Sporadic cryptosporidiosis case-control study with genotyping

We report a case-control study of sporadic cryptosporidiosis with genotyping of isolates from case-patients. A postal questionnaire was completed by 427 patients and 427 controls. We obtained genotyping data on isolates from 191 patients; 115 were Cryptosporidium hominis, and 76 were C. parvum. When all cryptosporidiosis cases were analyzed, three variables were strongly associated with illness: travel outside the United Kingdom, contact with another person with diarrhea, and touching cattle. Eating ice cream and eating raw vegetables were both strongly negatively associated with illness. Helping a child <5 years of age to use the toilet and the number of glasses of tap water drunk at home each day were also independently positively associated with risk. Eating tomatoes was negatively associated. For C. hominis infections, the strongly significant risk factors were travel abroad and changing diapers of children <5 years of age. For C. parvum, eating raw vegetables and eating tomatoes were strongly negatively associated with illness; touching farm animals was associated with illness.     

Cryptosporidium oocysts in water for human consumption

A study was carried out on the presence of oocysts ofCryptosporidium spp. in water for human consumption in the Province of Salamanca, Spain, using four different staining techniques: Ziehl-Neelsen, auramine, indirect immunofluorescence with monoclonal antibodies (Meridian, USA) and direct immunofluorescence with monoclonal antibodies (Pasteur, France). The presence of oocysts was detected in the water used for the washing of sand filters in the four water purifying plants and in the drinking water of two of the six geographical areas studied. The Ziehl-Neelsen and auramine staining techniques were found to have excellent diagnostic correlation. Immunofluorescence stainings with monoclonal antibodies proved to be less sensitive.     

Prevalence of Cryptosporidium in children with enteritis in Southern Italy

Cryptosporidium parvum is a protozoan which causes self-limiting diarrhea in immunocompetent subjects, and severe life-threatening disease in immunocompromised patients. Cryptosporidiosis is more common in developing countries and in infants. In this paper we have evaluated the prevalence of C. parvum in 368 hospitalized children with enteritis, of whom 359 were immunocompetent and 9 HIV-infected. Stool specimens were concentrated by sedimentation and stained with a modified Ziehl-Neelsen method. Cryptosporidium parvum oocysts were found in 7 (1.90%)out of 368 subjects. Six of these were immunocompetent (with an infection rate in this population of 1.67%) and 1 HIV-infected, asymptomatic except for diarrhea. In all children symptoms of enteritis and oocyst excretion cleared within 10 days. These results indicate that the prevalence of C. parvum as a causative agent of diarrheal illness in hospitalized immunocompetent children is rather low in our region (Apulia, South Italy).     

Serological evaluation of Cryptosporidium oocyst findings in the water supply for Sydney,Australia

From July to September, 1998, high levels of Cryptosporidium oocysts and Giardia cysts were detected in Sydney, Australia drinking water. To evaluate whether Sydney residents had an elevated risk of infection, serological responses to two Cryptosporidium antigen groups (15/17- and 27-kDa) were compared for 104 Sydney blood donors and 104 Melbourne blood donors. Over half of all donors had a detectable response to the 15/17-kDa antigen group (Sydney-56.7%, Melbourne-61.5%) and to the 27-kDa antigen group (Sydney-66.3%, Melbourne-77.9%). There were no statistically significant differences between Sydney and Melbourne donors in the intensity of serological responses for either the 15/17-kDa (p = 0.81) or the 27-kDa (p = 0.45) antigen groups. These results are not consistent with an elevated risk of Cryptosporidium infection among either Sydney or Melbourne blood donors, despite the detection of oocysts in the Sydney drinking water. Given the public health concerns over detecting oocysts in drinking water, serological studies offer a rapid and inexpensive method for comparing the levels of infection in an exposed and unexposed population.     

An outbreak of waterborne cryptosporidiosis associated with a public water supply in the UK.

In November and December 1992, an outbreak of waterborne cryptosporidiosis occurred in Bradford, a city in the North of England. In all 125 cases were involved, the majority of whom lived in part of the city which received its drinking water supply from a single water treatment works. A case control study demonstrated an association between illness and the consumption of tapwater from this source; those drinking large volumes being more likely to have been ill. Treated water from the defined source yielded cryptosporidial oocysts. Heavy rainfall was recorded in the catchment area of the reservoir supplying raw water to the treatment works, immediately prior to the probable time of infection, based on dates of onset of illness.     

Detection of Cryptosporidium oocysts and Giardia cysts in swimming pool filter backwash water concentrates by flocculation and immunomagnetic separation

The purpose of the present study was to evaluate techniques for detection of Giardia cysts and Cryptosporidium oocysts in swimming pool filter backwash water. Calcium carbonate flocculation was used for water samples concentration of 1 l filter backwash water samples. Immunomagnetic separation (IMS) was used for separation of cysts and oocysts from detrital material. Cysts and oocysts were then detected using direct immunofluorescence. ColorSeed C&G was used as an internal standard. Recoveries were examined at several processing points. Highest recoveries (23% Cryptosporidium, 18% Giardia) were obtained using lower filter backwash volumes, greater IMS volumes, and addition of Tween20 to backwash samples prior to processing. The combination of CaCO3 flocculation, IMS and direct immunofluorescence was found to be an effective tool for the detection and quantification of Giardia spp. and Cryptosporidium spp. in filter backwash water samples.     

Sporadic cryptosporidiosis decline after membrane filtration of public water supplies, England, 1996-2002

The incidence of sporadic cryptosporidiosis among 106,000 residents of 2 local government districts in northwest England before and after installation of membrane filtration of public water supplies was compared to that of 59,700 residents whose public water supplies remained unchanged. A national outbreak of foot and mouth disease in livestock during 2001 was associated with a decline in sporadic human cryptosporidiosis in all regions of the United Kingdom. In a Poisson regression model, membrane filtration was associated with an estimated 79% reduction (incidence ratio 0.207, 95% confidence intervals 0.099-0.431, p < 0.0001) after adjustment for the interval of the foot and mouth disease epidemic and the water source. Despite the confounding effect of that epidemic, membrane filtration of the public water supply was effective in reducing the risk for sporadic human Cryptosporidium infection in this population.     

The efficiency of ozonated water from a water treatment plant to inactivate Cryptosporidium oocysts during two seasonal temperatures

We investigated the efficiency of residual ozone from an advanced water treatment plant with an applied dose of 2.5 mg l^-1 to inactivate viable Cryptosporidium oocysts during summer (i.e. 24°C) and winter (i.e. 18.9°C) in Queensland, Australia. Containers for sample collection were inoculated with 1,000 oocysts l^-1 and filled with ozonated water. Ozone residual concentrations were measured at 0, 5 and 10 min intervals. Viability was determined by excystation. Non-ozonated water from the plant, trip and laboratory controls were also analysed. The applied ozone dose of 2.5 mg l^-1 produced an immediate residual concentration of 1.25 mg 1^-1 at 24°C and 1.34 mg 1^-1 at 18.9°C in unseeded samples. The initial ozone residual in seeded containers was 1.22±0.03 mg 1^-1 at 24°C and 1.37±0.04 mg 1^-1 at 18.9°C. There was a gradual increase in inactivation of oocysts, with 49% of oocysts inactivated at 0 min to 92% after 10 min at 24°C and 57% at 0 min to 92.8% at 10 min at 18.9°C.     

Cluster of non-tuberculous mycobacteraemia associated with water supply in a haemato-oncology unit

Non-tuberculous mycobacteria (NTM) are ubiquitous environmental organisms but rarely cause infections. Clinical, microbiological and epidemiological investigations and subsequent management of a cluster of NTM bacteraemia on a haemato-oncology unit are reported. From October 2007 to July 2008, five patients being managed for haematological malignancies developed pyrexia and general malaise. Mycobacterium mucogenicum (four patients) and Mycobacterium neoaurum (one patient) were identified from their blood cultures. The environment, in particular the water system, was investigated to identify the source of the infection and multiple water samples were cultured according to established criteria. NTM were also isolated from the hospital water system. Central venous catheters (CVCs) were removed and the patients were successfully treated with antibiotics. Environmental measures and changes in CVC care were introduced to prevent further episodes of NTM bacteraemia in these patients. Despite these measures, NTM continued to be present in the water system, but new clinical cases were not identified. NTM are common environmental organisms and are recognized as being difficult to remove from water systems. CVCs were presumed to be the portal of entry in this cluster of NTM bacteraemia, and the implementation of changes to CVC care protocols was successful in preventing further infections in this immunocompromised patient group.     

Prevalence of cryptosporidiosis in hiv-infected patients with diarrhoeal illness

Protozoans of the genus Cryptosporidium may cause serious diarrhoeal illness in immunocompromised hosts and especially in HIV-infected patients. In this study we have evaluated the frequency of Cryptosporidium in stools of 51 HIV-infected patients with diarrhoea. Laboratory diagnosis of cryptosporidiosis was performed of faecal samples concentrated by a formalin-ether sedimentation technique and stained by a modified cold Ziehl-Neelsen method. Results demonstrated that 17 (33.3%) of these patients were infected with Cryptosporidium. Moreover, Cryptosporidium infection was the first clinical marker of AIDS in 7 cases. Our data show that the prevalence of this parasitosis in HIV-infected people seems to be higher in our region (Apulia, South Italy), compared to other areas of the world.     

Occurrence of Cryptosporidium oocysts and Giardia cysts in Norwegian groundwater wells in bedrock

The occurrence of Cryptosporidium oocysts and Giardia cysts in Norwegian groundwater wells in bedrock has been investigated for the first time. Wells close to risk areas such as farming and septic tanks were chosen. In all, 20 water samples from 20 different waterworks were collected. The samples were analysed for Cryptosporidium and Giardia, using US EPA Method 1623. Turbidity was also measured. Water samples from 10 of the waterworks were also analysed for Clostridium perfringens by membrane filtration. Cryptosporidium was detected in the groundwater samples from 3 of the waterworks. Giardia and Clostridium perfringens were not detected. Too few samples were analysed to verify whether Giardia is indeed absent from bedrock wells, and further studies are recommended to give more reliable data.     

Control of an outbreak of carbapenem-resistant Pseudomonas aeruginosa in a haemato-oncology unit

An outbreak of a multidrug-resistant Pseudomonas aeruginosa producing metallo-β-lactamase (MBLPA) in a haemato-oncology unit was controlled using multidisciplinary interventions. The present study assesses the effects of these interventions by active surveillance of the incidence of MBLPA infection at the 1,240-bed tertiary care Kyoto University Hospital in Kyoto, Japan. Infection control strategies in 2004 included strengthening contact precautions, analysis of risk factors for MBLPA infection and cessation of urine collection. However, new MBLPA infections were identified in 2006, which prompted enhanced environmental cleaning, routine active surveillance, and restricting carbapenem usage. Between 2004 and 2010, 17 patients in the unit became infected with indistinguishable MBLPA strains. The final five infected patients were found by routine active surveillance, but horizontal transmission was undetectable. The MBLPA outbreak in the haemato-oncology unit was finally contained in 2008.     

Management and control of a carbapenem-resistant Acinetobacter baumannii outbreak in an intensive care unit

Objective

We had for aim to describe the identification and management of a 14-clonal carbapenem-resistant Acinetobacter baumannii (CRAB) outbreak, following admission of a known CRAB-infected patient in an ICU.

Methods

We reviewed the carriers’ files and outbreak management procedures.

Results

The index patient was admitted with strict isolation precautions. The outbreak started 2 months after his discharge. It persisted despite reinforcement of strict isolation precautions, staff and patient cohorting, and extensive environmental decontamination including 2 rounds of routine terminal cleaning and disinfection or 1 round of cleaning and disinfection followed by hydrogen peroxide treatment. A second epidemic peak, after 4 weeks without any case, led to another wide environmental sampling and decontamination rounds. The source of the CRAB outbreak was suspected to be the blood pressure cuffs Velcro. Switching to cuffs submersible in a disinfectant stopped the outbreak.

Conclusions

CRAB outbreaks are difficult to manage and sources of persistent colonization can be unexpected.     

Extended outbreak of cryptosporidiosis in a pediatric hospital, China

Four Cryptosporidium spp. and 6 C. hominis subtypes were isolated from 102 of 6,284 patients in 3 pediatric hospitals in People's Republic of China. A cryptosporidiosis outbreak was identified retrospectively. The outbreak lasted >1 year and affected 51.4% of patients in 1 hospital ward, where 2 C. hominis subtypes with different virulence were found.     

Nosocomial outbreak of Myroides odoratimimus urinary tract infection in a Tunisian hospital

We report a nosocomial outbreak of urinary tract infection caused by Myroides odoratimimus, previously called Flavobacterium odoratum, in the urology unit of a Tunisian hospital. From May to November 2010, seven isolates of M.?odoratimimus were recovered from urine. Pulsed-field gel electrophoresis clearly differentiated these isolates into two possibly related clones from two different periods. All patients but one had urinary calculi and underwent endourological surgery. All Myroides isolates were resistant to all antibiotics tested. Three patients were successfully treated with ciprofloxacin and rifampicin. Clinicians should be aware that M.?odoratimimus may induce serious and prolonged nosocomial outbreaks of urinary tract infections.     

上海某污水厂出水及其排放水体中隐孢子虫和贾第鞭毛虫的分析检测

目的：检测上海某污水厂处理出水及其排放水体黄浦汀上游中隐孢子虫和贾第鞭毛虫存在水平。方法：微孔滤膜过滤、乙酸乙酯福尔马林分离、Giemsa染色、油镜及相差显微镜观察。结果：对污水厂所取八次水样中，贾第氏虫孢囊检出6次，阳性率为75％，检出贾第氏虫孢囊最高含量为56个／10L；隐孢子虫卵囊共检出4次，阳性率为50％，检出隐孢子虫卵囊的最高含量为63个／10L；贾第氏虫孢囊与隐孢子虫卵囊的共同阳性率为12．5％。从其排放水体黄浦江上游所取的8份水样中，贾第氏虫孢囊共检出2次，阳性率为25％，最高含量为45个／10L；隐孢子虫卵囊只检出过1次，阳性率为12．5％，卵囊含量为30个／10L；同时检测出贾第氏虫孢囊和隐孢子虫卵囊的共同阳性率为0％。结论：上海城市污水处理厂应加强对两虫的去除工艺改进，减少上海城市供水生物安全风险。     

Development of Sensitive Detection of Cryptosporidium and Giardia from Surface Water in Iran

Background

The protozoan parasites Cryptosporidium spp. and Giardia are known to occur widely in both raw and drinking waters. They are two of the causative agents of waterborne outbreaks of gastroenteritis throughout the world. In the present study, a PCR assay and FA were developed for detection of Cryptosporidium oocysts and Giardia cyst in environmental samples.

Methods

We have detected Cryptosporidium spp. oocysts and Giardia cysts in seeded and unseeded environmental water samples by PCR method. Water samples were spiked with oocysts (50, 100,300,500) and filtrated with a 1.2-µm pore size cellulose nitrate and follow by DNA extraction and purification by QIAamp DNA mini kit. Nested-PCR assay amplified an 850 bp fragment of 18s rRNA gene specific for Cryptosporidium and 435 bp fragment of glutamate dehydrogenase (GDH) target gene for Giardia. Also many river water from north of Iran, be checked by these methods.

Results

Cryptosporidium and Giardia DNAs were detected in seeded water sample and Giardia was detected in all 5 water samples from river in north of Iran by nested- PCR and FA. Also in one river water sample, Cryptosporidium was detected.

Conclusion

This protocol is effective for detection of these waterborne parasites in treated and untreated water samples. This study can also serve as a platform for further investigations and research water source in Iran.     

Cost of illness in the 1993 waterborne Cryptosporidium outbreak,Milwaukee, Wisconsin

To assess the total medical costs and productivity losses associated with the 1993 waterborne outbreak of cryptosporidiosis in Milwaukee, Wisconsin, including the average cost per person with mild, moderate, and severe illness, we conducted a retrospective cost-of-illness analysis using data from 11 hospitals in the greater Milwaukee area and epidemiologic data collected during the outbreak. The total cost of outbreak-associated illness was 96.2 million US dollars: 31.7 million US dollars in medical costs and 64.6 million US dollars in productivity losses. The average total costs for persons with mild, moderate, and severe illness were 116 US dollars, 47 US dollars, and 7,808 US dollars, respectively. The potentially high cost of waterborne disease outbreaks should be considered in economic decisions regarding the safety of public drinking water supplies.     

Occurrence of Cryptosporidium oocysts and Giardia cysts in the Nakdong River and their removal during water treatment

This study was conducted in preparation of a pending Cryptosporidium regulation in Korea. The study had two main objectives: 1) to examine the occurrence of Cryptosporidium oocysts in the Nakdong River; and 2) to evaluate their removal during water treatment. Occurrence of Giardia cysts was also examined. Average (arithmetic mean) numbers of Cryptosporidium oocysts and Giardia cysts at the treatment intake site were 2.6 l^-1 and 4.8 l^-1, respectively. Generally, the number of Giardia cysts was higher than that of Cryptosporidium oocysts at more sites, but the difference was minimal. Comparison of tributaries indicated that livestock wastes were more serious pollutants than sewage in terms of protozoa contamination. In general, fewer oocysts and cysts were detected during winter. No correlation was found for such water quality parameters as T-N, T-P, TOC, DO, pH and temperature with the numbers of oocysts and cysts except for suspended solids, which showed the highest correlation (R²=0.55). Removal of Cryptosporidium oocysts was evaluated using a Cryptosporidium tracer, which has similar characteristics to Cryptosporidium oocysts. The tracer removal depended on turbidity removal. Coagulation followed by sedimentation resulted in 1.2–1.5 log removal of the tracer under optimal conditions. Filtration resulted in 1.3–1.5 log removal of the tracer. These treatability experiments showed that traditional water treatment processes could achieve 2.5–3.0 log removal of the oocysts.