Repeated infections with Schistosoma mansoni and liver fibrosis in undernourished mice.

The mouse model of schistosomal periportal fibrosis (Symmers' "pipestem" fibrosis), that develops in 30-50% of the infected animals, is not reproduced in undernourished mice. Host nutritional status is likely to be a variable that may influence the outcome and progression of infection, since it interferes with the dynamics of connective tissue changes occurring in chronic hepatic schistosomiasis. Re-infections increase the occurrence of periportal liver fibrosis in well-nourished animals, but it is not known how undernourished mice would behave being repeatedly re-infected. So, 21-day-old male albino Swiss mice were individually exposed to 30 cercariae (percutaneous route) of the BH strain of Schistosoma mansoni, 4 weeks after being on a low-protein diet. Control animals were fed on a commercial balanced chow for mice. The nutritional status was evaluated by body weight gain and measurement of food intake. Mice were divided into four groups: A1 (undernourished, single infected), A2 (well-nourished, single infected), B1 (undernourished, re-infected), B2 (well-nourished, re-infected). The primary infection was performed 4 weeks after ingesting the respective diet. Re-infections started 45 days later, with exposure to 15 cercariae, at 15 day intervals. Mice were sacrificed 18 weeks after the primary exposure. The livers were submitted to morphological (gross and microscopic pathology), morphometric (percentage of fibrosis; granuloma size; volume and numerical densities) by using semi-automatic morphometry, and biochemical (quantification of collagen as hydroxyproline) studies. Worm burdens and hepatic egg counting were also recorded. Values for body weight gains were always lower in undernourished mice, the effects of re-infection being minimal on this regard. Liver and spleen weights were higher in well-nourished mice (either single infected or re-infected) and mainly related to the type of ingested diet. A greater number of re-infected well-nourished mice developed periportal fibrosis, but undernourished re-infected animals did not reproduce this lesion. The percentage of fibrosis and hepatic collagen content were higher in well-nourished mice, but differences between single infected and re-infected groups were not statistically significant.

Giardiasis as a predictor of childhood malnutrition in Orang Asli children in Malaysia.

A cross-sectional study to examine the association of giardiasis with protein-energy malnutrition, vitamin A deficiency and iron deficiency anaemia was conducted among Orang Asli children in Selangor, Malaysia. A total of 281 children aged 2-15 years were studied. The data were collected using structured questionnaires, anthropometric measurements and laboratory analysis of blood and faecal samples. The results showed that 24.9% of the children were infected with Giardia duodenalis, while 56.5, 61.3 and 15.1% had significant underweight, stunting and wasting, respectively. Giardiasis was statistically identified as a strong predictor of significant wasting in this study population.

[Nutritional evaluation of children with enteroparasitosis]. / Avaliação nutricional em crianças com infecções por enteroparasitas.

PURPOSE: To evaluate the nutritious state in children of low social-economic class in order to look over a possible corelationship among this status and the infections caused by enteroparasites. METHODS: 103 children were submitted to a nutritions evolution and to accomplish a exam of serial samples. The method employed searched protozoan cystos, helmints eggs and larvae and it counted helmint eggs when presented through 4 different methods of diagnosis. RESULTS: The results obtained show that the poor environmental and social-economic conditions helped create a high infectious frequency caused by enteroparasites, mainly by Trichuris trichiura and Ascaris lumbricoides, among the helminthes, and Endolimax nana and Giardia lamblia, among the protozoans. light malnutrition without protein deficit was found in 93.55% and moderate malnutrition in 6.45% of the children malnutrition (30.7%). CONCLUSION: Then, it is possible to suggest that children besides bearing many parasitosis were not weth their nutritional state deeply compromised.

Avaliação nutricional em crianças com infecçoes por enteroparasitas / Nutritional evaluation of children with enteroparasitosis

PURPOSE: To evaluate the nutritious state in children of low social-economic class in order to look over a possible corelationship among this status and the infections caused by enteroparasites. METHODS: 103 children were submitted to a nutritions evolution and to accomplish a exam of serial samples. The method employed searched protozoan cystos, helmints eggs and larvae and it counted helmint eggs when presented through 4 different methods of diagnosis. RESULTS: The results obtained show that the poor environmental and social-economic conditions helped create a high infectious frequency caused by enteroparasites, mainly by Trichuris trichiura and Ascaris lumbricoides, among the helminthes, and Endolimax nana and Giardia lamblia, among the protozoans. light malnutrition without protein deficit was found in 93.55% and moderate malnutrition in 6.45% of the children malnutrition (30.7%). CONCLUSION: Then, it is possible to suggest that children besides bearing many parasitosis were not weth their nutritional state deeply compromised.

Gastrodiscoides hominis infection in a Nigerian-case report.

Gastrodiscoides hominis is a large fluke of pig and human and constitutes an important parasite of human in Assam, Indian, the Philippines and Southeast Asia. This parasite has not been reported in Nigeria and possibly other parts of Africa. This is a case report of a seven year old Nigerian child who presented with features of malnutrition and anaemia and was found to have Gastrodiscoides hominis and Ascaris lumbricoides. Following clearance of the worms there was tremendous improvement of the health status of the child. The detailed epidemiology of this parasite still remains to be studied in this environment.

Morphometric study of Schistosoma mansoni adult worms recovered from Undernourished infected mice.

Some unfavourable effects of malnutrition of the host on Schistosoma mansoni worm biology and structure have been reported based upon brigthfield microscopy. This paper aims to study by morphometric techniques, some morphological parameters in male and female adult worms recovered from undernourished albino mice in comparison with parasites recovered from well-fed infected mice. Undernourished animals were fed a multideficient and essentially low protein diet (RBD diet) and compared to well-fed control mice fed with the commercial diet NUVILAB. Seventy-five days post-infection with 80 cercarie (BL strain) animals were sacrificed. All adult worms were fixed in 10% formalin and stained with carmine chloride. One hundred male and 60 female specimens from each group (undernourished and control) were examined using an image system analysis Leica Quantimet 500C and the Sigma Scan Measurement System. The following morphometrical parameters were studied: body length and width, oral and ventral suckers, number and area of testicular lobes, length and width of ovary and uterine egg. For statistical analysis, the Student's t test for unpaired samples was applied. Significant differences (p < 0.05) were detected in body length and width, in parameters of suckers, uterine egg width, ovary length and area of testicular lobes, with lower values for specimens from undernourished mice. The nutritional status of the host has negative influence on S. mansoni adult worms, probably through unavailability of essential nutrients to the parasites.

Parasitological characteristics of Schistosoma mansoni infection in swiss mice with underlying malnutrition.

The effects of a protein-restricted diet (8% protein, 81% carbohydrate and 11% lipids) on Schistosoma mansoni infectivity, fecal egg excretion and intestinal egg distribution in Swiss (SW) mice were studied. Pregnant mice received a deficient diet from the middle of gestation until delivery. Seven-days-old mice were exposed to 50 cercariae (BH strain, Brazil). Offspring mice had a free access to the deficient diet since lactation until adulthood. The controls were fed with a commercial mice diet. A parasitological examination was performed between six and eight weeks post-infection while both groups were necropsied one week later. Mice on the experimental diet showed a significant loss in body weight. There was no significant difference (p > 0.05) in pre-patent period, kinetics of egg excretion and worm recovery from mice on either diet. Significant differences (p < 0.05) were found concerning to the percentage of deposited eggs in the distal segment of the small intestine from hosts on the experimental diet. Our data suggest that experimental malnutrition induced for a long term has no detrimental effect on the acute schistosomiais infection in SW mice.

Influência das condições socioeconômicas nas alterações nutricionais e na taxa de metabolismo de repouso em crianças escolares moradoras em favelas no município de São Paulo / Influence of socioeconomic conditions in the nutritional changes and rest metabolic rate in school children living in shantytowns of the city of São Paulo, Brazil

OBJETIVOS: Realizou-se um estudo transversal para avaliar a taxa de metabolismo de repouso (TMR) e condições socioeconômicas em 15 crianças escolares do sexo feminino; eutróficas (EU= estatura/idade > ou = 95 por cento e peso/idade entre 90-110por cento) e 15 com desnutrição pregressa (DP= estatura/idade < 95 por cento e peso/estatura entre 90-110 por cento) moradoras em favelas no município de São Paulo. MÉTODOS: Avaliou-se a TMR por calorimetria indireta, e a situação socioeconômica por entrevista domiciliar. RESULTADOS: O grupo DP apresentou TMR mais alta quando expressa por unidade de peso corpóreo (EU= 40,5 Kcal/kg/dia; DP=44,4 Kcal/kg/dia, p<0,05) e por quilograma de massa magra (EU= 49,2 Kcal/kg/dia; DP=52,5 Kcal/kg/dia, p<0,05); e diferenças significantes para renda per capita, analfabetismo materno, número de parasitas por criança, número de ordem entre os filhos e número de irmãos. Em análise multivariada as variáveis associadas à desnutrição foram renda per capita e analfabetismo materno. CONCLUSÕES: Embora os dois grupos tenham peso/estatura normais, a presença de baixa estatura leve foi acompanhada por alterações metabólicas e socioeconômicas típicas de um quadro de desnutrição.

Relationship of childhood protein-energy malnutrition and parasite infections in an urban African setting.

A clear understanding of protein-energy malnutrition (PEM), parasite infection and their interactions is essential in formulating health and development policies. We studied the prevalence of PEM indicators and the prevalence and/or intensity of infection in 558 Zairian children aged 4 months to 10 years. Multivariate analyses were used to estimate relationships between PEM indicators and parasitic infection. Stunting was found in 40.3% of children, wasting in 4.9% and kwashiorkor in 5.1%. The risk of stunting was significantly higher in children with Ascaris lumbricoides. The risk of wasting was higher in children with A. lumbricoides or Trichuris trichiura, whereas the risk of kwashiorkor was high with T. trichiura but very reduced in those with A. lumbricoides. Plasmodium infection was not related to nutritional indicators. These relationships highlight important interactions, both synergistic and antagonistic, between nutrition and parasites in central Africa.

Effects of severe protein restriction in levels of parasitemia and in mortality of mice acutely infected with Trypanosoma cruzi

Adult mice were submitted to different degrees of protein restriction for five weeks (4.75, 9.5, 14.25 and 19 per cent of protein in isocaloric diets with normal content of mineral and vitamins), being subsequently infected with two strains of Trypanosoma cruzi: 10(5) trypomastigotes of Y strain or 10(4) trypomastigotes of CL strain. The same diet was maintained for all animals and the infection was followed up by evaluation of blood parasites, mortality and intensity of lesions in the heart and skeleton muscle. Only severe protein restriction (4.75 per cent ) induced decrease in resistance to the infection with both the Y and CL strains of T. cruzi, which resulted in higher parasitemia and mortality. The inflammatory lesions in heart and skeleton muscle were less extensive in groups with severe protein restriction despite the increased number of parasite in muscle cells. Depression of immune mechanisms could be responsible for the reduced resistance and reduced inflammatory reaction after T. cruzi infection in severely protein restricted animals

Effects of severe protein restriction in levels of parasitemia and in mortality of mice acutely infected with Trypanosoma cruzi.

Adult mice were submitted to different degrees of protein restriction for five weeks (4.75, 9.5, 14.25 and 19% of protein in isocaloric diets with normal content of mineral and vitamins), being subsequently infected with two strains of Trypanosoma cruzi: 10(5) trypomastigotes of Y strain or 10(4) trypomastigotes of CL strain. The same diet was maintained for all animals and the infection was followed up by evaluation of blood parasites, mortality and intensity of lesions in the heart and skeleton muscle. Only severe protein restriction (4.75%) induced decrease in resistance to the infection with both the Y and CL strains of T. cruzi, which resulted in higher parasitemia and mortality. The inflammatory lesions in heart and skeleton muscle were less extensive in groups with severe protein restriction despite the increased number of parasite in muscle cells. Depression of immune mechanisms could be responsible for the reduced resistance and reduced inflammatory reaction after T. cruzi infection in severely protein restricted animals.

The impact of gastrointestinal parasites on protein-energy malnutrition in man.

There is no doubt that at high intensity of infection, intestinal parasites can cause severe illness and the death of their hosts. Even with the high prevalence of these infections, however, such severe cases are rare and the norm is for low to moderate numbers of parasites which cause few if any overt symptoms. Nevertheless, it has been argued that by causing subtle reductions in appetite, absorption, digestion and acute-phase status and increasing intestinal nutrient losses, these low-level but long-term infections could be responsible for the persistent, poor nutritional status of so many children in Third World communities. Although geographically, high parasite prevalence occurs in conjunction with high levels of protein-energy malnutrition, attempts to establish a cause and effect relationship have had very limited success with many investigators being unable to demonstrate any detrimental consequence of infection. The unimpressive results might be explained to some extent by the unusual features of helminth infections such as rapid reinfection, the overdisperse distribution pattern and the uncertainty of a host inflammatory response, but they also suggest that A. lumbricoides (on which most studies have concentrated) may be of little nutritional importance. It seems likely that the more invasive parasites, e.g. the hookworms, S. stercoralis, T. trichiura and perhaps G. lamblia may have a greater impact and clearly more studies are required here. Safe, cheap and effective anthelmintics are now available and, on the grounds of disease prevention, there is a case for their nationwide use. However, from the available evidence, it would be unwise to expect that such programmes would make a significant impact on the nutritional status of children in Third World communities.

Hookworm infection and protein-energy malnutrition: transverse evidence from two Malaysian ecological groups.

Anthropometric and parasitological data from cross-sectional studies of two groups of primary school children (Group I of Indian origin, 325 boys and 259 girls, age = 7 years; Group II of Malay origin, 284 boys and 335 girls, age = 7-9 years) from two different ecological settings in Peninsular Malaysia were examined for epidemiological evidence of an association between hookworm infection and protein-energy malnutrition. In both ecological groups, significant weight, height and haemoglobin deficits were observed in children with hookworm infection after adjustment for covariables including Ascaris and Trichuris infection intensities and other child and family characteristics. The deficits were related to the intensity of infection based on egg counts. These findings suggest that hookworm may be an important determinant of chronic protein-energy malnutrition, as well as anaemia, in areas where diets are generally inadequate in protein, energy, and iron. Well-controlled intervention studies are needed to confirm these observations.

Hypoalbuminemia in energy-malnourished rats infected with Nippostrongylus brasiliensis (Nematoda).

Rats fed a restricted amount (60% of ad libitum intake) of a well-balanced diet (protein energy:total energy ratio of 0.20) had a reduced growth rate but maintained near-normal plasma albumin concentrations. However, when such animals were infected with Nippostrongylus brasiliensis (a hookwormlike intestinal parasite), plasma albumin values fell precipitously, from a preinfection value of 34.7 g/L to 21.3 g/L on d 10 postinfection (p.i.). The hypoalbuminemia developed rapidly, without changes in body weight and despite an adequate amount of dietary protein. Similarly infected well-nourished animals showed a much less severe effect, plasma albumin values falling from 34.8 to only 31.3 g/L by d 10 p.i. Two measurements of gastrointestinal integrity, [51Cr]albumin leakage from the plasma and intestinal permeability to mono- and disaccharide sugars, suggested that the alterations in plasma albumin values could be explained on the basis of protein leakage into the gastrointestinal tract through parasite-induced lesions. Much greater changes in the indices of mucosal integrity were observed in the undernourished animals and overall it was clear that the energy-restricted animals had been far more severely affected by the parasite than their well-fed counterparts. The results are discussed with reference to the etiology of kwashiorkor in humans.