Antibacterial and Antioxidant Properties of Extracts of Yucca Baccata, a Plant of Northwestern Mexico, against Pathogenic Bacteria.

Introduction: Bacterial agents and oxidative reactions are involved in health and food preservation issues, and Yucca baccata (Y. baccata) can be a source of compounds with practical applications in both areas, but its investigation remains limited. Materials and Methods: Butanolic (YBE) and aqueous (YAE) extracts were obtained from the stem of Y. baccata. The total saponin, phenolic, and flavonoid contents were analyzed in the YBE and YAE. The antioxidant capacity of the extracts was determined by the DPPH, TEAC, FRAP, and ORAC assays. Seven Gram-positive and five Gram-negative pathogenic bacteria strains were used to determine the MIC and MBC. Results: Saponin contents were 30% and 1.81% (w/w) in the YBE and YAE, respectively. The total phenolic and flavonoid contents in the extracts were 29.5 µg GAEmg-1 (2.95%) and 5.58 µg GAEmg-1 (0.56%) in the YBE and 69.92 µg QEmg-1 (7.0%) and 1.65 µg QEmg-1 (0.165%) in the YAE. The antioxidant capacity values of YBE were 29.18 µg TEmg-1, 121.8 µg TEmg-1, 33.41 µg TEmg-1, and 156.84 µg TEmg-1 by the DPPH, TEAC, FRAP, and ORAC assays, respectively. YAE had lower antioxidant values than YBE (P < 0.05). Values of 80 mgmL-1 and 100 mgmL-1 were estimated for MIC and MBC of YBE against the Gram-positive bacteria. Values of 100 mgmL-1 and 120 mgmL-1 for MIC and MBC of YBE were estimated against the Gram-negative bacteria. No MIC and MBC were obtained for YAE. Conclusion: YBE exhibited higher antioxidant activity than YAE. Apparently, antibacterial properties of the YBE tended to be higher than those of the YAE.

Prevalence of overweight, obesity and central obesity and factors associated with BMI in indigenous yaqui people: a probabilistic cross-sectional survey.

BACKGROUND: The Yaquis are an Indigenous group who inhabit in the state of Sonora in northwestern Mexico. This group has experienced changes in their lifestyle, moving from a traditional lifestyle to a more modern one, resulting in an increase of obesity and its comorbidities. However, few studies have been done in this group. The aim of this study was to determine the prevalence of overweight, obesity and central obesity and to identify the factors associated with body mass index (BMI) in a representative sample of Indigenous Yaqui people from Sonora, Mexico. METHODS: A cross-sectional survey with multistage sampling was conducted among adults (N = 351) with residence in Yaqui traditional villages (Vícam, Pótam, Loma de Guamúchil, Loma de Bácum, Tórim, Ráhum, Huiribis or Belem). Anthropometric measurements were taken to diagnose overweight, obesity and central obesity. Food frequency and physical activity (PA) questionnaires designed for the Yaqui population were applied, as well as sociodemographic and clinical history questionnaires. The factors associated with BMI were assessed using multiple linear regression considering the complex design of the sampling. RESULTS: The prevalence of overweight, obesity and central obesity in the population were 36.5%, 35.0% and 76.0%, respectively. Having higher values of the modernization index (ß = 0.20, p = 0.049) was associated with a higher BMI, while having a higher consumption of a "prudent" dietary pattern (traditional dishes, fruits, vegetables and low-fat dairy) (ß = -0.58, p = 0.009) and performing a greater number of hours per week of vigorous PA (ß = -0.14, p = 0.017) were associated with a lower BMI. CONCLUSIONS: The prevalence of the studied abnormalities is high. The evidence presented in this study suggests that interventions are needed and more research is required to determine the appropriate components of such interventions, in order to meet the needs of the Yaqui people.

Enteric parasitic infection disturbs bacterial structure in Mexican children with autoantibodies for type 1 diabetes and/or celiac disease.

BACKGROUND: Intestinal bacterial dysbiosis and increased gut permeability are associated with higher risk of developing type 1 diabetes (T1D) or celiac disease (CD). There is a lack of information on parasitism involved in gut disturbance of predisposed children. We evaluated the effect of enteropathogenic parasites (Cryptosporidium spp., Cyclospora spp. G. lamblia, and Blastocystis spp.) on the bacterial structure of feces from children with autoantibodies for T1D or CD. Participants included 37 children under 18 years of age, from whom stools were analyzed for enteric parasites by qPCR and 22/37 for bacterial profile by sequencing the V3-V4 region of the 16s rRNA gene. Dietary, clinical, and socioeconomic data was recorded. RESULTS: Pathogens parasitized 28/37 participants, Cryptosporidium spp. was the most prevalent (62.2%), followed by both Cyclospora cayetanensis and Blastocystis spp (37.8%). There were no dietary differences (p > 0.05) attributable to parasitism. Co-infected participants with Cryptosporidium and Cyclospora did not differ (p = 0.064) from non-infected participants in bacterial alpha phylogenetic diversity. The same parasites' co-infection was associated with a decreased abundance of the Ruminococaceae (p = 0.04) and Verrucomicrobioceae families, of the Akkermansia genus (p = 0.009). There was a lower Firmicutes/Bacteroidetes ratio (p = 0.02) in infected than in uninfected participants. CONCLUSIONS: Cryptosporidium and Cyclospora affected the bacterial structure at family and genus levels, decreasing the ratio between Firmicutes and Bacteroidetes in children with auto-antibodies for T1D or CD, which could increase the risk of illness onset.

Microencapsulation of Carvacrol Using Pectin/Aloe-gel as a Novel Wound Dressing Films.

Recently, Pectin (PEC) and Aloe-Gel (AG) have received great attention for their use in the encapsulation of hydrophobic bioactive compounds such as Carvacrol (CAR). The aim of this study is to assess the physical, chemical and biological properties of a novel PEC/AG film and evaluate its capability to entrap CAR into microencapsulates. For this purpose, the casting method was used to prepare the PEC/AG membranes (70:30 % w/w). The CAR-loaded PEC/AG film was prepared adding different proportions of CAR (0.25%, 0.50% and 1.00% v/v) to the mixture of PEC/AG, previously emulsified with tween 80 (1.0%). The optical properties, Water Vapor Permeability (WVP), ATR-FTIR spectroscopy, microstructure, antibacterial activity and size of microcapsules were evaluated. The PEC/AG membranes loaded with CAR showed yellowish appearance and they were transparent to the UV electromagnetic radiation (190, 200 and 280 nm). The film prepared with the lowest amount of CAR (PC/AG-CAR-0.25%) showed the highest values of WVP (66.2%) and, according to SEM micrograph, the largest microcapsules (≈1005± 39 µm3). The FTIR analysis showed the characteristic absorption peaks located at 1015 cm-1 to 1030 cm-1 and a small shoulder to 990 cm-1 of benzene ring 1:2:4 substituted that suggested the presence of CAR-loaded in the PC/AG film. On the other hand, E. coli O157:H7 showed the highest sensitivity to the PEC/AG-CAR-1.00% film, while S. aureus was not sensitive.

Prevalence and associated risk factors for Giardia and Cryptosporidium infections among children of northwest Mexico: a cross-sectional study.

BACKGROUND: G. intestinalis and Cryptosporidium spp. are responsible for gastrointestinal infections worldwide. Contaminated food, feces, drinking water and predictors such as poverty, cultural and behavioral aspects have been involved in their transmission. Published studies about these infections are limited in Mexico. Cananea, Sonora is located in northwest Mexico and is one of the regions with the lowest marginalization index in the Sonora state. However, its rate of gastrointestinal infections increased from 48.7/1000 in 2003 to 77.9/1000 in 2010 in the general population. It was estimated that the prevalence of giardiasis can range from 20 to 30% in the Sonoran childhood population. However, the prevalence of giardiasis and cryptosporidiosis are unknown in Cananea, Sonora and they are likely contributing to its gastrointestinal infections rates. METHODS: A total of 173 children (average age 8.8 ± 2.8 years) participated in this cross-sectional study. Anthropometric measurements and stool analysis were performed. Socioeconomic, cultural and symptomatology information were collected. The association between the risk factors and intestinal parasitic infections was analyzed by multivariate analysis using the STATA/SE package at a significance level of p ≤ 0.05. RESULTS: More than half of the children (n = 103, 60%) had intestinal parasitic infections. Cryptosporidium spp. showed the highest prevalence (n = 47, 27%), which was followed by G. intestinalis (n = 40, 23%). Children with giardiasis and cryptosporidiosis had lower H/A and BMI/A Z scores than children who were free of these infections. Children with giardiasis were at higher risk (OR = 4.0; 95%CI = 1.11-13.02; p = 0.030) of reporting abdominal pain, and children who drank tap water were at higher risk (OR = 5.0; 95% CI = 1.41-17.20; p = 0.012) of cryptosporidiosis. CONCLUSIONS: This was the first epidemiological study conducted in children in the region of Cananea, Sonora in northwest Mexico. The findings revealed a high prevalence of cryptosporidiosis and giardiasis, and their interactions with multiple risk factors were investigated. This study suggested that giardiasis and cryptosporidiosis may play an important role as causative factors of gastrointestinal diseases in the study region. Regional authorities must analyze water for human consumption to search for Cryptosporidium spp. and G. intestinalis.

Use of a "Super-child" Approach to Assess the Vitamin A Equivalence of Moringa oleifera Leaves, Develop a Compartmental Model for Vitamin A Kinetics, and Estimate Vitamin A Total Body Stores in Young Mexican Children.

Background: Worldwide, an estimated 250 million children <5 y old are vitamin A (VA) deficient. In Mexico, despite ongoing efforts to reduce VA deficiency, it remains an important public health problem; thus, food-based interventions that increase the availability and consumption of provitamin A-rich foods should be considered.Objective: The objectives were to assess the VA equivalence of 2H-labeled Moringa oleifera (MO) leaves and to estimate both total body stores (TBS) of VA and plasma retinol kinetics in young Mexican children.Methods: ß-Carotene was intrinsically labeled by growing MO plants in a 2H2O nutrient solution. Fifteen well-nourished children (17-35 mo old) consumed puréed MO leaves (1 mg ß-carotene) and a reference dose of [13C10]retinyl acetate (1 mg) in oil. Blood (2 samples/child) was collected 10 times (2 or 3 children each time) over 35 d. The bioefficacy of MO leaves was calculated from areas under the composite "super-child" plasma isotope response curves, and MO VA equivalence was estimated through the use of these values; a compartmental model was developed to predict VA TBS and retinol kinetics through the use of composite plasma [13C10]retinol data. TBS were also estimated with isotope dilution.Results: The relative bioefficacy of ß-carotene retinol activity equivalents from MO was 28%; VA equivalence was 3.3:1 by weight (0.56 µmol retinol:1 µmol ß-carotene). Kinetics of plasma retinol indicate more rapid plasma appearance and turnover and more extensive recycling in these children than are observed in adults. Model-predicted mean TBS (823 µmol) was similar to values predicted using a retinol isotope dilution equation applied to data from 3 to 6 d after dosing (mean ± SD: 832 ± 176 µmol; n = 7).Conclusions: The super-child approach can be used to estimate population carotenoid bioefficacy and VA equivalence, VA status, and parameters of retinol metabolism from a composite data set. Our results provide initial estimates of retinol kinetics in well-nourished young children with adequate VA stores and demonstrate that MO leaves may be an important source of VA.

Use of real-time polymerase chain reaction to identify Entamoeba histolytica in schoolchildren from northwest Mexico.

INTRODUCTION: Entamoeba histolytica, E. dispar, and E. moshkovskii are morphologically identical, but intestinal amebiasis is caused only by E. histolytica. Mexico is among the countries with high amebae infection rates, although the contribution of pathogenic amoeba to the total detected cases remains unknown, especially in the northwestern dry region. Therefore, the aim of this study was to identify the actual prevalence of E. histolytica using real-time polymerase chain reaction (PCR) in schoolchildren of  northwestern Mexico. METHODOLOGY: Participants were children from five public elementary schools in the low-socioeconomic-level suburban areas of Hermosillo, Sonora, Mexico. One stool sample was collected from each child and analyzed by the Faust technique for Entamoeba spp. and by real-time PCR for E. histolytica. RESULTS: Analysis of stool  samples from 273 children (9.0 ± 1.5 years of age) resulted in 25 (9.2%) positive for E. histolytica/E. dispar/E. moshkovskii by the Faust technique; of these, 3 were positive for E. histolytica by real-time PCR. In addition, 2 samples that were negative for E. histolytica/E. dispar/E. moshkovskii by the Faust technique were positive by real-time PCR. CONCLUSIONS: The actual prevalence of E. histolytica in our study population was 1.8%, which is lower than those reported in previous studies in other Mexican regions.

Cryptosporidiosis: a neglected infection and its association with nutritional status in schoolchildren in northwestern Mexico.

INTRODUCTION: Undernutrition is a recognized public health problem in Mexican children and cryptosporidiosis is probably a factor contributing to this problem. However, it remains a neglected and poorly attended infection in Mexico. This study aimed to determine the prevalence of Cryptosporidium parvum and to establish its association with the nutritional status in schoolchildren of northwestern Mexico. METHODOLOGY: A total of 405 schoolchildren between 6 and 13 years of age were included in this study. Weight-for-age (W/A), height-for-age (H/A) and body mass index-for-age (BMI/A) Z scores were calculated. The Faust technique was used to detect intestinal parasites in stool samples and C. parvum coproantigen was detected by enzyme-linked immunosorbent assay (ELISA). RESULTS: The overall prevalence of C. parvum was 28.4%. Some of the study children were C. parvum free (n = 86) and some were C. parvum infected (n = 77). The prevalences of risk of undernutrition found in both groups of children for H/A, W/A, and BMI/A Z scores were 18%, 21% and 28%, respectively. Weight, ZW/A, and ZH/A were significantly higher in the C. parvum-free group compared to the C. parvum-infected group (p ≤ 0.05). The children with cryptosporidiosis were 2.7 times more likely to be at risk of undernutrition by W/A Z score and 2.9 times more likely to be at risk of undernutrition by ZH/A than were the C. parvum-free children. CONCLUSIONS: Cryptosporidiosis may be a contributing factor to childhood undernutrition in northwestern Mexico. The proper authorities must implement control and prevention measurements in Mexico and other developing countries.

Crosstalk between Zinc Status and Giardia Infection: A New Approach.

Zinc supplementation has been shown to reduce the incidence and prevalence of diarrhea; however, its anti-diarrheal effect remains only partially understood. There is now growing evidence that zinc can have pathogen-specific protective effects. Giardiasis is a common yet neglected cause of acute-chronic diarrheal illness worldwide which causes disturbances in zinc metabolism of infected children, representing a risk factor for zinc deficiency. How zinc metabolism is compromised by Giardia is not well understood; zinc status could be altered by intestinal malabsorption, organ redistribution or host-pathogen competition. The potential metal-binding properties of Giardia suggest unusual ways that the parasite may interact with its host. Zinc supplementation was recently found to reduce the rate of diarrhea caused by Giardia in children and to upregulate humoral immune response in Giardia-infected mice; in vitro and in vivo, zinc-salts enhanced the activity of bacitracin in a zinc-dose-dependent way, and this was not due to zinc toxicity. These findings reflect biological effect of zinc that may impact significantly public health in endemic areas of infection. In this paper, we shall explore one direction of this complex interaction, discussing recent information regarding zinc status and its possible contribution to the outcome of the encounter between the host and Giardia.

Marked antigiardial activity of Yucca baccata extracts: a potential natural alternative for treating protozoan infections.

Human giardiosis is a public health problem in Mexico, where the national prevalence was estimated to be up to 68%. Misuse of antiprotozoal drugs may result in low effectiveness and undesirable side effects. Research on natural products is a good strategy for discovering more effective antiparasitic compounds. This study evaluated the antigiardial activity of extracts of Yucca baccata, which is native to northwestern Mexico. Forty-two gerbils (females) were weighed and orally inoculated with 5 × 10(6) Giardia trophozoites. Two gerbils were selected at random to confirm infection. Forty living gerbils were randomly allocated into 5 treatment groups (8 per group). Gerbils were randomly assigned to be treated with 24.4 mg/mL, 12.2 mg/mL, and 6.1 mg/mL of extracts, metronidazole (2 mg/mL) or PBS, which were intragastrically administered once per day for 3 days. Nine gerbils died during the study course. On day 10 postinfection, gerbils were euthanized and trophozoites were quantified. Yucca extracts reduced, albeit not significantly, the trophozoite counts in the duodenum segment. Only the high-extract concentration significantly reduced the trophozoite counts in the proximal segment and it was similar to that of metronidazole. Extracts of Y. baccata may represent an effective and natural therapeutic alternative for human giardiosis.

Effects of dietary zinc manipulation on growth performance, zinc status and immune response during Giardia lamblia infection: a study in CD-1 mice.

Associations between Giardia lamblia infection and low serum concentrations of zinc have been reported in young children. Interestingly, relatively few studies have examined the effects of different dietary zinc levels on the parasite-infected host. The aims of this study were to compare the growth performance and zinc status in response to varying levels of dietary zinc and to measure the antibody-mediated response of mice during G. lamblia infection. Male CD-1 mice were fed using 1 of 4 experimental diets: adequate-zinc (ZnA), low-zinc (ZnL), high-zinc (ZnH) and supplemented-zinc (ZnS) diet containing 30, 10, 223 and 1383 mg Zn/kg respectively. After a 10 days feeding period, mice were inoculated orally with 5 × 106 G. lamblia trophozoites and were maintained on the assigned diet during the course of infection (30 days). Giardia-free mice fed ZnL diets were able to attain normal growth and antibody-mediated response. Giardia-infected mice fed ZnL and ZnA diets presented a significant growth retardation compared to non-infected controls. Zinc supplementation avoided this weight loss during G. lamblia infection and up-regulated the host's humoral immune response by improving the production of specific antibodies. Clinical outcomes of zinc supplementation during giardiasis included significant weight gain, higher anti-G. lamblia IgG antibodies and improved serum zinc levels despite the ongoing infection. A maximum growth rate and antibody-mediated response were attained in mice fed ZnH diet. No further increases in body weight, zinc status and humoral immune capacity were noted by feeding higher zinc levels (ZnS) than the ZnH diet. These findings probably reflect biological effect of zinc that could be of public health importance in endemic areas of infection.

Vitamin A-fortified milk increases total body vitamin A stores in Mexican preschoolers.

Vitamin A (VA) deficiency (VAD) continues to be a major nutritional problem in developing countries, including Central America. In Mexico, milk is a well-accepted vehicle for the administration of micronutrients, including VA, to preschoolers. Thus, we conducted a randomized, controlled, clinical trial to investigate the efficacy of daily consumption of 250 mL of VA-fortified milk (which provided 196 retinol equivalents/d) for 3 mo on VA stores in mildly to moderately VAD (serum retinol concentration 0.35-0.7 µmol/L) preschoolers who were not enrolled in a food assistance program. Twenty-seven mildly to moderately VAD children were randomly assigned based on screening measurements to either the intervention (n = 14) or control group (n = 13) (children in the control group did not receive placebo). All children in the control group and 79% (n = 11) of the children in the intervention group completed the study. The total body VA (TBVA) pool size was estimated using the deuterated retinol dilution technique before and after the intervention. After 3 mo, median changes in the serum retinol concentration for the intervention and control groups were 0.13 and -0.21 µmol/L, respectively (P = 0.009). Median changes in the TBVA stores were 0.06 and 0.01 mmol, respectively (P = 0.006) and estimated median changes in the liver VA concentration were 0.09 and 0.01 µmol/g, respectively (P = 0.002). The VA-fortified milk was well accepted among preschoolers and significantly increased TBVA stores, liver VA stores, and serum retinol concentration, indicating that it may be an effective means to ameliorate VAD in young Mexican children.

Persistence of intestinal parasitic infections during the national de-worming campaign in schoolchildren of northwestern Mexico: a cross-sectional study.

BACKGROUND: Intestinal parasitism remains a public health challenge in northwestern Mexico even when a twice yearly single dose of albendazole (400 mg) is administered to schoolchildren. We aimed to determine the current prevalence of intestinal parasitic infections in schoolchildren of northwestern Mexico. METHODS: The Faust and Kato Katz techniques were used to detect and identify the intestinal parasite species. One thousand two hundred and seventy eight children from 12 public schools were invited to participate in this study; 312 children participated in September 2003. RESULTS: Sixty eight percent of the subjects had intestinal parasites, 63% had protozoan infections, and 29%, 16% and 10% were infected with Giardia duodenalis, Hymenolepsisnana, and Entamoebahistolytica/dispar/moshkovskii respectively. Fifty children excreted eggs of Hymenolepsis nana. CONCLUSION: Educational strategies should be considered to support the national de-worming campaign, because albendazole alone will not sufficiently improve the health conditions of vulnerable populations.

Changes in serum zinc levels associated with giardiasis and dietary zinc intake in mice.

The association of giardiasis with the malabsorption of zinc remains controversial. This study investigated changes in serum zinc levels in Giardia-infected mice subjected to different dietary zinc regimens. Thirty-five mice (strain C(3)H/H(e)J) were randomly categorized into two groups. The first group was inoculated with 5 × 10(6) Giardia trophozoites (n = 18), and the second group remained Giardia free (n = 17). Each group (Giardia infected and Giardia free) was randomly classified into three subgroups and given low (9 mg Zn/kg), normal (33 mg Zn/kg), and high levels (288 mg Zn/kg) of dietary zinc over a 2-week period for acclimation. Fourteen days post-Giardia infection, all of the mice were euthanized and blood samples were collected. The number of trophozoites was quantified (hematocytometer), and serum zinc levels were determined via atomic absorption spectrophotometry. Significant increases in the median weights were only found in the Giardia-free mice (p < 0.05). A higher final median weight was found in the Giardia-free group when compared with that of the Giardia-infected group given low dietary zinc (p = 0.013). In the Giardia-infected group with low dietary zinc, the geometric mean of trophozoites was 3,498 ± 101 (SE) per milliliter. The Giardia-infected group had lower serum zinc levels than did the Giardia-free group with the high dietary zinc regimens (p < 0.05). Our results are consistent with studies among human populations, but further studies are required to elucidate the actual mechanism governing the zinc-giardiasis interaction.

Giardia lamblia infection and its implications for vitamin A liver stores in school children.

BACKGROUND: Vitamin A deficiency (VAD) is a nutritional problem affecting the health of people in developing countries because VAD compromises innate and adaptive immunity, increasing a person's predisposition toward infectious diseases. In addition, a high prevalence of infectious diseases continues to be a problem in developing countries, including Giardia lamblia. G. lamblia may be related to VAD because of its ability to change the intestinal architecture, thereby compromising the absorption of vitamin A. The aim of this study was to evaluate the effect of giardiasis on serum retinol levels and vitamin A liver stores in school children. METHODS: Thirty Giardia-infected school children participated in this study. Vitamin A liver stores were evaluated with the modified relative dose response (MRDR) technique, and antiparasitic treatment was administered. In addition, anthropometric and dietary data were collected. RESULTS: According to anthropometric indicators (age-appropriate Z scores for weight, height and body mass index) and daily vitamin A intake, the children had a normal nutritional status. Although the mean serum retinol levels did not change significantly after treatment for Giardia (p > 0.05), the MRDR values showed significant improvement (p < 0.002). CONCLUSION: Giardiasis not only compromises the vitamin A status through intestinal malabsorption, it also causes profound mobilization of liver retinol stores.

Efecto de la suplementación con una dosis masiva de vitamina A en niños de 6 a 36 meses de edad / Effect of massive vitamin A supplement in children from 6 to 36 months of age

Objetivo. Evaluar el impacto de la suplementación con una dosis masiva de vitamina A en el estado nutricio de dicha vitamina y del hierro, en niños de zonas urbanas marginadas de Hermosillo, Sonora, México. Material y métodos. Se seleccionaron 60 niños (6-36 meses), a los que se les administró una dosis de 100 00 UI (6-12 meses) y 200 000 UI (12-36 meses) de vitamina A en el Día Nacional de Salud de la Secretaría de Salud (junio de 1994). Se midieron niveles séricos de retinol, carotenioide, hierro, transferrina y ferritina, en tres fases: basal, a las dos semanas y después de tres meses. Resultados. En la primera fase, la mediana de retinol fue 0.7 µmol/l; en la segunda aumentó a 0.97 µmol/l (p< 0.001), y en la tercera disminuyó a 0.83 µmol/l (p> 0.05). Un 6.3 por ciento de los niños presentó deficiencia severa de vitamina A al inicio, y no se encontró ningún caso en las fases posteriores a la suplementación. En la fase basal, 42 por ciento de los casos presentaron deficiencia moderada y la mayoría fue normal en las siguientes fases. No hubo diferencias en los niveles de hierro y transferrina (p> 0.05), pero sí en ferritina (p< 0.001), lo que indica un mejoramiento en las reservas de hierro a los tres meses. Conclusiones. Las campañas de distribución de dosis masivas pueden tener un impacto importante en el estado nutricio de vitamina A y hierro