Antibiogram data from private hospitals in Hong Kong: 6-year retrospective study.

INTRODUCTION: The surveillance of antibiotic resistance is critical for the establishment of effective control strategies. The antibiotic resistance situations in private hospitals in Hong Kong have not been systematically described. The objective of the study was to analyse antibiogram data from private hospitals and describe the temporal trends of non-susceptibility percentages in this setting. METHODS: This retrospective descriptive study used antibiogram data from all private hospitals in Hong Kong that had been collected annually for 6 years (2014-2019). Data on six targeted bacteria and their corresponding multidrug-resistant organisms were included. RESULTS: The non-susceptibility percentages of isolates remained stable or decreased during the study period: methicillin-resistant Staphylococcus aureus had a stable prevalence of approximately 20%; extended-spectrum beta-lactamase-producing Escherichia coli and Klebsiella species had stable prevalences of 20% to 30% and 10% to 20%, respectively; multidrug-resistant Acinetobacter species had prevalences of approximately 2% to 8%, which decreased over time; multidrug-resistant Pseudomonas aeruginosa had prevalences of 0.0% to 0.3%; Streptococcus pneumoniae penicillin and macrolide non-susceptibility percentages were 2% to 9% and 71% to 79%, respectively. These values generally were comparable with findings from public hospitals and Residential Care Homes for the Elderly in Hong Kong. However, the prevalences of carbapenem-resistant Enterobacteriaceae, which are increasing in Hong Kong and other nations, were also increasing in our dataset despite their currently low values (<1% for Escherichia coli and <2% for Klebsiella species). CONCLUSION: The antibiotic resistance landscape among private hospitals in Hong Kong is satisfactory overall; there remains a need for surveillance, antibiotic stewardship, and other infection control measures.

Rapid antigen test during a COVID-19 outbreak in a private hospital in Hong Kong.

INTRODUCTION: In response to two nosocomial clusters of coronavirus disease 2019 (COVID-19) in our hospital, we adopted a series of strict infection control measures, including regular rapid antigen test (RAT) screening for high-risk patients, visitors, and healthcare workers. We evaluated the diagnostic performance of a locally developed RAT, the INDICAID COVID-19 Rapid Antigen Test (Phase Scientific, Hong Kong), using respiratory samples from both symptomatic and asymptomatic individuals. METHODS: Real-time reverse-transcription polymerase chain reaction (rRT-PCR)-confirmed deep throat saliva (DTS) and pooled nasopharyngeal swab and throat swab (NPS/TS) samples collected from 1 November to 30 November 2020 were tested by INDICAID. Screening RATs were performed on asymptomatic healthcare workers during a 16-week period (1 December 2020 to 22 March 2021). RESULTS: In total, 20 rRT-PCR-confirmed samples (16 DTS, four pooled NPS/TS) were available for RAT. Using the original sample, RAT results were positive in 17/20 samples, indicating 85% sensitivity (95% confidence interval [CI]=62.11%-96.79%). Negative RAT results were associated with higher cycle threshold (Ct) values. For samples with Ct values <25, the sensitivity was 100%. Of the 49 801 RATs collected from healthcare workers, 33 false positives and one rRT-PCR-confirmed case were detected. The overall specificity was 99.93% (95% CI=99.91%-99.95%). The positive and negative predictive values were 2.94% (95% CI=2.11%-4.09%) and 100%, respectively. CONCLUSION: The INDICAID COVID-19 RAT demonstrated good sensitivity for specimens with high viral loads and satisfactory specificity for low-risk, asymptomatic healthcare workers.

Antibiotic management of acute pharyngitis in primary care.

The Centre for Health Protection of the Department of Health has convened the Advisory Group on Antibiotic Stewardship Programme in Primary Care (the Advisory Group) to formulate guidance notes and strategies for optimising judicious use of antibiotics and enhancing the Antibiotic Stewardship Programme in Primary Care. Acute pharyngitis is one of the most common conditions among out-patients in primary care in Hong Kong. Practical recommendations on the diagnosis and antibiotic treatment of acute streptococcal pharyngitis are made by the Advisory Group based on the best available clinical evidence, local prevalence of pathogens and associated antibiotic susceptibility profiles, and common local practice.

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.

Community-associated methicillin-resistant Staphylococcus aureus skin and soft tissue infections in Hong Kong.

Community-associated methicillin resistant Staphylococcus aureus is an emerging cause of skin and soft tissue infections in Hong Kong, especially among certain ethnic minorities.

Clinical characteristics of nosocomial norovirus outbreaks in Hong Kong.

Norovirus outbreaks occur worldwide every year and have become more frequent over the last few years. There were extensive outbreaks in Hong Kong from May to July 2006 and our aim was to describe nosocomial outbreaks from 1 May 2006 to 31 July 2006 in this retrospective observational study. A total of 38 confirmed norovirus outbreaks involving 218 patients were identified. Most of these patients were elderly with a mean age of 74.5 years (range: 3 months to 97 years); 62% of them were either totally or partially dependent for help with daily activities, 83.9% had underlying chronic medical problems and 56% had limited mobility. In all, 97.2% of individuals presented with diarrhoea and only 46.3% of them had vomiting. The median duration for diarrhoea was 3 days and the longest 24 days. The median duration of vomiting was one day and the longest 15 days. Fever occurred in one-third of all cases. Reverse transcriptase-polymerase chain reaction was positive for norovirus in 72.6% cases. We conclude that nosocomial norovirus infection often involves frail elderly patients with limited mobility and that these patients may have more prolonged symptoms.

Japanese encephalitis in Hong Kong.

OBJECTIVES: To review past and present patterns of occurrence of Japanese encephalitis in Hong Kong and across Asia. A better understanding of the disease should facilitate the formulation of an effective strategic plan to prevent a future epidemic. DATA SOURCES: Report of local cases, and literature search of MEDLINE up to November 2004. STUDY SELECTION: Literature and data related to Japanese encephalitis. DATA EXTRACTION: Relevant information and data were reviewed by the authors. DATA SYNTHESIS: Since 16 July 2004, under the ordinance of Hong Kong, Japanese encephalitis has been a notifiable disease. In the past, Japanese encephalitis has reached epidemic proportions in Japan, South Korea, and some areas in China. It has spread globally and has a worldwide incidence of 35 000 to 50 000 cases per year with 10 000 deaths. Mortality is about 30% and survivors often suffer serious long-term morbidity. In 2004, there were five local cases of Japanese encephalitis in Hong Kong. Subsequent serological surveillance of serum samples from 1547 local inhabitants revealed that 37 were positive, ie 2.4% of local inhabitants had been exposed to the Japanese encephalitis virus in the past. Most local inhabitants are immunologically naive to Japanese encephalitis virus. Most infections in endemic areas are asymptomatic. Patients with symptomatic Japanese encephalitis usually present with fever, headache, and confusion. Other signs include neurosis, poliomyelitis, and convulsion. Investigations including magnetic resonance imaging, electroencephalography, and single photon emission computed tomography are not specific. A definitive diagnosis depends on serological studies. Treatment is mainly supportive. CONCLUSIONS: The control of Japanese encephalitis in Hong Kong relies on an accurate surveillance system, vector control, vector avoidance, and vaccination of the at-risk population. At present, vaccination should be limited to travellers to endemic areas who would stay for longer than 1 month.

Gemella bacteraemia characterised by 16S ribosomal RNA gene sequencing.

AIMS: To define epidemiology, clinical disease, and outcome of gemella bacteraemia by 16S rRNA gene sequencing. To examine the usefulness of the Vitek, API, and ATB systems in identifying two gemella species. METHODS: All alpha haemolytic streptococci other than Streptococcus pneumoniae isolated from blood cultures during a six year period were identified by conventional biochemical methods, the Vitek system, and the API system. 16S rRNA gene sequencing was performed on all isolates identified by both kits as gemella with >or= 95% confidence or by either kit as any bacterial species with < 95% confidence. The ATB expression system was used to identify the two isolates that were defined as gemella species by 16S rRNA gene sequencing. RESULTS: Of the 302 alpha haemolytic streptococci other than S pneumoniae isolated, one was identified as Gemella morbillorum, and another as Gemella haemolysans by 16S rRNA gene sequencing. The patient with monomicrobial G morbillorum bacteraemia was a 66 year old man with community acquired infective endocarditis with septic thromboemboli. The patient with G haemolysans bacteraemia was a 41 year old woman with hospital acquired polymicrobial bacteraemia during the neutropenic period of an autologous bone marrow transplant for non-Hodgkin's lymphoma, the first case of its kind in the English literature. The API and ATB expression systems only identified the second strain as G haemolysans at 94% and 99% confidence, respectively, whereas the Vitek system identified none of the two strains correctly at > 70% confidence. CONCLUSIONS: Gemella bacteraemia is uncommon. 16S rRNA gene sequencing is the method of choice for identification of gemella and gemella-like isolates.

Mollaret's meningitis revisited. Report of a case with a review of the literature.

Recurrent aseptic meningitis of Mollaret is a rare condition. We report a Chinese patient with Mollaret's meningitis and describe the characteristic cytological changes in the cerebrospinal fluid. The diagnosis and treatment of this condition is discussed with a review of the English literature.

A study of pre-antibiotic bacteriology in 125 patients with necrotizing enterocolitis.

Over a five-year period, 125 newborns with necrotizing enterocolitis (NEC) were managed by us. Their mean birthweight was 1700 g and mean maturity was 32 weeks. Before commencement of antibiotics, routine septic work-up was done in order to define the bacterial spectrum and antibiotic sensitivity. The study includes aerobic and anaerobic cultures of gastric and pharyngeal aspirates, blood cultures, umbilical swabs and culture of umbilical catheter tips in relevant cases. Peritoneal swab results were also analyzed if laparatomy was performed. Positive cultures were present in 45 patients (36%) with 55 positive specimens. Fifteen types of organism were isolated: the commonest was Enterobacter (29%), followed by E. coli (14.5%) and Klebsiella (13%). They were resistant to ampicillin and first-generation cephalosporin. These organisms were usually opportunistic pathogens. Overgrowth of them may be the cause of NEC. Regular review of the antibiotic sensitivity of these organisms allows prompt and appropriate choice of antibiotics. At the same time, antibiotic sensitivity for these organisms was analyzed to guide us in the choice of antibiotic therapy.

Clinical outcomes of bacteremic pneumococcal infections in an area with high resistance.

In a retrospective study designed to gather information in a region with high antimicrobial resistance, the outcomes of 216 episodes of laboratory-confirmed pneumococcal bacteremia treated in Hong Kong between 1995 and 2001 were assessed. The patients had a mean age (+/-standard deviation) of 40+/-33.7 years. In all patients, the clinical diagnosis was confirmed by isolation of Streptococcus pneumoniae from blood (n=216), cerebrospinal fluid (n=7) and/or other sterile sites (n=12). Penicillin nonsusceptibility was found in 37.5% of the isolates (20.8% intermediate and 16.7% resistant). Penicillin nonsusceptibility was not a risk factor for inpatient mortality (p=0.7), nor did it affect duration of fever (p=0.4), requirement for intensive care unit admission (p=0.4) or development of suppurative complications (p=0.2). Advanced age (OR 11.3, 95%CI 4.5-28.2, p<0.01), critical illness (OR 11.3, 95%CI 4.5-28.2, p<0.001) and discordant therapy (OR 4.3, 95%CI 1.7-10.9, p<0.002) involving agents with poor anti-pneumococcal activity (but not penicillins and broad-spectrum beta-lactam agents) were significantly associated with mortality.

Contemporary methicillin-resistant Staphylococcus aureus clones in Hong Kong.

Two hundred non-duplicate methicillin-resistant Staphylococcus aureus (MRSA) isolates causing bacteremia in patients in four major Hong Kong hospitals during the period 2000 to 2001 were characterized by antibiogram, pulsed-field gel electrophoresis (PFGE) using SmaI restriction enzymes, and determination of staphylococcal cassette chromosome mec (SCCmec) types. Nine PFGE types, A to I, were obtained. PFGE type A constituted 50% (99/200) of all isolates and was present in isolates from all four hospitals. PFGE types A to E, had previously been identified as the major types at one of the hospitals from 1988 to 2000. The majority had a resistance profile to tetracycline (T), erythromycin (E), clindamycin (D), gentamicin (G), tobramycin (To), and ciprofloxacin (Ci), and belonged to SCCmec type III; and representatives belonged to clonal complex 239 (CC 239) (MRSA with SCCmec type III and sequence type 239, designated ST 239-MRSA-III). PFGE types F to I were new patterns that had not been previously identified in isolates from Hong Kong. PFGE type F constituted 18% (35/200) of MRSAs, had resistance profile TEGToCi, and belonged to CC 5 (ST 5-MRSA-II). PFGE type G included 13% (26/200) of MRSAs, had resistance profile TECi, and belonged to CC 45 with SCCmec type I or II. PFGE type H had characteristics similar to those of CC 239, while PFGE type I included three isolates, two of which expressed resistance to oxacillin and fusidic acid only. Two of these strains had SCCmec IVa and carried sequence type 389, with a multilocus sequence typing allelic profile of 3-35-19-2-20-26-39. Contemporary MRSAs causing bacteremia in Hong Kong hospitals belong to three clonal complexes (CC 5, CC 45, and CC 239). The most prevalent MRSA clone in Hong Kong belongs to CC 239, with PFGE types A to E and H, SCCmec type III, ST 239, and a resistance profile of TEDGToCi.

Macrolide resistance in Streptococcus pneumoniae in Hong Kong.

Erythromycin resistance rates among penicillin-susceptible Streptococcus pneumoniae were 38 and 92% among penicillin-intermediate and -resistant S. pneumoniae isolates from Hong Kong, respectively, and 27% (43 of 158) of the isolates showed the MLS(B) phenotype, and the majority carried the ermB gene; 73% (115 of 158) displayed the M phenotype, and all possessed the mef gene. The MLS(B) phenotype was predominant in penicillin-susceptible, macrolide-resistant isolates and in penicillin-nonsusceptible isolates of serotype 6B, whilst the M phenotype was predominant in penicillin-intermediate or -resistant isolates belonging to serotype 23F or 19F. Extensive spread of clones of drug-resistant pneumococci has led to the widespread presence of macrolide resistance in S. pneumoniae in Hong Kong.

Evidence of clonal dissemination of multidrug-resistant Streptococcus pneumoniae in Hong Kong.

The relationship between the phenotypic and genotypic characteristics of 105 penicillin-intermediate or -resistant Streptococcus pneumoniae isolates saved during 1994 to 1997 at the Prince of Wales Hospital and Pamela Youde Nethersole Eastern Hospital, Hong Kong, was studied. The pbp genes for penicillin-binding proteins 1a, 2b, and 2x for each isolate were amplified by PCR, and the products were digested with restriction enzymes HinfI and AluI. A combination of the pulsed-field gel electrophoresis (PFGE) profiles, pbp fingerprints, and phenotypic characteristics of capsular types and antibiograms enabled these isolates to be divided into four major groups. Seventy-four percent (78 of 105) of the strains, belonging to serotypes 23F, 19F, and 14, showed indistinguishable pbp fingerprint patterns (group A1, 1-1-1, 1-1-1), with PFGE patterns belonging to group A and its subtypes, suggesting that these strains were closely related. Eighty-three percent (65 of 78) of these isolates were also resistant to tetracycline, erythromycin, chloramphenicol, and trimethoprim. The type 23F isolates were indistinguishable from representative strains of the Spanish 23F clone by these molecular methods, indicating that these strains may be variants of the Spanish 23F clone. Serotype 6B accounted for 19% (20 of 105) of the isolates with reduced penicillin susceptibility and was made up of variants belonging to four different pbp fingerprint groups with the PFGE pattern group B, the predominant group being indistinguishable from that of the Spanish 6B clone. Other PFGE and fingerprint groups were mainly obtained from penicillin-susceptible strains of various serotypes. The results suggest that the rapid emergence of drug-resistant S. pneumoniae in Hong Kong has been due to the rapid dissemination of several successful clones.

Pseudomonas septicaemia in apparently healthy children.

Among 27 cases of Pseudomonas septicaemia in the Department of Paediatrics of Queen Mary Hospital from 1981 to 1988, we have identified 10 children without known predisposing causes before presentation and report their clinical features. Six were infants, of whom 4 developed shock on admission and died. Ecthyma gangrenosum was present in 4 patients. Pseudomonas aeruginosa was isolated in 8 patients. All isolates, except Ps. cepacia, were sensitive to gentamicin. One patient had cyclical neutropenia. Another had an appendicular abscess. Salmonella was cultured from the stool in one patient. Although Pseudomonas septicaemia is normally considered to be associated with underlying immunodeficiency, in 22% it occurred in previously healthy children. Mortality is high especially in infants who develop septicaemic shock. It is advisable to cover for Pseudomonas septicaemia with aminoglycosides or ceftazidime in sick septic infants.

Ofloxacin versus co-trimoxazole for prevention of infection in neutropenic patients following cytotoxic chemotherapy.

The efficacy of ofloxacin in preventing infection in neutropenic patients following cytotoxic chemotherapy was evaluated and was compared with that of co-trimoxazole. A total of 102 patients with hematological malignancies were randomly selected to receive either co-trimoxazole or ofloxacin. All patients were monitored for compliance, occurrence of infection, and drug-related side effects. A surveillance culture of a rectal swab was performed regularly. A total of 25 of the 52 patients (48%) who received co-trimoxazole and 11 of the 50 patients (22%) who received ofloxacin developed fever during the study period (P less than 0.025). Gram-negative bacteremia occurred in nine patients in the co-trimoxazole group (17%) but in only one patient (2%) in the ofloxacin group (P less than 0.05). No patient in either group had documented gram-positive bacterial or Pneumocystis carinii infection. Poor performance status was the only identifiable factor associated with an increased incidence of bacteremia. The surveillance study showed that significantly fewer bacterial strains were resistant to ofloxacin than to co-trimoxazole and that acquisition of resistance to co-trimoxazole was more commonly observed than was acquisition of resistance to ofloxacin. Significantly more patients had skin rashes following co-trimoxazole than ofloxacin treatment (P less than 0.05). Ofloxacin was superior to co-trimoxazole in preventing infection in this population of neutropenic patients.