-
Clinical Microbiology Reviews Jan 2013Cryptosporidium is a protozoan parasite of medical and veterinary importance that causes gastroenteritis in a variety of vertebrate hosts. Several studies have reported... (Review)
Review
Cryptosporidium is a protozoan parasite of medical and veterinary importance that causes gastroenteritis in a variety of vertebrate hosts. Several studies have reported different degrees of pathogenicity and virulence among Cryptosporidium species and isolates of the same species as well as evidence of variation in host susceptibility to infection. The identification and validation of Cryptosporidium virulence factors have been hindered by the renowned difficulties pertaining to the in vitro culture and genetic manipulation of this parasite. Nevertheless, substantial progress has been made in identifying putative virulence factors for Cryptosporidium. This progress has been accelerated since the publication of the Cryptosporidium parvum and C. hominis genomes, with the characterization of over 25 putative virulence factors identified by using a variety of immunological and molecular techniques and which are proposed to be involved in aspects of host-pathogen interactions from adhesion and locomotion to invasion and proliferation. Progress has also been made in the contribution of host factors that are associated with variations in both the severity and risk of infection. Here we provide a review comprised of the current state of knowledge on Cryptosporidium infectivity, pathogenesis, and transmissibility in light of our contemporary understanding of microbial virulence.
Topics: Animals; Cryptosporidiosis; Cryptosporidium; Gastroenteritis; Host-Pathogen Interactions; Humans; Virulence; Virulence Factors
PubMed: 23297262
DOI: 10.1128/CMR.00076-12 -
The Lancet. Infectious Diseases Jan 2015Cryptosporidium spp are well recognised as causes of diarrhoeal disease during waterborne epidemics and in immunocompromised hosts. Studies have also drawn attention to... (Review)
Review
Cryptosporidium spp are well recognised as causes of diarrhoeal disease during waterborne epidemics and in immunocompromised hosts. Studies have also drawn attention to an underestimated global burden and suggest major gaps in optimum diagnosis, treatment, and immunisation. Cryptosporidiosis is increasingly identified as an important cause of morbidity and mortality worldwide. Studies in low-resource settings and high-income countries have confirmed the importance of cryptosporidium as a cause of diarrhoea and childhood malnutrition. Diagnostic tests for cryptosporidium infection are suboptimum, necessitating specialised tests that are often insensitive. Antigen-detection and PCR improve sensitivity, and multiplexed antigen detection and molecular assays are underused. Therapy has some effect in healthy hosts and no proven efficacy in patients with AIDS. Use of cryptosporidium genomes has helped to identify promising therapeutic targets, and drugs are in development, but methods to assess the efficacy in vitro and in animals are not well standardised. Partial immunity after exposure suggests the potential for successful vaccines, and several are in development; however, surrogates of protection are not well defined. Improved methods for propagation and genetic manipulation of the organism would be significant advances.
Topics: Antiprotozoal Agents; Cryptosporidiosis; Diagnostic Tests, Routine; Diarrhea; Global Health; Humans; Protozoan Vaccines
PubMed: 25278220
DOI: 10.1016/S1473-3099(14)70772-8 -
Clinical Microbiology Reviews Jul 1991Before 1982, only eight case reports of human cryptosporidiosis and fewer than 30 papers on Cryptosporidium spp. appeared in the biomedical literature. At that time,... (Review)
Review
Before 1982, only eight case reports of human cryptosporidiosis and fewer than 30 papers on Cryptosporidium spp. appeared in the biomedical literature. At that time, cryptosporidiosis was thought to be an infrequent infection in animals and rarely an opportunistic infection in humans. The concept of Cryptosporidium spp. as pathogens has changed dramatically within the past 8 years because of improved diagnostic techniques, increased awareness within the biomedical community, and the development of basic research programs in numerous laboratories. Presently, greater than 1,000 publications including over 400 case reports in the biomedical literature address Cryptosporidium spp. and cryptosporidiosis. Cryptosporidium parvum is now thought to be one of the three most common enteropathogens causing diarrheal illness in humans worldwide, especially in developing countries. It is likely that cryptosporidiosis was previously included in the 25 to 35% of diarrheal illness with unknown etiology. Because of the severity and length of diarrheal illness and because no effective therapy has been identified, cryptosporidiosis is one of the most ominous infections associated with AIDS. The role of C. parvum as an enteropathogen is well established; documentation of its role as a cause of hepatobiliary and respiratory diseases is now appearing in the literature. Our present understanding of the natural history, epidemiology, biology, and immunology of Cryptosporidium spp. as well as the clinical features, pathogenicity, and treatment of cryptosporidiosis are reviewed here.
Topics: Animals; Cryptosporidiosis; Cryptosporidium; Humans
PubMed: 1889046
DOI: 10.1128/CMR.4.3.325 -
Current Biology : CB Mar 2018The apicomplexan parasite Cryptosporidium parvum is the second leading cause of death in children due to diarrheal disease worldwide. Gibson and Striepen offer insights... (Review)
Review
The apicomplexan parasite Cryptosporidium parvum is the second leading cause of death in children due to diarrheal disease worldwide. Gibson and Striepen offer insights into the fascinating biology of this poorly understood parasite, and describe new strategies aimed at defeating it.
Topics: Cryptosporidiosis; Cryptosporidium; Humans
PubMed: 29510102
DOI: 10.1016/j.cub.2017.11.070 -
Clinical Microbiology and Infection :... Jun 2016Cryptosporidium has emerged as a significant cause of diarrhoeal disease worldwide, with severe health consequences for very young, malnourished children living in... (Review)
Review
Cryptosporidium has emerged as a significant cause of diarrhoeal disease worldwide, with severe health consequences for very young, malnourished children living in endemic areas and for individuals with highly impaired T-cell functions. In Europe, as elsewhere, the burden of disease has been difficult to measure as a result of the lack of appropriate, standardized surveillance and monitoring systems. The recent occurrence of large water- and foodborne outbreaks in several EU countries, as well as the results of many surveys of human and animal cryptosporidiosis, indicate that this parasite is widespread. Specific subtypes of the zoonotic Cryptosporidium parvum and the anthroponotic C. hominis are responsible for the majority of human cases in Europe. No treatment is currently available to clear the infection, but recent progress in genetic engineering of the parasite, coupled with advances in genomics, have opened important avenues for future research. Here we explore the possible reasons for underascertainment of cryptosporidiosis and the importance of accurate diagnosis in clinical management, the epidemiology of human cryptosporidiosis and key messages from recent outbreaks to highlight important interventions and emerging public health issues.
Topics: Cryptosporidiosis; Cryptosporidium; Disease Outbreaks; Europe; Genotype; Humans; Prevalence
PubMed: 27172805
DOI: 10.1016/j.cmi.2016.04.021 -
Eastern Mediterranean Health Journal =... Dec 2020Cryptosporidium is a waterborne intestinal parasite that causes diarrhoea in low and middle-income countries worldwide. Reports from Mediterranean countries have... (Review)
Review
BACKGROUND
Cryptosporidium is a waterborne intestinal parasite that causes diarrhoea in low and middle-income countries worldwide. Reports from Mediterranean countries have documented the prevalence of cryptosporidiosis in children at various ages, also among cancer patients, and in cases of chronic kidney disease, haemodialysis, and organ transplant. Untill now, modified-acid staining preceded by stool concentration preparation remains the leading screening diagnostic test for the infection. In Jordan, few studies for cryptosporidiosis have been performed during the last 3 decades.
AIMS
This paper reviewed the status of cryptosporidiosis in Jordan and tracked recent updates for this emerging protozoal infection among different population groups.
METHODS
In this study, an online search was conducted on Google Scholar and PubMed databases using the keywords: Jordan, cryptosporidiosis and Cryptosporidium to inspect studies done on this parasite in Jordan.
RESULTS
Only 9 articles were identified from 1994 to 2019. These were analysed in terms of population group, demography, clinical history and the diagnostic tools used.
CONCLUSION
Cryptosporidiosis is still neglected in Jordan as indicated by the low number of studies over the last 3 decades and the prevalence is diverse depending on the diagnostic test used and socioeconomic status.
Topics: Child; Cryptosporidiosis; Cryptosporidium; Diarrhea; Feces; Humans; Jordan; Prevalence
PubMed: 33355397
DOI: 10.26719/emhj.20.065 -
Advances in Parasitology 1988In this review I have examined the vast literature which has accumulated on Cryptosporidium, particularly in the past 3 years, in an attempt to highlight areas in which... (Review)
Review
In this review I have examined the vast literature which has accumulated on Cryptosporidium, particularly in the past 3 years, in an attempt to highlight areas in which progress has been made in relation to the organism and the disease, and to indicate areas in which knowledge is still lacking. Since 1982, a global effort by scientists and clinicians has been directed towards determining the nature of the disease in humans and the relative contribution of cryptosporidiosis to gastroenteritis. From published data, the incidence of diarrhoea is 1-5% in most developed countries, and 4-7% in less developed countries, when measured throughout the year and in all age groups. The frequency of cryptosporidiosis is highest in children aged between 6 months and 3 years, and in particular locations (e.g., day-care centres) and at particular times of the year. Although susceptibility to infection is life-long, one suspects that the lower prevalence among older children and adults is due to immunity acquired from frequent exposure. Other important factors contributing to higher prevalence are the season--it is more frequent in a wet, warm climate--association with travel to particular destinations, poor hygiene, intimate contact with certain animals, and congregation of large numbers of young previously unexposed children in day-care centres. The association between cryptosporidiosis and giardiasis presumably results from the existence of a common source of infection. The immune status of the host appears to be a major determinant of whether the infection is self-limiting or persistent. It is clear that both branches of the immune system are required for complete recovery, since T-lymphocyte dysfunction or hypogammaglobulinaemia can both lead to persistent illness. Chronic diarrhoea and malabsorption attributed to cryptosporidiosis also occur in the absence of evidence of immune defect. The importance of respiratory tract infection in humans, other than in the terminal stages of chronic illness, requires investigation. The infection has now been identified in all classes of vertebrates; it has been observed in all domestic animals including pets, and a wide range of wildlife including birds. Cryptosporidiosis seems to cause diarrhoea in young ruminants, less frequently in pets. In birds the parasite has been observed in the gastrointestinal tract, without ill effect, and in the respiratory tract, in which clinical symptoms of variable severity have been described. The mucosal response of the gastrointestinal tract to infection appears to vary among mammals and may be the key to the variable clinical manifestations observed.(ABSTRACT TRUNCATED AT 400 WORDS)
Topics: Acquired Immunodeficiency Syndrome; Animals; Cell Line; Coccidia; Cryptosporidiosis; Cryptosporidium; Diarrhea; Humans; Immune Tolerance; Respiratory Tract Infections
PubMed: 3289331
DOI: 10.1016/s0065-308x(08)60353-x -
Veterinary Research Aug 2017Gastrointestinal disease caused by the apicomplexan parasite Cryptosporidium parvum is one of the most important diseases of young ruminant livestock, particularly... (Review)
Review
Gastrointestinal disease caused by the apicomplexan parasite Cryptosporidium parvum is one of the most important diseases of young ruminant livestock, particularly neonatal calves. Infected animals may suffer from profuse watery diarrhoea, dehydration and in severe cases death can occur. At present, effective therapeutic and preventative measures are not available and a better understanding of the host-pathogen interactions is required. Cryptosporidium parvum is also an important zoonotic pathogen causing severe disease in people, with young children being particularly vulnerable. Our knowledge of the immune responses induced by Cryptosporidium parasites in clinically relevant hosts is very limited. This review discusses the impact of bovine cryptosporidiosis and describes how a thorough understanding of the host-pathogen interactions may help to identify novel prevention and control strategies.
Topics: Animals; Cattle; Cattle Diseases; Cryptosporidiosis; Cryptosporidium parvum; Host-Parasite Interactions
PubMed: 28800747
DOI: 10.1186/s13567-017-0447-0 -
PLoS Neglected Tropical Diseases Jun 2022Cryptosporidiosis is a major cause of diarrhoea in young children in low-and-middle-income countries. New interventions should be informed by evidence pertaining to risk...
BACKGROUND
Cryptosporidiosis is a major cause of diarrhoea in young children in low-and-middle-income countries. New interventions should be informed by evidence pertaining to risk factors and their relative importance. Inconsistencies in the literature may to some extent be explained by choice of methodology, furthermore, most previous risk factor studies compared cryptosporidiosis cases to diarrhoea cases of other aetiologies rather than with controls without diarrhoea.
METHODOLOGY/PRINCIPAL FINDINGS
We investigated a broad set of factors in under-2-year-olds presenting with diarrhoea to a hospital and a health center in southwestern Ethiopia. We applied quantitative cut-offs to distinguish between cryptosporidiosis and incidental Cryptosporidium infection or carriage, a hierarchical causal framework to minimize confounding and overadjustment, and a case-case-control design, to describe risk factors for both cryptosporidiosis and non-cryptosporidiosis diarrhoea. Moderate and severe acute malnutrition were strongly associated with both cryptosporidiosis and non-cryptosporidiosis diarrhoea. Previous healthcare attendance and low maternal education were only associated with cryptosporidiosis, whereas unsafe child stool disposal, prematurity and early cessation of exclusive breastfeeding were significantly associated with non-cryptosporidiosis diarrhoea only. By estimation of population attributable fractions, socioeconomic factors-specifically low maternal education-and public tap water use, were apparently more important risk factors for cryptosporidiosis than for non-cryptosporidiosis diarrhoea.
CONCLUSIONS/SIGNIFICANCE
Nutritional management of moderate acute malnutrition may be an effective intervention against cryptosporidiosis, particularly if combined with targeted therapy for cryptosporidiosis which, again, may mitigate nutritional insult. Focused caregiver education in healthcare settings and follow-up of children with acute malnutrition may prevent or improve outcomes of future episodes of cryptosporidiosis.
Topics: Case-Control Studies; Child; Child, Preschool; Cryptosporidiosis; Cryptosporidium; Diarrhea; Ethiopia; Female; Humans; Infant; Malnutrition; Risk Factors
PubMed: 35666717
DOI: 10.1371/journal.pntd.0010508 -
Current Opinion in Infectious Diseases Oct 2012The global significance of cryptosporidiosis is widespread and far-reaching. In this review, we present recent data about strain diversity and the burden of disease,... (Review)
Review
PURPOSE OF REVIEW
The global significance of cryptosporidiosis is widespread and far-reaching. In this review, we present recent data about strain diversity and the burden of disease, along with developments in therapeutic and preventive strategies.
RECENT FINDINGS
Cryptosporidium is an emerging pathogen that disproportionately affects children in developing countries and immunocompromised individuals. Without a diagnostic tool amenable for use in developing countries, the burden of infection and its relationship to growth faltering, malnutrition, and diarrheal mortality remain underappreciated. Disease incidence is also increasing in industrialized countries largely as a result of outbreaks in recreational water facilities. Advances in molecular methods, including subtyping analysis, have yielded new insights into the epidemiology of cryptosporidiosis. However, without practical point-of-care diagnostics, an effective treatment for immunocompromised patients, and a promising vaccine candidate, the ability to reduce the burden of disease in the near future is limited. This is compounded by inadequate coverage with antiretroviral therapy in developing countries, the only current means of managing HIV-infected patients with cryptosporidiosis.
SUMMARY
Cryptosporidiosis is one of the most important diarrheal pathogens affecting people worldwide. Effective methods to control and treat cryptosporidiosis among high-risk groups present an ongoing problem in need of attention.
Topics: Antigens, Protozoan; Antiparasitic Agents; Cost of Illness; Cryptosporidiosis; Cryptosporidium; Developed Countries; Developing Countries; Global Health; Humans
PubMed: 22907279
DOI: 10.1097/QCO.0b013e328357e569