Evaluation of the optimal number of faecal specimens in the diagnosis of cryptosporidiosis in AIDS and immunocompetent patients

Intestinal parasitism in pediatric oncology children receiving chemotherapy: unexpected low prevalence

Background

Children with underlying malignancies and those on chemotherapy are at risk for having intestinal parasitic infections, which can lead to a severe course and death. This cross-sectional study was done to assess the copro-parasitological and copro-molecular prevalence of entero-parasites in children with malignancies and those on chemotherapy.

Procedure

Stool samples were collected from 137 Egyptian hospitalized cancerous children with different malignancies in the National Cancer Institute, and receiving chemotherapy.

Faecal samples were examined microscopically. Genomic copro-DNA was extracted from fecal samples and amplified by 3 separate nPCR assays targeting Cryptosporidium, G. intestinalis and Entamoeba histolytica complex.

Result

The overall prevalence of enteroparasites was 6.6 % (9 cases). Only Giardia copro-DNA was encountered in 2 (1.4%) faecal samples of patients. Coproscopy detected parasites in 7 cases: Blastocystis spp. in 5 cases (3.6%), Hymenolepis nana in 1 case (0.7%) and Ascaris lumbericoides in 1 case (0.7%).

Conclusion

Low prevalence may be due to patient's use of prophylactic anti-parasitic and anti-fungal drugs, a standard protocol, basic hygienic practices and good nursing all of which are preventive against enteroparasites transmission. Among studied variables only diarrhoeic individuals who had a solid tumor, and soft/liquid stool with mucus and blood were predictors of intestinal parasitism.

Cryptosporidium in humans and animals-a one health approach to prophylaxis

Cryptosporidium is a major cause of moderate-to-severe diarrhoea in humans worldwide, second only to rotavirus. Due to the wide host range and environmental persistence of this parasite, cryptosporidiosis can be zoonotic and associated with foodborne and waterborne outbreaks. Currently, 31 species are recognized as valid, and of these, Cryptosporidium hominis and Cryptosporidium parvum are responsible for the majority of infections in humans. The immune status of the host, both innate and adaptive immunity, has a major impact on the severity of the disease and its prognosis. Immunocompetent individuals typically experience self-limiting diarrhoea and transient gastroenteritis lasting up to 2 weeks and recover without treatment, suggesting an efficient host antiparasite immune response. Immunocompromised individuals can suffer from intractable diarrhoea, which can be fatal. Effective drug treatments and vaccines are not yet available. As a result of this, the close cooperation and interaction between veterinarians, health physicians, environmental managers and public health operators is essential to properly control this disease. This review focuses on a One Health approach to prophylaxis, including the importance of understanding transmission routes for zoonotic Cryptosporidium species, improved sanitation and better risk management, improved detection, diagnosis and treatment and the prospect of an effective anticryptosporidial vaccine.

Molecular genotyping and sub-genotyping of Cryptosporidium spp. isolates from symptomatic individuals attending two major public hospitals in Madrid, Spain

Infections by members of the protozoan genus Cryptosporidium are among the most common causes of human gastrointestinal illness worldwide. In Spain cryptosporidiosis is not a compulsory notifiable disease, so the actual burden of the infection in both clinical and general populations remains largely unknown. We present here data on the diversity and frequency of the Cryptosporidium species and sub-genotypes identified in symptomatic individuals seeking medical care in two major hospitals in Madrid, Spain, between December 2013 and January 2015. Initial detection of the parasite was conducted on a total of 122 stool samples collected from 120 patients by microscopy with modified Ziehl-Neelsen and/or immunochromatographic tests. We used immunofluorescence, PCR-based methods and sequence analyses of the 60-kDa (GP60) glycoprotein and the small subunit ribosomal RNA (SSU rRNA) genes for confirmatory purposes and to characterize Cryptosporidium isolates. A total of 110 patients were confirmed with cryptosporidiosis. Overall, 101 isolates were successfully sub-genotyped at the GP60 locus, and an additional seven at the SSU rRNA locus. The analyses of all amplicons defined 10 distinct sequence types representing the GP60 family sub-genotypes IbA10G2 (78.7%), IeA11G3T3 (3.7%) of C. hominis, and the GP60 family sub-types IIaA15G2R1 (5.6%), IIaA18G6R1 (0.9%), IIcA5G3a (0.9%), IIdA18G1 (0.9%), IIdA19G1 (0.9%), IIdA21G1 (0.9%), and IIdA22G1 (0.9%) of C. parvum. A single isolate was assigned to C. felis (0.9%), two C. parvum isolates (1.9%) could not be characterized at the sub-genotype level and an additional four isolates (3.7%) were not typable. These results strongly suggest that transmission of cryptosporidiosis is mostly anthroponotic in origin in the clinical sample under study. We expect that our molecular epidemiological data will make a significant contribution to unravel the actual epidemiological situation of cryptosporidiosis in Spain, providing health care and policy makers with solid baseline information to unavoidably improve the national surveillance system and allocate additional resources to research, diagnosis, and treatment of cryptosporidiosis.

Cryptosporidium prevalence and risk factors among mothers and infants 0 to 6 months in rural and semi-rural Northwest Tanzania: a prospective cohort study

Background

Cryptosporidium epidemiology is poorly understood, but infection is suspected of contributing to childhood malnutrition and diarrhea-related mortality worldwide.

Methods/Findings

A prospective cohort of 108 women and their infants in rural/semi-rural Tanzania were followed from delivery through six months. Cryptosporidium infection was determined in feces using modified Ziehl-Neelsen staining. Breastfeeding/infant feeding practices were queried and anthropometry measured. Maternal Cryptosporidium infection remained high throughout the study (monthly proportion = 44 to 63%). Infection did not differ during lactation or by HIV-serostatus, except that a greater proportion of HIV-positive mothers were infected at Month 1. Infant Cryptosporidium infection remained undetected until Month 2 and uncommon through Month 3 however, by Month 6, 33% of infants were infected. There were no differences in infant infection by HIV-exposure. Overall, exclusive breastfeeding (EBF) was limited, but as the proportion of infants exclusively breastfed declined from 32% at Month 1 to 4% at Month 6, infant infection increased from 0% at Month 1 to 33% at Month 6. Maternal Cryptosporidium infection was associated with increased odds of infant infection (unadjusted OR = 3.18, 95% CI 1.01 to 9.99), while maternal hand washing prior to infant feeding was counterintuitively also associated with increased odds of infant infection (adjusted OR = 5.02, 95% CI = 1.11 to 22.78).

Conclusions

Both mothers and infants living in this setting suffer a high burden of Cryptosporidium infection, and the timing of first infant infection coincides with changes in breastfeeding practices. It is unknown whether this is due to breastfeeding practices reducing pathogen exposure through avoidance of contaminated food/water consumption; and/or breast milk providing important protective immune factors. Without a Cryptosporidium vaccine, and facing considerable diagnostic challenges and ineffective treatment in young infants, minimizing the overall environmental burden (e.g. contaminated water) and particularly, maternal Cryptosporidium infection burden as a means to protect against early infant infection needs prioritization.

Early infancy and childhood Cryptosporidium infection is associated with poor nutritional status, stunted growth, and cognitive deficits, yet minimal research is available regarding the burden and risk factors worldwide. Since there is no vaccine available, and because diagnostic challenges exist and treatment for children younger than one year is ineffective, prevention of early infancy infection through a better understanding of basic epidemiology is critical. This study was designed to investigate symptomatic and clinically silent infection amongst HIV-seropositive and HIV-seronegative mothers and their infants in a longitudinal cohort, and to indentify potential risk factors. Findings indicate that infants are living in a Cryptosporidium environment as demonstrated by the chronically high level of maternal infection throughout the 6-month post-partum period. Despite this, infant infection prevalence remains low until six months of age when it dramatically rises. The increase in infant infection corresponds to a reduction in exclusive breastfeeding. As expected, maternal infection is associated with increased infant infection, but unexpectedly, so is maternal hand washing prior to infant feeding. Since prevention may indeed be the “best medicine” for infants, investigation of beneficial breastfeeding practices, protective correlates in breast milk, and ways to reduce the maternal and environmental Cryptosporidium burden are needed.

A comparison of nested PCR assay with conventional techniques for diagnosis of intestinal cryptosporidiosis in AIDS cases from northern India

Cryptosporidiosis is a very important opportunistic infection and is responsible for significant morbidity and mortality in HIV/AIDS patients. Although current laboratory methods are generally considered adequate to detect high concentrations of oocysts, they fail to detect cases of cryptosporidiosis in many immunocompromised patients. The present study was done to determine the diagnostic efficacy of modified Ziehl-Neelsen (ZN), antigen detection ELISA, and a nested PCR assay for detection of Cryptosporidium in 58 adult AIDS cases with diarrhea from the ART clinic of Lok Nayak Hospital, New Delhi. Cryptosporidium was detected in 17 (29.4%), 39 (67.3%), and 45 (77.5%) cases by modified ZN staining, antigen ELISA, and nested PCR assay, respectively. Taking nested PCR as the gold standard, specificity of both modified ZN staining and Cryptosporidium antigen detection ELISA was 100% while the sensitivity of the tests was 37.8% and 86.6%, respectively. PCR was more sensitive than the other two diagnostic modalities but required a more hands-on time per sample and was more expensive than microscopy. PCR, however, was very adaptable to batch analysis, reducing the costs considerably. This assay can therefore have considerable advantages in the treatment of immunosuppressed individuals like AIDS patients, allowing their early diagnosis and decreasing the morbidity and the mortality.

Occurrence of Cryptosporidium spp. oocysts in raw and treated sewage and river water in north-eastern Spain

AIMS

To determine the occurrence and levels of Cryptosporidium parvum oocysts in wastewater and surface waters in north-eastern Spain.

METHODS AND RESULTS

Samples from five sewage treatment plants were taken monthly and quarterly during 2003. In addition, water was collected monthly from the River Llobregat (NE Spain) during the period from 2001 to 2003. All samples were analysed by filtration on cellulose acetate filters or through Envirocheck using EPA method 1623, followed by immunomagnetic separation and examination by laser scanning cytometry. All raw sewage, secondary effluent and river water samples tested were positive for Cryptosporidium oocysts. Of the tertiary sewage effluents tested, 71% were positive for Cryptosporidium oocysts. The proportion of viable oocysts varied according to the sample.

CONCLUSIONS

Two clear maxima were observed during spring and autumn in raw sewage, showing a seasonal distribution and a correlation with the number of cryptosporidiosis cases and rainfall events.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study provides the first data on the occurrence of Cryptosporidium oocysts in natural waters in north-eastern Spain.

Cryptosporidiosis in Kuwaiti children: seasonality and endemicity

OBJECTIVE

To detect the incidence of cryptosporidial infection in children presenting with gastrointestinal symptoms at the local hospital in Kuwait.

METHODS

Over a period of 3 years, September 1995 to August 1997, a single fecal sample from 3549 children was analyzed by modified saframin-methylene blue (SM-B) staining and a direct immunofluorescence test for the presence of Cryptosporidium oocysts.

RESULTS

Cryptosporidium oocysts were detected in 51 (10%) children with diarrhea. Prevalence was highest (73%) in children > 2 years of age compared with children < 2 years of age. The maximum number of cases, 38 of 51 (75%), was seen during the months January to April, indicating a marked seasonal variation. Polyparasitism was common in children with diarrhea; however, 43 of the 51 (84%) children with cryptosporidiosis had cryptosporidium infection only. Blastocystis hominis and Endolimax nana were the most common parasites detected (38% and 15%, respectively). Forty-seven of the 51 (90%) children with cryptosporidiosis were Kuwaiti and gave no history of travel abroad, suggesting that the infection was acquired indigenously. Sociodemographic information on children with cryptosporidiosis suggests three possible modes of transmission of infection: drinking contaminated water stored in overhead water tanks, person to person, or contact with infected animals.

CONCLUSION

In this study, we observed water-borne transmission of cryptosporidium infection in children with diarrhea. The infection is seasonal and endemic.

Paromomycin: no more effective than placebo for treatment of cryptosporidiosis in patients with advanced human immunodeficiency virus infection. AIDS Clinical Trial Group

To evaluate the efficacy of paromomycin for the treatment of symptomatic cryptosporidial enteritis in human immunodeficiency virus-infected adults, we conducted a prospective, randomized, double-blind, placebo-controlled trial before the widespread introduction of highly active antiretroviral therapy (HAART). Seven units under the auspices of the AIDS Clinical Trials Group enrolled 35 adults with CD4 cell counts of < or = 150/mm(3). Initially, 17 patients received paromomycin (500 mg 4 times daily) and 18 received matching placebo for 21 days. Then all patients received paromomycin (500 mg q.i.d.) for an additional 21 days. Clinical definitions of response were measured by an average number of bowel movements per day in association with concurrent need for antidiarrheal agents that was lower than that before study entry. There was no treatment response during the placebo-controlled phase of the study according to protocol-defined criteria (P=.88). Three paromomycin recipients (17.6%) versus 2 placebo recipients (14.3%) responded completely. Rates of combined partial and complete responses in the paromomycin arm (8 out of 17, 47.1%) and the placebo arm (5 out of 14, 35.7%) of the study were also similar (P=.72). The clinical course of cryptosporidiosis was quite variable. Paromomycin was not shown to be more effective than placebo for the treatment of symptomatic cryptosporidial enteritis. However, inadequate statistical power prevents definitive rejection of the usefulness of paromomycin as therapy for this infection.

Cryptosporidiosis in Houston, Texas. A report of 95 cases

Cryptosporidiosis is an important cause of diarrhea. We identified 95 patients with cryptosporidiosis over a 6-year period in our county hospital system, including 9 children and 86 adults infected with the human immunodeficiency virus (HIV). Risk factors included male-to-male sexual practices and Hispanic race. Diarrhea, weight loss, and gastrointestinal complaints were the most common symptoms at presentation. Among the HIV-infected adults, 20 (23%) developed biliary tract disease. Biliary involvement was associated with low CD4 counts. Treatment with paromomycin and antimotility agents was effective in reducing diarrheal symptoms in 54 of 70 (77%) patients with the acquired immunodeficiency syndrome (AIDS), although there was a high rate of relapse. Paromomycin did not prevent the development of biliary disease. Biliary disease responded to cholecystectomy or sphincterotomy with stent placement. Though often a cause of morbidity, cryptosporidiosis was only rarely the cause of death, even among patients with HIV. Cryptosporidiosis continues to be an important medical problem even in developed-countries. Current methods of prevention and treatment are suboptimal.