Cross-modulation of pathogen-specific pathways enhances malnutrition during enteric co-infection with Giardia lamblia and enteroaggregative Escherichia coli.

Diverse enteropathogen exposures associate with childhood malnutrition. To elucidate mechanistic pathways whereby enteric microbes interact during malnutrition, we used protein deficiency in mice to develop a new model of co-enteropathogen enteropathy. Focusing on common enteropathogens in malnourished children, Giardia lamblia and enteroaggregative Escherichia coli (EAEC), we provide new insights into intersecting pathogen-specific mechanisms that enhance malnutrition. We show for the first time that during protein malnutrition, the intestinal microbiota permits persistent Giardia colonization and simultaneously contributes to growth impairment. Despite signals of intestinal injury, such as IL1α, Giardia-infected mice lack pro-inflammatory intestinal responses, similar to endemic pediatric Giardia infections. Rather, Giardia perturbs microbial host co-metabolites of proteolysis during growth impairment, whereas host nicotinamide utilization adaptations that correspond with growth recovery increase. EAEC promotes intestinal inflammation and markers of myeloid cell activation. During co-infection, intestinal inflammatory signaling and cellular recruitment responses to EAEC are preserved together with a Giardia-mediated diminishment in myeloid cell activation. Conversely, EAEC extinguishes markers of host energy expenditure regulatory responses to Giardia, as host metabolic adaptations appear exhausted. Integrating immunologic and metabolic profiles during co-pathogen infection and malnutrition, we develop a working mechanistic model of how cumulative diet-induced and pathogen-triggered microbial perturbations result in an increasingly wasted host.

Epidemiology and Risk Factors for Cryptosporidiosis in Children From 8 Low-income Sites: Results From the MAL-ED Study.

Background: Cryptosporidium species are enteric protozoa that cause significant morbidity and mortality in children worldwide. We characterized the epidemiology of Cryptosporidium in children from 8 resource-limited sites in Africa, Asia, and South America. Methods: Children were enrolled within 17 days of birth and followed twice weekly for 24 months. Diarrheal and monthly surveillance stool samples were tested for Cryptosporidium by enzyme-linked immunosorbent assay. Socioeconomic data were collected by survey, and anthropometry was measured monthly. Results: Sixty-five percent (962/1486) of children had a Cryptosporidium infection and 54% (802/1486) had at least 1 Cryptosporidium-associated diarrheal episode. Cryptosporidium diarrhea was more likely to be associated with dehydration (16.5% vs 8.3%, P < .01). Rates of Cryptosporidium diarrhea were highest in the Peru (10.9%) and Pakistan (9.2%) sites. In multivariable regression analysis, overcrowding at home was a significant risk factor for infection in the Bangladesh site (odds ratio, 2.3 [95% confidence interval {CI}, 1.2-4.6]). Multiple linear regression demonstrated a decreased length-for-age z score at 24 months in Cryptosporidium-positive children in the India (ß = -.26 [95% CI, -.51 to -.01]) and Bangladesh (ß = -.20 [95% CI, -.44 to .05]) sites. Conclusions: This multicountry cohort study confirmed the association of Cryptosporidium infection with stunting in 2 South Asian sites, highlighting the significance of cryptosporidiosis as a risk factor for poor growth. We observed that the rate, age of onset, and number of repeat infections varied per site; future interventions should be targeted per region to maximize success.

Malaria parasitaemia, anaemia and malnutrition in children less than 15 years residing in different altitudes along the slope of Mount Cameroon: prevalence, intensity and risk factors.

BACKGROUND: Malaria, anaemia and malnutrition are frequently co-existing diseases that cause significant morbidity and mortality particularly among children. This study measured the prevalence, intensity and evaluated risk factors for malaria parasitaemia, anaemia and malnutrition among children living at low versus high altitude settings in the Mount Cameroon area. METHODS: A cross-sectional community based survey involving 828 children aged 6 months to 14 years was conducted between July and November 2017. Malaria parasitaemia was confirmed by light microscopy, haemoglobin concentration was measured using an auto haematology analyser, nutritional status was determined from the anthropometric measurements collected, and socioeconomic status related variables by the use of questionnaire. Anaemia and malnutrition were defined according to World Health Organization standards. Associations between predictor variables and primary outcomes were assessed using logistic regression analysis. RESULTS: Malaria parasite and anaemia were prevalent in 41.7% and 56.2% of the children, respectively while, malnutrition prevalence was 34.8% with wasting, underweight and stunting occurring in 25.7%, 19.9% and 23.7% of them respectively. Overall malaria parasite geometric mean density was 413/µL of blood (range 100-27,060). The odds of having malaria parasitaemia was highest in children 5-9 years of age [odd ratio (OR) = 1.69, P = 0.006], living in lowland (OR = 1.48, P = 0.008) as well as those whose domestic water was collected from an open source (streams/springs) (OR = 1.81, P = 0.005) than their counterparts. Being < 5 years (OR = 3.15, P = < 0.001) or 5-9 years (OR = 2.20, P < 0.001) of age, having malaria parasite (OR = 2.07, P = < 0.001) and fever in the past 2 days (OR = 1.52, P < 0.04) were identified as significant risk factors of anaemia while the age group < 5 years was the only significant risk (OR = 3.09, P = < 0.001) associated with malnutrition. CONCLUSION: While age specific attention should be given in the control of malaria (5-9 years), anaemia (< 10 years) and malnutrition (< 5 years), the existing malaria control programmes should be revised to integrate anaemia and malnutrition control strategies so as to improve upon the health of the children.

Could diet composition modulate pathological outcomes in schistosomiasis mansoni? A systematic review of in vivo preclinical evidence.

Schistosomiasis and malnutrition are often overlapped in poor communities, resulting in disproportionately high mortality rates. Currently, fragmented data make it difficult to define the relationship between diet and schistosomiasis. Thus, we systematically review the preclinical evidence on the impact of diet in Schistosoma mansoni infection. From a structured search, we recovered 27 original articles. All studies used mice and most of them investigated hypoproteic (70.37%), hyperlipidic (22.22%) or vitamin-deficient (7.41%) diets. Diets based on carbohydrate, zinc or milk supplementation were investigated at a reduced frequency (3.70% each). Hypoproteic diets attenuated parasitic load and granulomatous inflammation, but also reduced host resistance to S. mansoni infection, determining higher mortality rates. By stimulating steatohepatitis, parasitic load and granulomatous inflammation, hyperlipidic diets increase organ damage and mortality in infected animals. Although a high-sugar diet and vitamin restriction potentiate and zinc supplementation attenuates S. mansoni infection, the current evidence for these diets remains inconclusive. Analysis of methodological quality indicated that the current evidence is at high risk of bias due to incomplete characterization of the experimental design, diet composition and treatment protocols. From the bias analysis, we report methodological limitations that should be considered to avoid systematic reproduction of inconsistent and poorly reproducible experimental designs.

Prevalence and intensity of Ascaris lumbricoides infections in relation to undernutrition among children in a tea plantation community, Sri Lanka: a cross-sectional study.

BACKGROUND: Ascaris lumbricoides infections are one of the commonnest intestinal nematode infections in the world, with a profound negative effect on nutritional status among underprivileged populations. In Sri Lanka, Ascaris infections and low nutritional status still persist in the plantation sector. However, research regarding the association between Ascaris infections and nutritional status is scarce. The main purpose of this study was to determine the association between Ascaris infections and physical growth among children in a plantation sector in Sri Lanka. METHODS: A cross sectional study was conducted among 489 children aged between 1 and 12 years ina plantation sector, Sri Lanka, from January to April 2013. Anthropometric measurements were collected to assess height-for-age (HAZ), weight-for-age (WAZ) and weight-for-height (WHZ) to determine stunting, underweight and wasting respectively. Data on socio-demographic and antihelminthic treatment were ascertained using an interviewer administrated structured questionnaire. Stool samples were subjected to wet mount preparation followed byformaldehyde-ether sedimentation technique to diagnose Ascaris infection and a Kato Katz technique was performed to determine the eggs intensity. AnthroPlus, EpiInfo and SPSS software was used to analyze data. RESULTS: Of the study sample, 38.4% showed Ascaris lumbricoides infections. Light intensity infections (51%) were common in the infected children, followed by moderate (30%) and heavy (19%) infections. Prevalence of Ascaris infections was significantly associated with de-worming more than six months prior to the study. Prevalence of undernutrition among children was 61.7%. Forty-five per cent were underweight, while 24.1% and 21.5% of children were stunted and wasted respectively. However, no significant association was found between Ascaris infections status and undernutrition. Meanwhile, heavy intensity infections were associated with decreased values of WHZ (p = 0.020). CONCLUSIONS: Ascaris infections and undernutrition are still highly prevalent and a major public health problem in the plantation sector in Sri Lanka. Health and nutrition intervention programs should be implemented to increase the nutritional status of children.

Prebiotic inulin supplementation modulates the immune response and restores gut morphology in Giardia duodenalis-infected malnourished mice.

Malnutrition induces a state of growth retardation and immunologic depression, enhancing the host susceptibility to various infections. In the present study, it was observed that prebiotic supplementation either prior or simultaneously with Giardia infection in malnourished mice significantly reduced the severity of giardiasis and increased the body and small intestine mass, along with increased lactobacilli counts in faeces compared with malnourished-Giardia-infected mice. More specifically, prebiotic supplementation significantly increased the levels of anti-giardial IgG and IgA antibodies and anti-inflammatory cytokines IL-6 and IL-10 and reduced the pro-inflammatory cytokine TNF-α, along with increased levels of nitric oxide in both the serum and intestinal fluid of malnourished-prebiotic-Giardia-infected mice compared with malnourished-Giardia-infected mice. Histopathology and scanning electron microscopy of the small intestine also revealed less cellular and mucosal damage in the microvilli of prebiotic-supplemented malnourished-Giardia-infected mice compared with severely damaged mummified and blunted villi of malnourished-Giardia-infected mice. This is the first study to report that prebiotic supplementation modulated the gut morphology and improved the immune status even in malnourished-Giardia-infected mice.

Lysine requirements of moderately undernourished school-aged Indian children are reduced by treatment for intestinal parasites as measured by the indicator amino acid oxidation technique.

BACKGROUND: Lysine requirements of well-nourished children from developing regions have been found to be similar to those of children from developed regions (33.5 mg · kg⁻¹ · d⁻¹). However, intestinal parasites have been shown to increase lysine requirements in undernourished adults, and it is not known if a similar phenomenon occurs in undernourished children from poor and unsanitary environments. OBJECTIVE: Our objective was to measure the lysine requirement of moderately undernourished school-aged Indian children by the indicator amino acid oxidation technique before and after successful treatment for intestinal parasites. METHODS: Twenty-one undernourished school-aged children (∼8 y of age) with z scores between -2 SD and -3 SD for height-for-age or weight-for-age, who tested positive for intestinal parasites, were studied before and after successful antiparasite treatment. Children were fed any 2 of 7 levels of lysine intakes (5, 15, 25, 35, 50, 65, and 80 mg · kg⁻¹ · d⁻¹) in random order. The lysine requirement was determined by applying a 2-phase linear regression crossover analysis on the fractional oxidation rate of the tracer L-[1-¹³C] phenylalanine in response to the graded lysine intakes. RESULTS: The lysine requirement of undernourished children with intestinal parasite infestations was determined to be 42.8 mg · kg⁻¹ · d⁻¹ (95% CI: 32.6, 53.1 mg · kg⁻¹ · d⁻¹), and after successful antiparasitic treatment it was determined to be 35.5 mg · kg⁻¹ · d⁻¹ (95% CI: 25.5, 45.5 mg · kg⁻¹ · d⁻¹). The results were significantly different (P < 0.05), although the 95% CIs overlapped. CONCLUSIONS: The lysine requirement in undernourished children is similar to that of well-nourished children, and intestinal parasitic infestation increased the lysine requirement by ∼20%.

Low transformation growth factor-ß1 production and collagen synthesis correlate with the lack of hepatic periportal fibrosis development in undernourished mice infected with Schistosoma mansoni.

Undernourished mice infected (UI) submitted to low and long-lasting infections by Schistosoma mansoni are unable to develop the hepatic periportal fibrosis that is equivalent to Symmers' fibrosis in humans. In this report, the effects of the host's nutritional status on parasite (worm load, egg viability and maturation) and host (growth curves, biology, collagen synthesis and characteristics of the immunological response) were studied and these are considered as interdependent factors influencing the amount and distribution of fibrous tissue in hepatic periovular granulomas and portal spaces. The nutritional status of the host influenced the low body weight and low parasite burden detected in UI mice as well as the number, viability and maturation of released eggs. The reduced oviposition and increased number of degenerated or dead eggs were associated with low protein synthesis detected in deficient hosts, which likely induced the observed decrease in transformation growth factor (TGF)-ß1 and liver collagen. Despite the reduced number of mature eggs in UI mice, the activation of TGF-ß1 and hepatic stellate cells occurred regardless of the unviability of most miracidia, due to stimulation by fibrogenic proteins and eggshell glycoproteins. However, changes in the repair mechanisms influenced by the nutritional status in deficient animals may account for the decreased liver collagen detected in the present study.

Nutritional status, intestinal parasite infection and allergy among school children in northwest Ethiopia.

BACKGROUND: Parasitic infections have been shown to have deleterious effects on host nutritional status. In addition, although helmintic infection can modulate the host inflammatory response directed against the parasite, a causal association between helminths and allergy remains uncertain. The present study was therefore designed to evaluate the relationship between nutritional status, parasite infection and prevalence of allergy among school children. METHODS: A cross sectional study was performed involving school children in two elementary schools in Gondar, Ethiopia. Nutritional status of these children was determined using anthropometric parameters (weight-for-age, height-for-age and BMI-for-age). Epi-Info software was used to calculate z-scores. Stool samples were examined using standard parasitological procedures. The serum IgE levels were quantified by total IgE ELISA kit following the manufacturer's instruction. RESULT: A total of 405 children (with mean age of 12.09.1 ± 2.54 years) completed a self-administered allergy questionnaire and provided stool samples for analysis. Overall prevalence of underweight, stunting and thinness/wasting was 15.1%, 25.2%, 8.9%, respectively. Of the total, 22.7% were found to be positive for intestinal parasites. The most prevalent intestinal parasite detected was Ascaris lumbricoides (31/405, 7.6%). There was no statistically significant association between prevalence of malnutrition and the prevalence of parasitic infections. Median total serum IgE level was 344 IU/ml (IQR 117-2076, n=80) and 610 IU/ml (143-1833, n=20), respectively, in children without and with intestinal parasite infection (Z=-0.198, P>0.8). The prevalence of self reported allergy among the subset was 8%. IgE concentration was not associated either with the presence of parasitic infection or history of allergy. CONCLUSION: The prevalence of malnutrition, intestinal parasitism and allergy was not negligible in this population. In addition, there was no significant association between the prevalence of allergy and their nutritional status, and parasite infection. Further research prospective observational and intervention studies are required to address the question of causality between nutritional factors, parasites, and allergy.

[Malaria infection and nutritional status: results from a cohort survey of children from 6-59 months old in the Kivu province, Democratic Republic of the Congo]. / Infection palustre et état nutritionnel: résultats d'une cohorte d'enfants âgés de 6 à 59 mois au Kivu en République démocratique du Congo.

BACKGROUND: Despite a reduction in the magnitude of endemic malaria reported in recent years, malaria and protein-energy malnutrition (PEM) still remain major causes of morbidity and mortality in sub-Saharan Africa among children under five. The relationship between malaria and malnutrition remains a topic of controversy. We aimed to investigate malaria infection according to nutritional status in a community-based survey. METHODS: A cohort of 790 children aged 6 to 59 months and residing in eastern Democratic Republic of the Congo was followed-up from April 2009 to March 2010 with monthly visits. Data on nutritional status, morbidity between visits, use of insecticide-treated nets and malaria parasitemia were collected at each visit. The Z scores height for age, weight for age and weight for height were computed using the reference population defined by the WHO in 2006. Thresholds for Z scores were defined at -3 and -2. A binary logistic model of the generalized estimating equation (GEE) was used to quantify the association between PEM indicators and malaria parasitemia. Odds ratio (OR) and their 95% confidence interval (95% CI) were computed. RESULTS: After adjustment for season, children with severe stunting (height for age Z score<-3) were at lower risk of malaria parasitemia greater or equal to 5000 trophozoits/µL of blood as compared to those in with a better nutritional status (height for age Z score≥-2) (OR=0.48, 95% CI: 0.25-0.91). CONCLUSION: Severely stunted children are at a lower risk of high-level malaria parasitemia.

Novel in vitro and in vivo models and potential new therapeutics to break the vicious cycle of Cryptosporidium infection and malnutrition.

BACKGROUND: Although several animal models of cryptosporidiosis have been reported, most involve genetically or pharmacologically immune-suppressed hosts. METHODS: We report challenge with excysted (in vitro and in vivo) and unexcysted (in vivo) Cryptosporidium parvum oocysts in human colonic adenocarcinoma (HCT-8) cells and weaned nourished and malnourished C57BL/6 mice, following outcomes of growth rate, stool shedding, and tissue burden. We tested treatment with an oligodeoxynucleotide containing unmethylated CpG motif (CpG-ODN) and alanyl-glutamine in vivo and in vitro. RESULTS: C. parvum-challenged mice showed prolonged weight loss (>10% over 4 days), robust stool shedding (>3 logs/d over 7 days), and epithelial infection in the ileum, cecum, and colon. Of 2 potential therapeutic compounds evaluated in the model, CpG-ODN reduced body weight loss (to <6% on days 3-7 after challenge), reduced shedding of organisms (by 25% on days 1 and 3 after challenge), and decreased the burden of parasites in the ileum. Alanyl-glutamine showed similar benefits. In vitro findings suggested that effects on the epithelial component of the mucosa probably likely responsible for beneficial effects seen in vivo. CONCLUSIONS: Weaned mice provide a convenient and reproducible model of cryptosporidial disease, including its vicious cycle with body weight loss and heavier infection with malnutrition, and this model may be useful in exploring innovative therapeutic solutions for this challenging infectious disease.

Contribution of enteric infection, altered intestinal barrier function, and maternal malnutrition to infant malnutrition in Bangladesh.

BACKGROUND: Malnourished children are at increased risk for death due to diarrhea. Our goal was to determine the contribution of specific enteric infections to malnutrition-associated diarrhea and to determine the role of enteric infections in the development of malnutrition. METHODS: Children from an urban slum in Bangladesh were followed for the first year of life by every-other-day home visits. Enteropathogens were identified in diarrheal and monthly surveillance stools; intestinal barrier function was measured by serum endocab antibodies; and nutritional status was measured by anthropometry. RESULTS: Diarrhea occurred 4.69 ± 0.19 times per child per year, with the most common infections caused by enteric protozoa (amebiasis, cryptosporidiosis, and giardiasis), rotavirus, astrovirus, and enterotoxigenic Escherichia coli (ETEC). Malnutrition was present in 16.3% of children at birth and 42.4% at 12 months of age. Children malnourished at birth had increased Entamoeba histolytica, Cryptosporidium, and ETEC infections and more severe diarrhea. Children who became malnourished by 12 months of age were more likely to have prolonged diarrhea, intestinal barrier dysfunction, a mother without education, and low family expenditure. CONCLUSIONS: Prospective observation of infants in an urban slum demonstrated that diarrheal diseases were associated with the development of malnutrition that was in turn linked to intestinal barrier disruption and that diarrhea was more severe in already malnourished children. The enteric protozoa were unexpectedly important causes of diarrhea in this setting. This study demonstrates the complex interrelationship of malnutrition and diarrhea in infants in low-income settings and points to the potential for infectious disease interventions in the prevention and treatment of malnutrition.

GIARDIA DUODENALIS GENOTYPING NOT LINKED TO CLINICAL SYMPTOMATOLOGY AND NUTRITIONAL STATUS OF SCHOOL-AGED CHILDREN OF SOLEDAD AND GALAPA MUNICIPALITY SCHOOLS, ATLÁNTICO, COLOMBIA.

Giardia duodenalis genotypes A and B have been reported in Colombia. The population consisted of 235 schoolchildren whose ages ranged from 2 to 10 yr of age from the municipalities of Soledad and Galapa in the department of Atlántico, Colombia. Fecal samples were obtained and then analyzed in triplicate using the sedimentation in formalin-ether (Ritchie's method) and direct examination techniques. Of the 235 fecal samples, 35 samples were positive for G. duodenalis; positive samples were concentrated in a sucrose gradient and sonicated for 3 cycles of 20 sec. DNA extraction was performed, and the parasites were genotyped by conventional PCR amplifying a region of the ß-giardin gene. A general prevalence of G. duodenalis of 13.2% was found, and of these genotyped samples, 13 (56.7%) and 7 (20%) corresponded to genotype A, 1 (4.3%), and 3 (25%) corresponded to genotype B, and 9 (39.1%) and 2 (16.7%) were not defined, in the municipalities Soledad and Galapa, respectively. Additionally, 23 children were diagnosed with symptomatologic giardiasis, and 12 were asymptomatic; the most relevant symptoms were abdominal pain (7, 20%) and diarrhea (13, 56.7%). The nutritional status of children with Giardia genotypes A and B were as follows: 3 in a state of malnutrition (10%), 10 normal (33.3%), and 6 overweight and obese (20%) with genotype A, and 1 in a state of malnutrition (3.3%) and 3 normal (10%) with genotype B. The genotypes found in G. duodenalis did not show an association with nutritional status or with the clinical manifestations evaluated in schoolchildren.

Lactobacillus casei as a probiotic in malnourished Giardia lamblia-infected mice: a biochemical and histopathological study.

The study describes the in vivo activity of Lactobacillus casei in malnourished Giardia lamblia-infected BALB/c mice. By experimentation, it was found that daily administration of the probiotic 7 days before inoculation with Giardia trophozoites in malnourished mice efficiently reduced both the severity and duration of giardiasis. More specifically, excretion of Giardia cysts and trophozoites counts were reduced, while faecal lactobacilli counts increased significantly in probiotic-fed malnourished mice, compared with control mice. Interestingly, it was also observed that oral feeding of the probiotic to malnourished mice abrogated all the anthropometric and biochemical anomalies. Histologically, morphological and cellular alteration of microvillus membrane integrity revealed that probiotic administration ameliorated the mucosal damage in malnourished, probiotic-inoculated, Giardia-infected mice compared with the severe microvillus atrophy, œdematous and vacuolated epithelial cells, and ileitis in malnourished Giardia-infected mice. The results clearly show the antigiardial effect of the probiotic in vivo by modulating the gut cells to inhibit the colonization and multiplication of Giardia trophozoites, thus reducing the severity and duration of murine giardiasis.

Infection with Blastocystis spp. and its association with enteric infections and environmental enteric dysfunction among slum-dwelling malnourished adults in Bangladesh.

BACKGROUND: Blastocystis spp. (Blastocystis) is a widely distributed gastrointestinal protist frequently reported in countries with tropical and sub-tropical climate. We sought to determine the factors associated with Blastocystis infection and investigate its role on biomarkers of intestinal health among slum-dwelling malnourished adults in Bangladesh. METHODOLOGY: Total 524 malnourished adults with a body mass index ≤18.5 kg/m2 were included in this analysis. Presence of Blastocystis in feces was evaluated by TaqMan Array Card assays. PRINCIPAL FINDINGS: Blastocystis was tested positive in 78.6% of the participants. Prevalence of infection with atypical strains of enteropathogenic Escherichia coli (aEPEC) (56% vs. 38%, p<0.001), and Trichuris trichiura (28% vs. 15%, p-value = 0.02) was significantly greater in adults with Blastocystis, while Giardia intestinalis was significantly lower (8% vs. 14%, p-value = 0.04) in Blastocystis positive adults. Malnourished adults who were living in households with high crowding index (aOR = 2.18; 95% CI = 1.11, 4.65; p-value = 0.03), and infected with aEPEC (aOR = 2.14; 95% CI = 1.35, 3.44; p-value = 0.001) and Trichuris trichiura (aOR = 1.97; 95% CI = 1.08, 3.77; p = 0.03) were more likely to be infected with Blastocystis. A significant negative relationship was observed between Blastocystis and fecal concentrations of alpha-1 antitrypsin (ß = -0.1; 95% CI = -1.7, -0.1; p-value<0.001) and Reg1B (ß = -3.6; 95% CI = -6.9, -3.0; p-value = 0.03). CONCLUSIONS: The study findings suggest that the presence of Blastocystis in human intestine influences gut health and may have potential pathogenic role in presence of other pathogens.

Comparative evaluation of Cryptosporidium infection in malnourished and well-nourished children: Parasitic infections are affected by the interaction of nutritional status and socio-demographic characteristics.

Cryptosporidium, as a small protozoan parasite, is a leading cause of persistent diarrhea in children in developing countries and has both a short and long-term impact on the growth of children. In the present study, Cryptosporidium infection was compared in malnourished and well-nourished children by modified acid-fast staining, nested-polymerase chain reaction (nested-PCR) and loop-mediated isothermal amplification (LAMP) methods. As a case-control study, Cryptosporidium infection in 94 malnourished children was evaluated and compared with those of 188 age and gender-matched well-nourished children. Oocysts of Cryptosporidium were detected by modified acid-fast staining method. The extracted DNA was amplified by nested-PCR and LAMP techniques. In addition, positive amplicons were directly sequenced for phylogenetic analysis. Cryptosporidium oocysts were found in the stools of two (2.12 %) children who were hospitalized and had diarrhea by nested-PCR while three isolates (3.2 %) were found by LAMP. Cryptosporidium-positive children were more malnourished compared to those who were negative for Cryptosporidium infection but this important finding was not statistically significant. C. parvum was the main species of Cryptosporidium detected in malnourished children in northwest Iran. LAMP can be considered as a sensitive field monitoring assay in patients with low parasite burden. Nutritional status and socio-demographic factors may have interactive effects on the incidence and severity of parasitic diseases.

Impact of intestinal permeability, inflammation status and parasitic infections on infant growth faltering in rural Bangladesh.

A longitudinal study of 298 rural Bangladeshi infants found evidence of growth faltering starting at 3 months of age. Anthropometric status declined substantially in the first 2 years of life, with weight-for-height (WHZ) falling from - 0.49 to - 1.75, weight-for-age (WAZ) from - 1.18 to - 2.87 and height-for-age (HAZ) from - 1.00 to - 1.88. Higher concentrations of the acute-phase protein alpha-1-acid glycoprotein (AGP) and higher gut mucosal damage (as signified by raised lactulose:mannitol (L:M) ratios) were both associated with chronic malnutrition as indicated by poorer HAZ and WAZ scores (P = 0.011 and 0.005 for AGP and 0.039 and 0.019 for L:M ratio, respectively). Higher Hb levels were related to improved z-scores, while elevation of Giardia-specific IgM titre (GSIgM) was associated with poor WAZ and WHZ (P = 0.015 and 0.039, respectively). IgG did not show any significant association with z-scores and the L:M ratio did not correlate with any of the inflammation markers or Giardia infection. The prevalence of geohelminth infections was low (only 4 % in the total study period). However, the level of GSIgM indicated high endemicity of Giardia infection from early in life, although very few cysts were detected from stool samples. These findings suggest that rural Bangladeshi infants are being exposed to high levels of infection with concomitant gut damage and growth faltering.

Malnutrition and intestinal parasitic infections in school children of Gondar, North West Ethiopia.

BACKGROUND: In developing countries, malnutrition is a considerable health problem with prevalence ranges of 4-46%, with 1-10% severely malnourished. OBJECTIVES: This study aimed to determine the prevalence of malnutrition and intestinal parasitoses and identify risk factors of malnutrition in schoolchildren. SUBJECTS AND METHODS: A cross-sectional study was carried out on 322 schoolchildren, of age 6 to 14 years, attending private and government primary schools, in Gonder town, North West Ethiopia. The study was conducted from December 2006 to February 2007. Nutritional status of these children was determined using anthropometric parameters (weight-for-age, height-for-age and weight-for-height). Epi Info 2000 software was used to evaluate anthropometric results of each individual and formol-ether concentration technique was employed to identify parasites. RESULTS: The prevalence of underweight, stunting, wasting and intestinal parasitoses was 34.8%, 27%, 50% and 55.6%, respectively. Parasites encountered during the study were Ascaris lumbricoides (17.8%), Trichuiris trichiura (3.4%), hookworm (4.3%), Giardia lamblia (9%), Entamoeba histolytica (2.1%), Schistosoma mansoni (2.4%), Hymenolepis nana (4.7%) and Enterobius vermicularis (0.31%), respectively, in single infections. Only two cases of Strongyloides stercoralis was found in multiple infections and none in single infections. The prevalence of multiple parasitoses was 10.9%. Maternal literacy status, sex and age of the child were significantly associated with malnutrition (p < 0.05). CONCLUSION: Even though chronic type of malnutrition (stunting) was decreasing, indicators of acute type of malnutrition were increasing at a higher rate in the area. Implementation of maternal education and school feeding programs, avoidance of students from getting in contact with waste and river water were recommended to avoid malnutrition and intestinal parasitoses in children of the study area.

Proteomic profiling of splenic interstitial fluid of malnourished mice infected with Leishmania infantum reveals defects on cell proliferation and pro-inflammatory response.

Protein malnutrition is a risk factor for developing visceral leishmaniasis. Because we previously demonstrated that protein malnutrition and infection with Leishmania infantum disrupts the splenic microarchitecture in BALB/c mice, alters T cell-subsets and increases splenic parasite load, we hypothesize that splenic microenvironment is precociously compromised in infected animals that suffered a preceding malnutrition. To evaluate this, we characterized the abundance of proteins secreted in the splenic interstitial fluid (IF) using an iTRAQ-based quantitative proteomics approach. In addition, local levels of pro-inflammatory and proliferation molecules were analyzed. Whereas well-nourished infected animals showed increased IL-1ß and IL-2 levels, malnourished-infected mice displayed significant reduction of these cytokines. Remarkably, a two-weeks infection with L. infantum already modified protein abundance in the splenic IF of well-nourished mice, but malnourished animals failed to respond to infection in the same fashion. Malnutrition induced significant reduction of chemotactic and pro-inflammatory molecules as well as of proteins involved in nucleic acid and amino acid metabolism, indicating an impaired proliferative microenvironment. Accordingly, a significant decrease in Ki67 expression was observed, suggesting that splenocyte proliferation is compromised in malnourished animals. Together, our results show that malnutrition compromises the splenic microenvironment and alters the immune response to the parasite in malnourished individuals. SIGNIFICANCE: Protein malnutrition is recognized as an important epidemiological risk factor for developing visceral leishmaniasis (VL). Locally secreted factors present in the interstitial fluid have important roles in initiating immune responses and in regulating fluid volume during inflammation. However, the regulation of secreted factors under pathological conditions such as malnutrition and infection are widely unknown. To analyze how protein malnutrition alters secreted proteins involved in the immune response to L. infantum infection we evaluated the proteomic profile of the interstitial fluid of the spleen in malnourished BALB/c mice infected with L. infantum. Our work revealed new elements that contribute to the understanding of the immunopathological events in the spleen of malnourished animals infected with L. infantum and opens new pathways for consideration of other aspects that could improve VL treatment in malnourished individuals.