Giardia and Cryptosporidium in children with diarrhea, Kufra, Libya, a North African migration route city

Spatially explicit model of the Cryptosporidium and Giardia disease burden from surface and ground waters in urban and rural areas of the Three Gorges Reservoir watershed in Chongqing, China

Cryptosporidium and Giardia (major causes of diarrhea) are widely distributed in Chinese source waters and threaten human health. A new spatially explicit GloWPa-TGR-Crypt-Giar C1 model is presented to simultaneously estimate mean monthly (oo)cyst concentrations in surface and ground waters in the Three Gorges Reservoir (TGR) watershed. A quantitative risk assessment of protozoal infections considered different source waters, transmission pathways, regions, susceptible subpopulations, and drinking water treatments. Monthly mean Cryptosporidium oocyst and Giardia cyst concentrations ranged between 0.5-19.3 oocysts/10 L and 0.2-5.0 cysts/10 L in surface water, respectively, and 0.007-0.3 oocysts/10 L and 0.002-0. 2 cysts/10 L in groundwater. The cumulative disease burdens attributable to cryptosporidiosis and giardiasis were, respectively, 5.77×10-5 DALYs (disability-adjusted life years/person/year) and 4.63×10-6 DALYs in urban areas, and 6.35×10-4 DALYs and 8.84×10-5 DALYs in rural areas, which were much higher than the reference risk level recommended by the World Health Organization ([Formula: see text] DALYs). The annual burden associated with consuming surface water was calculated to be 3.84×10-4 DALYs for Cryptosporidium and [Formula: see text] DALYs for Giardia, whereas consuming groundwater entailed the lower burdens (1.26×10-5 and 3.50×10-6 DALYs, respectively). Most DALYs were a consequence of consumption of directly supplied surface water. Fifty percent of the health burden was carried by immunodeficiency with HIV. Children (0-4 years) were more likely to have an individual disease burden than adults (15-64 years). Males were more susceptible than females. Improving sanitation through adequate ozone and microfiltration treatment should be considered when attempting to reduce disease burden. Sensitivity analysis highlighted the importance of reducing (oo)cyst loads to protect the watershed. The methodology and results described will help in evaluating and reducing the burden of protozoal infection associated with surface and ground waters in the TGR and similar watersheds.

Prevalence of Hepatitis B and Hepatitis C in Migrants from Sub-Saharan Africa Before Onward Dispersal Toward Europe

Viral hepatitis is a global health care challenge due to its worldwide distribution, chronic persistence, complications, and high prevalence with unchecked conditions in areas like sub-Saharan Africa. A high proportion of asymptomatic infections allows serious complications and poses infection risk to destination populations. This study aimed to determine the prevalence of both HBV and HCV among 3248 migrants from different parts of sub-Saharan Africa newly arrived at Kufra, Libya, a remote agricultural North African city. All these migrants were required by the Libyan authorities to undergo a complete medical check-up for different purposes such as joining new jobs, and obtaining licenses for trade and commerce. UAT sera from 3248 migrants, aged 18-53 years, attending the Al Kufra city hospital from January 01 to December 31, 2019, were screened for HBsAg and anti-HCV antibody by rapid tests and positive samples were further tested by ELISA method. The results showed that 761/3248 (23.4%) of the migrants were positive for HBV and 1014/3248 (31.2%) were positive for HCV. Migrants from sub-Saharan Africa carry high rates of HBV and HCV infection. This suggests the importance of increased attention to actions to deal with findings among positive migrants, and for awareness about risks of transmission to the local population. Study results indicate the value of routine migrant monitoring, the need for awareness in destination country health authorities, and the potential for impact on migrant destination populations.

Epidemiological investigations of diarrhea in children in Praia city, Cape Verde

Introduction

Diarrheal disease is a major cause of infant mortality and morbidity in Africa and results primarily from contaminated food and water sources, but its prevalence predictors in Cape Verde are not completely known. For this reason, this study aimed to identify the etiological agents of diarrhea in Cape Verdean children and assess its associated risk factors.

Methods

A survey questionnaire was used, and a total of 105 stool samples from children with diarrhea aged 0-12 years at the Central Hospital of Praia (Santiago, Cape Verde) were analyzed. The analyses were carried out using Biofire FilmArray Gastrointestinal Panels. Possible risk factors for these pathogens were analyzed using logistic regression, chi-square tests, or Fisher's exact test.

Results

Among the bacteria, enteroaggregative Escherichia coli (45.71%; 95% CI: 36.71-56.70), enteropathogenic E. coli (40%; 95% CI: 30.56-50.02), Shigella/enteroinvasive E. coli (29.52%; 95% CI: 21.02-39.22), E. coli enterotoxigenic (12.38%; 95% CI: 6.76-20.24), Campylobacter sp. (10.48%; 95% CI: 5.35-1.97), Vibrio sp. (4.76%; 95% CI: 1.56-10.76), Clostridioides difficile (3.81%; 95% CI: 1.05-9.47), Vibrio cholerae (2.86%; 0.59-8.12), Shiga-like toxin-producing E. coli (2.86%; 0.59-8.12) and Salmonella sp. (0.95%; 0.02-5.19) were identified; four viruses, Rotavirus A (28.57%; 95% CI: 20.18-38.21), Sapovirus I. II. IV and V (11.43%; 95% CI: 6.05-19.11), Norovirus GI.GII (6.67%; 95% CI: 2.72-13.25) and Adenovirus F 40.41 (6.67%; 95% CI: 2.72-13.25) were also observed. All the pathogens detected in this study were found in coinfections. Significant associations with risk factors were found; specifically, having a bathroom at home reduced the risk of Campylobacter sp., having animals at home increased the risk of Shigella/EIEC infection, and drinking bottled water reduced the risk of Sapovirus infection.

Discussion

From the findings of this study, it can be concluded that, in Cape Verde, there is a high prevalence and diversity of pathogens among children. Our results could help to establish an adequate diagnosis and effective treatments for diarrheal disease.

Molecular characterisation of Giardia duodenalis from human and companion animal sources in the United Kingdom using an improved triosephosphate isomerase molecular marker

Giardia duodenalis is a protozoan parasite known for its ability to cause gastrointestinal disease in human and non-human mammals. In the UK, the full impact of this parasite has yet to be fully explored, due to the limited testing which has been undertaken in humans and the low-resolution assemblage-typing methods currently available. Rather than being primarily a travel-associated condition, a recent study has highlighted that an endemic Giardia cycle is present in the UK, although the source of human disease is unclear in the majority of cases. This study focussed on the improvement of one of the commonly used assemblage-typing assays, a nested topoisomerase phosphate (tpi) PCR, to increase the amplification success rate across both human and companion animal samples. After comparing published primers to full Giardia reference genomes, this marker protocol was optimised and then deployed to test a substantial number of human (n ​= ​79) and companion animal (n ​= ​174) samples to gain an insight into the molecular epidemiology of Giardia in the UK. One assemblage A1 and eleven assemblage A2 genotypes were detected in humans, along with and 25 assemblage B genotypes. Assemblage A1 genotypes, known to be human-infective, were found in three feline and one canine sample, while one feline sample contained assemblage A2. Additionally, four feline samples contained assemblage B, which is recognised as potentially human-infective. This study demonstrates the presence of potentially human-infective Giardia genotypes circulating in the companion animal population, notably with 17.4% (8/46) of feline-derived Giardia strains being potentially zoonotic. Using a modified tpi-based genotyping assay, this work highlights the potential for domestic pets to be involved in the endemic transmission of giardiasis in the UK and underlines the need for appropriate hygiene measures to be observed when interacting with both symptomatic and asymptomatic animals. It also serves to underline the requirement for further studies to assess the zoonotic risk of Giardia associated with companion animals in high-income countries.

Giardia duodenalis in patients with diarrhea and various animals in northeastern China: prevalence and multilocus genetic characterization

Background

Giardia duodenalis is a common parasitic diarrheal agent in humans, especially in developing countries. The aim of this study was to investigate the prevalence and multilocus genetic characterization of G. duodenalis in patients with diarrhea and animals in northeastern China, and to assess the epidemiological role of animals in the transmission of human giardiasis.

Methods

A total of 1739 fecal specimens from 413 diarrheal patients and 1326 animals comprising 16 mammal species were collected in Heilongjiang Province of China and screened for G. duodenalis by PCR and sequencing of the SSU rRNA gene. All G. duodenalis-positive specimens were subtyped by PCR and sequencing of the bg, tpi, and gdh genes. To detect additional mixed infections of different assemblages, assemblage A/B/E-specific PCRs were performed to amplify the tpi gene.

Results

Sequence analysis of the SSU rRNA gene determined the prevalence of G. duodenalis (5.81%, 24/413) in diarrheal patients, with a peak in minors aged 5–17 years, and identified assemblages A and B. MLG-AII and MLG-B1 were obtained based on concatenated nucleotide sequences of the bg, tpi, and gdh genes, with MLG-AII being identical to a cat-derived isolate reported previously. By sequence analysis of the SSU rRNA gene, G. duodenalis was detected in 214 (16.14%) animals belonging to 11 mammal species, with the prevalence ranging from 1.69 to 53.85%, and assemblages A to G were identified. Sequence analysis of the bg, tpi, and gdh genes from 46 specimens produced 31 MLGs, including MLG-AI (n = 1), MLG-B2–B8 (n = 18), and MLG-E1–E23 (n = 27).

Conclusions

The finding of G. duodenalis in diarrheal patients enhances consciousness of detecting G. duodenalis in clinical practice and emphasizes the importance of health education in local inhabitants, especially in the age group of 5–17 years. The identification of seven assemblages (A to G) and 33 MLGs reveals genetic heterogeneity of G. duodenalis in the investigated areas. Due to insufficient homology data on the zoonotic transmission of G. duodenalis, the precise epidemiological role that animals play in the transmission of human giardiasis needs to be assessed by more large-scale molecular epidemiological investigations of local humans and animals.

Graphical Abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s13071-022-05269-9.

The risk factors for intestinal Giardia spp infection: Global systematic review and meta-analysis and meta-regression

Parasitic infections are a public health concern as they can cause aggression, growth retardation, weight loss, anemia, and other health problems. In this study, a systematic review and meta-analysis were performed to find an association between the probable social-environmental risk factors including lack of safe drinking water, no hand washing, sex, age, no access to education, no access to toilet, and Giardia spp infection. We conducted literature research among international databases including Scopus, PubMed, Web of Science and Cochrane from1 January 1995 to March 15, 2020, including 23 articles with 102 studies while the odds ratio (OR) was calculated using 2 × 2 tables or extracted. The pooled effect size with 95% confidence intervals (CIs) was estimated using a random or fixed-effects model. The results show a significant association between intestinal Giardia spp infection risk and lack of safe drinking water (OR: 1.14; 95%CI: 1.02-1.25); no access to toilet (OR: 1.22; 95%CI: 1.07-1.37); and age (2-10 vs 10-30 year) (OR: 1.42; 95%CI: 1.09-1.78). An insignificant association was observed between intestinal Giardia spp infection risk and age (<2 vs 2-10 year) (OR: 0.89; 95%CI: 0.75-1.02); no access to education (OR: 1.10; 95%CI: 0.80-1.40); Sex (male vs female) (OR: 1.04; 95%CI: 0.74-1.34); and no handwashing (OR: 1.18; 95%CI: 0.87-1.49). The results of meta-regression also indicate that intestinal Giardia spp infection has decreased over time (C= -0.024, p-value = 0.03) significantly, and also by growth of human development index (HDI) (C= - 0.42, p-value = 0.29) insignificantly. Improvement of personal hygiene, sanitation and raising public awareness can be effective in reducing Giardia spp infections.

Molecular Epidemiology of Human Cryptosporidiosis in Low- and Middle-Income Countries

Cryptosporidiosis is one of the most important causes of moderate to severe diarrhea and diarrhea-related mortality in children under 2 years of age in low- and middle-income countries. In recent decades, genotyping and subtyping tools have been used in epidemiological studies of human cryptosporidiosis. Results of these studies suggest that higher genetic diversity of Cryptosporidium spp. is present in humans in these countries at both species and subtype levels and that anthroponotic transmission plays a major role in human cryptosporidiosis. Cryptosporidium hominis is the most common Cryptosporidium species in humans in almost all the low- and middle-income countries examined, with five subtype families (namely, Ia, Ib, Id, Ie, and If) being commonly found in most regions. In addition, most Cryptosporidium parvum infections in these areas are caused by the anthroponotic IIc subtype family rather than the zoonotic IIa subtype family. There is geographic segregation in Cryptosporidium hominis subtypes, as revealed by multilocus subtyping. Concurrent and sequential infections with different Cryptosporidium species and subtypes are common, as immunity against reinfection and cross protection against different Cryptosporidium species are partial. Differences in clinical presentations have been observed among Cryptosporidium species and C. hominis subtypes. These observations suggest that WASH (water, sanitation, and hygiene)-based interventions should be implemented to prevent and control human cryptosporidiosis in low- and middle-income countries.

Prevalence and Clinical Manifestations of Giardia intestinalis and Other Intestinal Parasites in Children and Adults in Algeria

Giardia intestinalis is one of the most common causes of parasite-induced diarrhea, abdominal pain, flatulence, and malabsorption. Yet, data on the epidemiology of G. intestinalis infections in North Africa are limited. The purpose of this study was to carry out a retrospective survey on the level of intestinal parasitism with a particular emphasis on G. intestinalis in children and adults in Algiers, Algeria. A total of 2,054 individuals from outpatient clinics or hospitalized at Beni-Messous University Hospital of Algiers undergoing stool microscopy for ova and parasites were included. The overall parasite infection rate was 28%. In the 567 parasite-positive samples, Blastocystis was found most frequently (57.3%), followed in frequency by Endolimax nana (41.0%), Entamoeba histolytica/dispar (19.6%), G. intestinalis (17.1%), Entamoeba coli (13.9%), Chilomastix mesnili (1.0%), Iodamoeba bütschlii (0.7%), Entamoeba hartmanni (0.5%), and Cryptosporidium spp. (0.2%). Intestinal parasites were generally more common in adults than in children, except for Giardia, which was more common in children (P = 0.0001). Giardia infection was independent of gender (P = 0.94). Compared with other intestinal parasitic infections, clinical manifestations, such as abdominal pain (P = 0.28) and diarrhea (P = 0.82), were found not to be significantly linked to Giardia infection. In conclusion, G. intestinalis is common in individuals referred to the University Hospital of Beni-Messous with digestive symptoms, particularly so in children. However, in our study, intestinal symptoms appeared not to be more linked to Giardia than to other intestinal parasites.

Cryptosporidium spp. and Giardia duodenalis emissions from humans and animals in the Three Gorges Reservoir in Chongqing, China

Cryptosporidium spp. and Giardia duodenalis are two waterborne protozoan parasites that can cause diarrhea. Human and animal feces in surface water are a major source of these pathogens. This paper presents a GloWPa-TGR-Crypto model that estimates Cryptosporidium and G. duodenalis emissions from human and animal feces in the Three Gorges Reservoir (TGR), and uses scenario analysis to predict the effects of sanitation, urbanization, and population growth on oocyst and cyst emissions for 2050. Our model estimated annual emissions of 1.6 × 10¹⁵ oocysts and 2.1 × 10¹⁵ cysts from human and animal feces, respectively. Humans were the largest contributors of oocysts and cysts, followed by pigs and poultry. Cities were hot-spots for human emissions, while districts with high livestock populations accounted for the highest animal emissions. Our model was the most sensitive to oocyst excretion rates. The results indicated that 74% and 87% of total emissions came from urban areas and humans, respectively, and 86% of total human emissions were produced by the urban population. The scenario analysis showed a potential decrease in oocyst and cyst emissions with improvements in urbanization, sanitation, wastewater treatment, and manure management, regardless of population increase. Our model can further contribute to the understanding of environmental pathways, the risk assessment of Cryptosporidium and Giardia pollution, and effective prevention and control strategies that can reduce the outbreak of waterborne diseases in the TGR and other similar watersheds.

High-Yield Purification of Giardia intestinalis Cysts from Fecal Samples

Giardia is an enteric protozoan parasite that causes gastroenteritis in all classes of vertebrates. It is ranked among the leading causes of death in children under 5 years of age. Giardiasis affects approximately 280 million people worldwide annually, a situation exacerbated by the low availability of effective treatments and the lack of a vaccine. In addition, the parasite is difficult to manipulate in in vitro environments, which hampers the development of effective disease management strategies. This article highlights the development of a method for the purification of viable Giardia cysts from fecal samples, verified by a trypan blue dye exclusion test. This protocol produces a 10-fold increase in yield over current methods. By combining sucrose flotation with gated filtration, the protocol significantly reduces the amount of debris in the purified cysts suspension. Cyst viability is verified by a trypan blue dye exclusion test. The ability to purify large quantities of Giardia from fecal samples could advance the development of effective treatments to target this worldwide prevalent parasite. © 2020 Wiley Periodicals LLC. Basic Protocol: Purification of Giardia cysts from fecal samples Support Protocol: Cyst viability test.

Individual and community-level risk factors in under-five children diarrhea among agro-ecological zones in southwestern Ethiopia

Under-five children diarrhea remains a major public health problem in resource-limited areas, including Ethiopia, due to multiple risk factors. This study aimed to identify individual and community-level risk factors affecting under-five children diarrhea (UFCD) in five districts of the Bench Maji Zone, southwestern Ethiopia. A community-based cross-sectional study was conducted from February to April 2018. A total of 826 households were recruited from five randomly selected districts using stratified sampling. A multivariable logistic regression model was fitted to identify risk factors associated with UFCD. The prevalence of UFCD in the study area was found to be 18.3%. Children less than six months of age are more at risk for diarrhea (95% CI for AOR2.5;1.23-4.90). Most probably initiating supplementary feedings before six months of age is one of the main risk factor for diarrhea (95% CI for AOR 0.65; 0.45-0.98). Similarly, mothers with low educational status (95% CI for AOR 0.30; 0.10-0.84), limited knowledge of mothers' about diarrhea (95% CI for AOR 0.24; 0.15-0.40), absence of hand washing among mothers/caregivers at critical times (95% CI for AOR 4.6; 2.88-7.67), and sharing of the residence with domestic animals (95% CI for AOR 2.87, 1.75-4.67) were the predictors of UFCD at individual-level. Children living in semi pastoral areas (95% CI for AOR 0.22; 0.10-0.50) unvaccinated children for rotavirus prevention (95% CI AOR 5.22, 3.33-8.20), households obtaining water from unimproved sources (95% CI for AOR 2.53; 1.60-4.40), and households with unimproved latrine facilities (95% CI for AOR 0.60; 0.33-0.99) were the risk factors of UFCD at the community-level. The study revealed that UFCD is a critical health concern in southwestern Ethiopia, where integrated intervention approach at individual and community level could help to alleviate the problem. At individual level, behavioral change intervention on handwashing, exclusive breast-feeding before the age of six months, and awareness on diarrhea prevention methods are critical areas of intervention. Likewise, provision of safe and adequate water source combined with household water chlorination, and vaccination for rotavirus are interventions at community that need to be integrated with the individual-level of intervention. This could significantly contribute for the reduction of UFCD in the resource limited areas through intersectoral collaboration of the health and other sectors.