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Total number of children with Cryptosporidium infection per month. The x-axis represents age of the child in months, and the y-axis represents total number of infected children per age-month. The solid-segment represents number of children with asymptomatic Cryptosporidium infection, and the lined-segment represents number of children with diarrhea from Cryptosporidium infection. In each month, the total possible number of children included is 392. A child who had both a diarrheal and asymptomatic stool positive in the same month was counted as having Cryptosporidium diarrhea. This figure demonstrates peaks of diarrheal Cryptosporidium infection at 10 and 17 months of age, and peaks of asymptomatic infection at 10–13 and 17 months of age. doi:10.1371/journal.pntd.0004564.g002
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Background
Cryptosporidiosis is a common cause of infectious diarrhea in young children worldwide, and is a significant contributor to under-five mortality. Current treatment options are limited in young children. In this study, we describe the natural history of Cryptosporidium spp. infection in a birth cohort of children in Bangladesh and evaluat...
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Background
Cryptosporidium spp. are infections the most frequent parasitic cause of diarrhea in humans and cattle. However, asymptomatic cases are less often documented than symptomatic cases or cases with experimentally infected animals. Cryptosporidium (C.) hominis infection accounts for the majority of pediatric cases in several countries, while...
Citations
... Overall, the prevalence of Cryptosporidium infection among Chinese children is notably lower compared to rates observed in children from certain developing countries. For instance, Bangladesh reported a rate of 77% [18], India's under-2-year-olds exhibited a rate of 92.4% [19], rural western Kenya's 6 to 24-montholds had a rate of 88.7% [20], and children under 2 years old from eight countries across Africa, Asia, and South America demonstrated an approximate rate of 65% [21]. Furthermore, when comparing China's prevalence to certain developed countries, the rates are also lower, such as Australia's Aboriginal children had a rate of 8.2% [22], and children with diarrhea in Switzerland had a rate of 5.5% [23]. ...
Background
Cryptosporidium is a highly pathogenic parasite responsible for diarrhea in children worldwide. Here, the epidemiological status and genetic characteristics of Cryptosporidium in children with or without diarrhea were investigated with tracking of potential sources in Wenzhou City, China.
Methods
A total of 1032 children were recruited, 684 of whom had diarrhea and 348 without, from Yuying Children’s Hospital in Wenzhou, China. Samples of stool were collected from each participant, followed by extraction of DNA, genotyping, and molecular identification of Cryptosporidium species and subtypes.
Results
Twenty-two of the 1032 (2.1%) children were infected with Cryptosporidium spp. with 2.5% (17/684) and 1.4% (5/348) in diarrhoeic and asymptomatic children, respectively. Four Cryptosporidium species were identified, including C. parvum (68.2%; 15/22), C. felis (13.6%; 3/22), C. viatorum (9.1%; 2/22), and C. baileyi (9.1%; 2/22). Two C. parvum subtypes named IIdA19G1 (n = 14) and IInA10 (n = 1), and one each of C. felis (XIXa) and C. viatorum (XVaA3g) subtype was found as well.
Conclusions
This is the first research that identified Cryptosporidium in children of Wenzhou, China, using PCR. Identification of zoonotic C. parvum, C. felis, C. viatorum, and their subtypes indicate potential cross-species transmission of Cryptosporidium between children and animals. Additionally, the presence of C. baileyi in children suggests that this species has a wider host range than previously believed and that it possesses the capacity to infect humans.
... Modified acid-fast staining 18 4.95 Modified acid-fast staining method was 33.83% in Waist province (Al-warid et al, 2010) in north of Baghdad and Jomah and Mallah (2016) (Korpe et al, 2016). Microscopically method is the common method for diagnosing oocysts of the Cryptosporidium parasite after staining with modified acid-fast stain (Morgan et al, 1998). ...
The present study aimed at using more than one method for the diagnosis of C. parvum parasites in feces samples taken from patients with diarrhea in Babylon province. Fecal samples initially examined by two methods, modified acid-fast stain and chromatographic immunoassay. Positive samples in the chromatographic immunoassay method examined by molecular method using two specific genes of this parasite (dihydrofolate reductase gene DHFR and 70-Kilodalton Heat Shock Protein Gene HSP70). The results of the present study showed that the percentage of C. parvum infection were 4.95% and 3.58% in the acid-fast stain and chromatographic immunoassay methods, respectively. Statistical analysis showed that there is no significant difference between the percentages of infection in the two methods. The results of the DNA extraction of positive samples in chromatographic immunoassay method and the use of two genes for this parasite (HPS70 and CH-DHFR) showed that only nine samples gave a positive result out of 13 with percentage of infection equal 2.47%. We conclude from the results of the current study that the C. parvum one of the parasitic causes of diarrhea in the province of Babylon, despite the low percentage of infection and the possibility of using more than one method to diagnose.
... Findings from GEMS supplemented previous observations that Cryptosporidium infections are linked to growth faltering and malnutrition [2,[4][5][6][7], which have been shown to increase the longer term risk of reduced physical fitness and diminished cognitive function [8]. Furthermore, malnutrition has been associated with an increased risk of Cryptosporidium-associated diarrhea [9], resulting in a vicious cycle of reinfection and repeated disease [10]. ...
... An association of Cryptosporidium diarrheal disease with subsequent malnutrition and increased mortality among infants and children living in low-and middle-income countries (LMICs) has long been recognized [2,[4][5][6], but differences in study design, populations, and diagnostic assays among studies did not allow comparisons of the magnitude of this effect. The use of standardized methods over 3 years in GEMS, across multiple sites in 2 continents, provided evidence supporting the widespread nature of a Cryptosporidium MSD disease burden that included an increased risk of associated stunting and mortality [1,7,22,23]. ...
... The ability to curb transmission through improvements in sanitation and hygiene is stymied by the ease of transmission (a low infectious inoculum, prolonged shedding, and persistence of viable oocysts in the environment) and resistance to heat and chlorination [24]. The lack of robust animal models, molecular genetic tools, and culture systems has impeded the development of drugs and vaccines [4,7]. Indications that vaccination might be an effective preventive strategy include suggestions of age-related acquisition of immunity in LMICs [25][26][27] and observations that mucosal antibodies confer protection in infants [28,29]. ...
Background:
As part of the Vaccine Impact on Diarrhea in Africa (VIDA) Study, we examined the prevalence, clinical presentation, and seasonality of Cryptosporidium in children to understand its relative burden after the introduction of rotavirus vaccine.
Methods:
VIDA was a 3-year, age-stratified, matched case-control study of medically attended acute moderate-to-severe diarrhea (MSD) in children aged 0-59 months residing in censused populations at sites in Kenya, Mali, and The Gambia. Clinical and epidemiologic data were collected at enrollment, and a stool sample was tested for enteropathogens by quantitative PCR. An algorithm was created based on the organism's cycle threshold (Ct) and association with MSD to identify the subset of Cryptosporidium PCR-positive (Ct <35) cases most likely to be attributed to MSD. Clinical outcomes were assessed at 2-3 months after enrollment.
Results:
One thousand one hundred six (22.9%) cases of MSD and 873 controls (18.1%) were PCR positive for Cryptosporidium; 465 cases (42.0%) were considered attributable to Cryptosporidium, mostly among children 6-23 months. Cryptosporidium infections peaked in The Gambia and Mali during the rainy season, while in Kenya they did not have clear seasonality. Compared with cases with watery MSD who had a negative PCR for Cryptosporidium, cases with watery MSD attributed to Cryptosporidium were less frequently dehydrated but appeared more severely ill using a modified Vesikari scale (38.1% vs 27.0%; P < 0.001), likely due to higher rates of hospitalization and intravenous fluid administration, higher prevalence of being wasted or very thin very thin (23.4% vs 14.7%; P < 0.001), and having severe acute malnutrition (midupper arm circumference <115 mm, 7.7% vs 2.5%; P < 0.001). On follow-up, Cryptosporidium-attributed cases had more prolonged and persistent episodes (43.2% vs 32.7%; P <0 .001) and linear growth faltering (change in height-for-age z score between enrollment and follow-up: -0.29 vs -0.17; P < 0.001).
Conclusions:
The burden of Cryptosporidium remains high among young children in sub-Saharan Africa. Its propensity to cause illness and further impact children longer term by compromising nutritional status early in life calls for special attention to enable appropriate management of clinical and nutritional consequences.
... Cryptosporidium diarrhea and subclinical infection have both been associated with stunted growth and cognitive deficits in children [2][3][4][5]. Despite the high morbidity from this infection, there is currently no effective treatment for infants younger than one year of age. ...
Background:
Cryptosporidium spp are responsible for significant diarrheal morbidity and mortality in under-five children. There is no vaccine, thus a focus on prevention is paramount. Prior studies suggest that person-to-person spread may be an important pathway for transmission to young children. Here we describe a longitudinal cohort study of 100 families with infants to determine rates of cryptosporidiosis within households during the COVID-19 pandemic.
Methods:
Families living in Mirpur, Bangladesh with one infant age 6-8 months were enrolled and followed with weekly illness survey and stool testing for Cryptosporidium for 8 months.
Results:
From December 2020 to August 2021, 100 families were enrolled. Forty-four percent of index children, and 35% of siblings had at least one Cryptosporidium infection. Shedding of Cryptosporidium occurred for a mean of 19 days (sd 8.3 days) in index infants, 16.1 days (sd 11.6) in children 1-5 years, and 16.2 days (sd 12.8) in adults. A longer duration of Cryptosporidium shedding was associated with growth faltering in infants. There was a spike in Cryptosporidium cases in May 2021, which coincided with a spike in SARS-CoV-2 cases in the region.
Conclusion:
In this intensive, longitudinal study of Cryptosporidium infection in families we found high rates of cryptosporidiosis in infants and children, and prolonged parasite shedding, especially among malnourished children. These data support that transmission within the household is an important route of exposure for young infants, and that treatment of non-diarrheal infection to interrupt person-to-person transmission within the home may be essential for preventing cryptosporidiosis in infants.
... infection has even been shown to be protective against enteropathogen-driven diarrhoea [21]), or alternatively, catch-up growth between diarrhoeal episodes may allow children to regain height after bouts of diarrhoea [22]. Indeed, birth cohort studies indicate that parasitic infection during the first 2 years of life impact linear height, even after controlling for diarrhoeal illness [23]. atrophy and crypt hyperplasia reduces the surface area of the small intestine, with fewer mature absorptive intestinal epithelial cells available for nutrient absorption and digestion. ...
Globally, stunting affects approximately 149.2 million children under 5 years of age. The underlying aetiology and pathophysiological mechanisms leading to stunting remain elusive, and therefore few effective treatment and prevention strategies exist. Crucial evidence directly linking parasites to stunting is often lacking - in part due to the complex nature of stunting, as well as a lack of critical multidisciplinary research amongst key age groups. Here, based on available studies, we present potential mechanistic pathways by which parasitic infection of mother and/or infant may lead to childhood stunting. We highlight the need for future multidisciplinary longitudinal studies and clinical trials aimed at elucidating the most influential factors, and synergies therein, that can lead to stunting, and ultimately towards finding solutions to successfully mitigate against it.
... Cryptosporidium diarrhea and subclinical infection have both been associated with stunted growth and cognitive deficits in children [2][3][4][5]. Despite the high morbidity from this infection, there is currently no effective treatment for infants younger than one year of age. ...
Background. Cryptosporidium spp are responsible for significant diarrheal morbidity and mortality in under-five children. There is no vaccine, thus a focus on prevention is paramount. Prior studies suggest that person-to-person spread may be an important pathway for transmission to young children. Here we describe a longitudinal cohort study of 100 families with infants to determine rates of cryptosporidiosis within households during the COVID-19 pandemic.
Methods. Families living in Mirpur, Bangladesh with one infant age 6-8 months were enrolled and followed with weekly illness survey and stool testing for Cryptosporidium for 8 months.
Results. From December 2020 to August 2021, 100 families were enrolled. Forty-four percent of index children, and 35% of siblings had at least one Cryptosporidium infection. Shedding of Cryptosporidium occurred for a mean of 19 days (sd 8.3 days) in index infants, 16.1 days (sd 11.6) in children 1-5 years, and 16.2 days (sd 12.8) in adults. A longer duration of Cryptosporidium shedding was associated with growth faltering in infants. There was a spike in Cryptosporidium cases in May 2021, which coincided with a spike in SARS-CoV-2 cases in the region.
Conclusion. In this intensive, longitudinal study of Cryptosporidium infection in families we found high rates of cryptosporidiosis in infants and children, and prolonged parasite shedding, especially among malnourished children. These data support that transmission within the household is an important route of exposure for young infants, and that treatment of non-diarrheal infection to interrupt person-to-person transmission within the home may be essential for preventing cryptosporidiosis in infants.
... Hence, 55% of urban Bangladeshi infants had at least three Giardia-positive stools over the first 2 years of age [33]. Rates up to 77% have been reported for Cryptosporidium infections in slum-dwelling Bangladeshi [59] and Indian [60] children. A Giardia infection rate of 33%, rarely associated with illness, has been reported in toddlers attending a day-care centre in the USA [61]. ...
Giardia duodenalis, Cryptosporidium spp., and Blastocystis sp. are common intestinal eukaryotic parasites affecting children in developed and resource-limited countries. Lack of information on the epidemiology and long-term stability in asymptomatic children complicates interpretation of transmission and pathogenesis. To assess the occurrence, genetic diversity, and temporal dynamics of intestinal eukaryotic parasites in young children, 679 stool samples from 125 toddlers attending six public day-care centres in Central Spain were collected bimonthly within a 1-year period. Detection and identification of species/genotypes were based on PCR and Sanger sequencing methods. Four eukaryotic species were identified: G. duodenalis (2.5‒31.6%), Cryptosporidium spp. (0.0‒2.4%), Blastocystis sp. (2.5‒6.4%), and Entamoeba dispar (0.0‒0.9%). Entamoeba histolytica and Enterocytozoon bieneusi were undetected. Sequence analyses identified assemblage A (63.6%) and B (36.4%) within G. duodenalis (n = 11), C. hominis (40%), C. parvum (40%), and C. wrairi (20%) within Cryptosporidium spp. (n = 5), and ST1 (3.8%), ST2 (46.2%), ST3 (15.4%), and ST4 (34.6%) within Blastocystis sp. (n = 26). Giardia duodenalis sub-assemblage AII/AIII was detected in a toddler for 10 consecutive months. Stable carriage of Blastocystis ST2 allele 9, ST3 allele 34, and ST4 allele 42 was demonstrated in five toddlers for up to 1 year. Conclusions: Giardia duodenalis and Blastocystis sp. were common in toddlers attending day-care centres in Central Spain. Long-term infection/colonization periods by the same genetic variant were observed for G. duodenalis (up to 10 months) and Blastocystis sp. (up to 12 months).
What is Known:
• Asymptomatic carriage of G. duodenalis and Blastocystis sp. is frequent in toddlers.
• The epidemiology and long-term stability of these eukaryotes in asymptomatic young children is poorly understood.
What is New:
• Long-term colonization/infection periods by the same genetic variant were described for Blastocystis sp. (up to 12 months) and G. duodenalis (up to 10 months).
... [21] . Children with asymptomatic and symptomatic cryptosporidiosis were found to gain less weight in the first month of infection, and once infected they are not liable to "catch up growth" and are predisposed to growth stunting [12] . Nevertheless, the mechanisms underlying growth impairments after infection are complex, and most likely linked to EED [21] . ...
... Infection with Cryptosporidium spp. has been linked to increased gut inflammation and villus architecture loss; and murine models suggest that immune signalling in the gut may be interrupted, resulting in enteropathy and poor growth [12] . Blastocystis spp. ...
... growth deficits and cognitive impairment [2,3]. While diarrheal disease caused by Cryptosporidium spp. is the second most common cause of death [4], a large number of asymptomatic or mild infections are not diagnosed and remain undetected in the community [5]. ...
... among infected children was very different from that among animals. Not surprisingly, the majority of cases in children were due to C. hominis, further confirming that human-to-human transmission of cryptosporidiosis predominates in the African continent [3,7,24]. However, subtyping at the gp60 gene locus revealed subtype IbA10G2 in these children, reinforcing previous data from isolates collected in the capital Antananarivo, as well as in the context of a large epidemiologic study in Africa that included Madagascar [5]. ...
... All children who tested positive for Cryptosporidium spp. in the present study were asymptomatic, supporting a previous hypothesis that a number of cryptosporidiosis cases are constantly circulating in communities, serving as a silent reservoir for younger children aged < 2 years [6]. The latter children are more likely to develop symptomatic diarrheal disease and suffer further consequences in terms of growth faltering and cognitive outcomes [2,3]. A similar situation has long been known in young animals, in particular calves and lambs infected with C. parvum [8,26]. ...
Background:
The aim of this study was to identify local transmission patterns of Cryptosporidium spp. infections among livestock and humans in four extremely rural and remote highland communities in Madagascar.
Methods:
In this cross-sectional study, households were randomly sampled throughout a 1-year study period, with one feces sample collected from each child (≤ 5 years old), sheep and cattle. Cryptosporidium spp. were identified using a nested PCR assay targeting the 18S ribosomal RNA gene. All samples positive for Cryptosporidium hominis were further subtyped by sequencing the 60-kDa glycoprotein gene (gp60). Spatial clustering methods were applied to analyze potential transmission patterns.
Results:
In total, 252 households participated in the study, and samples from 197 children, 862 cattle and 334 sheep were collected and included in the study. Of the samples collected, 11 (5.6%) from children, 30 (3.5%) from cattle and 42 (12.6%) from sheep tested positive for Cryptosporidium spp. Very little overlap in the species distribution between human and animal infections was found. Global (overall) and local (spatially defined) clustering was observed for Cryptosporidium spp. infections in sheep and for Cryptosporidium xiaoi/bovis infections among sheep and cattle.
Discussion:
The results of this analysis do not support the occurrence of defined disease outbreaks, rather they point to a continuous series of transmission events that are spatially aggregated. Despite the close coexistence between humans, sheep and cattle in the study area, mutual transmission was not observed. Hence, the study underlines the importance of sustained sanitation and hygiene measures to prevent cryptosporidiosis transmission among infants, since asymptomatic children serve as an infection reservoir. Similarly, the study highlights the importance of improving hygiene to reduce the transmission of Cryptosporidium spp. in livestock, an infection with serious consequences, especially in newborn calves.
... Cryptosporidium infection rarely occurs in immunocompetent persons but the infection results in approximately 10%-15% of cases of severe diarrhoea in malnourished children < 5 years old [8,18]. A very high prevalence of cryptosporidiosis (77%) was reported among slum-dwelling children in Bangladesh [19]. In Zambia, Cryptosporidium infection was diagnosed in 30.7% of all pre-schoolers in a peri-urban area [20]. ...
Cryptosporidiosis is an important protozoan disease with serious public health implications. The contribution of Cryptosporidium to colorectal cancer is still vaguely studied, but little evidence from experimental and epidemiological studies has suggested a possible association. This review discusses the epidemiology of cryptosporidiosis and colorectal cancer and attempts to unravel the possible link between the two diseases using epidemiological, pathological, molecular, and immunological evidence. The review stressed the need to undertake more studies in this relatively neglected field.
