Screening for latent tuberculous infection in people living with HIV infection in Auckland, New Zealand.

SETTING: New Zealand, which has a low incidence of tuberculosis (TB), has historically taken a risk-based approach to screening for latent tuberculous infection (LTBI) in adult people living with the human immunodeficiency virus infection (PLHIV). OBJECTIVE: To evaluate LTBI screening, treatment and outcomes in an adult PLHIV population. DESIGN: This was a retrospective clinical record review of an initial cohort of adult PLHIV attending the Auckland City Hospital HIV clinic in 2011, and a second cohort of adult PLHIV newly attending the clinic in 2014. We analysed high-risk (born in or acquiring HIV in a high TB incidence country) and low-risk patients using descriptive statistical methods. RESULTS: Of the 752 patients from the initial cohort, 416 (55%) had documentation of LTBI screening, which was positive in 74 (10%): 19/461 (4%) low-risk and 55/291 (19%) high-risk patients. LTBI treatment was received in 13 low-risk and 44 high-risk patients. Of 73 patients in the second cohort, 68 (93%) were screened. CONCLUSION: LTBI screening was incomplete in our clinic, but improved between 2011 and 2014. A significant number of patients with LTBI did not originate from a high TB incidence country.

Therapeutic drug monitoring of isoniazid and rifampicin during anti-tuberculosis treatment in Auckland, New Zealand.

SETTING: There is uncertainty as to the optimal therapeutic concentrations of anti-tuberculosis drugs to achieve cure. OBJECTIVE: To characterise the use of therapeutic drug monitoring (TDM), and identify risk factors and outcomes for those with concentrations below the drug interval. DESIGN: Patients treated for tuberculosis (TB) who had rifampicin (RMP) or isoniazid (INH) concentrations measured between 1 January 2005 and 31 December 2012 were studied retrospectively. Matched concentrations and drug dosing time were assessed according to contemporary regional drug intervals (RMP > 6 µmol/l, INH > 7.5 µmol/l) and current international recommendations (RMP > 10 µmol/l, INH > 22 µmol/l). Outcomes were assessed using World Health Organization criteria. RESULTS: Of 865 patients, 121 had concentrations of either or both medications. RMP concentrations were within the regional drug intervals in 106/114 (93%) and INH in 91/100 (91%). Concentrations were within international drug intervals for RMP in 76/114 (67%) and INH in 53/100 (53%). Low weight-based dose was the only statistically significant risk factor for concentrations below the drug interval. Of the 35 patients with low concentrations, 21 were cured, 9 completed treatment and 5 transferred out. There were no relapses during follow-up (mean 66.5 months). CONCLUSION: There were no clinically useful characteristics to guide use of TDM. Many patients had concentrations below international therapeutic intervals, but were successfully treated.

Necrotizing fasciitis: review of 82 cases in South Auckland.

BACKGROUND: Early recognition of necrotizing fasciitis (NF) can be difficult, but is important as infections progress rapidly and have significant mortality. The aim of this study of patients with NF was to determine the clinical characteristics at presentation, causative pathogens and subsequent clinical outcome. METHODS: We retrospectively reviewed consecutive patients with NF presenting to Middlemore Hospital from January 2000 to June 2006. RESULTS: Eighty-two patients were evaluated: 56% male, mean age 54.9 years (standard deviation 18.5), 40% Pacific Islanders. The site of infection was the lower limb in 46 (56%) patients, upper limb in 12 (15%) patients and perineum in 13 (16%) patients. Twenty-two (27%) patients were taking non-steroidal anti-inflammatory drugs, 29 (35%) had diabetes mellitus, 25 (30%) had gout and 17 (21%) had congestive heart failure. Forty-nine (60%) patients had a surgical procedure within 24 h of admission. Streptococcus pyogenes was isolated from tissue or blood cultures in 33 (40%) patients and 26 (32%) patients had polymicrobial infection. Twenty-five (30%) patients died, 17 (68%) within 72 h of admission. Independent predictors of mortality include congestive heart failure (P = 0.033) and a history of gout (P = 0.037). CONCLUSION: NF remains an important disease in our community with significant morbidity and mortality. Pacific Islanders were disproportionately represented. Early diagnosis of NF can be difficult and requires a high index of suspicion in all patients presenting with cellulitis or unexplained sepsis. Congestive heart failure and gout are independent predictors of mortality and patients with these conditions and sepsis need early assessment with more aggressive hospital triaging.

Propionibacterium acnes: an under-appreciated cause of post-neurosurgical infection.

BACKGROUND: Propionibacterium acnes is increasingly recognized as a cause of post-neurosurgical infection. This review of patients with P. acnes neurosurgical infection was carried out in order to determine clinical characteristics and outcomes in relation to duration of antimicrobial treatment. METHODS: We retrospectively reviewed the charts of consecutive patients with P. acnes isolated from neurosurgical specimens from 1 January 1999 to 30 June 2005. We defined P. acnes neurosurgical infection as isolation of P. acnes alone from a sterile neurosurgical site in a patient who clinically improved following treatment with an appropriate antibiotic. RESULTS: We identified 28 patients with definite P. acnes neurosurgical infection; median age 49 years (range 23-77); 15 (54%) male. All patients had prior neurosurgical procedures: 27 (96%) post-craniotomy. The median time from surgery to presentation was 54 days (range 12-1,578). Eighteen out of 28 (64%) patients who met the definition of neurosurgical infection had Gram-positive bacilli seen in at least one surgical specimen compared with only 2/56 (4%) patients who did not meet the definition (P < 0.0001). Intravenous benzyl penicillin +/- oral penicillin VK was the most common treatment. The median duration of antibiotic treatment for intracranial infection was 29 days. Five of nine patients who had extracranial bone-flap-associated infection had

Overnight prescription of oxygen in long term oxygen therapy: time to reconsider the guidelines?

BACKGROUND: Guidelines for long term oxygen therapy (LTOT) recommend increasing oxygen flow by 1 l/min overnight. A study was undertaken in patients with COPD on LTOT to determine the prevalence of overnight desaturation if the usual oxygen flow rate is not increased at night, whether resting oxygen saturation predicts overnight desaturation, and whether overnight desaturation correlates with health related quality of life (HRQL) and sleep quality. METHODS: A cross sectional prospective study was performed on consecutive patients with COPD on LTOT attending our regional outpatient oxygen service. All patients fulfilled standard criteria for LTOT, had been established on LTOT at a flow to achieve resting oxygen saturations >90%, but had not been instructed to increase oxygen flow overnight. Overnight desaturation was defined as <90% for > or =30% of the night on either of two consecutive nights. HRQL was evaluated with the SF-36 Health Survey Questionnaire, Chronic Respiratory Questionnaire, and the Pittsburgh Sleep Quality Index. RESULTS: Thirty eight patients (63% men) of mean (SD) age 73.5 (8.04) years and mean (SD) forced expiratory volume in 1 second 0.77 (0.35) l were evaluated. Overnight desaturation occurred in six (16%; 95% CI 4 to 27). Desaturators had mean (SD) resting oxygen saturation on room air of 88 (4.2)% compared with 90 (4.1)% in non-desaturators (p = 0.15), and corrected saturations of 93 (2.0)% versus 94 (2.0)% (p = 0.18). HRQL and sleep quality were poor but did not differ between desaturators and non-desaturators. CONCLUSIONS: Most patients did not exhibit overnight desaturation despite not increasing their LTOT prescription overnight. These results challenge the recommendation of routinely increasing overnight oxygen flow in patients receiving LTOT.

The stability of benzoyl peroxide formulations determined from isothermal microcalorimetric studies.

Recent developments in the analysis of microcalorimetric data output allow the possibility of determining both thermodynamic and kinetic parameters for complex reaction systems. Such experiments routinely take around 50 h, hence qualifying for the description rapid. The methods have earlier been applied to a study of the stability of benzoyl peroxide itself in aqueous suspension. This paper reports the results of isothermal microcalorimetric study of the stability of benzoyl peroxide in the presence of a wide range of excipients and in formulated materials. The results are shown to assist in formulation design, are achieved rapidly and are derived from direct experimental study of the complex systems themselves. That is, no ancillary information is required nor are the studies invasive or destructive.