Massive Cryptosporidium infections and chronic diarrhea in HIV-negative patients

Food and Drinking Water as Sources of Pathogenic Protozoans: An Update

This narrative review was aimed at collecting updated knowledge on the risk factors, illnesses caused, and measures for the prevention of protozoan infections transmitted by food and drinking water. Reports screened dated from 2019 to the present and regarded global prevalence in food handlers, occurrence in food and drinking water, impact on human health, and recently reported outbreaks and cases of severe infections attributable to the dietary route. Cryptosporidium spp., Cyclospora cayetanensis, Entamoeba histolytica, and Cystoisospora belli were the protozoans most frequently involved in recently reported waterborne and foodborne outbreaks and cases. Blastocystis hominis was reported to be the most widespread intestinal protozoan in humans, and two case reports indicated its pathogenic potential. Dientamoeba fragilis, Endolimax nana, and Pentatrichomonas hominis are also frequent but still require further investigation on their ability to cause illness. A progressive improvement in surveillance of protozoan infections and infection sources took place in developed countries where the implementation of reporting systems and the application of molecular diagnostic methods led to an enhanced capacity to identify epidemiological links and improve the prevention of foodborne and waterborne protozoan infections.

Bağışıklık Sistemi Baskılanmış Hastalarda Cryptosporidium spp. ve Giardia intestinalis Sıklığının Araştırılması

Amaç: Giardia intestinalis ve Cryptosporidium spp. türleri gelişmiş ve gelişmekte olan ülkelerde ishale neden olan bağırsak parazitleridir. Özelikle bağışıklık sistemi baskılanmış hastalarda ve çocuklarda tedavi edilemediğinde ölümcül olabilmektedir. Bu çalışmada Harran Üniversitesi Araştırma ve Uygulama Hastanesine başvuran bağışıklık sistemi baskılanmış hastaların dışkı örneklerinde Cryptosporidium spp. ve G.intestinalis sıklığının araştırılması amaçlanmıştır. Yöntem: Bu çalışma Ocak 2017 ve Ocak 2019 yılları arasında hastanemize başvuran bağışıklık sistemi baskılanmış ve ishal şikâyeti olan toplam 100 hasta ile gerçekleştirildi. Hastaların dışkı örneklerinde immünokromatografik (İK) metot ile Cryptosporidium spp. ve G. intestinalis antijenleri arandı ve nativ-lugol ve kinyoun asit fast boyama ile ookist, kist-trofozoit açısından incelendi. Bulgular: Toplam sekiz (%8) hastada G. intestinalis saptandı. Bunlardan yedisi (%14) çocuk hasta (n=50) ve biri (%2) yetişkin (n=50) bir kadın hasta olduğu tespit edildi. Hastaların 3 (%3)’ünde ise Cryptosporidium spp. görüldü. Bunlardan ikisi (%4) çocuk ve biri (%2) yetişkin kadın hastalar idi. Sonuçlarımız hem Cryptosporidium hem de G. intestinalis’in bağışıklık sistemi baskılanmış çocuk hastalarda (sırasıyla %4 ve %14) daha fazla saptandığını göstermiştir. Sonuç: Dışkı örneklerinde antijen saptayan İK metodun maliyeti yüksek olmasına rağmen çalışması kolay, erken sonuç vermesi ve etkensel tanı yöntemlerindeki zorluklara yardımcı olduğu görülmektedir. Sınırlı sayıda araştırılmış örnek bulunmasına rağmen bulgularımız bu iki parazitten kaynaklı enfeksiyonların Türkiye'de veya Avrupa ülkelerinde yapılan diğer çalışmalardaki görülme sıklığından daha yüksek olduğunu gösterdi.

Molecular prevalence of Cryptosporidium isolates among Egyptian children with cancer

Immunocompromised individuals especially children with cancer are at risk for acquiring cryptosporidiosis, which can result in severe morbidity and mortality. This work was conducted to evaluate the prevalence of Cryptosporidium parasite and its genotypes in children with cancer. Stool specimens were collected from 145 children in the Oncology unit of Pediatric Department, Zagazig University Hospital, Sharqiyah province, Egypt. Cryptosporidium infection was evaluated using modified Ziehl-Neelsen (MZN) staining and nested polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis. The prevalence of Cryptosporidium infection in oncological children was 29.7% using microscopy and 25.5% using nested PCR. Genotypic characterization showed that 23 (62.2%) had C. hominis, 11 (29.7%) C. parvum, and 3 specimens (8.1%) were mixed infection of both genotypes. Cryptosporidiosis was significantly associated with diarrhea. However, no statistically significant difference was detected between the age, gender, residency, animal contact and malignancy type concerning to Cryptosporidium infection. This study concluded that Cryptosporidium is a prevailing opportunistic parasite among children with cancer. It should be considered in oncological patients especially those suffering from diarrhea which requires proper management to reduce its complications.

Current pharmacotherapy of cryptosporidiosis: an update of the state-of-the-art

Introduction: Cryptosporidiosis has emerged as a major cause of diarrheal disease worldwide. It has especially serious health consequences for young, malnourished children living in endemic areas and for individuals with highly impaired T-cell function, such as HIV-positive individuals with low CD4 counts or immunosuppressed solid-organ transplant recipients.Areas covered: A selective literature search using PubMed was performed to review the available therapeutics to treat cryptosporidiosis, as well as related advances in drug development.Expert opinion: The only FDA-approved antiparasitic treatment in immunocompetent patients is nitazoxanide; however, it has failed to demonstrate convincing effectiveness among HIV-positive patients, immunosuppressed individuals and malnourished children. Thus, restoring HIV-positive patients' cellular immune response through effective antiretroviral therapy (ART), or reducing or changing immunosuppressive drugs, is important. Several new targets have been identified for chemotherapy, and the development of drugs for these targets has progressed, including parasite kinases, nucleic acid synthesis and processing, proteases and lipid metabolism. Candidate drugs that have been shown to be effective and safe in a neonatal calf model will most likely constitute the next advance for clinical trials in humans. However, developing an effective and inexpensive vaccination, as well as complementing structural preventive measures, would most decisively reduce the global cryptosporidiosis burden.

First Molecular Characterization of Cryptosporidium spp. in Patients Living with HIV in Honduras

Cryptosporidiosis is one of the most important causes of gastroenteritis in the world, especially in low- and middle-income countries. It is caused by the Apicomplexan parasite Cryptosporidium spp., and mainly affects children and immunocompromised people, in whom it can pose a serious threat to their health, or even be life threatening. In Honduras, there are no data on parasite species or on molecular diversity or Cryptosporidium subtypes. Therefore, a cross-sectional study was conducted between September 2019 and March 2020 for the molecular identification of Cryptosporidium spp. in 102 patients living with HIV who attended a national hospital in Tegucigalpa. Stool samples were analyzed by direct microscopy, acid-fast stained smears, and a rapid lateral flow immunochromatographic test. All samples that tested positive were molecularly analyzed to identify the species and subtype of the parasite using three different markers: gp60, cowp, and 18Sr. PCR products were also sequenced. Four out of 102 samples (3.92%) were positive for Cryptosporidiumparvum, and all were assigned to subtype IIa. These findings suggest a possible zoonotic transmission in this population.

Cryptosporidiosis among Hemodialysis Patients in Jordan: First Preliminary Screening Surveillance

Few studies have reported the incidence of cryptosporidiosis among hemodialysis patients worldwide. Currently many molecular and immunological assays have been developed for the sensitive diagnosis of cryptosporidiosis, but still, the microscopic detection of the parasitic infective stage (oocysts) in stool specimens using modified acid stain is regarded as a reliable sensitive technique which is widely used in many clinical labs. In the present study, a total of 133 stool samples were collected from hemodialysis patients and were screened for Cryptosporidium oocyst using formalin-ether concentration and modified acid-fast staining technique. Clinical and demographic data were also collected and analyzed. Cryptosporidium oocysts were recovered in 15/133 (11%) of the investigated hemodialysis patients. The age of patients ranged from 25 to 80 years (mean: 57.84 ± 12.22). Most of the Cryptosporidium-positive cases were recovered from males (73.7%) residing in rural villages in Irbid city (86.6%). The most repeatedly reported symptoms in the Cryptosporidium-positive patients were gastrointestinal symptoms, including diarrhea (15%), nausea (24%), abdominal pain (23%) and bloating (17%), in addition to general fatigue (32%) and weight loss (19%). No statistically significant associations for certain clinical symptoms or risk factors were found. The present study is the first preliminary study in Jordan that provided a brief screening for the incidence of cryptosporidiosis among hemodialysis patients.