Biomedical subjects

J B Rose

Publications and source records attributed to J B Rose.

At least 37 records · Page 2Linked to original sources

PubMed2000

Effect of high hydrostatic pressure on Cryptosporidium parvum infectivity.

The incidence of foodborne disease outbreaks caused by contaminated low-pH fruit juices is increasing. With recent mandatory pasteurization of apple juice and the industry's concerns of food safety, fruit juice processors are showing more interest in alternative nonthermal technologies that can kill >99.99% of microbial pathogens present in foods. The association of the coccidian protozoan, Cryptosporidium, with diarrheal disease outbreaks from contaminated tap water and fruit juice raises a safety concern in the food and beverage industries. The objective of this study was to evaluate the effects of high hydrostatic pressure (HHP) on C. parvum oocysts. Oocysts were suspended in apple and orange juice and HHP treated at 5.5 x 10(8) Pa (80,000 psi) for 0, 30, 45, 60, 90, and 120 s. Oocyst viability was assessed by excystation using bile salts and trypsin while the cell culture foci detection method was used to assess infectivity. Results indicated that HHP inactivated C. parvum oocysts by at least 3.4 log10 after 30 s of treatment. No infectivity was detected in samples exposed to > or =60 s of HHP and >99.995% inactivation was observed. This study demonstrated that HHP efficiently rendered the oocysts nonviable and noninfectious after treatment at 5.5 x 10(8) Pa.

Animals↗

PubMed1999

A risk assessment framework for the evaluation of skin infections and the potential impact of antibacterial soap washing.

Antibacterial soaps may have an important role in the control of skin infection. However, quantitative estimation of their benefit is difficult because of the problems associated with conducting epidemiologic studies. An alternative benefit estimation approach, quantitative microbial risk assessment, has application to this problem. This article sets forth the quantitative microbial risk assessment method and applies it specifically to the estimation of the reduction in risk of dermal infection from Staphylococcus aureus resulting from use of antibacterial soaps. A dose-response model was formulated by using available information on growth kinetics of the organism on the skin and dose data based on the inoculation of the forearm skin in volunteers. A predictive relationship for microbial growth on the skin was developed. These data were limited, and clearly more studies are needed on inoculation at more than one site and growth leading to infection on the skin with and without the use of germicidal soaps.However, by using relationships based on extant data sets, it was estimated that the use of germicidal soap could result in a substantial reduction in the risk of infection by S aureus. The estimated risk reduction was in general concordance with published results from epidemiologic studies conducted on military cadets. The methodology of quantitative microbial risk assessment has thus been shown to be applicable to this problem and may have broader applicability in other personal hygiene contexts.

Adult↗

PubMed1999

Use of quantitative microbial risk assessment for evaluation of the benefits of laundry sanitation.

The goal of this study was to evaluate the risk assessment process for quantifying the contribution of contamination in the home to microbial infections. Whereas risks of enteric pathogens spread through food has been assessed, the spread of fecal-oral pathogens through surfaces likely at low rates would be difficult to address through epidemiologic studies. An alternative is quantitative risk assessment. The 4-step process of hazard identification, dose-response, exposure assessment, and risk characterization can be used; however, exposure assessment may follow a complicated pathway consisting of survival and transference. Microbial hazards in the home have focused primarily on enteric bacteria. Dose-response data are available; however, the transfer from the hands to the dose is uncertain. Through day care studies, Shigella has been shown to be transferred in this manner, and a dose-response model is available. By using these data and information on the transference of bacteria between clothing and hands, risk estimates were made for contaminated laundry. Risks were calculated as high as 10 per million population to much lower levels associated with lower excretion rates of the bacteria in the feces. Approximately a 90% and 99% reduction in the probability of disease through laundering and use of a sanitizing detergent, respectively, were suggested by the models. Better data are needed on incidence of disease in the population, excretion rates over the course of an infection, amount of feces spread in the home, distribution of bacteria, survival, and the transfer of the bacteria from surfaces to the hands and to the mouth.

Clothing↗

PubMed1999

Postoperative nausea and vomiting in paediatric patients.

The past decade has witnessed the introduction of several significant innovations to combat POV, particularly the introduction of serotonin antagonists and the use of combinations of drugs for analgesia and control of POV. Based on current knowledge, the anaesthetic plan for a patient with a previous history of severe PONV and undergoing a procedure known to be associated with a high incidence of this problem should include premedication with a benzodiazepine and/or clonidine and the preferential use of regional anaesthetic techniques. If general anaesthesia is essential, anaesthetists should consider the use of propofol for both induction and maintenance of anaesthesia, together with avoidance of nitrous oxide, opioids and neuromuscular antagonists. Pain control is extremely important, and a peripheral regional block should be used if possible. A combination of prophylactic antiemetics such as dexamethasone, a 5-HT3 antagonist and an antiemetic of a different class (e.g. perphenazine or dimenhydrinate) should be administered. Non-pharmacological measures such as acupressure and suggestion should also be considered, together with nursing measures to avoid sudden movement from one position to another during the postoperative period. A quiet environment, adequate i.v. fluids and not forcing the patient to drink before discharge all contribute to decreased emesis. It is possible that the advent of a new class of antiemetic agents, the NKI antagonists, may have major effects on the incidence of this complication. Drugs in this group differ from other currently available drugs in having the ability to effectively block the emetic response to many stimuli in experimental animals. Postoperative vomiting remains a significant problem, resulting in patient suffering and prolonged recovery from anaesthesia. Our aim should be to eliminate this complication in all children who require surgery. It should not be considered merely as the 'big, little problem'.

Antiemetics↗

PubMed1999

Preoperative oral dextromethorphan does not reduce pain or analgesic consumption in children after adenotonsillectomy.

UNLABELLED: In this randomized, double-blinded, placebo-controlled, prospective study, we evaluated the analgesic efficacy of dextromethorphan 0.5 mg/kg or 1.0 mg/kg p.o. 1 h before adenotonsillectomy in 57 children 6-12 yr of age. Anesthetic management was standardized. Morphine 0.075 mg/kg i.v. and acetaminophen 25-35 mg/kg p.r. were administered after anesthetic induction but before the start of surgery. A 4-point behavioral score (1 = asleep, 2 = awake and calm, 3 = awake and crying, 4 = thrashing) was recorded on admission to and discharge from the postanesthesia care unit (PACU). In the PACU, pain was assessed with Children's Hospital of Eastern Ontario Pain Scale (CHEOPS) and recorded every 15 min until the patient was transferred to the day surgery unit (DSU). In the DSU, patients rated their pain using a 10-cm baseline 0-10 visual analog pain scale (VAS) every 30 min until they were discharged home. A 24-h VAS was obtained by phone interview, and parental satisfaction was scored (yes/no) regarding their child's postoperative analgesia. Morphine 0.025 mg/kg i.v. was administered to children with CHEOPS score >6, who verbalized pain, or who were crying in any consecutive 5-min observation periods in the PACU. Total morphine consumption was recorded. The study groups were comparable with respect to demographic variables. We were unable to detect any differences between study groups with respect to postoperative morphine consumption, CHEOPS, behavior scores, VAS, or parental satisfaction. IMPLICATIONS: Premedication with dextromethorphan 0.5 or 1.0 mg/kg p.o. does not improve postoperative analgesia in school-aged children who receive preemptive morphine 0.075 mg/kg i.v. and acetaminophen 25-35 mg/kg p.r. during nitrous oxide and desflurane anesthesia for adenotonsillectomy.

Acetaminophen↗

PubMed1999

A most-probable-number assay for enumeration of infectious Cryptosporidium parvum oocysts.

Cryptosporidium is globally established as a contaminant of drinking and recreational waters. A previously described cell culture infectivity assay capable of detecting infectious oocysts was adapted to quantify viable oocysts through sporozoite invasion and clustering of foci. Eight experiments were performed by using oocysts less than 4 months of age to inoculate host HCT-8 cell monolayers. Oocysts were diluted in a standard 5- or 10-fold multiple dilution format, levels of infection and clustering were determined, and the most probable number (MPN) of infectious oocysts in the stock suspension was calculated. The MPN was compared to the initial oocyst inoculum to determine the level of correlation. For oocysts less than 30 days of age, the correlation coefficient (r) was 0.9726 (0.9306 to 0.9893; n = 20). A two-tailed P value (alpha = 0.05) indicated that P was less than 0.0001. This strong correlation suggests that the MPN can be used to effectively enumerate infectious oocysts in a cell culture system. Age affected the degree of oocyst infectivity. Oocyst infectivity was tested by the focus detection method (FDM)-MPN assay and in BALB/c mice before and after treatment with pulsed white light (PureBrite). The FDM-MPN assay and animal infectivity assays both demonstrated more than a 4 log(10) inactivation. Municipal water systems and a host of other water testing organizations could utilize the FDM-MPN assay for routine survival and disinfection studies.

Animals↗

PubMed1999

Detection of viral pathogens by reverse transcriptase PCR and of microbial indicators by standard methods in the canals of the Florida Keys.

In order to assess the microbial water quality in canal waters throughout the Florida Keys, a survey was conducted to determine the concentration of microbial fecal indicators and the presence of human pathogenic microorganisms. A total of 19 sites, including 17 canal sites and 2 nearshore water sites, were assayed for total coliforms, fecal coliforms, Escherichia coli, Clostridium perfringens, enterococci, coliphages, F-specific (F(+)) RNA coliphages, Giardia lamblia, Cryptosporidium parvum, and human enteric viruses (polioviruses, coxsackie A and B viruses, echoviruses, hepatitis A viruses, Norwalk viruses, and small round-structured viruses). Numbers of coliforms ranged from <1 to 1, 410, E. coli organisms from <1 to 130, Clostridium spp. from <1 to 520, and enterococci from <1 to 800 CFU/100 ml of sample. Two sites were positive for coliphages, but no F(+) phages were identified. The sites were ranked according to microbial water quality and compared to various water quality standards and guidelines. Seventy-nine percent of the sites were positive for the presence of enteroviruses by reverse transcriptase PCR (polioviruses, coxsackie A and B viruses, and echoviruses). Sixty-three percent of the sites were positive for the presence of hepatitis A viruses. Ten percent of the sites were positive for the presence of Norwalk viruses. Ninety-five percent of the sites were positive for at least one of the virus groups. These results indicate that the canals and nearshore waters throughout the Florida Keys are being impacted by human fecal material carrying human enteric viruses through current wastewater treatment strategies such as septic tanks. Exposure to canal waters through recreation and work may be contributing to human health risks.

Clostridium↗

PubMed1999

Giardia, Cryptosporidium, and Cyclospora and their impact on foods: a review.

While the risk from pathogenic microorganisms in foods has been recognized for hundreds of years, bacterial agents are generally implicated as the contaminants. Although many outbreaks of gastroenteritis caused by protozoan pathogens have occurred, it is only in the last 3 years that attention has focused on protozoan association with foodborne transmission. Recognized as waterborne parasites, Giardia, Cryptosporidium, and Cyclospora have now been associated with several foodborne outbreaks. The oocysts and cysts of these organisms can persist and survive for long periods of time both in water and on foods. While Cyclospora oocysts require a maturation period, Cryptosporidium oocysts and Giardia cysts are immediately infectious upon excretion from the previous host. As a result, these parasites have emerged as public health risks and have become a concern to the food industry. More than 200 cases of foodborne giardiasis (seven outbreaks) were reported from 1979 to 1990. Four foodborne Cryptosporidium outbreaks (with a total of 252 cases) have been documented since 1993. Cyclospora caused a series of sporadic outbreaks of cyclosporasis throughout North America that have affected over 3,038 people since 1995. Control and prevention of protozoan foodborne disease depends upon our ability to prevent, remove, or kill protozoan contaminants. This review will address the biology, foodborne and waterborne transmission, survival, and methods for detection and control of Giardia, Cryptosporidium, and Cyclospora.

Animals↗

PubMed1998

Epidural analgesia in children with cerebral palsy.

PURPOSE: Two modalities of epidural analgesia in children with two types of cerebral palsy (CP) were compared for differences in the incidence of common complications (inadequate analgesia, hypopnea, hypoxaemia, sedation, vomiting, pruritus, urinary retention, and seizures). METHODS: Demographic, procedural and postoperative complication data were collected on children with CP receiving epidural analgesia. Information was recorded contemporaneously with the child's care by one of the authors on 92 consecutive children with CP (age, 107 +/- 50.1 mo; weight, 26 +/- 14.2 kg) who had undergone infra-umbilical orthopaedic or Nissen fundoplication procedures between December 1994 and December 1996. The first 44 patients received intermittent bolus (IB) epidural morphine and the next 48 received continuous infusion (CI) bupivacaine and fentanyl. Two forms of CP (spastic diplegia and quadriplegia) and the two modalities of analgesia were compared. RESULTS: Excellent analgesia was obtained in 91/92 patients. Excessive sedation occurred in six patients (6.5%) but only in IB patients, (P < 0.02 vs CI). Emesis occurred in 52% of patients, and was more common in diplegic than in quadriplegic patients (68% vs 38%, P < 0.01). Pruritus was observed in 29% of patients and was more common in diplegia than quadriplegia (48% vs 12.5%, P < 0.001). The incidences of hypopnea, hypoxaemia, urinary retention and seizures were not affected by the types of CP or analgesia and no difference in sedation was observed between spastic diplegic and quadriplegic patients. CONCLUSIONS: Continuous infusion of epidural bupivacaine and fentanyl provided excellent analgesia for children with CP without serious complications. Intermittent bolus epidural morphine was associated with a high incidence of excessive sedation and should be avoided in this population.

Analgesia, Epidural↗

PubMed1998

Waterborne cryptosporidiosis: current status.

In the past ten years Cryptosporidium oocysts have been shown to be common contaminants of water, causing at least 19 waterborne outbreaks of cryptosporidiosis which have affected more than 427 000 individuals. Recommended methods for oocyst isolation and enumeration are time-consuming and inefficient and experts state that the absence of Cryptosporidium oocysts in drinking water can never be guaranteed. In the UK alone, a National Research Programme costing pound3 million has been undertaken. Here, Huw Smith and Joan Rose review the current status of knowledge and identify approaches taken by UK and USA Government regulatory bodies in order to reduce the likelihood of waterborne transmission.

Journal Article↗

PubMed1998

Risk assessment of waterborne protozoa: current status and future trends.

Throughout the past decade much research has been directed towards identifying the occurrence, epidemiology, and risks associated with waterborne protozoa. While outbreaks are continually documented, sporadic cases of disease associated with exposure to low levels of waterborne protozoa are of increasing concern. Current methodologies may not be sensitive enough to define these low levels of disease. However, risk assessment methods may be utilised to address these low level contamination events. The purpose of this article is to provide an introduction to microbial risk assessment for waterborne protozoa. Risk assessment is a useful tool for evaluating relative risks and can be used for development of policies to decrease risks. Numerous studies have been published on risk assessment methods for pathogenic protozoa including Cryptosporidium and Giardia. One common notion prevails: microbial risk assessment presents interesting complications to the traditional chemical risk assessment paradigm. Single microbial exposures (non-threshold) are capable of causing symptomatic illness unlike traditional chemical exposures, which require a threshold to be reached. Due to the lack of efficient recovery and detection methods for protozoa, we may be underestimating the occurrence, concentration and distribution of these pathogenic micro-organisms. To better utilize the tool of microbial risk assessment for risk management practices, future research should focus in the area of exposure assessment.

Animals↗

PubMed1997

Risk assessment of opportunistic bacterial pathogens in drinking water.

This study was undertaken to examine quantitatively the risks to human health posed by heterotrophic plate count (HPC) bacteria found naturally in ambient and potable waters. There is no clear-cut evidence that the HPC bacteria as a whole pose a public health risk. Only certain members are opportunistic pathogens. Using the four-tiered approach for risk assessment from the National Academy of Sciences, hazard identification, dose-response modeling, and exposure through ingestion of drinking water were evaluated to develop a risk characterization, which estimates the probability of infection for individuals consuming various levels of specific HPC bacteria. HPC bacteria in drinking water often include isolates from the following genera: Pseudomonas, Acinetobacter, Moraxella, Aeromonas, and Xanthomonas. Other bacteria that are commonly found are Legionella and Mycobacterium. All these genera contain species that are opportunistic pathogens which may cause serious diseases. For example, the three nonfermentative gram-negative rods most frequently isolated in the clinical laboratory are (1) Pseudomonas aeruginosa, (2) Acinetobacter, and (3) Xanthomonas maltophilia. P. aeruginosa is a major cause of hospital-acquired infections with a high mortality rate. Aeromonas is sometimes associated with wound infections and suspected to be a causative agent of diarrhea. Legionella pneumophila causes 4%-20% of cases of community-acquired pneumonia and has been ranked as the second or third most frequent cause of pneumonia requiring hospitalization. The number of cases of pulmonary disease associated with Mycobacterium avian is rapidly increasing and is approaching the incidence of M. tuberculosis in some areas. Moraxella can cause infections of the eye and upper respiratory tract. The oral infectious doses are as follows in animal and human test subjects: P. aeruginosa, 10(8)-10(9); A, hydrophila, > 10(10); M. avium, 10(4)-10(7); and X. maltophilia, 10(6)-10(9). The infectious dose for an opportunistic pathogen is lower for immunocompromised subjects or those on antibiotic treatment. These bacteria have been found in drinking water at the following frequencies: P. aeruginosa, < 1%-24%; Acinetobacter, 5%-38%; X. maltophilia, < 1%-2%; Aeromonas, 1%-27%; Moraxella, 10%-80%; M. avium, < 1%-50%; and L. pneumophila, 3%-33%. These data suggest that drinking water could be a source of infection for some of these bacteria. The risk characterization showed that risks of infection from oral ingestion ranged from a low of 7.3 x 10(-9) (7.3/billion) for low exposures to Aeromonas to higher risks predicted at high levels of exposure to Pseudomonas of 9 x 10(-2) (98/100). This higher risk was only predicted for individuals on antibiotics. Overall, the evidence suggests that specific members of HPC bacteria found in drinking water may be causative agents of both hospital- and community-acquired infections. However, the case numbers may be very low and the risks represent levels generally less than 1/10,000 for a single exposure to the bacterial agent. Future research needs include (1) determining the seasonal concentrations of these bacteria in drinking water, (2) conducting adequate dose-response studies in animal subjects or human volunteers, (3) determining the health risks for an individual with multiple exposures to the opportunistic pathogens, and (4) evaluating the increase in host susceptibility conferred by antibiotic use or immunosuppression.

Acinetobacter↗

PubMed1997

Comparison of cuffed and uncuffed endotracheal tubes in young children during general anesthesia.

BACKGROUND: Uncuffed endotracheal tubes are routinely used in young children. This study tests a formula for selecting appropriately sized cuffed endotracheal tubes and compares the use of cuffed versus uncuffed endotracheal tubes for patients whose lungs are mechanically ventilated during anesthesia. METHODS: Full-term newborns and children (n = 488) through 8 yr of age who required general anesthesia and tracheal intubation were assigned randomly to receive either a cuffed tube sized by a new formula [size(mm internal diameter) = (age/4) + 3], or an uncuffed tube sized by the modified Cole's formula [size(mm internal diameter) = (age/4) + 4]. The number of intubations required to achieve an appropriately sized tube, the need to use more than 21.min-1 fresh gas flow, the concentration of nitrous oxide in the operating room, and the incidence of croup were compared. RESULTS: Cuffed tubes selected by our formula were appropriate for 99% of patients. Uncuffed tubes selected by Cole's formula were appropriate for 77% of patients (P < 0.001). The lungs of patients with cuffed tubes were adequately ventilated with 2 1.min-1 fresh gas flow, whereas 11% of those with uncuffed tubes needed greater fresh gas flow (P < 0.001). Ambient nitrous oxide concentration exceeded 25 parts per million in 37% of cases with uncuffed tubes and in 0% of cases with cuffed tubes (P < 0.001). Three patients in each group were treated for croup symptoms (1.2% cuffed; 1.3% uncuffed). CONCLUSIONS: Our formula for cuffed tube selection is appropriate for young children. Advantages of cuffed endotracheal tubes include avoidance of repeated laryngoscopy, use of low fresh gas flow, and reduction of the concentration of anesthetics detectable in the operating room. We conclude that cuffed endotracheal tubes may be used routinely during controlled ventilation in full-term newborns and children during anesthesia.

Anesthesia, General↗

PubMed1997

Coliphage and indigenous phage in Mamala Bay, Oahu, Hawaii.

Public concern over the discharge of primarily treated sewage by two offshore outfalls in Mamala Bay, Oahu, prompted a multidisciplinary study to determine the impact of such activities on the water quality in the bay and at adjacent recreational beaches. As part of this study, we determined the abundance of coliphage as an indicator of fecal pollution along with total viral direct counts and phages infective for Vibrio parahaemoltyicus 16 at stations in Mamala Bay in four quarterly samplings over 13 months. Coliphage (< 1 to 1.2 x 10(3)/liter) were found during each quarterly sampling along an offshore transect to the Sand Island waste treatment facility outfall. The nonpoint coastal stations (Pearl Harbor, Ala Wai Canal, and Ke'ehi Lagoon) had high levels of coliphage during the storm event sampling in February 1994 but much lower levels or none when sampled during dry weather. Coliphage were absent at all samplings at Waikiki Beach and at the control station off Diamond Head. Viral direct counts in eutrophic coastal stations (Pearl Harbor, Ke'ehi Lagoon, Ala Moana Beach, and Ala Wai canal) averaged 10(9)/liter, while counts at offshore stations ranged from 9 x 10(7) to 1 x 10(9) viruses/liter, values similar to those for other marine environments. Vibriophage were found mainly in eutrophic coastal environments (Ala Wai Canal, Pearl Harbor, and Ke'ehi Lagoon) and at the Sand Island Transect stations D1 and D2. The greatest abundance was found during the storm event (February 1994) sampling. These results suggest that the Sand Island outfall influenced the water quality of the immediate surrounding waters but had little effect on the quality of the recreational beaches. Nonpoint discharge sources appeared to be more important in the distribution of fecal indicators in the coastal zone.

Bacteriophages↗

PubMed1997

Comparison of PCR and plaque assay for detection and enumeration of coliphage in polluted marine waters.

A total of 68 marine samples from various sites impacted by sewage and storm waters were analyzed by both the plaque assay and a reverse transcriptase (RT) PCR technique for F(sup+)-specific coliphage. The coliphage levels detected by the plaque assay averaged 1.90 x 10(sup4) PFU/100.0 ml. Using a most probable number (MPN) PCR approach, the levels averaged 2.40 x 10(sup6) MPN-PCR units/100.0 ml. Two samples were positive by RT-PCR but negative by plaque assay, and 12 samples were positive by plaque assay but negative by RT-PCR (levels lower than 11.00 PFU/100.0 ml). The host system used for the plaque assay may detect somatic coliphage in addition to the F(sup+)-specific coliphage. When it is used as an indicator of pollution, contamination may be missed with more restrictive systems. The difference in results may be due to the sensitivity, specificity, or inhibition of RT-PCR in marine samples. This study provides information on quantifying PCR results by an MPN method and insights into interpretation of PCR data for detection of viruses in marine environments.

Journal Article↗

PubMed1997

An in vitro method for detecting infectious Cryptosporidium oocysts with cell culture.

Current assay methods to detect Cryptosporidium oocysts in water are generally not able to evaluate viability or infectivity. A method was developed for low-level detection of infective oocysts by using HCT-8 cells in culture as hosts to C. parvum reproductive stages. The infective foci were detected by labeling intracellular developmental stages of the parasite in an indirect-antibody assay with a primary antibody specific for reproductive stages and a secondary fluorescein isothiocyanate-conjugated antibody. The complete assay was named the focus detection method (FDM). The infectious foci (indicating that at least one of the four sporozoites released from a viable oocyst had infected a cell) were enumerated by epifluorescence microscopy and confirmed under Nomarski differential interference contrast microscopy. Time series experiments demonstrated that the autoreinfective life cycle in host HCT-8 cells began after 12 h of incubation. Through dilution studies, levels as low as one infectious oocyst were detected. The cell culture FDM compared well to other viability assays. Vital stains and excystation demonstrated that oocyst populations less than 1% viable (by vital dyes) and having a low sporozoite yield following excystation could not infect host cells. Until now, the water industry has relied on an oocyst detection method (under an information collection regulation) that is unable to determine viability. The quantifiable results of the cell culture method described demonstrate two important applications: (i) an infectivity assay that may be used in conjunction with current U.S. Environmental Protection Agency-mandated detection methodologies, and (ii) a method to evaluate oocyst infectivity in survival and disinfection studies.

Animals↗

PubMed1997

Environmental ecology of Cryptosporidium and public health implications.

Cryptosporidium has become the most important contaminant found in drinking water and is associated with a high risk of waterborne disease particularly for the immunocompromised. There have been 12 documented waterborne outbreaks in North America since 1985; in two of these (Milwaukee and Las Vegas) mortality rates in the immunocompromised ranged from 52% to 68%. The immunofluorescence antibody assay (IFA) using epifluorescence microscopy has been used to examine the occurrence of Cryptosporidium in sewage (1 to 120 oocysts/liter), filtered secondary treated wastewater (0.01 to 0.13 oocysts/liter), surface waters (0.001 to 107 oocysts/liter), groundwater (0.004 to 0.922 oocysts/liter) and treated drinking water (0.001 to 0.72 oocysts/liter). New rules are being developed (Information Collection Rule and Enhanced Surface Water Treatment Rule) to obtain more occurrence data for drinking water systems for use with new risk assessment models. Public health officials should consider a communication program to physicians treating the immunocompromised, nursing homes, develop a plan to evaluate cases of cryptosporidiosis in the community, and contribute to the development of public policies that limit contamination of source waters, improve water treatment, and protect public health.

Animals↗

PubMed1997

The role of seafood in foodborne diseases in the United States of America.

In the United States of America, seafood ranked third on the list of products which caused foodborne disease between 1983 and 1992. Outbreaks connected with fish vectors were caused by scombroid, ciguatoxin, bacteria and unknown agents; in shellfish, unknown agents, paralytic shellfish poisoning, Vibrio spp. and other bacteria, followed by hepatitis A virus, were responsible for the outbreaks. At least ten genera of bacterial pathogens have been implicated in seafood-borne diseases. Over the past twenty-five years, bacterial pathogens associated with faecal contamination have represented only 4% of the shellfish-associated outbreaks, while naturally-occurring bacteria accounted for 20% of shellfish-related illnesses and 99% of the deaths. Most of these indigenous bacteria fall into the family Vibrionaceae which includes the genera Vibrio, Aeromonas and Plesiomonas. In general, Vibrio spp. are not associated with faecal contamination and therefore faecal indicators do not correlate with the presence of Vibrio. Viruses are the most significant cause of shellfish-associated disease: in New York State, for example, 33% and 62% of 196 outbreaks between 1981 and 1992 were caused by Norwalk virus and gastrointestinal viruses (small round structured viruses), respectively. In addition, several illnesses are a result of toxic algal blooms, the growth of naturally occurring bacteria and diatoms causing neurotoxic shellfish poisoning, paralytic shellfish poisoning, diarrhoetic shellfish poisoning, amnesic shellfish poisoning and ciguatera. Current estimates place the annual number of ciguatera cases at 20,000 world-wide. Scombroid poisoning is the most significant cause of illness associated with seafood. Scombrotoxin is of bacterial origin and halophilic Vibrio spp. causing high histamine levels are implicated as the source. Scombroid poisoning is geographically diverse and many species have been implicated, namely: tuna, mahi-mahi, bluefish, sardines, mackerel, amberjack and abalone. Temperature abuse has been cited as a major cause of scombroid poisoning. For routine work, the use of faecal indicators to predict the relative level of faecal contamination should not be disposed of. However, the main source of seafood illness is due to species which are not predicted by these organisms. In order to protect public health, routine surveillance using new pathogen-specific techniques such as polymerase chain reaction should be used. This, in combination with risk assessment methods and hazard analysis and critical control points, will begin to address the need for improvement in the safety of seafood.

Animals↗