Reduced prevalence of Giardia duodenalis in iron-deficient Rwandan children

Occurrence and multilocus genotyping of Giardia duodenalis in diarrheic and asymptomatic children from South of Zhejiang province in China

Giardia duodenalis is an intestinal pathogen that is found globally. Children are more susceptible and often suffer severe consequences after infection. Despite this, the health effects of this pathogen continue to be poorly understood and neglected. In Wenzhou, Zhejiang province, China, stool samples were obtained from 1032 children who were admitted to Yuying Children's Hospital. Out of these, 684 presented with diarrhea, while 348 were asymptomatic. The stool samples were screened for G. duodenali by targeting the small subunit of the ribosomal RNA (SSU rRNA) gene. Subtypes of G. duodenalis were identified via amplification of the glutamate dehydrogenase (gdh), beta-giardin (bg), and triosephosphate isomerase (tpi) genes in samples positive for the G. duodenalis. The findings indicated the presence of G. duodenalis in 0.9 % (9/1032) of the samples, with 9/684 (1.3 %) of the samples originating from children with diarrhea and none from the asymptomatic samples. All 9 samples that tested positive for G. duodenalis were determined to be of assemblage A. Of these, 6 samples were effectively genotyped at all 3 loci, resulting in the identification of 3 distinct MLGs: MLG-AII1 (n = 1), MLG-AII2 (n = 4), and MLG-AII2 (n = 1), all belonging to G. duodenalis assemblage AII. This was the first study that confirmed G. duodenalis infections in children residing in southern Zhejiang, China, with comparatively low rates of infection. The detection of G. duodenalis assemblage AII indicates a possibility of transfer from one human to another. The parasite's effect on the health of young children requires special attention and consideration.

Anemia and undernutrition in intestinally parasitized schoolchildren from Gakenke district, Northern Province of Rwanda

Background

Rwanda is a sub-Saharan country, where intestinal parasite infections, anemia and undernutrition coexist. The purpose of this research is to study the relationship between intestinal parasite infections and undernutrition/anemia to clarify the priorities of intervention in the rural area of Gakenke district in the Northern Province of Rwanda.

Materials and methods

A total of 674 students from Nemba I School, participated in a cross-sectional study, in which their parasitological and nutritional status were analysed. Statistical analysis was performed by χ2 test, univariate analysis and Odds ratios (OR).

Results

A total of 95.3% of children presented intestinal parasitism, most of whom (94.5%) infected by protozoa and 36.1% infected by soil-transmitted helminths (STH), with Trichuris trichiura (27.3%) being the most prevalent. Multiple infections were found to be high (83.8%), with protozoa and STH co-infections in 30.6%. STH infections were mainly of low/moderate intensity. Neither infection nor STH infection of any intensity profile, was significantly related to anemia. In addition, STH infection, regardless of the intensity profile, was not associated with stunting, underweight or thinness. There was no difference between genders nor among ages in odds of anemia and nutritional status in STH-infected schoolchildren.

Conclusion

Multiparasitism remains high among Rwandan schoolchildren and is likely to cause nutritional problems. This work emphasizes the importance of keeping up health programs to reduce the prevalence of infection.

Nutritional status and intestinal parasites among young children from pastoralist communities of the Ethiopian Somali region

Pastoralist children in the Ethiopian Somali Regional State (ESRS) are at high risk for undernutrition and intestinal parasitic infections (IPIs). We assessed the nutritional status and its association with IPIs in 500 children <5 years of age in a clustered cross‐sectional study in Adadle district, ESRS. Stool samples were microscopically examined for IPIs and biomarkers for iron and vitamin A status, anthropometry, and food variety score (FVS) were assessed. Median (interquartile range [IQR]) FVS was 2.0 (2.0, 4.0), and 35% of children were exclusively breastfed up to age 6 months. Prevalence of stunting, wasting, underweight and mid‐upper arm circumference (MUAC) <12.5 cm was 30, 34, 40, and 16%, respectively. Median (IQR) haemoglobin, ferritin, and retinol‐binding protein concentrations were 9.5 g dL^‐1 (8.2, 10.9), 6.2 μg L^‐1 (4.0, 10.2), and 0.8 μmol L⁻¹ (0.67, 0.91), respectively. Prevalence of anaemia, iron, and vitamin A deficiency was 75, 91, and 30%, respectively. IPIs' prevalence was 47%; the most prevalent IPIs were Giardia lamblia (22%) and Ascaris lumbricoides (15%). Giardial infections but not A. lumbricoides increased the risk for MUAC <12.5 cm (adjusted odds ratio [aOR]: 3.50, 95% confidence interval [CI] [2.21, 5.54]). The odds for anaemia were 97% (aOR: 0.03, 95% CI [0.03, 0.07]) and 89% (aOR: 0.11, 95% CI [0.11, 0.23]) less for children with FVS >2 or with exclusive breastfeeding up to 6 months, respectively. Undernutrition and IPIs are alarmingly high in <5 years of age children in ESRS. Giardial infections and low nutritional adequacy of the diet seem to be major contributing factors to the precarious nutritional status and should be addressed by appropriate interventions.

Prevalence and molecular characterization of Strongyloides stercoralis, Giardia duodenalis, Cryptosporidium spp., and Blastocystis spp. isolates in school children in Cubal, Western Angola

BACKGROUND

Human infections by the gastrointestinal helminth Strongyloides stercoralis and the enteric protozoans Giardia duodenalis, Cryptosporidium spp. and Blastocystis spp. are not formally included in the list of 20 neglected tropical diseases prioritised by the World Health Organization. Although largely underdiagnosed and considered of lower public health relevance, these infections have been increasingly demonstrated to cause significant morbidity and even mortality globally, particularly among children living in resource-poor settings.

METHODS

In this cross-sectional survey the prevalence, frequency and molecular diversity of S. stercoralis, G. duodenalis, Cryptosporidium spp. and Blastocystis spp. were investigated in a school children population in the province of Benguela (Angola). A total of 351 stool samples were collected during January to June 2015. The presence of S. stercoralis and G. duodenalis was confirmed by qPCR methods. Giardia duodenalis assemblages and sub-assemblages were determined by multilocus sequence-based genotyping of the glutamate dehydrogenase and β-giardin genes of the parasite. Detection and identification of Cryptosporidium and Blastocystis species and subtypes was carried out by amplification and sequencing of a partial fragment of the small-subunit ribosomal RNA gene of both protozoan. Analyses of risk factors potentially associated with the transmission of these pathogens were also conducted.

RESULTS

Prevalences of S. stercoralis, G. duodenalis, Cryptosporidium spp., and Blastocystis spp. were estimated at 21.4% (95% CI: 17.1-25.7%), 37.9% (95% CI: 32.8-43.0%), 2.9% (95% CI: 1.1-4.5%) and 25.6% (95% CI: 21.18-30.2%), respectively. Overall, 64.1% (225/351) of the children were infected by at least one of the pathogens investigated. Sequence analyses of the 28 G. duodenalis isolates that were successfully genotyped allowed the identification of sub-assemblages AI (14.3%), AII (14.3%), BIII (7.1%) and BIV (25.0%). Discordant typing results AII/AIII and BIII/BIV were identified in 7.1% and 14.3% of the isolates, respectively. A total of five additional isolates (17.9%) were identified as assemblage B. Three Cryptosporidium species including C. hominis (70%), C. parvum (20%) and C. canis (10%) were found circulating in the children population under study. A total of 75 Blastocystis isolates were assigned to the subtypes ST1 (30.7%), ST2 (30.7%), ST3 (36.0%), ST5 (1.3%) and ST7 (1.3%), respectively. Children younger than seven years of age had significantly higher risk of infections by protozoan enteropathogens (PRR: 1.35, P < 0.01), whereas being underweight seemed to have a protective effect against these infections (PRR: 0.74, P = 0.005).

CONCLUSIONS

The burden of disease attributable to human strongyloidiasis, giardiosis, cryptosporidiosis and blastocystosis in Angola is considerably higher than initially estimated in previous surveys. Surveillance and control of these infections should be jointly tackled with formally considered neglected tropical diseases in order to maximize effort and available resources. Our data also demonstrate the added value of using molecular diagnostic methods in high transmission areas.

[Trace elements in serum of malnourished and well-nourished children living in Lubumbashi and Kawama]

Introduction

La place des éléments traces métalliques essentiels en nutrition humaine ne peut plus être ignorée. Les déficits d'apports, les carences secondaires souvent sous – estimées, et les carences iatrogènes font le lit de pathologies telles que les infections et autres. D'où leurs dosages ont une importance particulière pour en évaluer la gravité et faciliter une prise en charge précoce ou améliorer le régime alimentaire. Cette étude a eu pour objectif de déterminer le profil sanguin en éléments traces (cuivre, sélénium, zinc, fer, chrome, cobalt, etc) chez les enfants malnutris et biens nourris dans un milieu minier à Lubumbashi.

Méthodes

Trois cents onze cas ont été colligés, 182 malnutris et 129 biens nourris, dans une étude descriptive transversale, effectuée de juillet 2013 à décembre 2014. Pour lequel un échantillonnage exhaustif a été réalisé. Le dosage des métaux dans le sérum s'est fait à l’ ICP-OES (spectrométrie de masse à plasma gon induit) au laboratoire de l'Office Congolais de Contrôle de Lubumbashi.

Résultats

Les oligoéléments essentiels (cuivre, zinc, sélénium et fer) se retrouvent à des concentrations très basses chez les enfants malnutris comme chez les biens nourris. L'arsenic, le cadmium, le magnésium et le manganèse se présentent à des concentrations normales par rapport aux valeurs de références chez les enfants biens nourris. L'antimoine, le chrome, le plomb et le cobalt se retrouvent élevés chez les malnutris et biens nourris. Le nickel est normal chez les malnutris et les biens nourris. Le magnésium, manganèse se sont présentés à des taux très bas chez les enfants malnutris.

Conclusion

Les enfants malnutris et biens nourris présentent une malnutrition aux oligo-éléments essentiels associés aux éléments traces métalliques. Ce qui permet de supposer qu'une carence en micronutriments essentiel favorise l'absorption des métaux lourds.

Predominance of Giardia lamblia assemblage A among iron deficiency anaemic pre-school Egyptian children

Intestinal parasites and nutritional deficiency can coexist and influence each other. This study aimed to clarify the association between Giardia genotypes and presence of iron deficiency anaemia (IDA) among pre-school Egyptian children. Two groups (IDA and non-anaemic) of giardiasis children (44/group) were selected according to their recovery response after treatment of giardiasis. Each group included 24 and 20 gastrointestinal symptomatic and asymptomatic, respectively. Giardia human genotypes were performed by intergenic spacer (IGS) gene based polymerase chain reaction (PCR) with high-resolution melting curve (HRM). PCR/HRM proved that Tms of assemblage A and B ranged from 79.31 ± 0.29 to 84.77 ± 0.31. In IDA patients, assemblages A and B were found among 40/44 (90.9 %) and 4/44 (9.1 %), respectively, while in non-anaemic patients, assemblages A and B were found in 10/44 (22.7 %) and 32/44 (72.7 %), respectively, beside two (4.6 %) cases had mixed infection. The difference was statistically significant. No significant relation was found between symptomatic or asymptomatic assemblages and IDA as assemblage A was found in 21/24 (87.5 %) and 19/20 (95 %) of symptomatic and asymptomatic, respectively, while 3/24 (12.5 %) and 1/20 (5 %) of assemblage B were symptomatic was asymptomatic, respectively. A significant relation was found between assemblage A subtypes distribution among IDA patients as AI and AII were detected on 23 (52.3 %) and 16 (36.4 %) of patients, respectively, while one case (2.3 %) had mixed infection. In conclusion, assemblage A is predominant among IDA giardiasis children suggesting its role in enhancing the occurrence of IDA while B has a protective role.

Age-dependent decline and association with stunting of Giardia duodenalis infection among schoolchildren in rural Huye district, Rwanda

Giardia duodenalis infection is highly prevalent and a cause of underweight in pre-school children in rural Rwanda. The present study aimed at assessing the age-pattern of Giardia infection and its manifestation in older children, i.e., during school age. Stool samples were collected from 622 schoolchildren at two schools in the Huye district of southern Rwanda (rural, 301; urban, 321) and subjected to G. duodenalis specific PCR assays. Clinical and anthropometric data, socio-economic status and factors potentially associated with G. duodenalis infection were assessed. Of the 622 children (mean age, 10.4 years), 35.7% were infected with G. duodenalis (rural, 43.9%; urban, 28.0%; P<0.0001). Only few indicators of low socio-economic status were found to be associated with infection. In rural but not urban schoolchildren, infection prevalence declined significantly with age. G. duodenalis infection more than doubled the odds of stunting in both rural (adjusted OR, 2.35 (95%CI, 1.25-4.41)) and urban children (adjusted OR, 2.27 (95%CI, 1.01-5.09)). In the study area of rural southern Rwanda, G. duodenalis prevalence among children declined throughout school-age. The data suggest that while lacking overt clinical manifestation at high endemicity, G. duodenalis infection is a common cause of stunting in schoolchildren.