Towards a more accurate quantitative assessment of seasonal Cryptosporidium infection risks in surface waters using species and genotype information.

Many Cryptosporidium species/genotypes are not considered infectious to humans, and more realistic estimations of seasonal infection risks could be made using human infectious species/genotype information to inform quantitative microbial risk assessments (QMRA). Cryptosporidium oocyst concentration and species/genotype data were collected from three surface water surveillance programs in two river basins [South Nation River, SN (2004-09) and Grand River, GR (2005-13)] in Ontario, Canada to evaluate seasonal infection risks. Main river stems, tributaries, agricultural drainage streams, water treatment plant intakes, and waste water treatment plant effluent impacted sites were sampled. The QMRA employed two sets of exposure data to compute risk: one assuming all observed oocysts were infectious to humans, and the other based on the fraction of oocysts that were C. hominis and/or C. parvum (dominant human infectious forms of the parasite). Viability was not considered and relative infection risk was evaluated using a single hypothetical recreational exposure. Many sample site groupings for both river systems, had significant seasonality in Cryptosporidium occurrence and concentrations (p ≤ 0.05); occurrence and concentrations were generally highest in autumn for SN, and autumn and summer for GR. Mean risk values (probability of infection per exposure) for all sites combined, for each river system, were roughly an order of magnitude lower (avg. of SN and GR 5.3 × 10-5) when considering just C. parvum and C. hominis oocysts, in relation to mean infection risk (per exposure) assuming all oocysts were infectious to humans (5.5 × 10-4). Seasonality in mean risk (targeted human infectious oocysts only) was most strongly evident in SN (e.g., 7.9 × 10-6 in spring and 8.1 × 10-5 in summer). Such differences are important if QMRA is used to quantify effects of water safety/quality management practices where inputs from a vast array of fecal pollution sources can readily occur. Cryptosporidium seasonality in water appears to match the seasonality of human infections from Cryptosporidium in the study regions. This study highlights the importance of Cryptosporidium species/genotype data to help determine surface water pollution sources and seasonality, as well as to help more accurately quantify human infection risks by the parasite.

Infections with Chryseomonas luteola (CDC group Ve-1) and flavimonas oryzihabitans (CDC group Ve-2).

We have described 15 cases of infection due to Chryseomonas luteola and Flavimonas oryzihabitans isolated between May 1990 and May 1994. These infections were often associated with the presence of a foreign body, especially central venous access and joint prosthesis. The high frequency of isolating C. luteola and F. oryzihabitans probably expresses the awareness of the clinicians and the laboratory to the importance of these bacteria, especially in patients with the presence of a foreign material.

Invasive pneumococcal infections. A comparison between adults and children.

A similar number of adults and children had invasive pneumococcal infection. There was male predominance, and different ethnic distribution between children and adults. The majority of adults (78%), had underlying diseases, but this was less frequent in children (24%). The presenting illness differed between adults and children. Complications of invasive pneumococcal infection occurred more frequently in adults than in children. The mortality rate in adults was 21.5%; in children, only 3.8%. The rate of penicillin-resistant pneumococci at our hospital was 23%, while cefotaxime resistance was 4.2%. Penicillin-resistant pneumococci were not isolated more frequently from children than from adults. Patients with penicillin-resistant pneumococci had longer duration of hospitalization and more nosocomially acquired infections. No difference in the mortality rate was found between patients with resistant or sensitive pneumococci. Ninety-five percent of strains were included in the current vaccine, but less than 2% of patients had been vaccinated. Isolates prevalent in Europe and the United States (19, 5, 1, 14, 6, 18, 12, 4, 9, 23, 7) were also most prevalent in Jerusalem. The distribution of serotypes differed between children and adults, and between patients from whom resistant organisms were isolated as opposed to sensitive organisms.

Nosocomial coagulase-negative staphylococcal infections in bone marrow transplantation recipients with central vein catheter. A 5-year prospective study.

The purpose of this study was to examine coagulase-negative staphylococcal infections in bone marrow transplantation (BMT) patients with central vein catheters by investigating incidence, clinical relevance, risk factors, methicillin resistance, clinical impact of initial empiric antimicrobial therapy without vancomycin, and management of documented catheter-related infections. A 5-year prospective study was conducted with daily evaluation of 242 BMT patients during hospitalization, including clinical assessment and blood culture via the Hickman/Broviac catheter. If fever or infected appearance occurred, peripheral blood cultures or exit site cultures, respectively, were done. Results showed a septicemia incidence of 7.0%, including in 6 patients following colonization, in 1 patient with tunnel infection, in 1 patient with thrombophlebitis, in 1 patient with exit site infection, and in 8 patients with septicemia of unknown origin. Total colonization incidence was 7%, with colonization only in 11 patients who had 16 episodes; incidence of exit site infection was 3.7%. Age > or = 18 years was the only identified risk factor for developing staphylococcal infection (P = 0.03). Despite a methicillin resistance rate of 45% and omission of vancomycin from the routine initial empiric antimicrobial regimen, the clinical course of coagulase-negative staphylococcal infections was relatively benign. A single patient, who experienced marrow rejection, died on day +31 with septicemia and only one patient experienced microbiological failure with recurrent colonization. Bacteria grown in both aerobic and anaerobic bottles were more likely true bacteremia than contaminant (P = 0.03). We conclude that the hazard of coagulase-negative staphylococcal infection does not mandate inclusion of a glycopeptide in the initial empiric antimicrobial regimen in BMT patients, even during febrile neutropenia. Hickman/Broviac-related staphylococcal infections, except for tunnel infection or thrombophlebitis, can usually be treated successfully without removing the catheter.

Rotavirus infection and rotavirus serum antibody in a cohort of children from Gaza observed from birth to the age of one year.

Rotaviruses were studied in a cohort of children from Gaza, during their first year of life. Surveillance was effected through visits to the local health clinic by parents and infants, and to a lesser extent, field workers' home visits. The observed rate of diarrhoea (all causes), and of rotavirus-associated diarrhoea was 1.25 and 0.1 episode per child-year, respectively. Of the 130 diarrhoea episodes in the cohort, only 6.9% were rotavirus-associated. Only nine (37.5%) of 24 children in whom rotavirus antigen was detected experienced a bout of diarrhoeal illness. However, 59.2% of cohort children had rotavirus serum antibodies by one year of age. The data indicate that rotavirus excretion in Gazan children tends to be asymptomatic during the first year of life.

How to predict the immune status of poliovirus vaccinees? A comparison of virus neutralization at a very low serum dilution versus ELISA in a cohort of infants.

A cohort of children from Gaza was observed from birth to the age of one year. Blood specimens were collected at birth, before and after poliovirus vaccination and at one year of age. Poliovirus immunity before and after vaccination was assessed by ELISA and virus neutralization (NT). Positive predictive values for ELISA were between 81.5% and 90.8%. However, ELISA revealed a high frequency of false negatives, and unacceptably low negative predictive values between 28.6% and 55.4%. The history of poliovirus immunity in the cohort was further investigated by NT. A high level of seropositivity to poliovirus type 1 (PV-1) was found. In cord blood, 83.3% had a NT titre greater than or equal to 4 and 99.0% had a titre greater than or equal to 2. Similarly, by one year of age, 85.7% had a titre greater than or equal to 4 and 90.5% had a titre greater than or equal to 2. Seropositivity to PV-2 and PV-3 were slightly lower, ie 80.8% of children had a PV-2 titre greater than or equal to 4 and 75.4% had a PV-3 titre greater than or equal to 4. As for other developing areas, poliomyelitis eradication in Gaza will come about when universal vaccination fills all 'immunity gaps' and improved sanitation and housing reduces the endemicity of wild polioviruses.

Cytosine arabinoside as a major risk factor for Streptococcus viridans septicemia following bone marrow transplantation: a 5-year prospective study.

The incidence and clinical course of nosocomial septicemia with Streptococcus viridans was evaluated prospectively in 242 consecutive bone marrow transplant (BMT) recipients throughout their 15-213 days' (median 47) hospitalization, including 4-58 days (median 18) of neutropenia. Initial empiric therapy for febrile neutropenia consisted of mezlocillin, gentamicin and cefazolin; glycopeptide was excluded. S. viridans septicemia occurred in 23/209 (11%) subjects with underlying malignant disease, and only during neutropenia with concomitant mucositis: in 20 subjects (four with ampicillin-resistant strains), S. viridans septicemia occurred at onset of febrile neutropenia, 1-5 days (median 4.5) post-BMT. All survived with an uncomplicated clinical course. Thus, glycopeptide seems unnecessary in the initial empiric antibiotic regimen. The other three subjects demonstrated S. viridans septicemia (two with ampicillin-resistant strains) on day 11 post-BMT; two died. The major risk identified was cytosine arabinoside administration in the conditioning regimen (P < 0.01).

Diarrhea associated with rotaviruses, enterotoxigenic Escherichia coli, Campylobacter, and other agents in Costa Rican children, 1976-1981.

Rotaviruses, enterotoxigenic Escherichia coli, Salmonella, Shigella, and parasites were investigated in outpatient diarrheic children, and in hospitalized diarrheic and non-diarrheic children, between January 1976 and June 1979. In outpatient cases studied within 4 days of onset of symptoms, rotaviruses were the most common agents (45.3%); E. coli heat-stable enterotoxin ranked second (13.4%); Shigella was third (8.1%); Salmonella was fourth (7.3%). In 63.2%, one or more enteric agents were detected. In hospitalized non-diarrheic children, asymptomatic shedding of pathogens was rarely observed. A later survey of outpatient diarrheic children revealed Campylobacter fetus jejuni in 8%. In 5.5 years of observation rotaviruses were endemic with excess frequency in the dry and cooler months of December and January. The excess occurrence of bacterial pathogens did not coincide with that of rotaviruses.

Evaluation of chlorhexidine and povidone iodine activity against methicillin-resistant Staphylococcus aureus and vancomycin-resistant Enterococcus faecalis using a surface test.

Most published studies of the activity of biocides against methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococci (VRE) have been based on suspension tests. This study was undertaken to provide information on the effect of chlorhexidine and povidone iodine on bacteria dried on to surfaces, a situation in which biocide activity is known to be reduced. The inactivation of MRSA (10 strains), methicillin-sensitive Staphylococcus aureus (MSSA, 10 strains), VRE (nine strains) and vancomycin-sensitive Enterococcus faecalis (VSE, 10 strains) by 0.5% aqueous chlorhexidine gluconate or 10% povidone iodine was evaluated by applying the European surface test method. Povidone iodine was equally active against resistant and sensitive strains of both species with microbicidal effects (ME), i.e. the log(10)concentration of micro-organisms compared with controls treated with distilled water, after 1.5 min of 3.14 and 3.49 for VRE and VSE respectively, and 3.47 and 3.78 for MRSA and MSSA. Chlorhexidine was equally active against VRE and VSE (ME 3.37 vs. 3. 56 after 7 min, respectively), but was significantly less active against MRSA as opposed to MSSA (ME 3.07 vs. 3.83 after 10 min, P= 0. 017).

[Rotavirus and Campylobacter fetus jejuni associated with an outbreak of diarrhea in calves]. / Rotavirus y Campylobacter fetus jejuni asociados a un brote de diarrea en terneros.

Rotaviruses and Campylobacter fetus jejuni are ubiquitous agents of diarrheal disease in animals and humans. Under natural conditions they do not seem to cross inter-species barriers; a zoonosis has not been documented for man. However, animal rotaviruses might contribute to the emergence of new reassortment strains in view of their segmented genome, and thus, produce new antigenic variants. On the contrary, Campylobacter fetus jejuni produces a true zoonosis. Man acquires bacilli by ingesting water and foodstuffs contaminated with feces from infected animals. In an outbreak of diarrhea in 22 calves, rotavirus was detected in 8 (36%) and Campylobacter in 6 (27%). Three (14%) calves experienced double infection. There were no human cases involved in this outbreak.

[Diarrhea caused by Campylobacter fetus jejuni and other infective agents in children of the rural area of Puriscal, Costa Rica]. / Diarrea por Campylobacter fetus jejuni y otros agentes infecciosos en niños del área rural de Puriscal, Costa Rica.

Between September 1979 and September 1981 a field study was conducted on the etiology of diarrheal disease in the area of Puriscal, Costa Rica. The presence of enteric pathogens was investigated in the stools of 267 diarrheic children and 190 healthy controls. Both groups belong to yearly cohorts recruited at birth as part of a longitudinal multidisciplinary study of mothers and children. Campylobacter fetus jejuni was identified as the only pathogen in the stools of 24 diarrheic children (9%) and in four healthy controls (2%), a significant difference (p less than 0,05). The clinical features of the episodes were: irritability (77%), blood in stools (35%), anorexia (38,5%), and fever and vomiting (36%). Dehydration was not important among infected children (only one with 5% dehydration). All children received oral salt solutions and only two were treated with antibiotics. Rotaviruses were the main etiologic agents (17%) and Campylobacter ranked second (10,5%). The frequency of enterotoxigenic Enterobacteriaceae was similar in sick children and in controls (10% and 12% respectively).

Using Campylobacter spp. and Escherichia coli data and Bayesian microbial risk assessment to examine public health risks in agricultural watersheds under tile drainage management.

Human campylobacteriosis is the leading bacterial gastrointestinal illness in Canada; environmental transmission has been implicated in addition to transmission via consumption of contaminated food. Information about Campylobacter spp. occurrence at the watershed scale will enhance our understanding of the associated public health risks and the efficacy of source water protection strategies. The overriding purpose of this study is to provide a quantitative framework to assess and compare the relative public health significance of watershed microbial water quality associated with agricultural BMPs. A microbial monitoring program was expanded from fecal indicator analyses and Campylobacter spp. presence/absence tests to the development of a novel, 11-tube most probable number (MPN) method that targeted Campylobacter jejuni, Campylobacter coli, and Campylobacter lari. These three types of data were used to make inferences about theoretical risks in a watershed in which controlled tile drainage is widely practiced, an adjacent watershed with conventional (uncontrolled) tile drainage, and reference sites elsewhere in the same river basin. E. coli concentrations (MPN and plate count) in the controlled tile drainage watershed were statistically higher (2008-11), relative to the uncontrolled tile drainage watershed, but yearly variation was high as well. Escherichia coli loading for years 2008-11 combined were statistically higher in the controlled watershed, relative to the uncontrolled tile drainage watershed, but Campylobacter spp. loads for 2010-11 were generally higher for the uncontrolled tile drainage watershed (but not statistically significant). Using MPN data and a Bayesian modelling approach, higher mean Campylobacter spp. concentrations were found in the controlled tile drainage watershed relative to the uncontrolled tile drainage watershed (2010, 2011). A second-order quantitative microbial risk assessment (QMRA) was used, in a relative way, to identify differences in mean Campylobacter spp. infection risks among monitoring sites for a hypothetical exposure scenario. Greater relative mean risks were obtained for sites in the controlled tile drainage watershed than in the uncontrolled tile drainage watershed in each year of monitoring with pair-wise posterior probabilities exceeding 0.699, and the lowest relative mean risks were found at a downstream drinking water intake reference site. The second-order modelling approach was used to partition sources of uncertainty, which revealed that an adequate representation of the temporal variation in Campylobacter spp. concentrations for risk assessment was achieved with as few as 10 MPN data per site. This study demonstrates for the first time how QMRA can be implemented to evaluate, in a relative sense, the public health implications of controlled tile drainage on watershed-scale water quality.

Skin disease presenting as an outbreak of pseudobacteremia in a laboratory worker.

An outbreak of pseudobacteremia due to Streptococcus pyogenes (group A streptococci [GAS]) and methicillin-susceptible Staphylococcus aureus (MSSA) was traced to the venting procedure for aerobic bottles prior to their loading into the incubator of the BacT/Alert analyzer (Organon Teknika). Bacteria shed by a laboratory worker suffering from impetigo and cellulitis contaminated the aerobic bottles of 10 patients. All blood culture isolates, in addition to the isolates from the laboratory worker, were of the same GAS M and T types. All MSSA isolates from blood cultures and the index case's hands had the same lytic phage profile. Procedural breakdowns were identified in the laboratory. Bottles were vented outside the biological safety cabinet, gloves were not worn, and unprotected needles were used for the venting procedure. The source of the aspirated bacteria that contaminated the bottles was identified and the index case was treated promptly.

S-IgA cholera toxin and rotavirus antibody in human colostrum.

S-IgA antibodies against cholera toxin and rotavirus were assayed in 43 colostral samples by means of an enzyme-linked immunosorbent assay (ELISA). All specimens contained specific S-IgA antibodies against both antigens. Significant antibody titres to the antigens were demonstrated in almost all colostral samples.

Infections caused by Pseudomonas pickettii in association with permanent indwelling intravenous devices: four cases and a review.

Permanent indwelling intravenous devices (PIIDs) have become increasingly prevalent in the past decade. These devices offer the advantage of long-term and convenient venous access, but their not-infrequent colonization by bacterial or fungi can lead to bloodstream infection with or without sepsis. We describe a series of four patients with PIIDs who became infected with Pseudomonas pickettii, and we review the properties of this unusual organism and the clinical presentation of the infections it causes.

Group A streptococcus bacteremia at the Hadassah Medical Center in Jerusalem.

Streptococcus pyogenes bacteremia occurred in 104 patients over a 6-year period, during which time the annual incidence remained constant. The clinical and epidemiologic characteristics are described for 90 of these patients. Of the 90 patients, 90% had community-acquired infection, and 77% had an underlying illness predisposing them to infection. Skin infection was the cause of bacteremia in 61% of the cases. Septic shock developed in 13 patients. The overall mortality rate was 15%. An increased likelihood of death was associated with septic shock and diabetes mellitus.

Factors associated with nosocomial diarrhea and Clostridium difficile-associated disease on the adult wards of an urban tertiary care hospital.

A prospective survey of the adult inpatient population of an urban tertiary care hospital was conducted to determine factors associated with the development of nosocomial diarrhea and the acquisition of Clostridium difficile-associated disease. During the 3-month survey, 98 patients with nosocomial diarrhea were enrolled, and 38 controls were recruited. The controls were patients without diarrhea lying in beds adjacent to the affected patients. Factors significantly associated with nosocomial diarrhea were the administration of a special diet (P=0.02) and receipt of a greater number of different antibiotics (P=0.02). Among the 98 patients with diarrhea, Clostridium difficile toxin B was identified in the stool of 13. Factors found to be associated with the presence of toxin B as compared to other causes of nosocomial diarrhea were a greater number of individual antibiotics used during hospitalization (P=0.02) and receipt of a cephalosporin (P=0.03) or, more specifically, a third-generation cephalosporin (P=0.02). Among patients with nosocomial diarrhea, those who had toxin in their stool had a significantly higher total antibiotic burden (expressed as antibiotic days) than those with diarrhea due to other causes (P=0.01).

Acinetobacter baumannii at a tertiary-care teaching hospital in Jerusalem, Israel.

In a retrospective 10-year analysis of 3,536 patient-unique isolates, Acinetobacter baumannii imipenem susceptibility declined from 98.1 (1990) to 64.1% (2000), and ciprofloxacin susceptibility decreased from 50.5 to 13.1%. Imipenem median zone diameters decreased from 27. 7 (1997) to 18.8 mm (2000). No outbreaks were detected. Two clusters were identified for 41 strains genotyped by pulsed-field gel electrophoresis, but imipenem resistance was not clonal.

Natural history of rotavirus infection in the children of Santa María Cauqué.

A prospective observation of 45 cohort children from birth to three years of age permitted the collection of 5689 weekly stool specimens, along with frequent morbidity, dietary and growth data. Specimens tested by the ELISA showed that all children became infected with rotaviruses during the first three years of life, many repeatedly. The overall rotavirus incidence was 10.6 per 100 child-months (or 1.3 infections per child per year). Rotaviruses exhibited a high pathogenic potential estimated in 65%, but only about 10% of all diarrheas appeared associated with them. Rotaviruses occurred throughout the year but clustering was evident in August through December, with epidemics of greater severity in particular months of certain years. During outbreaks, from a third to one half of all children became infected with rotaviruses in a given month. This and the frequent association of rotaviruses with other enteric agents (34%) suggest that fecal-oral transmission is the main source of infection, a net result of the prevailing low socioeconomic level in the village setting.

Effect of feeding on infants' faecal flora.

In newborn English Infants, the predominant faecal bacteria were coliforms and bacteroides, as shown by Gram film, culture, and gas-liquid chromatography, whether they were bottle fed or exclusively breast fed. This contrasted with bifidobacterial predominance in faeces from breast-fed Nigerian infants. Presumably environmental factors other than exclusive breast feeding are also important for establishing the flora. No differences were detected between the flora of infants of atopic and non-atopic controls.