Mucosal-associated invariant T cells and Vδ2+ γδ T cells in community acquired pneumonia: association of abundance in sputum with clinical severity and outcome.

Mucosal-associated invariant T (MAIT) cells and Vδ2+ γδ T cells are anti-bacterial innate-like lymphocytes (ILLs) that are enriched in blood and mucosa. ILLs have been implicated in control of infection. However, the role of ILLs in community-acquired pneumonia (CAP) is unknown. Using sputum samples from a well-characterized CAP cohort, MAIT cell and Vδ2+ T cell abundance was determined by quantitative polymerase chain reaction (qPCR). Cytokine and chemokine concentrations in sputum were measured. The capacity of bacteria in sputum to produce activating ligands for MAIT cells and Vδ2+ T cells was inferred by 16S rRNA sequencing. MAIT cell abundance in sputum was higher in patients with less severe pneumonia; duration of hospital admission was inversely correlated with both MAIT and Vδ2+ T cell abundance. The abundance of both ILLs was higher in patients with a confirmed bacterial aetiology; however, there was no correlation with total bacterial load or the predicted capacity of bacteria to produce activating ligands. Sputum MAIT cell abundance was associated with interferon (IFN)-α, IFN-γ, and sputum neutrophil abundance, while Vδ2+ T cell abundance was associated with CXCL11 and IFN-γ. Therefore, MAIT and Vδ2+ T cells can be detected in sputum in CAP, where they may contribute to improved clinical outcome.

Multidrug resistant Enterobacteriaceae in New Zealand: a current perspective.

In this article we review mechanisms and potential transmission pathways of multidrug resistance in Enterobacteriaceae, with an emphasis on extended-spectrum ß-lactamase (ESBL)-production. This provides background to better understand challenges presented by this important group of antimicrobial resistant bacteria, and inform measures aimed at prevention and control of antimicrobial resistance in general. Humans and animals interact at various levels; household pets cohabit with humans, and other animals interact with people through direct contact, as well as through the food chain and the environment. These interactions offer opportunity for bacteria such as ESBL-producers to be shared and transmitted between species and, in turn, increase the risk of zoonotic and reverse-zoonotic disease transmission. A key step in curtailing antimicrobial resistance is improved stewardship of antimicrobials, including surveillance of their use, better infection-control and prevention, and a better understanding of prescribing practice in both veterinary and medical professions in New Zealand. This will also require prospective observational studies to examine risk factors for antimicrobial resistance. Due to the interconnectedness of humans, animals and the environment actions to effect the changes required should be undertaken using a One Health approach.

Haemophilus influenzae type b carriage and novel bacterial population structure among children in urban Kathmandu, Nepal.

Haemophilus influenzae type b (Hib) is a major cause of invasive bacterial infection in children that can be prevented by a vaccine, but there is still uncertainty about its relative importance in Asia. This study investigated the age-specific prevalence of Hib carriage and its molecular epidemiology in carriage and disease in Nepal. Oropharyngeal swabs were collected from children in Kathmandu, Nepal, from 3 different settings: a hospital outpatient department (OPD), schools, and children's homes. Hib was isolated using Hib antiserum agar plates, and serotyping was performed with latex agglutination. Hib isolates from children with invasive disease were obtained during active microbiological surveillance at Patan Hospital, Kathmandu, Nepal. Genotyping of disease and carriage isolates was undertaken using multilocus sequence typing (MLST). Swabs were taken from 2,195 children, including 1,311 children at an OPD, 647 children attending schools, and 237 children in homes. Overall, Hib was identified in 5.0% (110/2,195; 95% confidence interval [95% CI], 3.9% to 6.4%). MLST was performed on 108 Hib isolates from children carrying Hib isolates and 15 isolates from children with invasive disease. Thirty-one sequence types (STs) were identified, and 20 of these were novel STs. The most common ST isolates were sequence type 6 (ST6) and the novel ST722. There was marked heterogeneity among the STs from children with disease and children carrying Hib. STs identified from invasive infections were those commonly identified in carriage. This study provides evidence of Hib carriage among children in urban Nepal with genetically diverse strains prior to introduction of universal vaccination. The Hib carriage rate in Nepal was similar to the rates observed in other populations with documented high disease rates prior to vaccination, supporting implementation of Hib vaccine in Nepal in 2009.

Clinical profile of invasive pneumococcal diseases in Patan Hospital, Nepal.

BACKGROUND: Pneumococcal infection is one of the leading causes of pneumonia, meningitis and septicemia in developing countries. It accounts for one million deaths each year in children. OBJECTIVES: The objective of this study is to see the clinical profile of invasive pneumococcal disease, antibiotics sensitivity pattern and prevalent serotypes in children admitted at Patan Hospital. METHODS: This is a retrospective analytical study conducted in the department of Paediatrics, Patan hospital. The lab data of those children who grew pneumococci in their blood, cerebrospinal fluid or body fluids over a period of 3 years (January 2007 to Dec 2009) were collected and the case files were then studied. RESULTS: Out of 42 cases of invasive pneumococcal diseases studied admitted diagnoses included pneumonia, febrile seizure, bacteremia or septicemia, meningitis, acute gastroenteritis and glomerulonephritis. Twenty seven of them were children under five. The male to female ratio was 1.7:1. On investigation 64%, 52% and 5% of the patients had leucocytosis, anaemia, and leucopenia respectively. Twenty six of them had radiological changes suggestive of pneumonia. Streptococcus pneumoniae grew in 38 blood samples, 5 cerebrospinal fluid and 3 pleural fluids. Almost all of these isolates were sensitive to penicillin, cefotaxime, amoxycillin, choloramphenicol, erythromycin and ofloxacin and resistant to cotrimoxazole and gentamicin. Pneumococcal serotypes found in our study were 1, 14, 5, 23B, 6B, 8, 9A, 9V, 10A, 15 and 23F (11 serotypes). CONCLUSIONS: Penicillin is still the most effective antibiotic for streptococcal infection in our study. Of the pneumococcal serotypes identified; 36% were covered by the 7-valent pneumococcal conjugate vaccine, 54% each by PCV-10 and PCV-13, and 72% by the e 23 valent vaccines.

Population-based epidemiology of Staphylococcus aureus bloodstream infection in Canterbury, New Zealand.

BACKGROUND: Few contemporary reports describe population-based incidence of Staphylcoccus aureus bloodstream infection (SABSI). AIM: To describe longitudinal incidence of SABSI in a region of New Zealand with low MRSA prevalence. METHODS: Blood cultures growing S. aureus were identified from hospital laboratories between 1 July 1998 and 30 June 2006. Record linkage was used to combine information from local and national databases into a single patient event record. Information from the New Zealand census was used to determine regional incidence of disease. An address-based measure of deprivation was used to analyse the relationship between incidence and socioeconomic status. Morbidity data were not collected. RESULTS: 779 patients with SABSI were identified (482/779 (62%) male, 297/779 (38%) female). The crude incidence of S. aureus bacteraemia varied between 18.5-27.3/100 000 per annum. Three of 779 isolates (0.4%) were MRSA. Two hundred and seventy-seven of 776 (36%) patients with complete records had hospital-acquired SABSI. One hundred and forty-one of 778 patients (18%) died within 30 days and 235/778 (30%) died within a year. Proportional hazards survival models significantly associated age, male sex and more than 14 days of hospitalization in the year prior to index culture with adverse outcome. Higher socioeconomic status was associated with lower rates of SABSI (adjusted rate ratio 0.74, 95% confidence interval: 0.56-0.98, P= 0.007 after adjustment for age and sex, and comparing the highest and lowest deprivation quintiles). CONCLUSION: Population factors significantly influence SABSI incidence and survival. Further research is required to determine whether these have the potential to invalidate inter-hospital comparison of SABSI incidence as a measure of health-care quality.

Incidence and characteristics of viral community-acquired pneumonia in adults.

BACKGROUND: In adults, viral causes of community-acquired pneumonia (CAP) are poorly characterised. The aims of this study were to characterise the viral aetiology of CAP in adults by using an extensive array of viral diagnostic tests and to compare the characteristics of viral pneumonia with those of pneumococcal pneumonia. METHODS: Adults admitted to Christchurch Hospital over a 1-year period with CAP were included in the study. Microbiological testing methods included blood and sputum cultures, urinary antigen testing for Streptococcus pneumoniae and Legionella pneumophila, antibody detection in paired sera and detection of respiratory viruses in nasopharyngeal swabs by immunofluorescence, culture and PCR. RESULTS: Of 304 patients with CAP, a viral diagnosis was made in 88 (29%), with rhinoviruses and influenza A being the most common. Two or more pathogens were detected in 49 (16%) patients, 45 of whom had mixed viral and bacterial infections. There were no reliable clinical predictors of viral pneumonia, although several variables were independently associated with some aetiologies. The presence of myalgia was associated with pneumonia caused by any respiratory virus (OR 3.62, 95% CI 1.29 to 10.12) and influenza pneumonia (OR 190.72, 95% CI 3.68 to 9891.91). Mixed rhinovirus/pneumococcal infection was associated with severe disease. CONCLUSIONS: Virus-associated CAP is common in adults. Polymicrobial infections involving bacterial and viral pathogens are frequent and may be associated with severe pneumonia.

Concomitant Staphylococcus aureus bacteriuria is associated with poor clinical outcome in adults with S. aureus bacteraemia.

A retrospective cohort study was undertaken to determine the prognostic significance of Staphylococcus aureus bacteriuria in patients presenting to our hospital with S. aureus bacteraemia between January 2000 and December 2003. A total of 378 patients had at least one positive blood culture for S. aureus, of whom 221 had urine cultured within 24h of presentation. For this group, 206 case records could be retrieved for review. Of these patients, all had meticillin-susceptible S. aureus bacteraemia and 35 (17%) had S. aureus cultured in urine. Logistic regression analysis was used to control for age, genitourinary tract status and comorbidity. Concomitant S. aureus bacteriuria persisted as a significant risk factor for ICU admission [risk ratio (RR): 2.5; 95% confidence interval (CI): 1.06-4.36; P=0.04] and in-hospital mortality (RR: 2.18; 95% CI: 1.05-3.57; P=0.04). Other findings were that cerebrovascular disease in males and increasing age in both sexes were associated with in-hospital and one-year mortality. Prospective studies are warranted exploring the link between S. aureus bacteriuria and clinical outcome in patients with S. aureus bacteraemia.

Evaluation of the Mycoplasma Duo kit for the detection of Mycoplasma hominis and Ureaplasma urealyticum from urogenital and placental specimens.

This study compares the Mycoplasma Duo kit for the detection of genital mycoplasmas with conventional culture using A7 differential agar for the detection of Mycoplasma hominis and Ureaplasma urealyticum in clinical samples. Detection of the mycoplasmas is based on the specific metabolic properties of each organism to hydrolyse either arginine or urea. The Mycoplasma Duo test showed a significantly higher detection rate than did culture, although many of the culture-negative results may have been due to the presence of bacterial overgrowth.

The rapid evaluation of bacterial growth in blood cultures by selected ion flow tube-mass spectrometry (SIFT-MS) and comparison with the BacT/ALERT automated blood culture system.

We compared the performance of the BacT/ALERT automated blood culture system with real-time, quantitative volatile organic compound (VOC) detection by selected ion flow tube-mass spectrometry (SIFT-MS). Blood samples from healthy donors were artificially infected with 5 or 100 CFU of organisms commonly causing bacteremia. Positive results by SIFT-MS analysis of headspace gases were recorded for 53/60 (88.3%) bottles at 8h, and 58/60 (96.6%) bottles at 24 h. We conclude that SIFT-MS is a sensitive method for the detection of microbial VOCs. Furthermore, profiles of the VOCs detected may allow simultaneous identification of infecting organisms.

Childhood diarrhoea in a district in northeast Thailand: incidence and treatment choices.

Diarrhoeal disease is a major public health problem in Thailand. We collected information on childhood diarrhoea from a district in northeast Thailand, using various approaches which focus on both consumers and providers. The overall incidence of diarrhoea in the study area was 2.1 episodes per child per 12 months, with children under two years of age having a higher rate at 3.0 episodes per child per 12 months. Many episodes were not recognized as diarrhoeal episodes by caregivers, and treatment was sought in just over half of all episodes. Although children received an average of 2.4 items of medicine per episode, there was relatively low use of oral rehydration solutions. This study highlights the importance of assessing local beliefs when collecting data on diarrhoeal diseases in children, and the importance of continuing efforts to improve public health education on the management of diarrhoeal diseases.

Economics of chronic heart failure.

Chronic heart failure (CHF) is now recognized as a major and escalating public health problem. The costs of this syndrome, both in economic and personal terms, are considerable. The prevalence of CHF is 1-2% and appears to be increasing, in part because of ageing of the population. Economic analyses of CHF should include both direct and indirect costs of care. Healthcare expenditure on CHF in developed countries consumes 1-2% of the total health care budget. The cost of hospitalization represents the greatest proportion of total expenditure. Optimization of drug therapy represents the most effective way of reducing costs. Recent economic analyses in the Netherlands and Sweden suggest the costs of care are rising.

Rapid identification of Staphylococcus aureus from BacT/ALERT blood culture bottles by direct Gram stain characteristics.

The rapid identification of Staphylococcus aureus from positive blood cultures provides important clinical and therapeutic information. Using criteria based on direct Gram stain characteristics, an experienced microscopist was able to distinguish S aureus from other staphylococci isolated from BacT/ALERT blood culture bottles with an overall sensitivity of 89% and specificity of 98%. Furthermore, this method was readily taught to a clinical microbiologist who had not previously used the method first hand. Laboratories using the BacT/ALERT blood culture system should become familiar with these criteria so that S aureus bacteraemia can be identified rapidly.

Comparison of real-time PCR and conventional hemi-nested PCR for the detection of Bordetella pertussis in nasopharyngeal samples.

We directly compared a conventional hemi-nested PCR assay with a real-time (LightCycler) PCR assay for the detection of Bordetella pertussis in nasopharyngeal samples. Of the 152 samples tested, 49 (32%) were positive by first-round conventional PCR, 56 (37%) were positive by the hemi-nested PCR assay, and 39 (26%) were positive by the real-time assay. All samples testing positive with the real-time assay were also positive by the hemi-nested assay (both first- and second-round PCR), and all culture-positive samples tested positive by both PCR assays. These results suggest that the hemi-nested assay is more sensitive than the real-time assay for detecting B. pertussis.

Brain natriuretic peptide is stable in whole blood and can be measured using a simple rapid assay: implications for clinical practice.

OBJECTIVES: To compare the stability of brain natriuretic peptide (BNP) to that of N-terminal atrial natriuretic peptide (NT-ANP) in whole blood and plasma stored under different conditions. To compare a rapid, simple, direct (unextracted) BNP assay to a conventional assay using plasma extraction. DESIGN: Blinded, prospective, comparative study. SETTING: Tertiary referral cardiology department. SUBJECTS: Forty two subjects (24 men, 18 women) comprising 28 patients with left ventricular systolic dysfunction (LVSD) ranging from mild to severe and 14 healthy volunteers. MAIN OUTCOME MEASURES: Stability of NT-ANP and BNP when stored as whole blood or plasma at room temperature over three days. Reproducibility of measurements. RESULTS: BNP was stable in whole blood stored at room temperature for three days; mean change in concentration -7.4% (95% CI 0.6 to -14.8), (direct), -6.3% (5.0 to -16.4), (extracted); whereas a significant decline in BNP concentration was noted in plasma stored at room temperature; -23.2% (-13.7 to -31.6), (direct); -14.4% (-3.2 to -24.3), (extracted). By contrast a small nonsignificant rise in NT-ANP concentration was noted both in whole blood and plasma stored at room temperature for three days; whole blood +8.6% (+22.3 to -3.5), plasma +6.3%, (23.2 to -8.4). The reproducibility of the BNP measurements, and particularly the rapid, direct, measurement, was superior to that for NT-ANP. CONCLUSIONS: BNP is shown to be stable in whole blood for three days and can be measured using a rapid, simple assay. Routine assay of BNP is feasible in ordinary clinical practice and may be of value to general practitioners and hospital based physicians in the diagnosis and management of patients with LVSD. Samples can be sent to a central laboratory without special handling requirements.

Clinical and economic considerations in the use of third-generation oral cephalosporins.

A number of oral third-generation cephalosporins (cefixime, cefetamet pivoxil, ceftibuten and cefpodoxime proxetil) have been widely trialled and are becoming available. In addition, cefdinir may also be marketed. Compared with first- and second-generation agents, the oral third-generation cephalosporins have an improved antibacterial spectrum and reduced minimum inhibitory concentrations against common Gram-negative pathogens. In contrast, with the exception of cefdinir, they are less active against Staphylococcus aureus. They have favourable pharmacokinetic profiles and are generally administered in once- or twice-daily regimens. They are well tolerated, but cefixime has been associated with a particularly high rate of diarrhoea. Possible clinical indications for the use of oral third-generation cephalosporins include upper and lower respiratory, genitourinary and soft-tissue infections and follow-on treatment of severe infections requiring hospitalisation. At present, these drugs offer no particular clinical advantages over standard therapy in most circumstances. However, they may be considered where there is hypersensitivity to penicillins, a high incidence of resistance to first-line therapy in the community, or failure of standard therapy. Further studies are needed to define the efficacy of oral third-generation agents in the prevention of rheumatic fever and as follow-on therapy for severe infections. The oral third-generation cephalosporins are generally more expensive than standard agents, but detailed studies that include extended costs (e.g. treatment of adverse effects, treatment of clinical failure, return visits to physicians) have yet to be reported.

Female genital schistosomiasis.

Schistosoma haemtobium infection in travelers from endemic areas is usually asymptomatic, or presents with hematuria. Uncommon manifestations include neurological syndromes, genital dysaesthesias and watery or blood stained semen. This organism also causes disease within all structures of the female genital tract because of communications between pelvic venous complexes, and can occur long after return home. Schistosomiasis may not be suspected, resulting in delays in diagnosis and treatment. We present two cases which illustrate the diverse nature of this condition.

Perniosis (chilblains) of the thigh: report of five cases, including four following river crossings.

Perniosis, or chilblains, are skin lesions that occur as an abnormal reaction to cold, damp environments. We describe five cases of perniosis affecting the thighs. Four of the five cases occurred after wading across mountain rivers. Histological changes of deep perniosis and panniculitis were seen in a skin biopsy from one of the cases. In each case there was marked pain and discomfort, and lesions resolved over more than 1 week.

Acute mountain sickness in the Southern Alps of New Zealand.

AIM: To assess the incidence and impact of acute mountain sickness in the Southern Alps of New Zealand. METHODS: Over a 22 month period, mountaineers in the Mount Cook region were asked to complete a questionnaire at the completion of their climbing excursions. The questionnaire recorded demographic data and incorporated the Lake Louise scoring system to assess the presence of acute mountain sickness. RESULTS: Of the 114 subjects who completed the questionnaire, 30 (26%) developed acute mountain sickness. The incidence was higher amongst those who slept above 2500 m (50%). Of those with acute mountain sickness, 33% reported that their symptoms resulted in no reduction in activity, while 13% reported a moderate or severe reduction in activity. CONCLUSION: Mountaineers climbing in New Zealand's Southern Alps should be aware of the risk of acute mountain sickness, especially for those sleeping above 2500 m.

Persistence of iodine deficiency 25 years after initial correction efforts in the Khumbu region of Nepal.

AIMS: To assess the current status of, and understanding about iodine deficiency disorders among Sherpa residents of the Khumbu region of Nepal, 25 years after the introduction of iodised oil injections. METHODS: Several groups of Khumbu Sherpas were studied and goitre rate, urinary iodine level and cretinism prevalence were measured as indicators of iodine deficiency. Subjects were also questioned in detail about their food consumption, with particular reference to salt use, and about their understanding of the causes and treatment of iodine deficiency disorders. RESULTS: The prevalences of goitre, deaf-mutism and cretinism were 21%, 1.3% and 0.5% respectively (compared to 92%, 4.7% and 5.9% in 1966). No cretins had been born since 1966. The median urine iodine concentration was 35 microg/L. Most people preferred uniodised Tibetan rock salt, although 44% regularly consumed iodised salt. All granulated salt tested from the local market contained adequate amounts of iodine. Only 11% of those surveyed knew that goitre was caused by iodine deficiency CONCLUSIONS: Although prevalences of iodine deficiency disorders are much less than 30 years ago, iodine deficiency continues to be a major problem in Khumbu and demands a clear control strategy, combining ongoing iodine supplementation and education. Iodised salt is usually the best approach to control of iodine deficiency disorders for most regions of the world but the Khumbu experience shows that local cultural and commercial factors can severely limit its impact. To be successful, control programme for iodine deficiency disorders also needs assessment of the salt trade, monitoring, education and occasional targeted interventions with iodised oil or other supplements.