pulmonary tuberculosis

OBJECTIVE To assess the effect of micronutrient supplementation on tuberculosis (TB) patient outcomes. MATERIAL AND METHODS The randomized, double-blinded, placebo-controlled study was conducted in pulmonary TB patients undergoing directly observed treatment short course/ tratamiento acortado estrictamente supervisado (TAES/ DOTS) at IMSS in Ciudad Juarez, Chihuahua, Mexico, who were recruited during August 2005-July 2006. Consecutive patients received zinc and vitamin A supplements or matched placebo for four months. Dietary intake, blood zinc and vitamin A, immune response (IFN-gamma,TNF-alpha, and IL-10 mRNA), and sputum smear conversion were measured. RESULTS The proportion of micronutrient compared to placebo group subjects with a negative sputum smear by month 3 was significantly increased (p= 0.03). This occurred subsequent to increased TNF-alpha and IFN-gamma and decreased IL-10 observed at month 2. Micronutrient supplementation appeared to accelerate the beneficial therapeutic effect of chemotherapy. CONCLUSIONS The earlier elimination of bacilli from sputum was associated with improved zinc status and Th1 immune response. The therapeutic effect of vitamin A was less evident.

Residential Exposure to Urban Traffic Is Associated with Increased Carotid Intima-Media Thickness in Children

Chronic exposure to urban traffic pollution is documented to promote atherosclerosis in adults but little is known about its potential effects in children. Our study examined the association of long-term exposure to traffic with carotid intima-media thickness (cIMT) in 287 healthy children. Residential proximity and distance-weighted traffic density (DWTD) were used as proximity markers for traffic-related air pollution exposure. The multivariable analyses revealed that children residing <100 meters from the nearest heavily trafficked road had cIMT mean and maximum measurements that were increased by 15% and 11% compared to those living ≥ 200 meters away (P = 0.0001). Similar increases in cIMT were identified for children in the highest versus lowest DWTD tertile. Children who resided 100–199 meters from traffic or in the middle DWTD tertile also exhibited increased cIMT but these differences were not statistically significant. No statistically significant differences were identified between residential distance to traffic or DWTD and systemic inflammation indicators (CRP, IL-6). The study results suggest that exposure to urban traffic promotes arterial remodeling in children. This finding is important since even small increases in cIMT over time can potentially lead to earlier progression to atherosclerosis. It is also important because traffic-related pollution is potentially modifiable.

Food Insufficiency in the Households of Reproductive-Age Ecuadorian Women: Association with Food and Nutritional Status Indicators

Data from a nationally representative survey of Ecuadorian households with reproductive-aged women (n = 10,784) were used to analyze the prevalence of household food insufficiency (HFI) and its association with sociodemographic characteristics, food acquisition and expenditure patterns, dietary diversity, and anthropometric indicators. Fifteen percent of households had food insufficiency and 15% had marginal food sufficiency. HFI was associated with poverty-linked indicators. Marginally food sufficient households reported social and economic capital than food which appeared protective against HFI. Food insufficiency was associated with reduced household acquisition/expenditures on high quality protein and micronutrient-rich food sources. HFI was not associated with adult or adolescent female overweight/obesity but was associated with short adult stature (< 1.45 m). The ongoing nutrition transition in Ecuador is expected to continue to modify population food security, diet, and nutrition. Systematic surveillance of household level food security is needed to inform recent food-related policies and programs implemented by the Ecuadorian government.