Hand-touch contact assessment of high-touch and mutual-touch surfaces among healthcare workers, patients, and visitors

BACKGROUND

Unlike direct contact with patients' body, hand hygiene practice is often neglected by healthcare workers (HCWs) and visitors after contact with patients' environment. Contact with hospital environmental items may increase risk of pathogen transmission.

AIM

To enumerate the number of hand-touch contacts by patients, HCWs and visitors with any hospital environmental items.

METHODS

All contact-episodes between person and item were recorded by direct observation in a six-bed cubicle of acute wards for 33 working days. High-touch and mutual-touch items with high contact frequencies by HCWs, patients, and visitors were analysed.

FINDINGS

In total, 1107 person-episodes with 6144 contact-episodes were observed in 66 observation hours (average: 16.8 person-episodes and 93.1 contact-episodes per hour). Eight of the top 10 high-touch items, including bedside rails, bedside tables, patients' bodies, patients' files, linen, bed curtains, bed frames, and lockers were mutually touched by HCWs, patients, and visitors. Bedside rails topped the list with 13.6 contact-episodes per hour (mean), followed by bedside tables (12.3 contact-episodes per hour). Using patients' body contacts as a reference, it was found that medical staff and nursing staff contacted bedside tables [rate ratio (RR): 1.741, 1.427, respectively] and patients' files (RR: 1.358, 1.324, respectively) more than patients' bodies, and nursing staff also contacted bedside rails (RR: 1.490) more than patients' bodies.

CONCLUSION

Patients' surroundings may be links in the transmission of nosocomial infections because many are frequently touched and mutually contacted by HCWs, patients, and visitors. Therefore, the focus of hand hygiene education, environmental disinfection, and other system changes should be enhanced with respect to high-touch and mutual-touch items.

Use of the human colorectal adenocarcinoma (Caco-2) cell line for isolating respiratory viruses from nasopharyngeal aspirates

The human colorectal adenocarcinoma‐derived Caco‐2 cell line was evaluated as a means isolating common respiratory viruses from nasopharyngeal aspirates for the diagnosis of respiratory diseases. One hundred eighty‐nine direct immunofluorescence positive nasopharyngeal aspirates obtained from patients with various viral respiratory diseases were cultured in the presence of Caco‐2 cells or the following conventional cell lines: LLC‐MK2, MDCK, HEp‐2, and A549. Caco‐2 cell cultures effectively propagated the majority (84%) of the viruses present in nasopharyngeal aspirate samples compared with any positive cultures obtained using the panel cells (78%) or individual cell line MDCK (38%), HEp‐2 (21%), LLC‐MK2 (27%), or A549 (37%) cell lines. The differences against individual cell line were statistically significant (P = < 0.000001). Culture in Caco‐2 cells resulted in the isolation of 85% (36/42) of viruses which were not cultivated in conventional cell lines. By contrast, 80% (24/30) of viruses not cultivated in Caco‐2 cells were isolated using the conventional panel. The findings indicated that Caco‐2 cells were sensitive to a wide range of viruses and can be used to culture a broad range of respiratory viruses. J. Med. Virol. 85:874–879, 2013. © 2013 Wiley Periodicals, Inc.

Development of anti-influenza A compounds: a pilot study

1. There is no effective anti-H5N1 avian influenza agent. 2. A chemical compound— BFDBSC—can inhibit H5N1 virus infection in cell cultures, and such inhibition might be attributable to its halogenated benzoyl residues. 3. This pilot study assessed anti- H5N1 activity and toxicity of four chemical compounds with halogenated benzoyl residues in cell culture system. 4. Two compounds—FPBFDBSC and BFB-gallate— showed higher antiviral effectsthan BFDBSC, whearas the other two—BFB-borneol and BFB-menthol—showed lower antiviral effects. These compounds did not show toxicity. 5. The halogenated benzoyl residues may play a key role in anti-H5N1 effects. However, all these compounds showed poor solubility, which may limit their utility

Wild animal surveillance for coronavirus HKU1 and potential variants of other coronaviruses

1. Although CoV-HKU1 was not identified in any of the studied animals, a coronavirus closely related to SARS-CoV (bat-SARS-CoV) was identified in 23 (19%) of 118 wild Chinese horseshoe bats by reverse transcriptase polymerase chain reaction (RT-PCR). 2. Complete genome sequencing and phylogenetic analysis showed that bat-SARS-CoV formed a distinct cluster with SARS-CoV as group 2b coronaviruses, distantly related to known group 2 coronaviruses. 3. Most differences between the bat-SARS-CoV and SARS-CoV genomes were observed in the spike gene. The presence of a29-bp insertion in ORF 8 of bat-SARS-CoV genome, not in most human SARS-CoV genomes, suggests that it has a common ancestor with civet SARS-CoV. 4. Antibody against recombinant bat-SARS-CoV nucleocapsid protein was detected in 84% of Chinese horseshoe bats using an enzyme immunoassay.Neutralising antibody to human SARS-CoV was also detected in those with lower viral loads.5. This study also revealed a previously unknown diversity of coronaviruses in bats, which are important natural reservoir for coronaviruses including SARS-CoV-like viruses.

Epidemiology of coronavirus-associated respiratory tract infections and the role of rapid diagnostic tests: a prospective study

1. Coronaviruses accounted for 1.6% (98/6272) of respiratory tract infections based on nasopharyngeal aspirate samples. 2. HCoV-OC43 was the most common coronavirus detected,followed by HCoV-NL63, CoVHKU1,and HCoV-229E. 3. Although CoV-HKU1 infections were most often associated with the upper respiratory tract, more severe illness (pneumonia,acute bronchiolitis, and asthmatic exacerbation) may occur, especially in those with underlying disease. In young children, CoV-HKU1 infection is associated with a high rate of febrile seizures (50%). 4. CoV-HKU1 and HCoV-OC43 infections peaked in winter, in contrast to HCoV-NL63, which mainly occurred in early summer and autumn, but was absent in winter. 5. Reverse transcriptase polymerase chain reaction is useful for the rapid diagnosis of coronavirus infections.

Primary infective spondylodiscitis caused by Lactococcus garvieae and a review of human L. garvieae infections

We report the first case of primary infective spondylodiscitis due to Lactococcus garvieae, confirmed by 16S rRNA gene sequencing, in the absence of concomitant endocarditis in a patient with long-standing gastritis on famotidine. He responded to a 6-week course of ampicillin. The gastrointestinal tract is probably the source of infection.

Infection of immunocompromised patients by avian H9N2 influenza A virus

Avian influenza A (H9N2) virus is transmitted sporadically from avian species to human causing mild diseases in immunocompetent person. We report two cases of human infection in immunocompromised patients in Hong Kong between 2008 and 2009. One patient had uneventful recovery with viral shedding at day 10 after symptom onset despite her underlying acute lymphoblastic leukaemia. The other patient with post-bone marrow transplant chronic graft-versus-host disease and bronhioltis obliterans went into respiratory failure. Genetic analysis revealed that these cases were caused by different genetic variants which are circulating in poultry in this region. Review of literature identified another 9 human cases reported in Southern China since 1988. It is possible that human infection with H9N2 is more common than what has been recognized. Continuous surveillance of H9N2 influenza virus infection in human is warranted.

Human rhinovirus C: a newly discovered human rhinovirus species

Although often ignored, human rhinoviruses (HRVs) are the most frequent causes of respiratory tract infections (RTIs). A group of closely related novel rhinoviruses have recently been discovered. Based on their unique phylogenetic position and distinct genomic features, they are classified as a separate species, HRV-C. After their discovery, HRV-C viruses have been detected in patients worldwide, with a reported prevalence of 1.4-30.9% among tested specimens. This suggests that the species contribute to a significant proportion of RTIs that were unrecognized in the past. HRV-C is also the predominant HRV species, often with a higher detection rate than that of the two previously known species, HRV-A and HRV-B. HRV-C infections appear to peak in fall or winter in most temperate or subtropical countries, but may predominate in the rainy season in the tropics. In children, HRV-C is often associated with upper RTIs, with asthma exacerbation and wheezing episodes being common complications. The virus has also been detected in children with bronchitis, bronchiolitis, pneumonia, otitis media, sinusitis and systemic infections complicated by pericarditis. As for adults, HRV-C has been associated with more severe disease such as pneumonia and exacerbation of chronic obstructive pulmonary disease. However, larger clinical studies with asymptomatic controls are required to better define the significance of HRV-C infection in the adult population. On the basis of VP4 sequence analysis, a potential distinct subgroup within HRV-C has also been identified, although more complete genome sequences are needed to better define the genetic diversity of HRV-C.

Sequential introduction of single room isolation and hand hygiene campaign in the control of methicillin-resistant Staphylococcus aureus in intensive care unit

Background

After renovation of the adult intensive care unit (ICU) with installation of ten single rooms, an enhanced infection control program was conducted to control the spread of methicillin-resistant Staphylococcus aureus (MRSA) in our hospital.

Methods

Since the ICU renovation, all patients colonized or infected with MRSA were nursed in single rooms with contact precautions. The incidence of MRSA infection in the ICU was monitored during 3 different phases: the baseline period (phase 1); after ICU renovation (phase 2) and after implementation of a hand hygiene campaign with alcohol-based hand rub (phase 3). Patients infected with extended spectrum beta-lactamase (ESBL)-producing Escherichia coli and Klebsiella species were chosen as controls because they were managed in open cubicles with standard precautions.

Results

Without a major change in bed occupancy rate, nursing workforce, or the protocol of environmental cleansing throughout the study period, a stepwise reduction in ICU onset nonbacteraemic MRSA infection was observed: from 3.54 (phase 1) to 2.26 (phase 2, p = 0.042) and 1.02 (phase 3, p = 0.006) per 1000-patient-days. ICU onset bacteraemic MRSA infection was significantly reduced from 1.94 (phase 1) to 0.9 (phase 2, p = 0.005) and 0.28 (phase 3, p = 0.021) per 1000-patient-days. Infection due to ESBL-producing organisms did not show a corresponding reduction. The usage density of broad-spectrum antibiotics and fluoroquinolones increased from phase 1 to 3. However a significant trend improvement of ICU onset MRSA infection by segmented regression analysis can only be demonstrated when comparison was made before and after the severe acute respiratory syndrome (SARS) epidemic. This suggests that the deaths of fellow healthcare workers from an occupational acquired infection had an overwhelming effect on their compliance with infection control measures.

Conclusion

Provision of single room isolation facilities and promotion of hand hygiene practice are important. However compliance with infection control measures relies largely on a personal commitment, which may increase when personal safety is threatened.

Successful control of vancomycin-resistant Enterococcus faecium outbreak in a neurosurgical unit at non-endemic region

Vancomycin-resistant enterococci (VRE) have emerged in many parts of the world, but have only been reported sporadically in Hong Kong. We report an outbreak of vancomycin-resistant Enterococcus faecium (VREfm) in a neurosurgical unit at a tertiary teaching hospital between 3 March and 3 April 2009 in Hong Kong. During the outbreak investigation, clinical samples from 193 (91.5%) of 211 patients who had stayed in the neurosurgical unit and 506 environmental samples were screened for VREfm. Besides the index case, another 3 (1.6%) out of 192 patients were found to be positive for VREfm. Two (0.4%) out of 506 environmental samples were positive for VREfm. All four clinical and two environmental isolates were found to be clonally related by pulse-field gel electrophoresis. The risk factors for nosocomial acquisition of VREfm included advanced age (P=0.047), presence of nasogastric tubing (P=0.002) and tracheostomy (P<0.001), and the use of β-lactam antibiotics (P<0.001) and vancomycin (P=0.001). Contrary to other VRE outbreaks in which the spread was rapid, the neurosurgical patients' immobilization because of coma and mechanical ventilation dependency, and the vigilant practice of hand hygiene by health-care workers successfully limited the number of secondary cases despite the delayed recognition of the index case. All patients with VREfm were labeled in the hospital network information system so that stringent infection control measures with contact precautions would be carried out once these patients were readmitted to prevent its spread in our locality.

Q fever: underdiagnosed in Hong Kong?

We report the first imported case of chronic Q fever with multi-organ involvement seen in Hong Kong. Although the disease is found worldwide, its chronic form is very rare in our locality. Familiarity with the clinical presentation, useful diagnostic tools, and appropriate treatment is necessary for the prevention of the serious morbidity and mortality associated with chronic Q fever. To the best of our knowledge, this article represents the first comprehensive review to compare the local experience with Q fever with international data, and establishes a management approach for this unusual infectious disease while suggesting possible explanations for its exceptionally low incidence in this locality.

Prevention of nosocomial transmission of swine-origin pandemic influenza virus A/H1N1 by infection control bundle

After the outbreak of severe acute respiratory syndrome in Hong Kong, the importance of preventing nosocomial transmission of respiratory viruses has become a top priority in infection control. During the containment and early mitigation phases of the swine-origin influenza virus (S-OIV) A H1N1 pandemic, an infection control bundle consisting of multiple coherent measures was organised by our infection control team to minimise nosocomial transmission. This included repeated open staff forum achieving high attendance; early recognition of index cases among inpatients by liberal testing; early relief of sick staff from work; directly observed hand hygiene practice during outbreaks; and monitoring of compliance with infection control practice. During the first 100 days (from 1 May to 8 August 2009) when the first 100 laboratory-confirmed patients with S-OIV and 12 infected healthcare workers (HCWs) were identified, a total of 836 asymptomatic exposed persons (184 patients and 652 HCWs) were required to undergo a seven-day medical surveillance. The infection control nurses monitored them for the onset of symptoms. Four (0.48%) exposed persons (one house officer, two non-clinical staff, and one patient) were virologically confirmed with S-OIV. Not wearing a surgical mask either by the exposed persons during contact with the index cases (4/4 vs 264/832, P = 0.010) or vice versa (4/4 vs 300/832, P = 0.017, Fisher's exact test) were found to be significant risk factors for nosocomial acquisition of S-OIV.

Comparative host gene transcription by microarray analysis early after infection of the Huh7 cell line by SARS coronavirus and human coronavirus 229E

During the early stages of infection, SARS-CoV produces more severe perturbation of host cell gene expression in a human epithelial cell line of liver origin than the HCoV-229E.

Clinical features and molecular epidemiology of coronavirus-HKU1-associated community-acquired pneumonia

1. Coronavirus (CoV)-HKU1 accounts for 2.4% of community-acquired pneumonia. 2. Clinical features alone cannot differentiate this entity from other community-acquired pneumonia. 3. Further studies are needed to understand the significance of CoV-HKU1 in upper respiratory tract infection and its potential to cause outbreaks of acute viral respiratory illnesses.

Viral loads in clinical specimens and SARS manifestations

1. A high viral load in nasopharyngeal aspirate (with or without a high viral load in serum) is a useful prognostic indicator of respiratory failure or mortality. The presence of viral RNA in multiple body sites is also indicative of poor prognosis. 2. Early treatment with an effective antiviral agent before day 10 may decrease the peak viral load, and thus ameliorate the clinical symptoms and mortality, and reduce viral shedding and the risk of transmission

Molecular epidemiology of community-associated methicillin-resistant Staphylococcus aureus

1. Community-associated methicillin-resistant Staphylococcus aureus (MRSA) strains with diverse genetic backgrounds are emerging in Hong Kong. 2. Intra-familial spread of community-associated MRSA is common.

Differential susceptibility of different cell lines to swine-origin influenza A H1N1, seasonal human influenza A H1N1, and avian influenza A H5N1 viruses

BACKGROUND

The novel swine-origin influenza A H1N1 virus (S-OIV) causes the current pandemic. Its tissue tropism and replication in different cell lines are not well understood.

OBJECTIVE

Compare the growth characteristics of cell lines infected by S-OIV, seasonal influenza A H1N1 (sH1N1) and avian influenza A H5N1 (H5N1) viruses and the effect of temperature on viral replication.

STUDY DESIGN

Cytopathic effect (CPE), antigen expression by immunofluorescence (IF) and viral load profile by quantitative RT-PCR in 17 cell lines infected by S-OIV, sH1N1 and H5N1 were examined. Comparison of their replication efficiency in chick embryo was performed. The effect of temperature on viral replication in Madin-Darby canine kidney (MDCK) cells was determined by TCID(50) at 33 degrees C, 37 degrees C and 39 degrees C for 5 consecutive days.

RESULTS

S-OIV replicated in cell lines derived from different tissues or organs and host species with comparable viral load to sH1N1. Among 13 human cell lines tested, Caco-2 has the highest viral load for S-OIV. S-OIV showed a low viral load with no CPE or antigen expression in pig kidney cell PK-15, H5N1 demonstrated the most diverse cell tropism by CPE and antigen expression, and the highest viral replication efficiency in both cell lines and allantoic fluid. All three viruses demonstrated best growth at 37 degrees C in MDCK cells.

CONCLUSION

Cell line growth characteristics of S-OIV, sH1N1 and H5N1 appear to correlate clinically and pathologically with involved anatomical sites and severity. Low replication of S-OIV in PK-15 suggests that this virus is more adapted to human than swine.