Prevalence and genotyping of Cryptosporidium isolated from HIV/AIDS patients in urban areas of Thailand

Molecular detection of Cryptosporidium spp., Giardia duodenalis, and Enterocytozoon bieneusi in school children at the Thai-Myanmar border

Few data are available on the genetic identity of enteric protists Cryptosporidium spp., Giardia duodenalis, and Enterocytozoon bieneusi in humans in Thailand. In this study, 254 stool samples were collected from primary school children from Ratchaburi Province at the Thai-Myanmar border and examined for Cryptosporidium spp., G. duodenalis, E. bieneusi and Cyclospora cayetanensis using PCR techniques. The genotype identity of the pathogens was determined by DNA sequence analysis of the PCR products. Cryptosporidium felis was found in 1 stool sample, G. duodenalis in 19 stool samples, and E. bieneusi in 4 stool samples. For G. duodenalis, sub-assemblage AII was the dominant genotype, but one infection with assemblage F was found. The E. bieneusi genotypes found included known genotypes D and J, and one novel genotype (HPTM1). Cyclospora cayetanensis was not detected in any samples. Results of the preliminary study indicate that children at the Thai-Myanmar border from Ratchaburi Province, Thailand are infected with diverse zoonotic genotypes of Cryptosporidium spp., G. duodenalis, and E. bieneusi.

Cryptosporidiosis in HIV-positive patients and related risk factors: A systematic review and meta-analysis

Cryptosporidium is one of the major causes of diarrhea in HIV-positive patients. The aim of this study is to systematically review and meta-analyze the prevalence of Cryptosporidium in these patients. PubMed, Science Direct, Google Scholar, Web of Science, Cochrane and Ovid databases were searched for relevant studies dating from the period of 1 January 2000 to 31 December 2017. Data extraction for the included studies was performed independently by two authors. The overall pooled prevalence was calculated and subgroup analysis was performed on diagnostic methods, geographical distribution and study population. Meta-regression was performed on the year of publication, proportion of patients with diarrhea, and proportion of patients with CD4 < 200 cells/mL. One hundred and sixty-one studies and 51,123 HIV-positive participants were included. The overall pooled prevalence of Cryptosporidium infection in HIV-positive patients was 11.2% (CI95%: 9.4%–13.0%). The pooled prevalence was estimated to be 10.0% (CI95%: 8.4%–11.8%) using staining methods, 13.5% (CI95%: 8.9%–19.8%) using molecular methods, and 26.3% (CI95%: 15.0%–42.0%) using antigen detection methods. The prevalence of Cryptosporidium in HIV patients was significantly associated with the country of study. Also, there were statistical differences between the diarrhea, CD4 < 200 cells/mL, and antiretroviral therapy risk factors with Cryptosporidiosis. Thus, Cryptosporidium is a common infection in HIV-positive patients, and safe water and hand-hygiene should be implemented to prevent cryptosporidiosis occurrence in these patients.

High prevalence of Cryptosporidium infection caused by C. scrofarum and C. suis among pigs in Thailand

Cryptosporidium spp. is an important intestinal protozoan causing diarrhea among both healthy and immunocompromised patients especially those with HIV/AIDS. Cryptosporidium spp. can be transmitted via foodborne, waterborne and person-to-person routes. In addition, several Cryptosporidium species are zoonotic. This study aimed to determine the prevalence of Cryptosporidium infection among pigs raised in both smallholder (<50 heads/farm) and large scale farms (50-500 heads/farm) in Chonburi Province, eastern Thailand using nested PCR amplifying the small subunit of the ribosomal RNA (SSU-rRNA) gene. DNA sequencing was also performed to identify the species of Cryptosporidium. A total of 245 fecal samples were collected from 11 pig farms. The overall prevalence of Cryptosporidium infection was 20.8% (51/245) which were found in both smallholder and small large scale pig farms. The prevalence of Cryptosporidium infection among pigs aged ≤6 months was significantly higher than those aged >6 months (p < .001). Among 51 Cryptosporidium positive samples, Cryptosporidium scrofarum (42/51, 82.4%) and Cryptosporidium suis (9/51, 17.6%) were identified. The prevalence of C. scrofarum infection observed among pigs aged ≤6 months was significantly higher when compared with those aged >6 months (20.7% and 2.1%, respectively, p < .001). The high prevalence of C. scrofarum and C. suis infections among pigs could be a potential source of infection to humans.

"Enterocytozoon bieneusi and Cryptosporidium: a cross-sectional study conducted throughout Thailand"

BACKGROUND

Enterocytozoon bieneusi and Cryptosporidium spp. are prevalent zoonotic parasites associated with a high burden among children. To date only limited molecular epidemiological data on E. bieneusi and Cryptosporidium spp. in humans living in Thailand has been published.

METHODS

PCR-based tools were used to detect and characterize E. bieneusi and Cryptosporidium spp. The internal transcribed spacer (ITS) region of the rRNA gene was used to investigate E. bieneusi, and the small subunit (SSU) rRNA gene was used to investigate Cryptosporidium spp., and 697 fecal samples from villagers and school children in rural areas in Thailand were analyzed.

RESULTS

The infection rates were 2.15% (15/697) for E. bieneusi and 0.14% (1/697) for Cryptosporidium spp. The prevalence of E. bieneusi was significantly high in Loei province. Sequence analysis indicated that the Cryptosporidium isolate was C. parvum. Nine E. bieneusi genotypes were identified, EbpC, Peru12, TMH6, TMH3, TMH7, H, D, and two novel genotypes TMLH1 and TMLH2. E. bieneusi prevalence was significantly higher in male participants than in female participants, and in children aged 3-15 years than in participants aged > 15 years.

CONCLUSIONS

The prevalence, genotypes, and zoonotic potential of E. bieneusi were found to vary significantly high even in one country. Transmission routes and key animal carriers of E. bieneusi may be associated with differences in hygiene, sanitation, and cultural behaviors. Further molecular studies including longitudinal studies will be required to unveil epidemiological characteristics of these opportunistic intestinal protozoa in all over the countries.

A retrospective molecular study of Cryptosporidium species and genotypes in HIV-infected patients from Thailand

Background

Opportunistic infections represent a serious health problem for HIV-infected people. Among enteric infections, cryptosporidiosis, a severe and life-threatening diarrheal disease, is of particular importance in low economic settings where access to anti-retroviral therapy is limited. Understanding transmission routes is crucial in establishing preventive measures, and requires the use of informative genotyping methods. In this study, we performed a retrospective analysis of Cryptosporidium species in 166 stool samples collected from 155 HIV-infected patients during 1999–2004 at the Siriraj Hospital in Bangkok, Thailand.

Results

Microscopic examination of stools identified 104 of the 155 patients as positive for Cryptosporidium. Other common pathogens identified were microsporidia, Isospora, Giardia, Strongyloides and Opisthorchis. All samples were tested by amplification of a fragment of the 18S rDNA locus, and sequencing showed the presence of Cryptosporidium hominis (n = 42), C. meleagridis (n = 20), C. canis (n = 12), C. felis (n = 7), C. suis (n = 6) and C. parvum (n = 5). Genotyping at the glycoprotein 60 (gp60) locus revealed substantial variability in isolates of C. hominis and C. meleagridis. Among C. hominis isolates, subtype IeA11G3T3 was the most prevalent, but allelic family Id was the more diverse with four subtypes described, two of which were identified for the first time. Among C. meleagridis isolates, seven subtypes, two of which were new, were found in the allelic family IIIb, along with new subtypes in allelic families IIIe and IIIg. In the four C. parvum isolates, subtype IIoA16G1, a rare subtype previously reported in a Swedish patient who had traveled to Thailand, was identified.

Conclusions

This study confirms the high susceptibility of HIV-infected individuals to infection with different Cryptosporidium species and subtypes, and further stresses the importance of surveillance for opportunistic intestinal protozoans.

Electronic supplementary material

The online version of this article (10.1186/s13071-019-3348-4) contains supplementary material, which is available to authorized users.

Cryptosporidiosis: A zoonotic disease concern

Cryptosporidiosis is considered to be a crucial zoonotic disease caused by worldwide distributing parasitic protozoa called Cryptosporidium spp. Cryptosporidiosis becomes a major public health and veterinary concern by affecting in human and various host range species of animals. Essentially, its importance of infection is increasing because of the high incidence in young children, immunocompromised persons, or immunodeficiency syndrome patients, especially in HIV/AIDS, and it is also one of the most causes of mortality in those patients who infected with Cryptosporidium spp. as well as young animals. All domestic animal, livestock, wildlife, and human can be potential reservoirs that contribute Cryptosporidium spp. to food and surface waters and transmitted to other hosts through fecal-oral route. The oocyst stage of Cryptosporidium spp. can remain infective and resistant to various environmental exposure and also resistant to many general disinfecting agents including chlorination which normally used in water treatment. Therefore, the understanding of these zoonotic pathogens is very essential in both animal and human health. This review focuses on the biology, life cycle, transmission, diagnosis, treatment, prevention, and control of this protozoan infection to emphasize and remind as the significant One Health problem.

Prevalence of Cryptosporidium species isolated from HIV/AIDS patients in southwest of Iran

This study aimed to determine the prevalence and species of Cryptosporidium among HIV/AIDS patients in southwest of Iran. Two hundred fifty faecal samples from HIV patients were examined for the presence of Cryptosporidium oocysts using a conventional coproscopic approach. Such oocysts were detected in 18 (7.2%) out of 250 faecal samples. Genomic DNAs from 250 samples were then subjected to a nested-PCR-RFLP technique targeting different loci of 18S rRNA gene for species identification. Out of 250 samples, 27 (10.8%) were positive for different Cryptosporidium spp; Restriction patterns resulting from the digestion of the nested amplicon with restriction endonucleases VspI and SspI showed that C. parvum (70.38%) was the most prevalent species, followed by C. hominis (25.92%) and C. meleagridis (3.7%), respectively. The mean CD4+ T-cell count was 215 cells/μL. There was a strong association between cryptosporidiosis and CD4+ T-cell count (P = 0.000) with the highest prevalence recorded among patients with CD4+ T-cell count < 200 cells/μL. This confirms that there is a low opportunity for this parasite to get established as the patients CD4+ T-cell count increases. Also HIV infection increased the risk of having Cryptosporidium. Our epidemiological findings are useful for any preventive intervention to control disease diffusion.

Prevalence and Multilocus Genotyping Analysis of Cryptosporidium and Giardia Isolates from Dogs in Chiang Mai, Thailand

The occurrence and zoonotic potential of Cryptosporidium spp. and Giardia duodenalis isolated from dogs in Chiang Mai, Thailand were determined. Fecal samples were collected from 109 dogs between July and August 2008. Cryptosporidium spp. infection was determined by immunofluorescent assay (IFA), PCR assays that amplify Cryptosporidium heat-shock protein 70 kDa (hsp70), and two PCR assays that amplify a small subunit-ribosomal RNA (SSU-rRNA). Giardiaduodenalis infection was identified using zinc sulfate centrifugal flotation, IFA, and four PCR assays that amplify the Giardia glutamate dehydrogenase (gdh), beta-giardin (bg), and generic and dog-specific assays of triosephosphate isomerase (tpi) genes. Overall prevalence of Cryptosporidium spp. and G.duodenalis was 31.2% and 45.9%, respectively. Sequence analysis of 22 Cryptosporidium-positive samples and 21 Giardia-positive samples revealed the presence of C.canis in 15, and C. parvum in 7, G. duodenalis Assemblage C in 8, D in 11, and mixed of C and D in 2 dogs. Dogs in Chiang Mai were commonly exposed to Cryptosporidium spp. and G. duodenalis. Cryptosporidium parvum can be isolated from the feces of dogs, and all G. duodenalis assemblages were dog-specific. Dogs could be a reservoir for a zoonotic Cryptosporidium infection in humans, but further studies will be required to determine the clinical and zoonotic importance.

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.

Molecular detection and prevalence of Giardia duodenalis and Cryptosporidium spp. among long-tailed macaques (Macaca fascicularis) in Thailand

Giardia duodenalis and Cryptosporidium spp. are divergent protozoal intestinal parasites that infect human beings and other animals, including non-human primates. Although long-tailed macaques (Macaca fascicularis) reside in human communities in Thailand, the prevalence of Giardia spp. and Cryptosporidium spp. in these primates has not been previously investigated. The objective of this study was to evaluate long-tailed macaques living near human communities as possible hosts of these intestinal parasites. In 2014, 200 fecal samples were randomly collected from long-tailed macaques living in different areas of Lopburi province, Thailand, and tested with a panel of PCR assays for Giardia spp. and Cryptosporidium spp. G. duodenalis assemblage B was most frequently detected (6%), while assemblage A and an inconclusive assemblage were detected in single samples, for a total G. duodenalis infection rate of 7%. Two samples (1%) tested positive for Cryptosporidium spp., which were both classified as monkey genotypes. No significant associations were found between G. duodenalis infection and sex or location of macaques. This study indicates that long-tailed macaques can carry G. duodenalis and, to a lesser extent, Cryptosporidium spp. monkey genotype. These results warrant education of residents and tourists to limit contact with long-tailed macaques and to take hygienic precautions to mitigate risk of zoonotic and anthroponotic transmission of these parasites between people and macaques.

Molecular identification of Cryptosporidium spp. in seagulls, pigeons, dogs, and cats in Thailand

Zoonotic Cryptosporidium spp., particularly C. meleagridis, C. canis, and C. felis, are enteric protozoa responsible for major public health concerns around the world. To determine the spread of this parasite in Thailand, we conducted molecular identification of Cryptosporidium spp. from animal samples around the country, by collecting and investigating the feces of seagulls (Chroicocephalus brunnicephalus and Chroicocephalus ridibundus), domestic pigeons (Columba livia domestica), dogs, and cats. Seagull and pigeon samples were collected at the seaside and on the riverside to evaluate their potential for waterborne transmission. Ten pigeon samples were combined into one set, and a total of seven sets were collected. Seventy seagull samples were combined into one set, and a total of 13 sets were collected. In addition, 111 dog samples were collected from cattle farms, and 95 dog and 80 cat samples were collected from a temple. We identified C. meleagridis in pigeons, Cryptosporidium avian genotype III in seagulls, C. canis in dogs, and C. felis in cats. In the temple, the prevalence was 2.1% (2/95) for dogs and 2.5% (2/80) for cats. No Cryptosporidium was found in dog samples from cattle farms. These are the first findings of C. meleagridis in domestic pigeons, and Cryptosporidium avian genotype III in seagulls. Our study invites further molecular epidemiological investigations of Cryptosporidium in these animals and their environment to evaluate the public health risk in Thailand.

Intestinal parasitic infections in HIV-infected patients, Lao People's Democratic Republic

Background

HIV infection is an emerging problem in Laos. We conducted the first prospective study on intestinal parasites, including opportunistic protozoa, in newly diagnosed HIV infected patients, with or without diarrhea. The aims were to describe the spectrum of infections, to determine their prevalence and to assess their associations with diarrhea, CD4 cell count, place of residence and living conditions.

Methodology

One to three stool samples over consecutive days were obtained from 137 patients. The Kato thick smear method, formalin-ethyl concentration and specific stains for coccidia and microsporidia diagnosis were performed on 260 stool samples. Baseline characteristics regarding relevant demographics, place of residence and living conditions, clinical features including diarrhea, were collected using a standardized questionnaire.

Principal Findings

The 137 patients were young (median age: 36 years) and severely immunocompromised (83.9% at WHO stage 3 or 4, median CD4 cell count: 41/mm³). Diarrhea was present in 43.0% of patients. Parasite infection was found in 78.8% of patients, infection with at least two species in 49.6%. Prevalence rates of protozoan and helminth infections were similar (54.7% and 58.4% respectively). Blastocystis sp. was the most frequent protozoa (26.3%). Cryptosporidium sp., Cytoisospora belli and microsporidia, found at low prevalence rates (6.6%, 4.4%, 2.9%, respectively), were described for the first time in Laos. Cryptosporidium sp. was associated with persistent diarrhea. Strongyloides stercoralis was the most prevalent helminth following Opisthorchis viverrini (20.4% and 47.5% respectively). The most immunocompromised patients, as assessed by a CD4 count ≤ 50 cells/mm³, were more likely to be infected with intestinal parasites.

Conclusions/Significance

HIV infection was mainly diagnosed at an advanced stage of immunosuppression in Lao patients. Intestinal parasite infections were highly prevalent regardless of their diarrheal status. Opportunistic infections were reported. Improving the laboratory diagnosis of intestinal parasite infections and the knowledge on their local risk factors is warranted.

Burden of disease from cryptosporidiosis

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.