Cryptosporidiosis in people: it's not just about the cows

Enteric protozoal infections in camels: Etiology, epidemiology, and future perspectives

Camels have great potential as a safety valve for current and future food security for pastoralists, agropastoralists, and urban populations. Enteric protozoal diseases are important causes of economic losses in camels; however, they are poorly concerned globally. The most common members of enteric protozoa are Balantidium, Eimeria, Giardia, and Cryptosporidium. Some of them threaten human health as humans can be infected by consuming food or water contaminated with camel feces, particularly in poor communities with inadequate sanitation and low-quality healthcare facilities. For these reasons, a comprehensive and careful investigation was conducted on some enteric protozoal diseases of camels to present an updated insight into the etiology, epidemiology, and future trends in diagnosing and controlling camel enteric protozoa. Future studies on the camel enteric protozoa should be carried out to develop advanced diagnostic approaches in diverse farm animal species. Moreover, the protozoan zoonotic potential should be considered to secure human health.

Prevalence, risk factor and diversity of Cryptosporidium in cattle in Latvia

The epidemiology of Cryptosporidium spp. in Latvia was investigated by testing fecal samples from 926 animals aged from one day to 24 years for the presence of Cryptosporidium spp. oocysts. The samples were collected from 87 cattle farms and from four slaughterhouses, and analyzed by conventional and fluorescent microscopy, followed by Cryptosporidium species and C. parvum subtype differentiation. Moreover, using a questionnaire, we surveyed factors that could be relevant as risk factors of Cryptosporidium spp. infection on the farms. Cryptosporidium spp. were shed by 33.8% of the investigated cattle and at least one shedding animal was found on 77.8% of the farms. In the present study, all four Cryptosporidium species reported to commonly infect cattle and two additional Cryptosporidium species (C. scrofarum and C. ubiquitum) were identified. In addition, mix infections of C. parvum/C. bovis, C. bovis/C. ryanae, C. parvum/C. ryanae, C. parvum/C. andersoni and C. bovis/C. andersoni were observed. C. parvum and C. bovis was mostly prevalent in young animals (0-3 months old) and in addition, diarrhea associated with C. parvum infection was observed only in very young animals. Cryptosporidium andersoni and C. ryanae in age group 0-3 months was observed in low prevalence, while a higher proportion of animals with diarrhea associated with C. andersoni infection was observed in very young animals and with C. ryanae in animals age group 4-24 months. Eight previously described C. parvum subtypes were observed. The majority of the subtypes were in the IIa subtype family, while one subtype was identified from the IId subtype family. The most common subtype was IIaA15G2R1, which was found in 34.2% of the C. parvum successfully subtyped samples. The probability of Cryptosporidium spp. associated diarrhea in cattle decreased significantly with the age of the animals and a prolonged period during which calves were fed with milk.

An annotated checklist of the eukaryotic parasites of humans, exclusive of fungi and algae

The classification of "parasites" in the medical field is a challenging notion, a group which historically has included all eukaryotes exclusive of fungi that invade and derive resources from the human host. Since antiquity, humans have been identifying and documenting parasitic infections, and this collective catalog of parasitic agents has expanded considerably with technology. As our understanding of species boundaries and the use of molecular tools has evolved, so has our concept of the taxonomy of human parasites. Consequently, new species have been recognized while others have been relegated to synonyms. On the other hand, the decline of expertise in classical parasitology and limited curricula have led to a loss of awareness of many rarely encountered species. Here, we provide a comprehensive checklist of all reported eukaryotic organisms (excluding fungi and allied taxa) parasitizing humans resulting in 274 genus-group taxa and 848 species-group taxa. For each species, or genus where indicated, a concise summary of geographic distribution, natural hosts, route of transmission and site within human host, and vectored pathogens are presented. Ubiquitous, human-adapted species as well as very rare, incidental zoonotic organisms are discussed in this annotated checklist. We also provide a list of 79 excluded genera and species that have been previously reported as human parasites but are not believed to be true human parasites or represent misidentifications or taxonomic changes.

Prevalence and multilocus genotyping of Cryptosporidium spp. in cattle in Jiangxi Province, southeastern China

Cryptosporidium is a genus of single-celled protozoa, infecting a wide range of animals and humans. Although Cryptosporidium infections of cattle have been reported in some provinces in China, there is no available information on the prevalence and predominant species of Cryptosporidium in cattle in Jiangxi province. To investigate the prevalence of Cryptosporidium in cattle in Jiangxi province of China, 556 fecal samples were collected from eight farms in four cities and the SSU rRNA locus of Cryptosporidium was amplified from the DNA of each fecal sample by PCR. The overall prevalence of Cryptosporidium was 12.8% (71/556) in cattle in Jiangxi province, with 24.3% (54/222) in Nanchang city, 7.8% (13/166) in Gao'an city, 3.7% (4/108) in Xinyu city, and 0.0% (0/60) in Ji'an city. The differences of the prevalence rates by region, breed, and age groups were statistically significant. All positive PCR products of Cryptosporidium were successfully sequenced and identified as three Cryptosporidium species, namely Cryptosporidium bovis (1/556, 0.18%), Cryptosporidium ryanae (7/556, 1.3%), and Cryptosporidium andersoni (63/556, 11.3%). Furthermore, 36 C. andersoni isolates were successfully classified into three MLST (multilocus sequence typing) subtypes based on four genetic loci (MS1, MS2, MS3, and MS16). The predominant MLST subtype was A4, A4, A4, A1 (n = 30). These findings not only revealed the prevalence and predominant species of Cryptosporidium in cattle in Jiangxi province, but also provided a baseline for studying the genetic structure of C. andersoni, offering a novel resource for better understanding of the epidemiology of Cryptosporidium infection in cattle in Jiangxi province, southeastern China.

A Cryptosporidium parvum genotype shift between week old and two week old calves following administration of a prophylactic antiprotozoal

This study looked to assess the stability of Cryptosporidium parvum genotypes in calves between the final day of treatment with the antiprotozoal halofuginone lactate and seven days post-treatment. Paired faecal samples were collected on the final day of treatment and seven days later from 54 calves across seven farms in South-west England. The presence of Cryptosporidium species was detected using polymerase chain reaction targeting the 18 s rDNA. The presence and genotype of C. parvum was determined by PCR and amplicon sequencing targeting the gp60 locus. On farms where C. parvum was detected at both sampling times there was a distinct genotype shift. Detection of gp60 genotype IIaA15G2R1 decreased from 40% to 7% while IIaA17G1R1 increased from 0% to 41%, supplemented by IIaA16G3R1 in one sample. A shift in C. parvum genotypes present in calves within a one week sampling timeframe has not been described prior to this study, indicating that the timeframe is likely suitable for observing variation in C. parvum populations and interactions with antiprotozoal control strategies.

Molecular epidemiology of Cryptosporidium spp. in calves in Estonia: high prevalence of Cryptosporidium parvum shedding and 10 subtypes identified

We investigated the molecular epidemiology of Cryptosporidium spp. in Estonia by testing fecal samples from 486 calves aged <2 months, raised on 53 cattle farms, for the presence of Cryptosporidium DNA. The parasites were identified and characterized by sequencing of the 18S rRNA gene and of the 60 kDa glycoprotein (gp60) gene. Moreover, using a questionnaire, we surveyed factors that could be relevant for animal-to-human and human-to-animal transmission of Cryptosporidium spp. on the farms. Cryptosporidium spp. were shed by 23% of the investigated calves and at least one shedding calf was found on 66% of the farms. Cryptosporidium parvum was the most common species shed, while C. bovis and C. ryanae were also detected. More than half of the calves aged 8-14 days shed C. parvum. Nine previously described C. parvum subtypes (IIaA14G1R1, IIaA16G1R1, IIaA17G1R1, IIaA18G1R1, IIaA19G1R1, IIaA20G1R1, IIaA21G1R1, IIaA22G1R1 and IIaA16G2R1) and an apparently novel subtype IIlA21R2 were found. Calves from farms that reported spreading manure on fields during spring had 10 times higher odds to shed Cryptosporidium spp. in their feces than calves from farms that did not. Calves aged 8-14 days had higher odds to shed IIa18G1R1 as well as IIaA16G1R1 than younger calves.

Prevalence and risk factors for cryptosporidiosis: a global, emerging, neglected zoonosis

Background

Cryptosporidiosis is a zoonotic disease caused by the important parasitic diarrheal agent Cryptosporidium spp. Cryptosporidiosis occurs in all classes of animals and man with a rapidly expanding host range and increased importance since the occurrence of human immunodeficiency virus/acquired immunodeficiency syndrome in man.

Objectives

To review the global picture of cryptosporidiosis in man and animals with emphasis on prevalence and risk factors.

Methods

Current relevant literature on cryptosporidiosis was reviewed.

Results

Cryptosporidiosis is widely distributed and the risk factors vary from one region to another with hygiene and immune status as important risk factors.

Conclusions

Cryptosporidium spp. associated mortality has not only been reported in immune-compromised patients, but also in immune-competent patients. Yet in many countries not much attention is paid to the control and prevention of this infection in animals and man. The neglect of this disease despite the serious threat it poses to animals, their husbandry, and humans, has led the World Health Organization to list it among globally neglected diseases. To control and prevent this infection more effort needs to be directed at controlling the risk factors of the infection in man and animals.

AVALIAÇÃO DE FATORES EPIDEMIOLÓGICOS E SANITÁRIOS ASSOCIADOS À INFECÇÃO POR Cryptosporidium spp. EM CÃES DOMICILIADOS

Resumo O gênero Cryptosporidium é composto por protozoários com grande capacidade de reprodução e disseminação. Sua transmissão pode ocorrer indiretamente pela ingestão de água e alimentos contaminados com oocistos viáveis ou diretamente entre animais, entre humanos ou entre animais e humanos. Em diversas partes do mundo, animais de companhia tem sido citados como fontes potenciais de infecção por Cryptosporidium spp. O presente estudo teve como objetivo avaliar a ocorrência da infecção por Cryptosporidium spp. em cães domiciliados na cidade do Recife, estado de Pernambuco, Brasil, bem como a associação da infecção com dados epidemiológicos e sanitários. Foram analisadas 97 amostras de fezes de caninos domiciliados, utilizando-se as técnicas de centrífugo-sedimentação em formol-éter com posterior coloração pelo método de Kinyoun. A análise estatística foi realizada por meio dos testes Qui-quadrado de Pearson e Exato de Fisher, com nível de significância de 5,0%. Detectou-se positividade de 31,9% (31/97), tratando-se do primeiro registro de ocorrência da infecção por Cryptosporidium spp. na espécie canina no nordeste brasileiro, verificando-se associação significativa entre a taxa de infecção e a assistência médica veterinária, vacinação recebida e o tipo de ambiente de criação dos cães.

Cryptosporidiosis Drug Discovery: Opportunities and Challenges

The apicomplexan parasite Cryptosporidium is the second most important diarrheal pathogen causing life-threatening diarrhea in children, which is also associated with long-term growth faltering and cognitive deficiency. Cryptosporidiosis is a parasitic disease of public health concern caused by Cryptosporidium parvum and Cryptosporidium hominis. Currently, nitazoxanide is the only approved treatment for cryptosporidium infections. Unfortunately, it has limited efficacy in the most vulnerable patients, thus there is an urgent need for a safe and efficacious cryptosporidiosis drug. In this work, we present our current perspectives on the target product profile for novel cryptosporidiosis therapies and the perceived challenges and possible mitigation plans at different stages in the cryptosporidiosis drug discovery process.

COMPARAÇÃO DA EFICIÊNCIA DAS COLORAÇÕES DE ZIEHL-NEELSEN MODIFICADO E SAFRANINA MODIFICADA NA DETECÇÃO DE OOCISTOS DE Cryptosporidium spp. (EUCOCCIDIORIDA, CRYPTOSPORIDIIDAE) A PARTIR DE AMOSTRAS FECAIS DE BEZERROS DE 0 A 3 MESES

Resumo A criptosporidiose bovina é causada principalmente por quatro espécies distintas: Cryptosporidium parvum, Cryptosporidium bovis, Cryptosporidium ryanae e Cryptosporidium andersoni. A espécie Cryptosporidium parvum (Ordem: Eucoccidiorida, Família: Cryptosporidiidae) é considerada de alto potencial zoonótico, podendo infectar humanos por intermédio da eliminação de oocistos tanto pelos bovinos quanto pelo próprio humano. O objetivo desta pesquisa foi verificar a ocorrência de oocistos de Cryptosporidium spp. em amostras fecais de bezerros (75 machos e 77 fêmeas), tendo sido coletadas 152 amostras de fezes de animais do nascimento até os três meses de idade. O material foi submetido às técnicas de coloração de Ziehl-Neelsen modificado e Safranina modificada, as lâminas foram observadas em toda sua extensão ao microscópio óptico para a verificação da presença de oocistos desta enteroparasitose. Os resultados demonstraram 17,1% (26/152) de positividade no total das amostras examinadas e a análise estatística revelou não haver diferença entre o sexo e as técnicas de coloração utilizadas neste estudo. Conclui-se que a infecção por Cryptosporidium spp. esta presente nas propriedades avaliadas, porém são necessários mais estudos para que o risco de infecção seja mensurado adequadamente e medidas profiláticas implementadas.

Clinical findings and survival in 56 sick neonatal New World camelids

BACKGROUND

Information pertaining to clinical presentation and outcome of neonatal New World camelids (NWC) is limited when compared to calves and foals.

HYPOTHESIS

Values of variables at admission and subsequent treatment would predict survival in sick neonatal NWC.

ANIMALS

Fifty-six client-owned sick neonatal NWC presented over a 10-year period to the Purdue University Veterinary Teaching Hospital.

METHODS

A retrospective study was performed. Inclusion criteria were NWC less than 30 days of age with complete medical records that presented between 2000 and 2010.

RESULTS

The median age at presentation was 1 day (range 1-20). The most common diagnoses were systemic inflammatory response syndrome (50%), congenital defects (41%), ophthalmic lesions (21%), sepsis (16%), and gastrointestinal diseases (16%). Sixty-six percent of NWC survived to discharge. Clinicopathologic findings on admission were variable and not specific for disorders. Factors associated with survival were absence of choanal atresia (P = .001, OR: 55.9 [2.5-1,232]), administration of llama plasma (P = .013, OR: 4.9 [1.4-17.7]), and antimicrobial treatment with trimethoprim-sulfamethoxazole (TMS) (P = .016, OR: 6.5 [1.3-32.2]).

CONCLUSIONS AND CLINICAL IMPORTANCE

The use of antibiotics, particularly TMS, and llama plasma are recommended in sick neonatal NWC. Results from this study could contribute toward defining a NWC-specific sepsis scoring system.

Cryptosporidiosis - an occupational risk and a disregarded disease in Estonia

Background

Cases of cryptosporidiosis have not been officially reported in Estonia after the year 2000, and the disease appears to be either under-diagnosed or under-reported.

Findings

Based on a human case of cryptosporidiosis contracted during faecal sampling in dairy farms, cattle considered to be sources of infection were analysed for Cryptosporidium spp. by a modified Ziehl Neelsen technique and molecular typing. C. parvum subtype IIaA16G1R1 was detected from the human case and from calves from one of nine farms enrolled in the study providing strong circumstantial evidence of zoonotic transmission from calves to humans.

Conclusion

Cryptosporidiosis presents an occupational risk to people with cattle contact, and may also be a risk to the human population in general. Thus increased public and medical awareness is warranted.

Fecal shedding of Cryptosporidium oocysts in healthy alpaca crias and their dams

OBJECTIVE

To determine the apparent prevalence of shedding of Cryptosporidium spp in healthy alpaca crias and their dams on 14 farms in New York and 1 farm in Pennsylvania.

DESIGN

Cross-sectional study.

ANIMALS

110 alpaca crias and their 110 dams.

PROCEDURES

Fecal samples were obtained from 220 alpacas at 14 alpaca farms in New York and 1 farm in Pennsylvania. For each animal, age, sex, and health condition were recorded. A fecal score (1 = normally formed; 2 = soft or loose; 3 = diarrhetic) was recorded for each cria. Cryptosporidium oocysts were identified in fecal samples by a direct immunofluorescence assay.

RESULTS

Apparent prevalence of fecal shedding of Cryptosporidium oocysts was 8% (95% confidence interval, 4% to 15%) in dams and was 7% (95% confidence interval, 3% to 13%) in crias. There was no significant difference in age between dams with positive fecal test results for Cryptosporidium oocysts (median age, 4 years; range, 3 to 8 years) and dams with negative results (median age, 4 years; range, 2.5 to 19 years). No significant difference was found in age between crias with positive fecal test results (median age, 20 days; range, 7 to 53 days) and those with negative results (median, 36 days; range, 2 to 111 days). No significant difference in fecal scores was found between crias with positive versus negative fecal test results.

CONCLUSIONS AND CLINICAL RELEVANCE

A higher than previously reported apparent prevalence of fecal shedding of Cryptosporidium oocysts in healthy alpacas was found. A zoonotic risk should be considered, especially for Cryptosporidium parvum.

A rare Cryptosporidium parvum genotype associated with infection of lambs and zoonotic transmission in Italy

An outbreak of cryptosporidiosis occurred in a mixed sheep/cattle farm of Central Italy in October 2011. A total of 450 ovines (250 sheep and 200 lambs) and 140 bovines (130 cows and 10 calves) were housed in two separated units, at the time of the outbreak. About half of the lambs had diarrhea due to Cryptosporidium sp. with a mortality rate of 80%; calves were not infected. Genomic DNA was extracted from an archived slide and from fecal specimens, and the parasite was identified as Cryptosporidium parvum by PCR and sequence analysis at the CpA135 gene. Genotyping at the GP60 gene showed the presence of a very rare genotype, IIaA20G2R1. Shortly after the outbreak was identified, the son of the farm's owner, aged 18 months, experienced an acute gastroenteritis and was hospitalized due to recurrent episodes of diarrhea, fever, vomiting and lack of appetite. The feces tested negative for bacteria and viruses, whereas cryptosporidiosis was diagnosed by microscopy and an immunochromatographic test. Molecular typing identified the C. parvum genotype IIaA20G2R1 in the feces of the child. This is the first case of transmission of cryptosporidiosis in Italy involving lambs as source of oocysts infectious to humans.

Prevalence of cryptosporidiosis in dairy cattle, cattle-keeping families, their non-cattle-keeping neighbours and HIV-positive individuals in Dagoretti Division, Nairobi, Kenya

This paper reports a study estimating the prevalence of cryptosporidiosis, an emerging zoonosis, in people and cattle in Dagoretti, Nairobi. A repeated cross-sectional survey was carried out among randomly selected cattle keepers in Dagoretti, their dairy cattle and their non-cattle-keeping neighbours in the dry and wet seasons of 2006. A survey was also carried out among a group of people living with human immunodeficiency virus (HIV). Faecal samples were examined for Cryptosporidium oocysts using the modified Ziehl-Neelsen method; 16 % of the samples were also examined using immunofluorescence antibody (IFA) technique. Quality control consisted of blind reviews of slides, examining split samples and confirming slide results with IFA. We found that members of dairy households had a dry season cryptosporidiosis prevalence of 4 % and wet season prevalence of 0.3 %, and non-dairy households, a prevalence of 5 and 0 %, respectively. The cattle dry season prevalence was 15 %, and the wet season prevalence, 11 %. The prevalence in people living with HIV was 5 %. The laboratory quality control system showed some inconsistency within and between different tests, indicating challenges in obtaining consistent results under difficult field and working conditions. In conclusion, this is the first reported study to simultaneously survey livestock, livestock keepers and their neighbours for cryptosporidiosis. We failed to find evidence that zoonotic cryptosporidiosis is important overall in this community. This study also draws attention to the importance of quality control and its reporting in surveys in developing countries.

Unexpected results from large-scale cryptosporidiosis screening study in calves in Tanzania

A study was undertaken to investigate Cryptosporidium infection in crossbreed dairy calves in two districts in Tanzania. A total of 943 fecal samples from 601 dairy calves were included in the study, with calves from both smallholder dairy farms and from large-scale and medium-scale dairy farms. The modified Ziehl-Neelsen (mZN) technique was used to examine 710 samples, and 13 of these were considered to be positive for Cryptosporidium. These 13 samples considered positive by mZN, along with the remaining 233 samples, were analysed by immunofluorescent antibody test (IFAT). Of these 246 samples examined by IFAT, 15 samples, 10 of which were considered positive by mZN, were also examined by the auramine phenol technique, and 5 samples, all of which were considered positive by mZN, were analysed by PCR. The results from the IFAT, auramine phenol and PCR analyses demonstrated that none of the samples contained Cryptosporidium oocysts, indicating that, cryptosporidiosis is currently not a problem in dairy calves in these regions of Tanzania. These unexpected results are discussed with respect to other reports on cryptosporidiosis in calves that suggest that this parasite is a serious calf disease globally, and particularly in relation to studies from Tanzania. We suggest that results from studies of cattle in Tanzania, in which mZN has been used as the sole analytical method, should be treated with caution.

Investigation into the Prevalence of Cryptosporidium Infection in Calves among Small-Holder Dairy and Traditional Herds in Tanzania

A cross-sectional study was conducted to determine prevalence and risk factors of cryptosporidiosis in bovine from two contrasting production system in and around Tanga municipality between May 2003 and January 2004. The study populations comprised 117 calves aged ≤3 months, randomly selected from 44 smallholders dairy and traditional managed herds, respectively. Individual calf and herd-level information was collected using a structured questionnaire and feacal samples were screened for Cryptosporidium spp oocysts using the modified Ziehl-Neelsen method. Overall, 35% of the calves in the study were shedding Cryptosporidium spp oocysts, with at least one positive calf detected in 54.5% of herds. Independent risk factors for cryptosporidiosis were: age ≥1 to ≤2 months and level of cleanness of calf house floor categorized as dirty (P < .05). Similarly an increases risk of Cryptosporidium spp infection was found in calves from smallholder dairy units compared to traditional herds (P < .05). The finding highlights that Cryptosporidium spp is prevalent among calves in the area under study. The high prevalence of cryptosporidiosis detected in this study suggests that it may have a significant impact on livestock industry and that the close interaction between cattle and human may play a role in zoonotic transmission to humans.