Nosocomial transmission of rotavirus from patients admitted with diarrhea

Molecular Detection of Rotavirus in Mollusks from the Oued El Maleh Estuary of Mohammedia, Morocco

Viral outbreaks can result from the consumption of contaminated bivalve mollusks. However, despite the regulation related to enteric bacteria in food products, the consumption of raw and undercooked mollusks remains linked to viral epidemics in human populations. Real-time RT-PCR is a highly sensitive approach for detecting and quantifying enteric viruses, and after eliminating enzymatic amplification inhibitors from samples of interest, sensitive and specific tests, like real-time RT-PCR, can facilitate the detection and quantification of a wide range of viruses that are concentrated in mollusk digestive tissues. The aim of the present study was to evaluate the prevalence of Group-A rotaviruses in mussel (Mytilus edulis Linnaeus, 1758) specimens (n=576) collected downstream of the Oued El Maleh Estuary, which is along the coast of Mohammedia City in Morocco, using real-time RT-PCR. Rotavirus A RNA was detected in 37.5% (n=18) of the 48 sample batches, and viral loads ranged from 0.42×101 to 1.8603×104 genomic copies per g digestive tissue. Most (72.22%) of the positive samples were collected during the wet season (September-April), and the probability of detecting rotaviruses was significantly greater during the wet season than during the dry season (P<0.001). Monitoring Rotavirus A and similar viruses in shellfish may help prevent viral contamination and preserve public health.

Prospective surveillance of nosocomial viral infections during and after hospitalization at a university children's hospital

BACKGROUND

In Switzerland 5% to 10% of hospitalized adults acquire nosocomial infections (NI) but few data are available in children. Most former studies on NI in hospitalized children analyzed specific units or pathogens and neglected the postdischarge period. We aimed to prospectively assess viral NI occurring during and shortly after hospitalization in children.

METHODS

Prospective surveillance was performed during a 24-month period. Electronic standardized questionnaires were completed for each patient by physicians during hospital stay. On a ward-based rotational schedule, follow-up information was obtained from a subset of patients 1 week after hospital discharge. NI were defined using CDC recommendations.

RESULTS

Overall, 6250 patients (34,608 patient hospitalization days, PHD) were enrolled and 1272 patients were recruited for postdischarge surveillance. Mean hospitalization duration was 5 days. Fifty-two (0.8%) patients acquired 54 viral NI during hospitalization and 12 patients (1.1%) acquired 12 viral NI after hospital discharge (NI incidence: 1.9 per 1000 PHD including follow-up period). NI rate in infants was higher compared with children >12 months old (2.0% vs. 0.8%; P 0.05) and the infant ward also had the highest incidence (4.0 NI per 1000 PHD). Most NI were gastrointestinal tract infections with 55% caused by rotavirus infection. NI rates were highest between November and March.

CONCLUSIONS

A significant part of NI will only be detected if surveillance includes the immediate postdischarge period. Given the strong seasonality of pediatric NI, intensifying hygiene measurements particularly on infant wards and prior to the cold season would be beneficial in reducing NI incidence.

[Emergence pathogens infections in ENT Department of Children's hospital in 2005-2008]

INTRODUCTION

The development of medicine, in this the new techniques and antibiotic therapy enlarged the survivability of patients in hospital. Applying antibiotics caused breakthrough in treatment stepping out in ill's group infections treated in hospital, however enlarging resistance is natural this effect, resulting from: the selection of resistant strains, the formation of new mechanisms of resistance, and/or the spreading of gene of resistance. Multidrug-resistant strains were included to emergence-pathogens group: MRSA, penicillin-resistant Streptococcus pneumoniae, VRE, Gram-negative producing beta-lactamase of type the ESBL and/or resistant to carbapenems. Emergence-pathogens occurrence leads to: therapeutic failures, the use extorts in therapy of dear medicines or with possibility of workings undesirable. The multidrug-resistant strains spread in hospital environment easily, especially on departments about high waste of medicines with the patients' simultaneously large susceptibility on infection, resulting mainly with state of reduced resistance of organism. The control of hospital infections recognize by present hospitality for the most important criterion of quality of work.

AIM

Analysis of the emergence-pathogens isolated during treatment in hospital in 2005-2008, from special regard the ENT Department.

MATERIAL AND METHODS

50586 children treated in this period in hospital in which was executed 39386 bacteriological investigations, in this 6528 (12.9%) children in ENT Department in which was executed 1566 bacteriological investigations (3.98%). The diagnostics were executed according to routine microbiological procedures with qualification of resistance to antibiotics.

RESULTS

Emergence-pathogens infection was confirmed at 2369 children's (4.68%) treated in Hospital, in this in ENT Department at 84 children (1.29%). The most frequent emergence-pathogens in ENT Department were Streptococcus pyogenes, Streptococcus pneumoniae penicillin-resistant and average sensitive on penicillin, Staphylococcus aureus methicillin-resistant and Rotavirus.

CONCLUSIONS

Streptococcus pneumoniae penicillin-resistant and average sensitive to penicillin and Rotavirus infections are the most frequent hospital infections. The systematic microbiological supervision is indispensable in prevention the spreading of infections of the emergence-pathogens in hospital.

[Ten-year retrospective study of rotavirus infection in the province of Castellón (Spain)]

OBJECTIVE

To determine the percentage of rotavirus infection in children aged less than 14 years old and the epidemiology in area 02 of the province of Castellón (Spain).

MATERIAL AND METHODS

We performed a retrospective study from January 1995 to December 2004 in which 14,068 stool samples from pediatric patients with acute gastroenteritis were analyzed. The variables analyzed were sex, age, origin, diagnosis of rotavirus, and date of diagnosis. Differences were considered statistically significant if p<0.05.

RESULTS

Rotavirus was detected in 11.9% of the samples (1687 cases) in the 10 years of the study, 12.14 % corresponded to boys and 11.81% to girls (p=0.5459). The mean age of the population was 2.63 years. The highest percentage of cases occurred in the group aged 1- 4 years old (14.1%; p<0.001) and in outpatients (12.76%; p<0.05). In this geographical region, there was a significant tendency (p<0.001) for rotavirus to occur in the winter months.

CONCLUSION

Rotavirus is one of the main causes of morbidity in children both in the hospital and the outpatient setting. Children aged less than 4 years old are most frequently affected, especially those aged 1 year. The infection appears mainly in winter.

[Nosocomial rotavirus infections in a pediatric unit: surveillance during four successive winters]

The incidence of rotavirus and RSV outbreaks during winter seasons leads to overcrowding of pediatric units in the Paris area, and increases the risk of viral nosocomial infections in hospitalized young infants.

OBJECTIVE

The aim of this study was to measure the incidence of rotavirus nosocomial infections in children less than 2 years of age during 4 consecutive winters.

METHODS

All infants admitted in the pediatric unit during the winter were prospectively screened for rotavirus with a stools exam. All children with negative stools examination on admission but developing diarrhea after 2 days of hospitalization underwent a new screening test for rotavirus in stools.

RESULTS

During the 4 consecutive winters, the global incidence of nosocomial rotavirus infection was 13.9% (12.7 to 15.9%). Asymptomatic carriage of rotavirus was detected in 3% of admitted infants. The risk of nosocomial rotavirus infection increases with young age and the length of hospital stay.

CONCLUSION

The incidence of nosocomial rotavirus infections was high in this unit. It is related to overcrowding due to coincidence of diarrhea and bronchiolitis outbreaks in the Paris area and to the young age of hospitalized patients.

Rotavirus vaccines and the prevention of hospital-acquired diarrhea in children

Rotavirus, the major cause of severe acute dehydrating gastroenteritis in children less than 5 years of age, is responsible for an estimated 20-50% of all hospitalizations for diarrhea and approximately 440,000 deaths annually, primarily in the developing world. Rotavirus vaccines are considered the most promising means for disease prevention. While the prime rationale for developing rotavirus vaccines has been the enormous burden of rotavirus infection leading to severe and fatal disease, a secondary benefit may be the prevention of nosocomial rotavirus diarrhea. We have reviewed the burden of intra-hospital-acquired rotavirus infections from several countries and found that in the United States alone, as many as 25% of rotavirus hospitalizations or approximately 16,000-18,000 hospitalizations each year might be due to rotavirus infections acquired within hospitals. To countries with low rotavirus-associated mortality, prevention of these infections and the resulting economic savings therefore represent an important secondary goal. Several rotavirus vaccines are in development, and two candidates are currently being tested in large-scale safety and efficacy trials. Development of safe and effective rotavirus vaccines will protect children worldwide against the severe consequences of rotavirus infections including prolonged hospitalizations for nosocomially acquired infections.

Gastroenteritis aguda nosocomial e infección asintomática por rotavirus y astrovirus en niños hospitalizados

BACKGROUND

Nosocomial gastroenteritis is frequent in pediatric hospital wards. Between 20% and 50% of gastroenteritis cases caused by rotavirus and astrovirus are of nosocomial origin.

OBJECTIVE

To determine the incidence of nosocomial rotavirus and astrovirus gastroenteritis in our environment, the incidence of asymptomatic infection with these viruses, and to identify the G serotypes of the rotaviruses detected.

METHODS

We performed a prospective study of all children under 2 years of age admitted to a neonatology unit over a 1-year period who were followed-up for the presence of diarrhea and periodic study of feces to detect the presence of rotavirus and astrovirus antigens by enzyme immunoassay (EIA). Patients with gastroenteritis also underwent bacteria stool culture, adenovirus detection by EIA, calcivirus detection by polymerase chain reaction, and analysis of rotavirus G serotypes by EIA with monoclonal antibodies.

RESULTS

Of 666 children admitted without diarrhea, 60 presented nosocomial gastroenteritis (9 % of patients admitted and 1.75 per 100 days of hospital stay): 34 presented rotavirus (5 % of patients) and two presented astrovirus (0.3 % of patients). Of the 329 patients without diarrhea who were studied, viral elimination was detected in 27: rotavirus in 23 patients and astrovirus in four. Viral infection was detected on admission in 13 patients (4 %) and after 72 hours in 14 patients (4.2 %) (asymptomatic nosocomial infection). No differences in the distribution of rotavirus G serotypes were observed between community-acquired and nosocomial gastroenteritis.

CONCLUSIONS

These data confirm the importance of viral etiology in nosocomial gastroenteritis and allow us to evaluate asymptomatic fecal elimination of rotavirus as one of the factors in the transmission of this infection.

Nosocomial spread of viral disease

Viruses are important causes of nosocomial infection, but the fact that hospital outbreaks often result from introduction(s) from community-based epidemics, together with the need to initiate specific laboratory testing, means that there are usually insufficient data to allow the monitoring of trends in incidences. The most important defenses against nosocomial transmission of viruses are detailed and continuing education of staff and strict adherence to infection control policies. Protocols must be available to assist in the management of patients with suspected or confirmed viral infection in the health care setting. In this review, we present details on general measures to prevent the spread of viral infection in hospitals and other health care environments. These include principles of accommodation of infected patients and approaches to good hygiene and patient management. They provide detail on individual viral diseases accompanied in each case with specific information on control of the infection and, where appropriate, details of preventive and therapeutic measures. The important areas of nosocomial infection due to blood-borne viruses have been extensively reviewed previously and are summarized here briefly, with citation of selected review articles. Human prion diseases, which present management problems very different from those of viral infection, are not included.

[Nosocomial rotavirus infections in a general pediatric ward: epidemiology, molecular typing and risk factors]

OBJECTIVES

Nosocomial rotavirus infections induce difficult problems for pediatric wards during winter epidemics. This prospective study was carried out to measure their incidence in a general pediatric ward by using epidemiological tools, clinical and molecular methods, and to examine the main factors increasing the risk of cross contamination.

MATERIAL AND METHODS

The study was carried out on children, younger than three years old, hospitalized between 15 November 1996 and 1 March 1997. We examined the feces of all children for rotavirus on admission and during their hospital stay if they had developed diarrhea. The strains were typed by RNA electrophoresis. A cohort study was done to identify the factors of exposure to risk.

RESULTS

Three hundred twenty-six of the 415 hospitalized infants were studied. One hundred and five were hospitalized for gastroenteritis, including 39 (37.1%) with rotavirus infection. Among 221 infants admitted without diarrhea, 11 (5.0%) had an asymptomatic community infection and nine (4.3%) developed nosocomial gastroenteritis. The only significant predisposing factor (P = 0.003) for nosocomial infection was the distance between the hospital rooms and the nurses station. Despite the low level of typing (51%), the molecular study suggested a wide diversity of nosocomial and community strains.

CONCLUSION

The relatively low incidence of nosocomial infections found may be due to routine assignment to individual rooms, the isolation of infants admitted with acute diarrhea, and the policy of routine detection of asymptomatic carriers with the use of similar isolation measures for these children.

Methods for subtyping and molecular comparison of human viral genomes

The development over the past two decades of molecular methods for manipulation of RNA and DNA has afforded molecular virologists the ability to study viral genomes in detail that has heretofore not been possible. There are many molecular techniques now available for typing and subtyping of viruses. The available methods include restriction fragment length polymorphism analysis, Southern blot analysis, oligonucleotide fingerprint analysis, reverse hybridization, DNA enzyme immunoassay, RNase protection analysis, single-strand conformation polymorphism analysis, heteroduplex mobility assay, nucleotide sequencing, and genome segment length polymorphism analysis. The methods have certain advantages and disadvantages which should be considered in their application to specific viruses or for specific purposes. These techniques are likely to become more widely used in the future for epidemiologic studies and for investigations into the pathophysiology of virus infections.

Distribution of human rotavirus G types circulating in Paris, France, during the 1997-1998 epidemic: high prevalence of type G4

Group A human rotavirus G genotypes were determined by means of reverse transcription-PCR in 170 stool specimens from children with acute diarrhea admitted to a Paris children's hospital during a 1-year survey (1997 to 1998). The isolates all belonged to types G1 to G4, with type G4 predominating (60%).

Monitoring rotavirus environmental contamination in a pediatric unit using polymerase chain reaction

Rotavirus environmental contamination in a pediatric unit was investigated. Surfaces were swabbed, then viruses eluted, ultracentrifuged, and detected by polymerase chain reaction (PCR) amplification. Of 55 samples, 25 (46%) tested positive. Rotavirus RNA was more prevalent on surfaces in direct contact with children (thermometers and play mats) than on other environmental surfaces (washbasins, door handles, etc). PCR has proved useful for monitoring rotavirus environmental contamination.

The current status of the rotavirus vaccine

The US just licensed of an oral tetravalent rhesus reassortant vaccine for routine immunization of infants against rotavirus. The virus was first identified 25 years ago and is now recognized to be the most common single cause of severe diarrhea throughout the world. Most children suffer at least one infection and reinfection is common. Studies of natural immunity show that breastfeeding may merely delay onset of primary infection and that maternal immunity has little effect-especially in developing countries where onset in early infancy is common. Immunity, furthermore, appears to be serotype-specific. Early attempts to develop a vaccine focused on animal forms of rotavirus. More recent efforts have created human-animal reassortants that have been far more successful.

Prevalence of astrovirus infection among Chilean children with acute gastroenteritis

The frequency of astrovirus infection in 456 Chilean children with diarrhea was determined by enzyme-linked immunosorbent assay, reverse transcriptase PCR, and cell culture. Astrovirus was detected in 16.5% of rotavirus-negative and 7% of rotavirus-positive samples obtained from emergency rooms or hospitals and in 11% of samples from day care centers. HAst-1 was the predominant serotype identified.

Viral hazards to and from health care workers

Much attention has been directed towards nosocomial transmission of viruses as a result of clear evidence of patient-to-staff and staff-to-patient transmission of the blood-borne viruses HIV and hepatitis B virus. Although the relatively long incubation periods of these viruses, together with the frequency of asymptomatic infections, renders problems for surveillance it has been possible to study modes of transmission and levels of risk over a number of years. Information on trends of incidence of other nosocomial virus infections has been difficult to obtain for a number of reasons. Often, an outbreak in the health care setting parallels an epidemic in the community. Although it may be possible to define nosocomial transmission from recording dates of onset of illness relative to admission date and, at times, demonstrate circulation of a common strain by molecular techniques, the relative contributions of patient-to-staff and staff-to-patient transmission may be difficult to clarify. In this review, details are presented of the major viruses associated with nosocomial transmission with examples of infections to and from staff where these have occurred. The major defences against patient-to-staff and staff-to-patient transmission are awareness of potential risks, education and adherence to infection control policies, immunization of staff, effective decontamination and sterilization and the adoption of 'Universal Precautions' in patient care. In addition, there may be occasions when additional measures should be considered including isolation, cohorting and the use of specific chemo- and immunoprophylaxis.

Nosocomial gastroenteritis in two infant wards over 26 months

We retrospectively reviewed 209 cases of nosocomial diarrhea in two infant wards at St Göran's Children's Hospital. They occurred from April 1987 to May 1989, when 3105 patients spent 26,355 hospital days. The hospital is a 250-bed tertiary center with university affiliation. Fourteen percent of patients at risk developed nosocomial diarrhea, and the relative attack rate was 1.1 episodes per 100 hospital days. A probable viral etiology was found in 47% of patients. Rotavirus was most frequent and occurred during the community rotavirus seasons. Also small, round, structured viruses were common, and two outbreaks of astrovirus gastroenteritis occurred. Failure to detect a virus was particularly common among infants younger than 4 months. However, a seasonal distribution and peaks concordant with defined clusters in older patients, suggest also that some of these detection-negative cases may have a viral etiology.

VP4 genotyping of human rotavirus in the United States

The VP4 (P) and VP7 (G) types of 171 rotavirus isolates obtained from children with diarrhea in the United States were characterized by PCR typing assays. Strains P1G1 predominated (71%); this was followed by strains P1G3 (20%) and P2G2 and P1G4 (2% each). Mixed types were identified in five (3%) specimens. Two (1%) strains bearing the P3 genotype (P3G1 and P3G2) were found in children with severe dehydrating diarrhea, although the P3 genotype has been regarded as a possible marker for virus attenuation.