Global distribution, public health and clinical impact of the protozoan pathogen cryptosporidium

A fractional perspective on the transmission dynamics of a parasitic infection, considering the impact of both strong and weak immunity

Infectious disease cryptosporidiosis is caused by the cryptosporidium parasite, a type of parasitic organism. It is spread through the ingestion of contaminated water, food, or fecal matter from infected animals or humans. The control becomes difficult because the parasite may remain in the environment for a long period. In this work, we constructed an epidemic model for the infection of cryptosporidiosis in a fractional framework with strong and weak immunity concepts. In our analysis, we utilize the well-known next-generation matrix technique to evaluate the reproduction number of the recommended model, indicated by [Formula: see text]. As [Formula: see text], our results show that the disease-free steady-state is locally asymptotically stable; in other cases, it becomes unstable. Our emphasis is on the dynamical behavior and the qualitative analysis of cryptosporidiosis. Moreover, the fixed point theorem of Schaefer and Banach has been utilized to investigate the existence and uniqueness of the solution. We identify suitable conditions for the Ulam-Hyers stability of the proposed model of the parasitic infection. The impact of the determinants on the sickness caused by cryptosporidiosis is highlighted by the examination of the solution pathways using a novel numerical technique. Numerical investigation is conducted on the solution pathways of the system while varying various input factors. Policymakers and health officials are informed of the crucial factors pertaining to the infection system to aid in its control.

The Parasitism and Tumors Carcinogenesis: A Review Subject

BACKGROUND

Multi-factorial reasons are an induction to cause cancer. Different infections and infestations with viruses, bacteria, and parasites have been detected for many years to be related to human carcinogenesis.

PURPOSE

The study aimed to review all ideas of tumor carcinogenesis and its associations with parasitic infections and infestations.

METHODS

We reviewed several articles (published and imprinted) by selecting, extracting, and synthesizing data about the relationship between cancers and parasites.

RESULTS

Several helminths infections as schistosomiasis, are highly carcinogenic agents for bladder cancer, whereas trypanosomiasis has a bi-model role in cancer development. Leishmaniasis may be a cause of hepatocarcinoma, skin cancer, and lymphomas. In addition, malaria appears to be causative in the carcinogenesis of some cancers; as Burkitt lymphoma. Also, data from previous studies suggested that Strongyloides stercoralis may be a relevant co-factor in lymphomas.

CONCLUSION

There are different mechanisms of parasitic infection to be enhancing in carcinogenesis of cancer in human.

Changing Molecular Profiles of Human Cryptosporidiosis Cases in Scotland as a Result of the Coronavirus Disease, COVID-19 Pandemic

Cryptosporidium, the most frequently reported parasite in Scotland, causes gastrointestinal illness resulting in diarrhoea, nausea and cramps. Two species are responsible for most cases: Cryptosporidium hominis (C. hominis) and Cryptosporidium parvum (C. parvum). Transmission occurs faecal-orally, through ingestion of contaminated food and water, or direct contact with faeces. In 2020, the COVID-19 pandemic led to global restrictions, including national lockdowns to limit viral transmission. Such interventions led to decreased social mixing, and reduced/no local and international travel, which are factors associated with transmission of multiple communicable diseases, including cryptosporidiosis. This report assessed the impact of the pandemic on Scottish cryptosporidiosis cases, and identified changes in circulating molecular variants of Cryptosporidium species. Molecular data generated using real time PCR and GP60 nested-PCR assays on laboratory-confirmed cryptosporidiosis cases reported during 2018-22 were analysed. The Scottish Microbiology Reference Laboratories (SMiRL), Glasgow, received 774 Cryptosporidium-positive faeces during 2018-22, of which 486 samples were successfully subtyped. During this time period, C. hominis (n = 155; 21%) and C. parvum (n = 572; 77%) were the most commonly detected species. The total number of cases during 2020, which was greatly affected by the pandemic, was markedly lower in comparison to case numbers in the 2 years before and after 2020. The most predominant C. hominis family detected prior to 2020 was the Ib family which shifted to the Ie family during 2022. The most common C. parvum variant during 2018-22 was the IIa family, however a rise in the IId family was observed (n = 6 in 2018 to n = 25 in 2022). The dominant C. hominis subtype IbA10G2, which accounted for 71% of C. hominis subtypes in 2018-19 was superseded by three rare subtypes: IeA11G3T3 (n = 15), IdA16 (n = 8) and IbA9G3 (n = 3) by 2022. Frequently reported C. parvum subtypes in 2018-19 were IIaA15G2R1 and IIaA17G1R1, accounting for 59% of total C. parvum subtypes. By 2022, IIaA15G2R1 remained the most common (n = 28), however three unusual subtypes in Scotland emerged: IIdA24G1 (n = 7), IIaA16G3R1 (n = 7) and IIaA15G1R2 (n = 7). Continuous monitoring of Cryptosporidium variants following the pandemic will be essential to explore further changes and emergence of strains with altered virulence.

Gastrointestinal Infection in South African Children under the Age of 5 years: A Mini Review

Objective

To estimate gastroenteritis disease and its etiological agents in children under the age of 5 years living in South Africa.

Methods

A mini literature review of pertinent articles published in ScienceDirect, PubMed, GoogleScholar, and Scopus was conducted using search terms: "Gastroenteritis in children," "Gastroenteritis in the world," Gastroenteritis in South Africa," "Prevalence of gastroenteritis," "Epidemiological surveillance of gastroenteritis in the world," and "Causes of gastroenteritis".

Results

A total of 174 published articles were included in this mini review. In the last 20 years, the mortality rate resulting from diarrhea in children under the age of 5 years has declined and this is influenced by improved hygiene practices, awareness programs, an improved water and sanitation supply, and the availability of vaccines. More modern genomic amplification techniques were used to re-analyze stool specimens collected from children in eight low-resource settings in Asia, South America, and Africa reported improved sensitivity of pathogen detection to about 65%, that viruses were the main etiological agents in patients with diarrhea aged from 0 to 11 months but that Shigella, followed by sapovirus and enterotoxigenic Escherichia coli had a high incidence in children aged 12-24 months. In addition, co-infections were noted in nearly 10% of diarrhea cases, with rotavirus and Shigella being the main co-infecting agents together with adenovirus, enteropathogenic E. coli, Clostridium jejuni, or Clostridium coli.

Conclusions

This mini review outlines the epidemiology and trends relating to parasitic, viral, and bacterial agents responsible for gastroenteritis in children in South Africa. An increase in sequence-independent diagnostic approaches will improve the identification of pathogens to resolve undiagnosed cases of gastroenteritis. Emerging state and national surveillance systems should focus on improving the identification of gastrointestinal pathogens in children and the development of further vaccines against gastrointestinal pathogens.

Microbiota-produced indole metabolites disrupt mitochondrial function and inhibit Cryptosporidium parvum growth

Cryptosporidiosis is a leading cause of life-threatening diarrhea in young children in resource-poor settings. To explore microbial influences on susceptibility, we screened 85 microbiota-associated metabolites for their effects on Cryptosporidium parvum growth in vitro. We identify eight inhibitory metabolites in three main classes: secondary bile salts/acids, a vitamin B6 precursor, and indoles. Growth restriction of C. parvum by indoles does not depend on the host aryl hydrocarbon receptor (AhR) pathway. Instead, treatment impairs host mitochondrial function and reduces total cellular ATP, as well as directly reducing the membrane potential in the parasite mitosome, a degenerate mitochondria. Oral administration of indoles, or reconstitution of the gut microbiota with indole-producing bacteria, delays life cycle progression of the parasite in vitro and reduces the severity of C. parvum infection in mice. Collectively, these findings indicate that microbiota metabolites impair mitochondrial function and contribute to colonization resistance to Cryptosporidium infection.

Cryptosporidium parvum hijacks a host's long noncoding RNA U90926 to evade intestinal epithelial cell-autonomous antiparasitic defense

Cryptosporidium is a zoonotic apicomplexan parasite that infects the gastrointestinal epithelium and other mucosal surfaces in humans. It is an important opportunistic pathogen in AIDS patients and a leading cause of infectious diarrhea and diarrheal-related death in children worldwide. The intestinal epithelial cells provide the first line of defense against Cryptosporidium infection and play a central role in activating and regulating the host's antiparasitic response. Increasing evidence suggests that long noncoding RNAs (lncRNAs) participate in host-pathogen interactions and play a regulatory role in the pathogenesis of diseases but the underlying molecular mechanisms are not fully understood. We previously identified a panel of host lncRNAs that are upregulated in murine intestinal epithelial cells following Cryptosporidium infection, including U90926. We demonstrate here that U90926 is acting in a pro-parasitic manner in regulating intestinal epithelial cell-autonomous antiparasitic defense. Inhibition of U90926 resulted in a decreased infection burden of the parasite while overexpression of U90926 showed an increase in infection burden in cultured murine intestinal epithelial cells. Induction of U90926 suppressed transcription of epithelial defense genes involved in controlling Cryptosporidium infection through epigenetic mechanisms. Specifically, transcription of Aebp1, which encodes the Aebp1 protein, a potent modulator of inflammation and NF-κB signaling, was suppressed by U90926. Gain- or loss-of-function of Aebp1 in the host's epithelial cells caused reciprocal alterations in the infection burden of the parasite. Interestingly, Cryptosporidium carries the Cryptosporidium virus 1 (CSpV1), a double-stranded (ds) RNA virus coding two dsRNA fragments, CSpV1-dsRdRp and CSpV1-dsCA. Both CSpV1-dsRdRp and CSpV1-dsCA can be delivered into infected cells as previously reported. We found that cells transfected with in vitro transcribed CSpV1-dsCA or CSpV1-dsRdRp displayed an increased level of U90926, suggesting that CSpV1 is involved in the upregulation of U90926 during Cryptosporidium infection. Our study highlights a new strategy by Cryptosporidium to hijack a host lncRNA to suppress epithelial cell-autonomous antiparasitic defense and allow for a robust infection.

Infectious Disease Sensitivity to Climate and Other Driver-Pressure Changes: Research Effort and Gaps for Lyme Disease and Cryptosporidiosis

Climate sensitivity of infectious diseases is discussed in many studies. A quantitative basis for distinguishing and predicting the disease impacts of climate and other environmental and anthropogenic driver-pressure changes, however, is often lacking. To assess research effort and identify possible key gaps that can guide further research, we here apply a scoping review approach to two widespread infectious diseases: Lyme disease (LD) as a vector-borne and cryptosporidiosis as a water-borne disease. Based on the emerging publication data, we further structure and quantitatively assess the driver-pressure foci and interlinkages considered in the published research so far. This shows important research gaps for the roles of rarely investigated water-related and socioeconomic factors for LD, and land-related factors for cryptosporidiosis. For both diseases, the interactions of host and parasite communities with climate and other driver-pressure factors are understudied, as are also important world regions relative to the disease geographies; in particular, Asia and Africa emerge as main geographic gaps for LD and cryptosporidiosis research, respectively. The scoping approach developed and gaps identified in this study should be useful for further assessment and guidance of research on infectious disease sensitivity to climate and other environmental and anthropogenic changes around the world.

Microbiota produced indole metabolites disrupt host cell mitochondrial energy production and inhibit Cryptosporidium parvum growth

Cryptosporidiosis is a leading cause of life-threatening diarrhea in young children in resource-poor settings. Susceptibility rapidly declines with age, associated with changes in the microbiota. To explore microbial influences on susceptibility, we screened 85 microbiota- associated metabolites enriched in the adult gut for their effects on C. parvum growth in vitro. We identified eight inhibitory metabolites in three main classes: secondary bile salts/acids, a vitamin B 6 precursor, and indoles. Growth restriction of C. parvum by indoles did not depend on the host aryl hydrocarbon receptor (AhR) pathway. Instead, treatment impaired host mitochondrial function and reduced total cellular ATP, as well as directly reduced the membrane potential in the parasite mitosome, a degenerate mitochondria. Oral administration of indoles, or reconstitution of the gut microbiota with indole producing bacteria, delayed life cycle progression of the parasite in vitro and reduced severity of C. parvum infection in mice. Collectively, these findings indicate that microbiota metabolites contribute to colonization resistance to Cryptosporidium infection.

Prevalence of Cryptosporidium spp. in Horses from communities of the Mapuche native people, Araucanía Region, Chile

BACKGROUND

There are no studies of potential zoonotic diseases in Mapuche communities' horses.

OBJECTIVES

The objective of this study was to determine the prevalence of Cryptosporidium in horses of the Mapuche communities.

STUDY DESIGN

This was a cross-sectional study.

METHODS

Faecal samples from 100 randomly selected horses (n = 100) were taken from rural Mapuche communities from four municipalities from the Araucanía Region. These samples were processed with the modified Ziehl-Neelsen staining technique and grouped by sex, age and municipality.

RESULTS

The general prevalence of Cryptosporidium spp. was 67.0% (n = 67). The prevalence was 51.0% (n = 51) in males and 49.0% (n = 49) in females, and there is no gender association to the presentation of Cryptosporidium spp. The prevalence by municipality was 60.0%, 80.0%, 64.0% and 64.0% in Curarrehue, Lonquimay, Padre las Casas and Teodoro Schmidt, respectively. The above shows no significant association between the sector and the presence of Cryptosporidium spp. The prevalence by age was 95.4% of horses tested positive for Cryptosporidium between birth and 6 years of age. About 27.3% of horses were tested positive in the age group between 7 and 10 years. There was no presence of Cryptosporidium spp. in the age group older than 11 years, showing a significant relationship between the age of the animal and the presence of Cryptosporidium (P ˂ 0.05).

MAIN LIMITATIONS

The sample analysis did not specifically identify the type of Cryptosporidium, and it was not possible to evaluate the zoonotic risk in the Mapuche communities.

CONCLUSIONS

Cryptosporidium spp. is present in working horses in Mapuche communities, with a 67.7% general prevalence, and there is a significant association between this parasite and the age of the horses, being higher in the age group between 0 and 6 years, with a prevalence of 95.4%. There may be a potential zoonotic risk in the Mapuche communities.

Cryptosporidiosis: From Prevention to Treatment, a Narrative Review

Cryptosporidiosis is a water- and food-borne zoonotic disease caused by the protozoon parasite of the genus Cryptosporidium. C. hominis and C. parvum are the main two species causing infections in humans and animals. The disease can be transmitted by the fecal-oral route as well as the respiratory route. The infective stage (sporulated oocysts) is resistant to different disinfectants including chlorine. Currently, no effective therapeutic drugs or vaccines are available to treat and control Cryptosporidium infection. To prevent cryptosporidiosis in humans and animals, we need to understand better how the disease is spread and transmitted, and how to interrupt its transmission cycle. This review focuses on understanding cryptosporidiosis, including its infective stage, pathogenesis, life cycle, genomics, epidemiology, previous outbreaks, source of the infection, transmission dynamics, host spectrum, risk factors and high-risk groups, the disease in animals and humans, diagnosis, treatment and control, and the prospect of an effective anti-Cryptosporidium vaccine. It also focuses on the role of the One Health approach in managing cryptosporidiosis at the animal-human-environmental interface. The summarized data in this review will help to tackle future Cryptosporidium infections in humans and animals and reduce the disease occurrence.

Deep glance on the antiparasitic anticancer activities of wheat germ oil in chronically infected immunosuppressed mice with cryptosporidiosis

Cryptosporidium species are the major cause of water-borne epidemics of diarrhea in both developing and developed countries that vary from self-limited in immunocompetent patients to severe life-threatening in the immunocompromised hosts. There was a proven correlation between cryptosporidiosis and colorectal cancers, although, studies in this field are still limited. Wheat germ oil (WGO) is a natural product with a known antiparasitic effect and potential antiproliferative activities. This study aimed to evaluate the antiparasitic and anticancer activities of WGO in chronically infected immunosuppressed mice compared to Nitazoxanide (NTZ). This experimental case-control study was performed in the period from January till September 2021. Eighty immunosuppressed bred laboratory mice were divided into 4 groups, 20 mice each; GI non-infected; negative control (NC), GII infected non treated; positive control (PC), GII infected, and treated with NTZ, GIV infected, and treated with WGO. Parasitological, histopathological, and immunohistochemical examinations were performed with estimating the rate of maximal survival for the study groups. Parasitological examination revealed a marked reduction in the mean Cryptosporidium spp. oocyst counts in the stool of GIV compared to PC, and GIII (P-value < 0.001). Histopathological and immunohistochemical examinations showed the best results with GIV which revealed restoration of normal villous pattern, with no dysplasia or malignancy could be detected. GIV showed the best survival rate compared to PC and GIII. WGO is an extremely promising agent that has an excellent therapeutic effect against cryptosporidiosis with the ability to control the tumorigenesis process in the chronically infected immunosuppressed hosts.

Molecular detection and genetic characterization of Cryptosporidium in kindergarten children in Southern Xinjiang, China

Cryptosporidium is a common cause of diarrhea in children globally. However, there is limited information on the prevalence and genetic characteristics of Cryptosporidium in children in Xinjiang, China. This study aimed to assess the genetic characteristics and epidemiological status of Cryptosporidium in kindergarten children in Southern Xinjiang, China. A total of 609 fecal samples were collected from kindergartners aged 2-6 years from 11 counties in Southern Xinjiang, China. We used nested PCR amplification of the partial SSU rDNA gene to screen samples for Cryptosporidium spp. Isolates containing Cryptosporidium parvum and C. hominis were further subtyped for a gene encoding a 60-kDa glycoprotein (gp60). We used MEGA7 to construct a phylogenetic tree to study the genetic relationship between the gp60 subtypes of these two species via the Maximum Likelihood method based on the Tamura-Nei model. Only 1.3% (8/609) of asymptomatic children were confirmed to be infected with Cryptosporidium, with a 2.0% (6/299) infection rate in boys and 0.6% (2/310) infection rate in girls. Three Cryptosporidium species were identified including C. felis (37.5%; 3/8), C. hominis (37.5%; 3/8), and C. parvum (25.0%; 2/8). Three C. hominis subtypes (IbA9G3, IdA14, and IfA12G1) and two C. parvum subtypes (IIdA14G1 and IIdA15G1) were also found. This study is the first to identify the presence of Cryptosporidium in kindergarten children in Southern Xinjiang, China. The presence of zoonotic C. parvum subtypes IIdA14G1 and IIdA15G1 indicates the possible cross-species transmission of Cryptosporidium between children and animals.

Intestinal Parasitic Infections Among Pediatric Patients in a Metropolitan City of Bangladesh With Emphasis on Cryptosporidiosis

Introduction

Gastrointestinal parasitic infections are one of the global health concerns in developing countries like Bangladesh. Among them, Cryptosporidium spp. plays an essential role in causing diarrhea, malnutrition, and poor cognitive function, especially in children. This study was conducted to identify the frequency of Cryptosporidium cases and other parasitic agents. 

Methods

A cross-sectional observational study was conducted among 219 hospitalized children with diarrhea. The conventional microscopic technique was applied for parasitic detection. Particular staining (modified Ziehl-Neelsen) procedure was performed to identify oocysts of Cryptosporidium spp. A polymerase chain reaction (PCR) was performed to determine the SSU rRNA and gp60 gene of Cryptosporidium. 

Results

Cysts of Giardia duodenalis (2.3%), ova of Ascaris lumbricoides (1.4%,), Trichuris trichiura (0.5%), and both A. lumbricoides and T. trichiura (0.9%) were identified in samples through wet mount preparation. The distribution of Cryptosporidium spp. as detected by the staining method and nested PCR was 1.4% and 4.1%, respectively. 

Conclusion

Factors independently associated with Cryptosporidium infection are unsafe water, lack of regular hand washing, and insufficiency of exclusive breastfeeding. This study reports, presumably for the first time, the detection of Cryptosporidium oocysts in Chattogram metropolitan city of Bangladesh.

Cryptosporidium: Still Open Scenarios

Cryptosporidiosis is increasingly identified as a leading cause of childhood diarrhea and malnutrition in both low-income and high-income countries. The strong impact on public health in epidemic scenarios makes it increasingly essential to identify the sources of infection and understand the transmission routes in order to apply the right prevention or treatment protocols. The objective of this literature review was to present an overview of the current state of human cryptosporidiosis, reviewing risk factors, discussing advances in the drug treatment and epidemiology, and emphasizing the need to identify a government system for reporting diagnosed cases, hitherto undervalued.

Genetic diversity of Cryptosporidium species in Njoro Sub County, Nakuru, Kenya

Cryptosporidium spp. cause cryptosporidiosis in humans through zoonotic and anthroponotic transmission. Previous studies illustrated the significance of domestic animals as reservoirs of this parasite. Cryptosporidium occurs in Njoro River; a main source of water to humans and animals. However, there is no information on the Cryptosporidium spp. and genotypes circulating in Njoro Sub County. A total of 2174 samples from humans, cattle, chickens, sheep and goats were assessed for the presence of Cryptosporidium spp. Thirty-three positive samples were subsequently successfully sequenced and compared to Cryptosporidium sequences in the GenBank repository using NCBI's (National Center for Biotechnology Information) online BLAST (Basic Local Alignment Search Tool) algorithmic program. Sequence alignment was done using the Clustal W program and phylogenetic analysis was executed in MEGA X (Molecular Evolutionary Genetics Analysis version X). The prevalence of cryptosporidiosis in Njoro Sub County is 6.99%. Cryptosporidium spp. present in the watershed showed great genetic diversity and nine Cryptosporidium species were recorded: Cryptosporidium parvum, Cryptosporidium hominis, Cryptosporidium ubiquitum, Cryptosporidium meleagridis, Cryptosporidium andersoni, Cryptosporidium baileyi, Cryptosporidium muris, Cryptosporidium xiaoi and Cryptosporidium viatorum. This is the first study to report the presence of C. viatorum in Kenya. Cattle is the major reservoir of zoonotic Cryptosporidium spp. while goats harbored the lowest number of species. Humans and domestic animals drink the contaminated water from Njoro River, humans are therefore, exposed to a high cryptosporidiosis risk.

Clinical Parasitology and Parasitome Maps as Old and New Tools to Improve Clinical Microbiomics

A growing body of evidence shows that dysbiotic gut microbiota may correlate with a wide range of disorders; hence, the clinical use of microbiota maps and fecal microbiota transplantation (FMT) can be exploited in the clinic of some infectious diseases. Through direct or indirect ecological and functional competition, FMT may stimulate decolonization of pathogens or opportunistic pathogens, modulating immune response and colonic inflammation, and restoring intestinal homeostasis, which reduces host damage. Herein, we discuss how diagnostic parasitology may contribute to designing clinical metagenomic pipelines and FMT programs, especially in pediatric subjects. The consequences of more specialized diagnostics in the context of gut microbiota communities may improve the clinical parasitology and extend its applications to the prevention and treatment of several communicable and even noncommunicable disorders.

LncRNA XR_001779380 Primes Epithelial Cells for IFN-γ-Mediated Gene Transcription and Facilitates Age-Dependent Intestinal Antimicrobial Defense

Interferon (IFN) signaling is key to mucosal immunity in the gastrointestinal tract, but cellular regulatory elements that determine interferon gamma (IFN-γ)-mediated antimicrobial defense in intestinal epithelial cells are not fully understood. We report here that a long noncoding RNA (lncRNA), GenBank accession no. XR_001779380, was increased in abundance in murine intestinal epithelial cells following infection by Cryptosporidium, an important opportunistic pathogen in AIDS patients and a common cause of diarrhea in young children. Expression of XR_001779380 in infected intestinal epithelial cells was triggered by TLR4/NF-κB/Cdc42 signaling and epithelial-specific transcription factor Elf3. XR_001779380 primed epithelial cells for IFN-γ-mediated gene transcription through facilitating Stat1/Swi/Snf-associated chromatin remodeling. Interactions between XR_001779380 and Prdm1, which is expressed in neonatal but not adult intestinal epithelium, attenuated Stat1/Swi/Snf-associated chromatin remodeling induced by IFN-γ, contributing to suppression of IFN-γ-mediated epithelial defense in neonatal intestine. Our data demonstrate that XR_001779380 is an important regulator in IFN-γ-mediated gene transcription and age-associated intestinal epithelial antimicrobial defense. IMPORTANCE Epithelial cells along the mucosal surface provide the front line of defense against luminal pathogen infection in the gastrointestinal tract. These epithelial cells represent an integral component of a highly regulated communication network that can transmit essential signals to cells in the underlying intestinal mucosa that, in turn, serve as targets of mucosal immune mediators. LncRNAs are recently identified long noncoding transcripts that can regulate gene transcription through their interactions with other effect molecules. In this study, we demonstrated that lncRNA XR_001779380 was upregulated in murine intestinal epithelial cells following infection by a mucosal protozoan parasite Cryptosporidium. Expression of XR_001779380 in infected cells primed host epithelial cells for IFN-γ-mediated gene transcription, relevant to age-dependent intestinal antimicrobial defense. Our data provide new mechanistic insights into how intestinal epithelial cells orchestrate intestinal mucosal defense against microbial infection.

Risk Evaluation of Pathogenic Intestinal Protozoa Infection Among Laboratory Macaques, Animal Facility Workers, and Nearby Villagers From One Health Perspective

Background: Previous epidemiological studies have confirmed non-human primates (NHPs) as reservoirs for Cryptosporidium spp. , Giardia intestinalis, and Enterocytozoon bieneusi. It highlights the possibility of interspecies transmission between humans and macaques in laboratory animal facilities. This study aimed to investigate the prevalence of pathogenic intestinal protozoan infections in macaques and humans and to determine the risk of cross-species transmission from One Health view.

Materials and Methods: A total of 360 fecal samples, including 310 from the four Macaca mulatta groups, 25 from the facility workers in a laboratory animal facility, and 25 from the villagers nearby in Yongfu country, southeast China, were collected. Nested PCR assays were done for detecting protozoan pathogens from all the specimens. Furthermore, potential risk factors (gender, age, and direct contact) on the occurrence of intestinal protozoa infection among different sub-groups were evaluated. A phylogenetic and haplotype network analysis was conducted to examine the genetic structure and shared patterns of E. bieneusi and Cyclospora cayetanensis.

Results: The pathogenic intestinal protozoa were detected in both human and macaque fecal samples. A total of 134 (37.2%) samples were tested positive, which included 113 (36.4%) macaques, 14 (56.0%) facility workers, and 7 (28.0%) villagers, respectively. There was no significant difference in four intestinal protozoa infections between facility workers and villagers (χ² = 2.4, P > 0.05). However, the positive rate of pathogenic intestinal protozoa in the facility workers, who had direct contact with macaques, was significantly higher [odds ratio (OR) = 0.31, 95% confidence interval (CI): 0.09–1.00, P < 0.05).Thirty-three ITS genotypes of E. bieneusi were identified, including five known genotypes (PigEBITS7, Peru8, Henan V, D, and CM1) and six novel genotypes (MEB1–6). Seven haplotypes were identified in the network analysis from C. cayetanensis-positive samples. Meanwhile, a phylogenetic and haplotype analysis confirmed the presence of zoonotic subtypes in NHPs and humans.

Conclusion: The data collected from this study confirmed a high prevalence of intestinal protozoan infection in humans and macaques. These results warrant workers of such facilities and residents to limit contact with infected animals in order to minimize related health risks. The need for comprehensive strategies to mitigate the risk of zoonotic transmission, especially from a One Health perspective, is recommended.

Spatiotemporal epidemiology of cryptosporidiosis in the Republic of Ireland, 2008-2017: development of a space-time "cluster recurrence" index

Background

Ireland frequently reports the highest annual Crude Incidence Rates (CIRs) of cryptosporidiosis in the EU, with national CIRs up to ten times the EU average. Accordingly, the current study sought to examine the spatiotemporal trends associated with this potentially severe protozoan infection.

Methods

Overall, 4509 cases of infection from January 2008 to December 2017 were geo-referenced to a Census Small Area (SA), with an ensemble of geo-statistical approaches including seasonal decomposition, Local Moran’s I, and space–time scanning used to elucidate spatiotemporal patterns of infection.

Results

One or more confirmed cases were notified in 3413 of 18,641 Census SAs (18.3%), with highest case numbers occurring in the 0–5-year range (n = 2672, 59.3%). Sporadic cases were more likely male (OR 1.4) and rural (OR 2.4), with outbreak-related cases more likely female (OR 1.4) and urban (OR 1.5). Altogether, 55 space–time clusters (≥ 10 confirmed cases) of sporadic infection were detected, with three “high recurrence” regions identified; no large urban conurbations were present within recurrent clusters.

Conclusions

Spatiotemporal analysis represents an important indicator of infection patterns, enabling targeted epidemiological intervention and surveillance. Presented results may also be used to further understand the sources, pathways, receptors, and thus mechanisms of cryptosporidiosis in Ireland.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-021-06598-3.

Microbiome in human cancers

A microbiome is defined as the aggregate of all microbiota that reside in human digestive system and other tissues. This microbiota includes viruses, bacteria, fungi that live in various human organs and tissues like stomach, guts, oesophagus, mouth cavity, urinary tract, vagina, lungs, and skin. Almost 20 % of malignant cancers worldwide are related to microbial infections including bacteria, parasites, and viruses. The human body is constantly being attacked by microbes during its lifetime and microbial pathogens that have tumorigenic effects in 15-20 % of reported cancer cases. Recent scientific advances and the discovery of the effect of microbes on cancer as a pathogen or as a drug have significantly contributed to our understanding of the complex relationship between microbiome and cancer. The aim of this study is to overview some microbiomes that reside in the human body and their roles in cancer.

Absence of Cryptosporidium hominis and dominance of zoonotic Cryptosporidium species in patients after Covid-19 restrictions in Auckland, New Zealand

Coronavirus disease-2019 (Covid-19) nonpharmaceutical interventions have proven effective control measures for a range of respiratory illnesses throughout the world. These measures, which include isolation, stringent border controls, physical distancing and improved hygiene also have effects on other human pathogens, including parasitic enteric diseases such as cryptosporidiosis. Cryptosporidium infections in humans are almost entirely caused by two species: C. hominis, which is primarily transmitted from human to human, and Cryptosporidium parvum, which is mainly zoonotic. By monitoring Cryptosporidium species and subtype families in human cases of cryptosporidiosis before and after the introduction of Covid-19 control measures in New Zealand, we found C. hominis was completely absent after the first months of 2020 and has remained so until the beginning of 2021. Nevertheless, C. parvum has followed its typical transmission pattern and continues to be widely reported. We conclude that ~7 weeks of isolation during level 3 and 4 lockdown period interrupted the human to human transmission of C. hominis leaving only the primarily zoonotic transmission pathway used by C. parvum. Secondary anthroponotic transmission of C. parvum remains possible among close contacts of zoonotic cases. Ongoing 14-day quarantine measures for new arrivals to New Zealand have likely suppressed new incursions of C. hominis from overseas. Our findings suggest that C. hominis may be controlled or even eradicated through nonpharmaceutical interventions.

Occurrence of Cryptosporidium Oocysts and Helminth Ova on Dried Crayfish (Procambarus clarkii) Sold in Kaduna State, Nigeria

Cryptosporidium spp. and helminths are responsible for diarrhoal illness in humans and many other animals. The transmission routes of these parasites suggest a risk for human infection through contaminated foods. In order to determine the occurrence of Cryptosporidium oocysts and helminth ova on dried crayfish (Procambarus clarkii) sold in Zaria and Kaduna Central market, Kaduna State, 100 crayfish samples were examined using the modified Ziehl-Neelsen staining technique for Cryptosporidium oocyst and the flotation technique for helminth ova. The measurements of the oocysts from the positive samples were estimated by using a calibrated microscope eyepiece. The prevalence of Cryptosporidium oocysts in dried crayfish was 20.0 % while the location-based prevalence was 43.3 %, 5.0 %, and 12.0 % for Sabo, Samaru and Kaduna central market, respectively. Micrometry revealed that the oocysts size ranged from 3.68 µm to 4.7 µm. Also, the prevalence of helminth ova in dried crayfish was 19 %, while the specific prevalence based on location showed a higher prevalence in Sabo (30.0 %) than in Kaduna central market (18.0 %) and Samaru (5.0 %). The helminth eggs recovered from this study included: Toxocara spp. (4.0 %), Ascaris spp. (7.0 %), Trichuris spp. (4.0 %), Schistosoma spp. (2.0 %), Ancylostoma spp. (1.0 %), and Capillaria spp. (1.0 %). The analysis of the questionnaires revealed that 71 (71.0 %) of the respondents ate uncooked cray-fish and 44.0 % used their bare hands to handle the cray-fish. There was no statistically significant association (P > 0.05) between the prevalence of Cryptosporidium oocysts or helminth ova and the locations sampled. This study has shown that dried crayfish obtained from markets within the study area were contaminated with parasite ova and oocysts, thus public enlightenment on the dangers of the consumption of raw or undercooked dried crayfish should be well publicized.

Cryptosporidial Infection Suppresses Intestinal Epithelial Cell MAPK Signaling Impairing Host Anti-Parasitic Defense

Cryptosporidium is a genus of protozoan parasites that infect the gastrointestinal epithelium of a variety of vertebrate hosts. Intestinal epithelial cells are the first line of defense and play a critical role in orchestrating host immunity against Cryptosporidium infection. To counteract host defense response, Cryptosporidium has developed strategies of immune evasion to promote parasitic replication and survival within epithelial cells, but the underlying mechanisms are largely unclear. Using various models of intestinal cryptosporidiosis, we found that Cryptosporidium infection caused suppression of mitogen-activated protein kinase (MAPK) signaling in infected murine intestinal epithelial cells. Whereas expression levels of most genes encoding the key components of the MAPK signaling pathway were not changed in infected intestinal epithelial cells, we detected a significant downregulation of p38/Mapk, MAP kinase-activated protein kinase 2 (Mk2), and Mk3 genes in infected host cells. Suppression of MAPK signaling was associated with an impaired intestinal epithelial defense against C. parvum infection. Our data suggest that cryptosporidial infection may suppress intestinal epithelial cell MAPK signaling associated with the evasion of host antimicrobial defense.

Toxoplasmosis, cryptosporidiosis, and isosporiasis in HIV-negative immunocompromised patients: A single-centre study, Ottawa, Ontario, Canada

BACKGROUND

Historically, patients with HIV have been at the highest risk of infection with opportunistic protozoans such as Toxoplasma, Cryptosporidium, and Isospora. Among patients with HIV who are compliant with antiretroviral therapy, the likelihood of acquiring an opportunistic infection is low. The risk of infection is harder to mitigate in the growing number of HIV-negative immunodeficient patients, such as people with hematological malignancies or those who are post-transplantation.

METHODS

We conducted a retrospective case series of patients with documented Toxoplasma infections between 2008 and 2017 and with Cryptosporidium and Isospora infections between 2014 and 2017 at the Ottawa Hospital.

RESULTS

During the study period, there were 10 confirmed cases of toxoplasmosis, 20 cases of cryptosporidiosis, and 2 cases of isosporiasis. Cryptosporidiosis (95%) and toxoplasmosis (60%) occurred more frequently among HIV-negative patients, whereas isosporiasis cases were limited to HIV-positive patients. Among patients with cryptosporidiosis, the most common underlying cause of immunosuppression in HIV-negative individuals was solid organ transplantation (15.79%), followed by diabetes (10.53%), end-stage renal disease (5.26%), and hematologic malignancy (5.26%). Seventy percent of patients had no known cause of immunosuppression. The most common underlying condition associated with toxoplasmosis was hematological malignancy (50%), followed by solid organ transplantation (33.33%), and solid tumours (16.66%).

CONCLUSIONS

This study's results suggest that Cryptosporidium infections are more common among immunocompetent patients in Ottawa, whereas Toxoplasma infections are more common among HIV-negative patients with acquired immunodeficiencies. As the demographics of immunocompromised individuals continue to evolve, screening for protozoal infections in high-risk populations may become clinically important.

Prevalence of Cryptosporidium Infection in the Global Population: A Systematic Review and Meta-analysis

BACKGROUND

Cryptosporidium is a protozoan parasite that can infect both humans and animals and cause cryptosporidiosis. We aimed to estimate the global prevalence of Cryptosporidium infection.

METHODS

In this study, Web of Science, Medline and PubMed were searched for relative articles, published between January 1, 1960 and January 1, 2018. Included articles were restricted to English language and that sample size of articles was not less than 50. Studies with no information on the study period, location, method of diagnosis, sample size and number of infected people were excluded. Studies about outbreak, laboratory report or immunocompromised population were excluded as well. The quality of the included publications was assessed. The prevalence of cryptosporidiosis was estimated by DerSimonian-Laird random-effects model, after converting by the Freeman-Tukey type double arcsine transformation.

FINDINGS

From 13,064 publications selected by literature search, 221 studies were included in the meta-analysis. The global pooled prevalence of Cryptosporidium infection was 7.6 % (95% CI: 6.9-8.5). The highest estimated prevalence of Cryptosporidium infection was in Mexico (69.6%, 95% CI 66.3-72.8), Nigeria (34.0%, 95% CI 12.4-60.0), Bangladesh (42.5%, 95% CI 36.1-49.0) and Republic of Korea (8.3%, 95% CI 4.4-13.2) among general residents, patients, school children and healthy population, respectively. The estimated prevalence was high in people from low-income country, people with gastrointestinal symptoms, people younger than 5 years old and residents not living in urban areas.

CONCLUSIONS

These estimates indicate the substantial prevalence of Cryptosporidium infection in the world, which may provide a theoretical basis for the formulation of the prevention strategy about Cryptosporidium.

Influence of weather and climate on cryptosporidiosis-A review

Studies have shown that climatic factors can significantly influence transmission of many waterborne diseases. However, knowledge of the impact of climate variability on cryptosporidiosis is much less certain. Associations between the incidence of cryptosporidiosis and climatic variables have been reported in several countries. Given that the identified relationships were not consistently reported across studies, it is not known whether these were country-specific observations or can be considered more globally. Variation in the disease risk in both low- and middle-income countries and high-income countries presents new challenges and opportunities to enact responsive changes in research and public health policies. Available epidemiological evidence of the influence of weather and climate on cryptosporidiosis is reviewed. Fourteen studies met the inclusion criteria, and most studies showed that the incidence of cryptosporidiosis is highly sensitive to climatic conditions, especially temperature, rainfall and relative humidity. The identified associations varied across studies, with different conditions of importance and lag times across different locations. Therefore, there is a need for countries at risk to assess Cryptosporidium transmission routes based on the spatiotemporal patterns of the disease and what role climate and other socio-ecological changes play in the transmission. Information gathering will then allow us to provide information for evidence-based control strategies and mitigation of transmission. This review offers new perspectives on the role of climate variability on Cryptosporidium transmission. It highlights different epidemiological approaches adopted and provides the potential for future research and surveillance to reduce the disease burden. By evaluating the epidemiological transmission of this organism in high-income countries, all mitigation strategies, for example filtration and water catchment management, can be used as exemplars of preventing infection in low- to middle-income countries.

Asymptomatic Cryptosporidium infections in ewes and lambs are a source of environmental contamination with zoonotic genotypes of Cryptosporidium parvum

Protozoan parasites of the Cryptosporidium genus cause severe cryptosporidiosis in newborn lambs. However, asymptomatic infections also occur frequently in lambs and ewes. In sheep, the most commonly detected Cryptosporidium species are C. ubiquitum, C. xiaoi and C. parvum. Due to a lack of relevant information about such infections in France, we investigated the situation on five dairy sheep farms in the Pyrénées-Atlantiques Department in south-western France in December 2017. Individual fecal samples were collected from 79 female lambs (5–17 days old) and their mothers (72 ewes). Oocysts were screened using Heine staining before and after Bailenger concentrations. Cryptosporidium species identification and genotyping were performed using real-time PCR and gp60 gene sequencing. No cases of clinical cryptosporidiosis were observed in the 79 lambs. Microscopically, Cryptosporidium spp. oocysts were observed in only one lamb on one farm (prevalence 1.3%) and one ewe on another farm (prevalence 1.4%). By contrast, Cryptosporidium spp. DNA was detected in 17 ewes (prevalence ranging from 10.5% to 50% depending on the farm) and in 36 lambs (prevalence ranging from 0% to 77.8% depending on the farm). Only zoonotic Cryptosporidium parvum IId and IIa genotypes were identified when genotyping was possible. Cryptosporidium ubiquitum and C. xiaoi were detected on one and three farms, respectively. We conclude that healthy young lambs and their mothers during the peripartum period could be a source of environmental contamination with oocysts.

Cryptosporidium and Colon Cancer: Cause or Consequence?

The number of cancers attributable to infectious agents represents over 20% of the global cancer burden. The apicomplexan intracellular parasite Cryptosporidium is currently considered one of the major causes of mild and severe diarrhea worldwide. However, less attention has been paid to its tumorigenic potential despite the high exposure of humans and animals to this ubiquitous parasite. Herein, we discuss the potential causal link between Cryptosporidium infection and digestive cancer, with particular emphasis on colon cancer, based on increasing clinical, epidemiological and experimental pieces of evidence supporting this association. In addition, we highlight the current knowledge about the potential mechanisms by which this parasite may contribute to cell transformation and parasite-induced cancer.

Molecular Basis of P131 Cryptosporidial-IMPDH Selectivity-A Structural, Dynamical and Mechanistic Stance

Cryptosporidiosis accounts for a surge in infant (<5 years) mortality and morbidity. To date, several drug discovery efforts have been put in place to develop effective therapeutic options against the causative parasite. Based on a recent report, P131 spares inosine monophosphate dehydrogenase (IMPDH) in a eukaryotic model (mouse IMPDH (mIMPDH)) while binding selectively to the NAD⁺ site in Cryptosporidium parvum (CpIMPDH). However, no structural detail exists on the underlining mechanisms of P131-CpIMPDH selective targeting till date. To this effect, we investigate the selective inhibitory dynamics of P131 in CpIMPDH relative to mIMPDH via molecular biocomputation methods. Pairwise sequence alignment revealed prominent variations at the NAD⁺ binding regions of both proteins that accounted for disparate P131 binding activities. The influence of these variations was further revealed by the MM/PBSA energy estimations coupled with per-residue energy decomposition which monitored the systematic binding of the compound. Furthermore, relative high-affinity interactions occurred at the CpIMPDH NAD⁺ site which were majorly mediated by SER22, VAL24, PRO26, SER354, GLY357, and TYR358 located on chain D. These residues are unique to the parasite IMPDH form and not in the eukaryotic protein, highlighting variations that account for preferential P131 binding. Molecular insights provided herein corroborate previous experimental reports and further underpin the basis of CpIMPDH inhibitor selectivity. Findings from this study could present attractive prospects toward the design of novel anticryptosporidials with improved selectivity and binding affinity against parasitic targets.

Kinetic modeling of the synergistic thermal and spectral actions on the inactivation of Cryptosporidium parvum in water by sunlight

Water contamination with the enteroprotozoan parasite Cryptosporidium is a current challenge worldwide. Solar water disinfection (SODIS) has been proved as a potential alternative for its inactivation, especially at household level in low-income environments. This work presents the first comprehensive kinetic model for the inactivation of Cryptosporidium parvum oocysts by sunlight that, based on the mechanism of the process, is able to describe not only the individual thermal and spectral actions but also their synergy. Model predictions are capable of estimating the required solar exposure to achieve the desired level of disinfection under variable solar spectral irradiance and environmental temperature conditions for different locations worldwide. The thermal contribution can be successfully described by a modified Arrhenius equation while photoinactivation is based on a series-event mechanistic model. The wavelength-dependent spectral effect is modeled by means of the estimation of the C. parvum extinction coefficients and the determination of the quantum yield of the inactivation process. Model predictions show a 3.7% error with respect to experimental results carried out under a wide range of temperature (30 to 45 °C) and UV irradiance (0 to 50 W·m^-2). Furthermore, the model was validated in three scenarios in which the spectral distribution radiation was modified using different plastic materials common in SODIS devices, ensuring accurate forecasting of inactivation rates for real conditions.

Cryptosporidium and Cryptosporidiosis: The Perspective from the Gulf Countries

The present review discusses the burden of cryptosporidiosis in the Gulf Cooperation Council (GCC), which is underreported and underestimated. It emphasizes that the Cryptosporidium parasite is infecting inhabitants and expatriates in the Gulf countries. Children under 5 years are a vulnerable group that is particularly affected by this parasitic disease and can act as carriers, who contribute to the epidemiology of the disease most probably via recreational swimming pools. Various risk factors for cryptosporidiosis in the GCC countries are present, including expatriates, predisposing populations to the infection. Water contamination, imported food, animal contact, and air transmission are also discussed in detail, to address their significant role as a source of infection and, thus, their impact on disease epidemiology in the Gulf countries' populations.

Survival and infectivity of Toxoplasma gondii and Cryptosporidium parvum oocysts bioaccumulated by Dreissena polymorpha

AIMS

The study was aimed to understand the depuration process of Cryptosporidium parvum and Toxoplasma gondii oocysts by zebra mussel (Dreissena polymorpha), to consider the use of the zebra mussel as a bioremediation tool.

MATERIALS AND METHODS

Two experiments were performed: (i) individual exposure of mussel to investigate oocyst transfers between bivalves and water and (ii) in vivo exposure to assess the ability of the zebra mussel to degrade oocysts.

RESULTS

(i) Our results highlighted a transfer of oocysts from the mussels to the water after 3 and 7 days of depuration; however, some oocysts were still bioaccumulated in mussel tissue. (ii) Between 7 days of exposure at 1000 or 10 000 oocysts/mussel/day and 7 days of depuration, the number of bioaccumulated oocysts did not vary but the number of infectious oocysts decreased.

CONCLUSION

Results show that D. polymorpha can release oocysts in water via (pseudo)faeces in depuration period. Oocysts remain bioaccumulated and infectious oocyst number decreases during the depuration period in zebra mussel tissues. Results suggest a degradation of bioaccumulated C. parvum and T. gondii oocysts.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study highlighted the potential use of D. polymorpha as a bioremediation tool to mitigate of protozoan contamination in water resources.

A retrospective epidemiological analysis of human Cryptosporidium infection in China during the past three decades (1987-2018)

Background

Cryptosporidiosis is an emerging infectious disease of public health significance worldwide. The burden of disease caused by Cryptosporidium varies between and within countries/areas. To have a comprehensive understanding of epidemiological status and characteristics of human Cryptosporidium infection in China since the first report in 1987, a retrospective epidemiological analysis was conducted by presenting differences in the prevalence of Cryptosporidium by province, year, population, living environment and season and possible transmission routes and risk factors as well as genetic characteristics of Cryptosporidium in humans.

Methodology/Principal findings

A systematic search was conducted to obtain epidemiological papers of human Cryptosporidium infection/cryptosporidiosis from PubMed and Chinese databases. Finally, 164 papers were included in our analysis. At least 200,054 people from 27 provinces were involved in investigational studies of Cryptosporidium, with an average prevalence of 2.97%. The prevalence changed slightly over time. Variable prevalences were observed: 0.65–11.15% by province, 1.89–47.79% by population, 1.77–12.87% and 0–3.70% in rural and urban areas, respectively. The prevalence peak occurred in summer or autumn. Indirect person-to-person transmission was documented in one outbreak of cryptosporidiosis in a pediatric hospital. 263 Cryptosporidium isolates were obtained, and seven Cryptosporidium species were identified: C. hominis (48.3%), C. andersoni (22.43%), C. parvum (16.7%), C. meleagridis (8.36%), C. felis (3.04%), C. canis (0.76%) and C. suis (0.38%).

Conclusions/Significances

This systematic review reflects current epidemiological status and characteristics of Cryptosporidium in humans in China. These data will be helpful to develop efficient control strategies to intervene with and prevent occurrence of human Cryptosporidium infection/cryptosporidiosis in China as well as have a reference effect to other countries. Further studies should focus on addressing a high frequency of C. andersoni in humans and a new challenge with respect to cryptosporidiosis with an increasing population of elderly people and patients with immunosuppressive diseases.

Cryptosporidium is a major cause of diarrheal disease in humans globally. Due to the lack of effective drug treatment and vaccine prevention against cryptosporidiosis, it is particularly important to develop efficient control strategies to intervene with and prevent Cryptosporidium infection in humans. The present review presented and analyzed epidemiological status and characteristics of Cryptosporidium infection in humans in China since the first report in 1987. To date, epidemiological investigations of Cryptosporidium infecion have been carried out in different populations in 27 provinces, autonomous regions, and municipalities. Average prevalence of Cryptosporidium was 2.97% (5,933/200,054). Like other infectious disease, due to poor sanitation conditions in rural areas, people living in rural areas had a significantly higher prevalence of Cryptosporidium (1.77–12.87%) than those living in urban areas (0–3.70%). Seven Cryptosporidium species were identified, including C. hominis, C. andersoni, C. parvum, C. meleagridis, C. felis, C. canis and C. suis. This retrospective epidemiological analysis indicates wide geographical distribution of human Cryptosporidium infection/cryptosporidiosis in China.

Factors Associated With Cryptosporidium Infection Among Adult HIV Positive Population in Contact With Livestock in Namwala District, Zambia

Cryptosporidium spp. is one of the leading causes of diarrhoeal disease globally. In Zambia, the burden of Cryptosporidium infection in the general human population is unknown and factors associated with it are unclear. A study was conducted to determine the prevalence of Cryptosporidium spp. and identify factors associated with its infection among Human Immunodeficiency Virus (HIV) positive individuals in contact with livestock in Namwala district of Zambia. Three hundred and twenty six stool samples were collected from HIV infected individuals presenting at local health centers in Namwala district of Zambia between August 2015 and June 2016. The Meriflour Cryptosporidium/Giardia test kit was used to test for presence of oocysts. Demographic information such as age and sex and information on hypothesized risk factors was collected using a structured questionnaire. Overall prevalence of Cryptosporidium infection was 9.5% (95% CI = 6.7–13.2%); 13.3% and 7.1% among male and female participants, respectively. Males were 2.5 times more likely to be infected than females whereas the divorced had higher odds of being infected (OR = 14.8). Participants who kept animals had a higher prevalence (11.4%) than those that did not (7.0%). Those that shared water with neighbors were 5.7 times more likely to be infected than those who did not. We conclude that Cryptosporidium infection is prevalent among HIV positive adults in Namwala district and infection is associated with sex, marital status and sharing water sources among neighbors. Community sensitization is required to create awareness and reduce human exposure to Cryptosporidium infection.

Use of the bivalve Dreissena polymorpha as a biomonitoring tool to reflect the protozoan load in freshwater bodies

Cryptosporidium parvum, Toxoplasma gondii and Giardia duodenalis are worldwide pathogenic protozoa recognized as major causal agents of waterborne disease outbreaks. To overcome the normative process (ISO 15553/2006) limitations of protozoa detection in aquatic systems, we propose to use the zebra mussel (Dreissena polymorpha), a freshwater bivalve mollusc, as a tool for biomonitoring protozoan contamination. Mussels were exposed to three concentrations of C. parvum oocysts, G. duodenalis cysts or T. gondii oocysts for 21 days followed by 21 days of depuration in clear water. D. polymorpha accumulated protozoa in its tissues and haemolymph. Concerning T. gondii and G. duodenalis, the percentage of protozoa positive mussels reflected the contamination level in water bodies. As for C. parvum detection, oocysts did accumulate in mussel tissues and haemolymph, but in small quantities, and the limit of detection was high (between 50 and 100 oocysts). Low levels of T. gondii (1-5 oocysts/mussel) and G. duodenalis (less than 1 cyst/mussel) were quantified in D. polymorpha tissues. The ability of zebra mussels to reflect contamination by the three protozoa for weeks after the contamination event makes them a good integrative matrix for the biomonitoring of aquatic ecosystems.

More Than Half Prevalence of Protozoan Parasitic Infections Among Diarrheic Outpatients in Eastern Tigrai, Ethiopia, 2019; A Cross-Sectional Study

Background

Protozoan infections remain a major public health concern in Ethiopia, which causes malnutrition, protein and iron deficiencies, increment of health costs, hospitalization and long-term deleterious effects. In Tigrai, particularly, in the study area, there are limited literatures on the prevalence of protozoa and associated factors among diarrheic outpatients. Thus, aimed to determine the prevalence and associated factors of protozoan infections among diarrheic outpatients in Eastern Tigrai.

Methods

Health facility-based cross-sectional study was conducted in Eastern Tigrai, Ethiopia from April to October 2019 among diarrheic outpatient in health facilities of Adigrat. Four hundred one eighteen study participants were included consecutively. The stool samples were examined via direct wet mount following formal-ether concentration technique. Both interviewer based and self-administrated questionnaires were used to collect demographic data and factors associated with protozoan infections. Data were analyzed and computed using BM SPSS statistics version 22.0. P-value=0.05 at 95% confidence interval declared statistically significant.

Results

Out of 418 diarrheic outpatients, the overall prevalence of protozoan infection was 59.3% (248/418). A higher percentage of intestinal protozoan infection was recorded for females 130 (31.1%). Using well water as a source of drinking, poor hand washing habits before eating, not home latrine, dirty and untrimmed fingernails were the most important risk factors identified. E. histolytica complex and Giardia duodenalis were the most predominant protozoan infections detected among diarrheic outpatients.

Conclusion

The present study showed that diarrheic outpatients in the study area were heavily infected with protozoan parasitic infection. E. histolytica complex and Giardia duodenalis were the most predominant protozoans detected among diarrheic outpatients. Using well water as a source of drinking, poor handwashing habit before eating, not having home latrine, dirty and untrimmed fingernails were most important risk factors identified. So, cooperative action and health education on preventive measure are needed to reduce protozoan infections in Tigrai, particularly in the study area. The present study showed that diarrheic outpatients in the study area were heavily infected with protozoan parasitic infection.

Risk Factors for Sporadic Cryptosporidiosis in the Netherlands: Analysis of a 3-Year Population Based Case-Control Study Coupled With Genotyping, 2013-2016

Background

In 2012, cryptosporidiosis cases increased in the Netherlands, but no single source was identified. In April 2013, we began a 3-year population-based case-control study coupled with genotyping to identify risk factors for sporadic cryptosporidiosis.

Methods

Cryptosporidium cases were laboratory confirmed (by microscopy or polymerase chain reaction), and the species (ie, C. hominis or C. parvum) was determined. We analyzed data by study year, combined and by species. We performed single-variable analysis, and variables with a P value of ≤ .10 were included in a multivariable logistic regression model adjusting for age, sex, and season.

Results

The study included 609 cases and 1548 frequency-matched controls. C. parvum was the predominant species in the first 2 study years, shifting to C. hominis in the third year. Household person-to-person transmission and eating barbequed food were strongly associated with being a case. Eating tomatoes was negatively associated. When the analysis was stratified by study year, person-to-person transmission was an independent risk factor. Analysis by species identified different risk factors for cases infected with C. parvum and C. hominis.

Conclusion

This was the first case-control study examining risk factors for sporadic cryptosporidiosis in the Netherlands. Providing information about Cryptosporidium exposure during outdoor activities and improvements in hygiene within households could prevent future sporadic infections.

SODIUM BICARBONATE REMEDIATION OF ANTHROPOGENIC CONTAMINATION OF WATER AT THE GBNERR IN MISSISSIPPI

Grand Bay National Estuarine Research Reserve (GBNERR) is an important ecosystem in the Mississippi Gulf Coast. The GBNERR may be a potential source for contamination with anthropogenic bacterial pathogens that may play a significant role in the causation of waterborne human diseases. The objective of this study was to evaluate the interaction of physicochemical and microbiological water quality parameters at the GBNERR, determine quantitative levels and establish the potential for remediation of post-contamination of water and seafood by human fecal pollution from anthropogenic sources at the reserve. Water samples were collected aseptically from Bayous Heron, Cumbest, Point Aux Chenes Bay and Bangs Lake (Pine-O-Pine). Physicochemical parameters were determined using standard protocols. Eight bacterial species including Campylobacter were concentrated from water samples by membrane filtration. Water samples were tested for the presence of traditional indicator microorganisms including: heterotrophic (HPC), total coliforms (TC), fecal coliforms (FC) and enterococcus (ENT) in CFU/ml concentrations. Mean values of temperature, specific conductivity, dissolved oxygen and pH were within acceptable levels in comparison to MDEQ, USEPA and the USGS standards during the time of investigation. However, the values of turbidity in Grand Bay water exceeded USEPA recommended levels in several occasions during the investigation. Data from this study indicates significant variability (p < 0.0001) in mean bacteria concentrations between sites. The data also indicates significant impact of Sodium bicarbonate treatment in the remediation of post contamination and survival of pathogens from the GBNERR Bayous Heron, Cumbest and Pine-O-Pine when compared with control findings. The interaction of physicochemical and microbiological parameters of water through external chemical manipulation by Sodium bicarbonate may provide utility in the remediation of post-contamination with anthropogenic pathogens such as E. coli, Enterococci, Campylobacter, Vibrio, Giardia and Cryptosporidium. Presence of high numbers of indicator bacteria suggest public health concerns for oyster and shellfish consumers as well as other water contact activities. Hence, control strategies should be developed and implemented to prevent or remediate any future contamination of the GBNERR waters citing the economic impact of such contamination on shell fish fishing activities at the reserve.

Involvement of Cryptosporidium parvum Cdg7_FLc_1000 RNA in the Attenuation of Intestinal Epithelial Cell Migration via Trans-Suppression of Host Cell SMPD3

Intestinal infection by Cryptosporidium parvum causes inhibition of epithelial turnover, but underlying mechanisms are unclear. Previous studies demonstrate that a panel of parasite RNA transcripts of low protein-coding potential are delivered into infected epithelial cells. Using in vitro and in vivo models of intestinal cryptosporidiosis, we report here that host delivery of parasite Cdg7_FLc_1000 RNA results in inhibition of epithelial cell migration through suppression of the gene encoding sphingomyelinase 3 (SMPD3). Delivery of Cdg7_FLc_1000 into infected cells promotes the histone methyltransferase G9a-mediated H3K9 methylation in the SMPD3 locus. The DNA-binding transcriptional repressor, PR domain zinc finger protein 1, is required for the assembly of Cdg7_FLc_1000 into the G9a complex and associated with the enrichment of H3K9 methylation at the gene locus. Pathologically, nuclear transfer of Cryptosporidium parvum Cdg7_FLc_1000 RNA is involved in the attenuation of intestinal epithelial cell migration via trans-suppression of host cell SMPD3.

Toxoplasma gondii and Other Zoonotic Protozoans in Mediterranean Mussel ( Mytilus galloprovincialis) and Blue Mussel ( Mytilus edulis): A Food Safety Concern?

Mediterranean mussels ( Mytilus galloprovincialis) and blue mussels ( Mytilus edulis) are among the most consumed fishery products, but they are frequent vehicles of foodborne infection worldwide. In this study, we investigated the occurrence and seasonality of zoonotic protozoans in mussels farmed or sold at retail outlets in Italy. We collected and tested 1,440 M. galloprovincialis and 180 M. edulis. Pooled samples were molecularly tested for Giardia duodenalis, Cryptosporidium spp., and Toxoplasma gondii and then sequenced. Sixty-two (45.9%; 95% confidence interval, 37.5 to 54.3%) mussel pools tested positive for one or more of the investigated pathogens. Both Mytilus species and samples from all the investigated areas harbored pathogens. Mussels were statistically more contaminated by Cryptosporidium spp., followed by T. gondii and G. duodenalis assemblage A, and M. galloprovincialis was more contaminated than M. edulis ( P < 0.01). Contamination was more likely in mussels at retail outlets ( P < 0.05) than in those from farms and in mussels collected in spring ( P < 0.01) than in other seasons. This is the first report of T. gondii found in M. galloprovincialis in Italy and in M. edulis in Europe. The detection of zoonotic protozoans in a widely consumed food source indicates the need for a more detailed microbiological risk analysis, especially considering that bivalve mollusks are often consumed raw worldwide.

Anthroponotic transmission of Cryptosporidium parvum predominates in countries with poorer sanitation: a systematic review and meta-analysis

Background

Globally cryptosporidiosis is one of the commonest causes of mortality in children under 24 months old and may be associated with important longterm health effects. Whilst most strains of Cryptosporidium parvum are zoonotic, C. parvum IIc is almost certainly anthroponotic. The global distribution of this potentially important emerging infection is not clear.

Methods

We conducted a systematic review of papers identifying the subtype distribution of C. parvum infections globally. We searched PubMed and Scopus using the following key terms Cryptospor* AND parvum AND (genotyp* OR subtyp* OR gp60). Studies were eligible for inclusion if they had found C. parvum within their human study population and had subtyped some or all of these samples using standard gp60 subtyping. Pooled analyses of the proportion of strains being of the IIc subtype were determined using StatsDirect. Meta-regression analyses were run to determine any association between the relative prevalence of IIc and Gross Domestic Product, proportion of the population with access to improved drinking water and improved sanitation.

Results

From an initial 843 studies, 85 were included in further analysis. Cryptosporidium parvum IIc was found in 43 of these 85 studies. Across all studies the pooled estimate of relative prevalence of IIc was 19.0% (95% CI: 12.9–25.9%), but there was substantial heterogeneity. In a meta-regression analysis, the relative proportion of all C. parvum infections being IIc decreased as the percentage of the population with access to improved sanitation increased and was some 3.4 times higher in those studies focussing on HIV-positive indivduals.

Conclusions

The anthroponotic C. parvum IIc predominates primarily in lower-income countries with poor sanitation and in HIV-positive individuals. Given the apparent enhanced post-infectious virulence of the other main anthroponotic species of Cryptosporidium (C. hominis), it is important to learn about the impact of this subtype on human health.

Electronic supplementary material

The online version of this article (10.1186/s13071-018-3263-0) contains supplementary material, which is available to authorized users.

CALCIUM OXIDE REMEDIATION OF ANTHROPOGENIC CONTAMINATION OF WATER AT THE GBNERR IN MISSISSIPPI

Grand Bay National Estuarine Research Reserve (GBNERR) is an important ecosystem in the Mississippi Gulf Coast. The GBNERR may be a potential source for contamination with anthropogenic bacterial pathogens that may play a significant role in the causation of waterborne human diseases. The objective of this study was to evaluate the interaction of physicochemical and microbiological water quality parameters at the GBNERR, determine quantitative levels and establish the potential for remediation of post-contamination of water and seafood by human fecal pollution from anthropogenic sources at the reserve. Water samples were collected aseptically from Bayous Heron, Cumbest, Point Aux Chenes Bay and Bangs Lake (Pine-O-Pine). Physicochemical parameters were determined using standard protocols. Eight bacteria/parasitic species including Cryptosporidium were concentrated from water samples by membrane filtration. Water samples were tested for the presence of traditional indicator microorganisms including: heterotrophic (HPC), total coliforms (TC), fecal coliforms (FC) and enterococcus (ENT) in CFU/ml concentrations. Mean values of temperature, specific conductivity, dissolved oxygen and pH were within acceptable levels in comparison to MDEQ, USEPA and the USGS standards during the time of investigation. However, the values of turbidity in Grand Bay water exceeded USEPA recommended levels in several occasions during the investigation. Data from this study indicates significant variability (p < 0.0001) in mean bacteria concentrations between sites. The data also indicates significant impact of Calcium oxide treatment in the remediation of post contamination and survival of pathogens from the GBNERR Bayous Heron, Cumbest and Pine-O-Pine when compared with control findings. The interaction of physicochemical and microbiological parameters of water through external chemical manipulation by Calcium oxide may provide utility in the remediation of post-contamination with anthropogenic pathogens such as E. coli, Enterococci, Campylobacter, Vibrio, Giardia and Cryptosporidium. Presence of high numbers of indicator bacteria suggest public health concerns for oyster and shellfish consumers as well as other water contact activities. Hence, control strategies should be developed and implemented to prevent or remediate any future contamination of the GBNERR waters citing the economic impact of such contamination on shell fish fishing activities on the reserve.

Community-based surveillance of Cryptosporidium in the indigenous community of Boliwong, Philippines: from April to December 2017

OBJECTIVES

For the first time, Boliwong, an indigenous community in the Philippines, was surveyed for the prevalence of Cryptosporidium from April to December 2017.

METHODS

Cryptosporidium oocysts were detected in samples from the river, creek, and water pumps via immunomagnetic separation techniques, and from human and animal concentrated faecal samples using the modified Ziehl-Neelsen technique.

RESULTS

Seven of the 24 water samples (29.2%) were positive for Cryptosporidium, with the highest concentration (0.8 oocyst/L) detected in the creek. Of 35 fecal samples from different animal groups, 8 (21.6%) were positive for Cryptosporidium oocysts. The highest intensity of oocyst shedding was detected in dogs (χ² =8.00). Of the 137 human fecal samples, 39 (28.5%) were infected with Cryptosporidium. In this study, 3 risk factors were found to be associated with infection: (1) location (crude odds ratio [cOR], 16.39; 95% confidence interval [CI], 2.11 to 127.41; p=0.008), (2) drinking water from the natural spring (cOR, 0.29; 95% CI, 0.11 to 0.82; p<0.05), and (3) using an open pit as a sanitary toilet facility (cOR, 2.44; 95% CI, 1.14 to 5.20; p<0.05). When the cOR was adjusted, using an open pit as a sanitary toilet facility remained a significant risk factor of infection (adjusted OR, 0.41; 95% CI, 0.19 to 0.90; p<0.05).

CONCLUSIONS

There is a potentially emerging Cryptosporidium zoonosis in Boliwong, Lagawe, Philippines. It is recommended that the toilet facilities and the water system in the community be rehabilitated to avoid any possible disease outbreak. Health education is also needed in the community to maintain proper hygiene and sanitation practices.

Socio-Behavioral Risk Factors Associated with Cryptosporidiosis in HIV/AIDS Patients Visiting the HIV Referral Clinic at Cape Coast Teaching Hospital, Ghana

Objective:

To identify the socio-behavioral risk factors associated with cryptosporidiosis among HIV/AIDS patients with chronic diarrhea symptoms visiting the HIV referral clinic at Cape Coast Teaching Hospital, Ghana.

Methods:

A cross-sectional study was conducted among 50 HIV/AIDS patients with recurrent diarrhea. Questionnaires were administered to collect social and behavioral risk factors associated with Cryptosporidium and other opportunistic protozoan parasitic infections in HIV patients. Stool samples were collected for the diagnosis of enteric protozoan pathogens using modified Ziehl-Neelsen and acid-fast staining methods. CD4⁺ cells counts of study subjects were obtained from patients clinical records. The data obtained were analyzed using Pearson chi-square and multivariate-adjusted statistics tool on SPSS 16 for Windows.

Results:

Twenty-seven (54%) of the subjects were infected with enteric protozoan pathogens. The prevalences of Cryptosporidium, Cyclospora and Microsporidium infections were 46%, 32% and 16%, respectively. Cryptosporidium infection was significantly associated with drinking water (ײ=13.528, p<0.001), Cyclospora was associated with the type of drinking water (ײ=14.931, p<0.001) and toilet facilities used by the study subjects (ײ=12.463, p<0.01), whiles Microsporidium infection was associated with hand washing behavior (ײ=12.463, p<0.01). Enteric protozoans were frequently encountered among subjects with CD4+ T-cell count <200 cells/mm³. However, coinfection of Cyclospora spp & Cryptosporidium spp was not observed in CD4⁺ cell count <200 and >500 cells/mm^3. Multivariate analysis showed that the risk factor for Cryptosporidium infection among HIV/AIDS patients was the source of drinking water (pipe borne water 76.2% prevalence: sachet water 25%; OR=0.10, 95%CI: 0.03-0.39, p<0.001).

Conclusion:

We report the risk factor for exposure of Cryptosporidium infection among HIV/AIDS patients for the first time in Ghana. The contamination of drinking water by protozoan parasites should be a public health concern. These results provide the stepping block to understand the transmission dynamics of Cryptosporidium and other opportunistic pathogens in HIV/AIDS infected patients in Ghana.

A review of wildlife tourism and meta-analysis of parasitism in Africa's national parks and game reserves

The recent increase of parasitic diseases associated with wildlife tourism can be traced to human contact with wildlife and intense modification of wildlife habitat. The continental estimates of parasitic diseases among visited wildlife-tourists and mammalian wildlife present in conservation areas are lacking; therefore, a general review was necessary to provide insights into Africa's parasitic disease burden and transmission between humans and wildlife. A two-step analysis was conducted with searches in Ovid MEDLINE, EMBASE, PubMed, Web of Science and Global Health. All diseases reported without prevalence were grouped and analysed as categorical data while meta-analysis of prevalence rates of parasitic diseases in wildlife from national parks and reserves in Africa was conducted. Only 4.7% of the tourist centres reported routine wildlife diagnosis for parasitic diseases. Disease intensity shows that cryptosporidiosis and seven other parasitic diseases were observed in both human and wildlife; however, no significant difference in intensity between human and wildlife hosts was observed. Schistosomiasis intensity reports showed a significant increase (P < 0.05) while entamoebiasis showed a significant decrease (P < 0.05) in humans as compared to wildlife. Visiting tourists were more infected with malaria, while wildlife was more infected with parasitic gastroenteritis (PGE). The meta-analysis of wildlife revealed the highest prevalence of PGE with mixed parasites and lowest prevalence of Giardia spp. at 99.9 and 5.7%, respectively. The zoonotic and socioeconomic impact of some of these parasites could pose a severe public threat to tourism. Pre- and post-travel clinical examinations are important for tourists while routine examination, treatment and rational surveillance are important for these animals to improve wildlife tourism.

Risk factors for Cryptosporidium infection in low and middle income countries: A systematic review and meta-analysis

BACKGROUND

Cryptosporidium infection causes gastrointestinal disease and has a worldwide distribution. The highest burden is in developing countries.

OBJECTIVES

We sought to conduct a systematic review and meta-analysis to identify Cryptosporidium risk factors in Low and Middle Income countries (LMICs).

METHODS

Medline Ovid and Scopus databases were searched with no restriction on year or language of publication. All references were screened independently in duplicate and were included if they presented data on at least 3 risk factors. Meta-analyses using random effects models were used to calculate overall estimates for each exposure.

RESULTS

The most frequently reported risk factors in the 15 included studies were overcrowding, household diarrhoea, poor quality drinking water, animal contact, open defecation/ lack of toilet and breastfeeding. The combined odds ratio for animal contact was 1.98 (95%CI: 1.11-3.54) based on 11 studies and for diarrhoea in the household 1.98 (95%CI: 1.13-3.49) based on 4 studies. Open defecation was associated with a pooled odds ratio of 1.82 (95%CI: 1.19-2.8) based on 5 studies. Poor drinking water quality was not associated with a significant Cryptosporidium risk, odds ratio 1.06 (95%CI: 0.77-1.47). Breastfeeding was protective with pooled odds ratio 0.4 (95%CI: 0.13-1.22), which was not statistically significant.

CONCLUSIONS

Based on the included studies, crowded living conditions, animal contact and open defecation are responsible for the majority of Cryptosporidium cases in LMICs. Future studies investigating Cryptosporidium risk factors should have a good study design and duration, include appropriate number of cases, select suitable controls, investigate multiple relevant risk factors, fully report data and perform multivariate analysis.

Selection and evaluation of housekeeping genes as endogenous controls for quantification of mRNA transcripts in Theileria parva using quantitative real-time polymerase chain reaction (qPCR)

The reliability of any quantitative real-time polymerase chain reaction (qPCR) experiment can be seriously compromised by variations between samples as well as between PCR runs. This usually result from errors in sample quantification, especially with samples that are obtained from different individuals and tissues and have been collected at various time intervals. Errors also arise from differences in qPCR efficiency between assays performed simultaneously to target multiple genes on the same plate. Consequently, the derived quantitative data for the target genes become distorted. To avoid this grievous error, an endogenous control, with relatively constant transcription levels in the target individual or tissue, is included in the qPCR assay to normalize target gene expression levels in the analysis. Several housekeeping genes (HKGs) have been used as endogenous controls in quantification studies of mRNA transcripts; however, there is no record in the literature of the evaluation of these genes for the tick-borne protozoan parasite, Theileria parva. Importantly, the expression of these genes should be invariable between different T. parva stocks, ideally under different experimental conditions, to gain extensive application in gene expression studies of this parasite. Thus, the expression of several widely used HKGs was evaluated in this study, including the genes encoding β-actin, glyceraldehyde-3-phosphate dehydrogenase (GAPDH), 28S rRNA, cytochrome b and fructose-2.6-biphosphate aldolase (F6P) proteins. The qPCR analysis revealed that the expression of genes encoding cytochrome b, F6P and GAPDH varied considerably between the two T. parva stocks investigated, the cattle-derived T. parva Muguga and the buffalo-derived T. parva 7014. 28S rRNA and β-actin gene expression was the most stable; thus, these genes were considered suitable candidates to be used as endogenous control genes for mRNA quantification studies in T. parva.