High prevalence of selected viruses and parasites and their predictors in Malawian children

A 10-year (2014-2023) review of complementary food development in sub-Saharan Africa and the impact on child health

Complementary foods (CFs) commonly consumed by infants and young children (IYC) in sub-Saharan Africa (SSA) are processed using either single or multi-grain ingredients through simple technologies such as fermentation, malting and roasting. Interestingly, CFs (e.g., ogi, kunu, and dabo) are prepared and fed to infants alongside breastmilk until they are completely weaned up to the infant's second birthday. The grains used for preparing CFs can be contaminated with bacterial and chemical contaminants as a result of poor harvesting, handling or storage practices. The stage at which IYC are introduced to CFs is of utmost importance as it aids in addressing malnutrition and improving their overall health and well-being. Complementary feeding practices across SSA are influenced by socio-economic, cultural and geographical factors such that improper introduction can result in dire health consequences including immune suppression, severe foodborne diseases, poor child growth and development, and sometimes death from malnutrition. Malnutrition often occurs from inadequacies of nutrient intakes and assimilation which affect the ability to maintain normal body functions such as growth, learning abilities, resistance to and recovery from diseases. In SSA, IYC malnutrition still poses an enormous concern, therefore indicating the need for intervention strategies such as the promotion of indigenous crops and elevating traditional knowledge and technologies for formulating CFs. This paper clearly highlights the diversity of CFs in SSA, ingredients utilized, processing techniques, contamination by bacteria and chemicals, and demonstrates the consequences of consuming contaminated CFs, and their influence on IYC health as well as approaches to ensuring safety and scaling up indigenous CFs.

Exploring the Funding Challenges Faced by Small NGOs: Perspectives from an Organization with Practical Experience of Working in Rural Malawi

Malawi is a small landlocked country in Southern Africa, which faces a number of development challenges. It is one of the world's poorest nations and over 70% of the population live below the International Poverty Line of $2.15 per day. Health inequalities are a well-documented problem and those most affected are women and children. Non-governmental organizations (NGOs) play a vital role in supplementing government efforts to provide health services to vulnerable people in areas that are difficult to reach. The World Medical Fund (WMF) is a small medical charity that operates in the central, rural, Nkhotakota region of Malawi where many children lack access to even basic health services. To date, WMF has successfully provided free care and treatment for over 400,000 sick children, but its initiatives, such as mobile clinics, rely entirely on external donations. Since 2000, the funding resources available to small NGOs have declined and efforts to attract funding have become increasingly competitive. Frequently, the criteria used for funding decisions are too rigid, and do not reflect the difficult operating conditions on the ground in rural Africa. As one of the world's most highly resource constrained healthcare environments, Malawi illustrates the need for more flexible funding criteria from donors so that NGOs can carry out their work to save children's lives.

Seasonal variation of diarrhoeal pathogens among Guinea-Bissauan children under five years of age

BACKGROUND

Diarrhoea remains a major cause of childhood morbidity and mortality in low-income countries (LICs). The frequency of diarrhoeal episodes may vary by season, yet few prospective cohort studies have examined seasonal variation among various diarrhoeal pathogens using multiplex qPCR to analyse bacterial, viral and parasitic pathogens.

METHODS

We combined our recent qPCR data of diarrhoeal pathogens (nine bacterial, five viral and four parasitic) among Guinea-Bissauan children under five years old with individual background data, dividing by season. The associations of season (dry winter and rainy summer) and the various pathogens were explored among infants (0-11 months) and young children (12-59 months) and those with and without diarrhoea.

RESULTS

Many bacterial pathogens, especially EAEC, ETEC and Campylobacter, and parasitic Cryptosporidium, prevailed in the rainy season, whereas many viruses, particularly the adenovirus, astrovirus and rotavirus proved common in the dry season. Noroviruses were found constantly throughout the year. Seasonal variation was observed in both age groups.

CONCLUSION

In childhood diarrhoea in a West African LIC, seasonal variation appears to favour EAEC, ETEC, and Cryptosporidium in the rainy and viral pathogens in the dry season.

Association between asymptomatic infections and linear growth in 18-24-month-old Malawian children

Inadequate diet and frequent symptomatic infections are considered major causes of growth stunting in low-income countries, but interventions targeting these risk factors have achieved limited success. Asymptomatic infections can restrict growth, but little is known about their role in global stunting prevalence. We investigated factors related to length-for-age Z-score (LAZ) at 24 months by constructing an interconnected network of various infections, biomarkers of inflammation (as assessed by alpha-1-acid glycoprotein [AGP]), and growth (insulin-like growth factor 1 [IGF-1] and collagen X biomarker [CXM]) at 18 months, as well as other children, maternal, and household level factors. Among 604 children, there was a continuous decline in mean LAZ and increased mean length deficit from birth to 24 months. At 18 months of age, the percentage of asymptomatic children who carried each pathogen was: 84.5% enterovirus, 15.5% parechovirus, 7.7% norovirus, 4.6% rhinovirus, 0.6% rotavirus, 69.6% Campylobacter, 53.8% Giardia lamblia, 11.9% malaria parasites, 10.2% Shigella, and 2.7% Cryptosporidium. The mean plasma IGF-1 concentration was 12.5 ng/ml and 68% of the children had systemic inflammation (plasma AGP concentration >1 g/L). Shigella infection was associated with lower LAZ at 24 months through both direct and indirect pathways, whereas enterovirus, norovirus, Campylobacter, Cryptosporidium, and malaria infections were associated with lower LAZ at 24 months indirectly, predominantly through increased systemic inflammation and reduced plasma IGF-1 and CXM concentration at 18 months.

Intestinal parasitic infections and associated risk factors in diabetic patients: a case-control study

Diabetes mellitus (DM) is a metabolic disease that puts the individual at immune-suppression state. The present study aims to detect the burden of intestinal parasites and associated risk factors among diabetic patients in a case-control study. Stool samples from 100 diabetic patients, and 100 non-diabetic controls attending Beni-Suef University Hospital were collected and processed by direct smear examination, concentration technique, permanent staining by modified Ziehl-Neelsen and modified trichrome stains, and culture on nutrient agar plates. The overall prevalence of intestinal parasites was 38%; higher in diabetic patients (44%) than control group (32%) with non-statistical significance. The most predominant intestinal parasites detected among diabetics were Blastocystis hominis (29%), followed by Cryptosporidium sp. (12%), Giardia lamblia (7%), Microsporidia sp. (5%), Entamoeba histolytica/dispar, Hymenolepis nana, and Capillaria philippinensis (each representing 2%). No statistical difference was detected between both groups in all parasites except for Microsporidia sp. (P = 0.008). In diabetic patients; age ≥ 41 years, living in rural areas, and patients having uncontrolled and complicated DM were significantly associated with intestinal parasitosis by univariate analysis (P = 0.016, 0.035, 0.014, 0.043) respectively. By multivariate analysis, age and rural residence were the only statistically significant risk factors (OR = 6.192, and 2.614) respectively. Intestinal parasites were highly associated with diarrhea (P < 0.001), and flatulence (P = 0.042) in the diabetic patients. Diabetic patients should be screened routinely for intestinal parasites, especially the opportunistic ones, and treated for their overall well-being.

Molecular detection of Cryptosporidium spp., Giardia duodenalis, and Enterocytozoon bieneusi in school children at the Thai-Myanmar border

Few data are available on the genetic identity of enteric protists Cryptosporidium spp., Giardia duodenalis, and Enterocytozoon bieneusi in humans in Thailand. In this study, 254 stool samples were collected from primary school children from Ratchaburi Province at the Thai-Myanmar border and examined for Cryptosporidium spp., G. duodenalis, E. bieneusi and Cyclospora cayetanensis using PCR techniques. The genotype identity of the pathogens was determined by DNA sequence analysis of the PCR products. Cryptosporidium felis was found in 1 stool sample, G. duodenalis in 19 stool samples, and E. bieneusi in 4 stool samples. For G. duodenalis, sub-assemblage AII was the dominant genotype, but one infection with assemblage F was found. The E. bieneusi genotypes found included known genotypes D and J, and one novel genotype (HPTM1). Cyclospora cayetanensis was not detected in any samples. Results of the preliminary study indicate that children at the Thai-Myanmar border from Ratchaburi Province, Thailand are infected with diverse zoonotic genotypes of Cryptosporidium spp., G. duodenalis, and E. bieneusi.

Impact of sampling depth on pathogen detection in pit latrines

Wastewater based epidemiology (WBE) is increasingly used to provide decision makers with actionable data about community health. WBE efforts to date have primarily focused on sewer-transported wastewater in high-income countries, but at least 1.8 billion people in low- and middle-income countries (LMIC) use onsite sanitation systems such as pit latrines and septic tanks. Like wastewater, fecal sludges from such systems offer similar advantages in community pathogen monitoring and other epidemiological applications. To evaluate the distribution of enteric pathogens inside pit latrines-which could inform sampling methods for WBE in LMIC settings unserved by sewers-we collected fecal sludges from the surface, mid-point, and maximum-depth of 33 pit latrines in urban and peri-urban Malawi and analyzed the 99 samples for 20 common enteric pathogens via multiplex quantitative reverse transcription PCR. Using logistic regression adjusted for household population, latrine sharing, the presence of a concrete floor or slab, water source, and anal cleansing materials, we found no significant difference in the odds of detecting the 20 pathogens from the mid-point (adjusted odds ratio, aOR = 1.1; 95% confidence interval = 0.73, 1.6) and surface samples (aOR = 0.80, 95% CI = 0.54, 1.2) compared with those samples taken from the maximum depth. Our results suggest that, for the purposes of routine pathogen monitoring, pit latrine sampling depth does not strongly influence the odds of detecting enteric pathogens by molecular methods. A single sample from the pit latrines' surface, or a composite of surface samples, may be preferred as the most recent material contributed to the pit and may be easiest to collect.

Molecular diversity of Giardia duodenalis in children under 5 years from the Manhiça district, Southern Mozambique enrolled in a matched case-control study on the aetiology of diarrhoea

Giardia duodenalis is an enteric parasite commonly detected in children. Exposure to this organism may lead to asymptomatic or symptomatic infection. Additionally, early-life infections by this protozoan have been associated with impaired growth and cognitive function in poor resource settings. The Global Enteric Multicenter Study (GEMS) in Mozambique demonstrated that G. duodenalis was more frequent among controls than in diarrhoeal cases (≥3 loosing stools in the previous 24 hours). However, no molecular investigation was conducted to ascertain the molecular variability of the parasite. Therefore, we describe here the frequency and genetic diversity of G. duodenalis infections in children younger than five years of age with and without diarrhoea from the Manhiça district in southern Mozambique enrolled in the context of GEMS. Genomic DNA from 757 G. duodenalis-positive stool samples by immunoassay collected between 2007-2012, were reanalysed by multiplex PCR targeting the E1-HP and C1-P21 genes for the differentiation of assemblages A and B. Overall, 47% (353) of the samples were successfully amplified in at least one locus. Assemblage B accounted for 90% (319/353) of all positives, followed by assemblage A (8%, 29/353) and mixed A+B infections (1%, 5/353). No association between the presence of a given assemblage and the occurrence of diarrhoea could be demonstrated. A total of 351 samples were further analysed by a multi-locus sequence genotyping (MLSG) approach at the glutamate dehydrogenase (gdh), ß-giardin (bg) and triose phosphate isomerase (tpi) genes. Overall, 63% (222/351) of samples were genotyped and/or sub-genotyped in at least one of the three markers. Sequence analysis revealed the presence of assemblages A (10%; 23/222) and B (90%; 199/222) with high molecular diversity at the nucleotide level within the latter; no mixed infections were identified under the MLSG scheme. Assemblage A sequences were assigned to sub-assemblages AI (0.5%, 1/222), AII (7%, 15/222) or ambiguous AII/AIII (3%, 7/222). Within assemblage B, sequences were assigned to sub-assemblages BIII (13%, 28/222), BIV (14%, 31/222) and ambiguous BIII/BIV (59%, 132/222). BIII/BIV sequences accumulated the majority of the single nucleotide polymorphisms detected, particularly in the form of double peaks at chromatogram inspection. This study demonstrated that the occurrence of gastrointestinal illness (diarrhoea) was not associated to a given genotype of G. duodenalis in Mozambican children younger than five years of age. The assemblage B of the parasite was responsible for nine out of ten infections detected in this paediatric population. The extremely high genetic diversity observed within assemblage B isolates was compatible with an hyperendemic epidemiological scenario where infections and reinfections were common. The obtained molecular data may be indicative of high coinfection rates by different G. duodenalis assemblages/sub-assemblages and/or genetic recombination events, although the exact contribution of both mechanisms to the genetic diversity of the parasite remains unknown.

Human parechovirus are emerging pathogens with broad spectrum of clinical syndromes in adults

Parechoviruses are emerging pathogens of humans often affecting the pediatric age group, with a growing line of evidence implicating them as agents of a broad spectrum of clinical syndromes in adults. However, because many clinicians are not familiar with the manifestation of the infections, they are not included in the list of diagnostic pathogens. Furthermore, due to the indistinguishable feature of the infection compared with other common pathogens, a large number of cases are likely to go unchecked. Some may develop asymptomatic infection and recover without overt clinical disease. In this manuscript, we reviewed available literature on parechovirus infection in adult and summarized information relating to epidemiology, clinical manifestation, laboratory diagnosis, and therapeutics. The information provided should help in early case detection and support an evidence-based clinical decision.

Metagenomics of the faecal virome indicate a cumulative effect of enterovirus and gluten amount on the risk of coeliac disease autoimmunity in genetically at risk children: the TEDDY study

OBJECTIVE

Higher gluten intake, frequent gastrointestinal infections and adenovirus, enterovirus, rotavirus and reovirus have been proposed as environmental triggers for coeliac disease. However, it is not known whether an interaction exists between the ingested gluten amount and viral exposures in the development of coeliac disease. This study investigated whether distinct viral exposures alone or together with gluten increase the risk of coeliac disease autoimmunity (CDA) in genetically predisposed children.

DESIGN

The Environmental Determinants of Diabetes in the Young study prospectively followed children carrying the HLA risk haplotypes DQ2 and/or DQ8 and constructed a nested case-control design. From this design, 83 CDA case-control pairs were identified. Median age of CDA was 31 months. Stool samples collected monthly up to the age of 2 years were analysed for virome composition by Illumina next-generation sequencing followed by comprehensive computational virus profiling.

RESULTS

The cumulative number of stool enteroviral exposures between 1 and 2 years of age was associated with an increased risk for CDA. In addition, there was a significant interaction between cumulative stool enteroviral exposures and gluten consumption. The risk conferred by stool enteroviruses was increased in cases reporting higher gluten intake.

CONCLUSIONS

Frequent exposure to enterovirus between 1 and 2 years of age was associated with increased risk of CDA. The increased risk conferred by the interaction between enteroviruses and higher gluten intake indicate a cumulative effect of these factors in the development of CDA.

Norovirus transmission mediated by asymptomatic family members in households

The transmission of human norovirus excreted from infected persons occasionally causes sporadic infections and outbreaks. Both symptomatic patients and asymptomatic carriers have been reported to contribute to norovirus transmission, but little is known about the magnitude of the contribution of asymptomatic carriers. We carried out a 1-year survey of residents of a district of Bangkok, Thailand to determine the percentage of norovirus transmissions originating from asymptomatic individuals. We screened 38 individuals recruited from 16 families from May 2018 to April 2019 for GI and GII genotypes. Norovirus was detected every month, and 101 of 716 stool samples (14.1%) from individuals with no symptoms of acute gastroenteritis were norovirus-positive. The average infection frequency was 2.4 times per person per year. Fourteen genotypes were identified from the positive samples, with GII.4 being detected most frequently. Notably, 89.1% of the norovirus-positive samples were provided by individuals with no diarrhea episode. Similar to cases of symptomatic infections in Thailand, asymptomatic infections were observed most frequently in December. We detected 4 cases of NV infection caused by household transmission, and 3 of the 4 transmissions originated from asymptomatic individuals. We also identified a case in which norovirus derived from an asymptomatic individual caused diarrhea in a family member. These results suggest that asymptomatic individuals play a substantial role in both the maintenance and spreading of norovirus in a community through household transmission.

Parechovirus A Pathogenesis and the Enigma of Genotype A-3

Parechovirus A is a species in the Parechovirus genus within the Picornaviridae family that can cause severe disease in children. Relatively little is known on Parechovirus A epidemiology and pathogenesis. This review aims to explore the Parechovirus A literature and highlight the differences between Parechovirus A genotypes from a pathogenesis standpoint. In particular, the curious case of Parechovirus-A3 and the genotype-specific disease association will be discussed. Finally, a brief outlook on Parechovirus A research is provided.

Molecular detection of enteric viruses in the stool samples of children without diarrhea in Bangladesh

A number of molecular epidemiological studies reported the detection of enteric viruses in asymptomatic children. The role of these viruses in an asymptomatic infection remains unclear. This study investigated the enteric viruses in the stool samples collected from children without diarrhea. Stool samples were collected during June to October 2016, from 227 children who lived in Matlab, Bangladesh. Seventeen enteric viruses, including rotavirus A, B, and C (RVA, RVB, and RVC), norovirus GI (NoV GI), norovirus GII (NoV GII), sapovirus (SaV), adenovirus (AdV), human astrovirus (HAstV), Aichivirus (AiV), human parechovirus (HPeV), enterovirus (EV), human bocavirus (HBoV), Saffold virus (SAFV), human cosavirus (HCoSV), bufavirus (BufV), salivirus (SalV), and rosavirus (RoV), were investigated by RT-PCR method. One hundred and eighty-two (80.2%; 182/227) samples were positive for some of these viruses, and 19.8% (45/227) were negative. Among the positive samples, 46.7% (85/182) were a single infection, and 53.3% (97/182) were coinfection with multiple viruses. The HCoSV was the most prevalent virus (41.4%), followed by EV (32.2%), NoV GII (25.6%), HPeV (8.8%), RVA (6.2%), AdV (5.7%), AiV (5.3%), SAFV (4.4%), and SaV (2.6%). Each of NoV GI, HAstV, HBoV, and BufV was detected at 0.4%. However, RVB, RVC, SalV, and RoV were not detected in this study. Phylogenetic analysis showed that diverse HCoSV species and genotypes were circulating in Bangladesh, and four strains of species A are proposed to be new genotypes. The data indicated that non-diarrheal Bangladeshi children were asymptomatically infected with wide varieties of enteric viruses.

Presence of Giardia lamblia in stools of six- to 18-month old asymptomatic Malawians is associated with children's growth failure

Aim

Despite high pathogen burden and malnutrition in low‐income settings, knowledge on relationship between asymptomatic viral or parasitic infections, nutrition and growth is insufficient. We studied these relationships in a cohort of six‐month‐old Malawian infants.

Methods

As part of a nutrient supplementation trial for 12 months, we documented disease symptoms of 840 participant daily and anthropometric measurements every three months. Stool specimens were collected every six months and analysed for Giardia lamblia, Cryptosporidium species and enterovirus, rotavirus, norovirus, parechovirus and rhinovirus using polymerase chain reaction (PCR). The prevalence of the microbes was compared to the children's linear growth and the dietary.

Results

The prevalence of the microbes was similar in every intervention group. All age groups combined, children negative for G. lamblia had a mean standard deviation (SD) of −0.01 (0.49) change in length‐for‐age Z‐score (LAZ), compared to −0.12 (0.045) among G. lamblia positive children (difference −0.10, 95% CI −0.21 to −0.00, p = 0.047). The LAZ change difference was also statistically significant (p = 0.042) at age of 18–21 months but not at the other time points.

Conclusion

Asymptomatic G. lamblia infection was mainly associated with growth reduction in certain three‐month periods. The result refers to the chronic nature of G. lamblia infection.