Rodrigo X. Armijos

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.

PCR DETECTION AND IDENTIFICATION OF LEISHMANIA PARASITES IN CLINICAL SPECIMENS IN ECUADOR: A COMPARISON WITH CLASSICAL DIAGNOSTIC METHODS

A simplified polymerase chain reaction (PCR)-based assay was used for detection and typing of Leishmania parasites in clinical specimens from patients suspected of cutaneous leishmaniasis. Using cultures as the reference standard, our PCR detection method was more sensitive (92%) than classical diagnostic techniques, including microscopy (42% sensitivity), histologic staining (33%), and IgG enzyme-linked immunosorbent (20%). The PCR assay was also 100% specific. Parasites in both lesion biopsies and isolates cultured from lesion aspirates were identified as Leishmania braziliensis by PCR. In this study, we have demonstrated the suitability of simplified PCR assays for the simultaneous diagnosis and typing of parasites causing cutaneous leishmaniasis in a developing country where leishmaniasis is endemic.

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%).

Predictors and Nutritional Consequences of Intestinal Parasitic Infections in Rural Ecuadorian Children

The study investigated the prevalence, risk factors, and nutritional consequences of intestinal parasitic infections (IPI) in rural Ecuadorian children. A total of 244 children aged 0.2-14 years were studied. The data were collected using a structured questionnaire, anthropometry, and laboratory analysis of blood and fecal samples. The results showed that 90 per cent of the subjects were infected with at least one pathogenic IPI: 51 per cent with helminths, 37.6 per cent with protozoa, and 21.4 per cent with both. Giardia-infected children had a risk for stunted growth that was twice that of other children (51.7 vs. 33.1 per cent; OR = 2.16, 95 per cent CI = 1.13-4.15; p = 0.01). They also had significantly reduced mean hemoglobin levels compared with their non-infected counterparts (11.8 +/- 1.5 vs. 12.2 +/- 1.4 g/dl; p = 0.023). However, the proportion diagnosed with iron-deficiency anemia was slightly, but not significantly, increased (29.4 vs. 24.3 per cent). The most consistent predictor of Giardia and other protozoal IPI risk was a high intra-/peri-domicilliary concentration of domestic animals. Children who lived in such households had an infection risk that was two to five times greater than that of their non-infected counterparts. The data indicate that Giardia intestinalis infection has an adverse impact on child linear growth and hemoglobin. They also suggest that domestic animals may be an important reservoir for Giardia and other intestinal protozoal infections observed in the Ecuadorian children studied.

Epidemiology of leishmaniasis in Ecuador: Current status of knowledge: A review

Although leishmaniasis is regarded as a significant health problem in Ecuador by the Ministry of Health, and the incidence has increased over the last years, an official map on the geographic distribution of disease and sand fly vectors or a control strategy do not exist yet. This article reviews the current situation based on published information to improve our knowledge and understand the epidemiological situation of leishmaniasis in Ecuador in order to help future research and to develop a national control strategy. The disease is endemic in most provinces throughout Pacific coastal region, Amazonian lowlands, and some inter-Andean valleys with a total 21,805 cases reported during 1990-2003. Whereas cutaneous leishmaniasis (CL) is found throughout Ecuador, mucocutaneous leishmaniasis (MCL) appears to be restricted to the Amazon region; one, parasitologically unconfirmed case of visceral form was reported in 1949. Most human infections are caused by Leishmania (Viannia) spp., which is distributed in the subtropical and tropical lowlands; infections due to L. (Leishmania) spp. are found in the Andean highlands and in the Pacific lowlands as well. The proven vectors are Lutzomyia trapidoi and Lu. ayacuchensis. Canis familiaris, Sciurus vulgaris, Potos flavus, and Tamandua tetradactyla have been found infected with Leishmania spp. It is estimated that around 3000-4500 people may be infected every year, and that 3.1 to 4.5 millions people are estimated to be at risk of contracting leishmaniasis.

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.

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.

Nutritional status and cutaneous leishmaniasis in rural Ecuadorian children

The relationship between nutritional status and cutaneous leishmaniasis (CL) was evaluated in 230 children living in a rural subtropical rainforest in Northwest Ecuador. One-third of the subjects had evidence of either current (13 per cent) or past CL infection (21 per cent). Subjects with current (4.71 +/- 0.44 mg) or previous disease (4.29 +/- 0.35 mg) had lower mean daily dietary iron intakes than non-infected children (5.45 +/- 0.2 mg; chi 2 = 0.048), but not energy, protein, or other micronutrients. The low dietary iron intake data was corroborated by the reduced mean haemoglobin values observed in children with current (11.7 +/- 0.3 mg/dL) or past infection (11.3 +/- 0.2 mg/dL) compared to non-infected subjects (12.7 +/- 0.15 mg/dL; F-ratio = 17.0, P < 0.0001). Mean hematocrit values were also lower in the two infected groups (37.4 +/- 0.9 per cent and 37.4 +/- 0.6 per cent v. 39.5 +/- 0.5 per cent; F-ratio = 4.23, P = 0.0175). Furthermore, they were more likely to suffer from iron-deficiency anaemia than their non-infected counterparts (chi 2 = 4.64, P = 0.03). However, the children with active disease accounted for most of the excess risk for anemia (Fishers exact test P = 0.009; OR = 10.0, exact 95 per cent CI = 1.37-111.8). Finally, growth stunting (< -2SD height-for-age) was more common in subjects with current (54 per cent) or past infection (51 per cent) compared to those without CL history (31 per cent; chi 2 = 8.03, P = 0.004).(ABSTRACT TRUNCATED AT 250 WORDS)

Itraconazole in the treatment of New World mucocutaneous leishmaniasis

Background  A well‐tolerated oral drug is required for the treatment of mucocutaneous leishmaniasis (MCL). Current parenteral treatment regimens with pentavalent antimonials are associated with marked toxicity and significant rates of relapse.

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.