Human brucellosis in South Africa: Public health and diagnostic pitfalls

Human brucellosis in South Africa (SA) is under-diagnosed and under-reported. This is because many clinicians have little or no experience in managing affected patients, and in part because of the nonspecific and insidious nature of the disease. A case of human brucellosis caused by Brucella melitensis in a patient from the Western Cape Province of SA is described, and the resulting exposure of staff members at two medical microbiology laboratories, as well as the public health investigation that was conducted, are discussed. The objective of this article is to highlight the need for strengthening integration between public health, medical and veterinary services and exposing deficiencies in public health, veterinary and laboratory practices

Molecular characterisation and epidemiological investigation of an outbreak of blaOXA-181 carbapenemase-producing isolates of Klebsiella pneumoniae in South Africa

BACKGROUND : Klebsiella pneumoniae is an opportunistic pathogen often associated with nosocomial infections. A suspected outbreak of K. pneumoniae isolates, exhibiting reduced susceptibility to carbapenem antibiotics, was detected during the month of May 2012 among patients admitted to a haematology unit of a tertiary academic hospital in Cape Town, South Africa (SA). OBJECTIVES : An investigation was done to determine possible epidemiological links between the case patients and to describe the mechanisms of carbapenem resistance of these bacterial isolates. Methods. Relevant demographic, clinical and laboratory information was extracted from hospital records and an observational review of infection prevention and control practices in the affected unit was performed. Antimicrobial susceptibility testing including phenotypic testing and genotypic detection of the most commonly described carbapenemase genes was done. The phylogenetic relationship of all isolates containing the blaOXA-181 carbapenemase gene was determined by pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing. Results. Polymerase chain reaction analysis identified a total of seven blaOXA-181-positive, carbapenem-resistant K. pneumoniae isolates obtained from seven patients, all from a single unit. These isolates were indistinguishable using PFGE analysis and belonged to sequence type ST-14. No other carbapenemase enzymes were detected. CONCLUSION : This is the first documented laboratory-confirmed outbreak of OXA-181-producing K. pneumoniae in SA, and highlights the importance of enforcing strict adherence to infection control procedures and the need for ongoing surveillance of antibiotic-resistant pathogens in local hospitals.Global Disease and Detection Funding, Centre for Opportunistic Tropical and Hospital Infections,National Institute for Communicable Diseases and the National Health Laboratory Service, Johannesburg.http://www.sama.co.zahb201

Diagnosis of community-acquired pneumonia in children : South African Thoracic Society guidelines (part 2)

BACKGROUND. Accurate diagnosis and attribution of the aetiology of pneumonia are important for measuring the burden of disease, implementing appropriate treatment strategies and developing more effective interventions. OBJECTIVES. To produce revised guidelines for the diagnosis of pneumonia in South African (SA) children, encompassing clinical, radiological and aetiological methods. METHODS. An expert group was established to review diagnostic evidence and make recommendations for a revised SA guideline. Published evidence was reviewed and graded using the British Thoracic Society grading system. RESULTS. Diagnosis of pneumonia should be considered in a child with acute cough, fast breathing or difficulty breathing. Revised World Health Organization guidelines classify such children into: (i) severe pneumonia; (ii) pneumonia (tachypoea or lower chest indrawing); or (iii) no pneumonia. Malnourished or immunocompromised children with lower chest indrawing should be managed as cases of severe pneumonia. Pulse oximetry should be done, with hospital referral for oxygen saturation <92%. A chest X-ray is indicated in severe pneumonia or when tuberculosis (TB) is suspected. Microbiological investigations are recommended in hospitalised patients or in outbreak settings. Improved aetiological methods show the importance of co-infections. Blood cultures have a low sensitivity (<5%), for diagnosing bacterial pneumonia. Highly sensitive, multiplex tests on upper respiratory samples or sputum detect multiple potential pathogens in most children. However, even in symptomatic children, it may be impossible to distinguish colonising from causative organisms, unless identification of the organism is strongly associated with attribution to causality, e.g. respiratory syncytial virus, Mycobacterium tuberculosis, Bordetella pertussis, influenza, para-influenza or severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Investigations for TB should be considered in children with severe pneumonia who have been hospitalised, in a case of a known TB contact, if the tuberculin skin test is positive, if a child is malnourished or has lost weight, and in children living with HIV. Induced sputum may provide a higher yield than upper respiratory sampling for B. pertussis, M. tuberculosis and Pneumocystis jirovecii. CONCLUSIONS. Advances in clinical, radiological and aetiological methods have improved the diagnosis of childhood pneumonia.HJZ and SAM are supported by the South African Medical Research Council.The South African Medical Research Councilhttp://www.samj.org.zaam2021Paediatrics and Child Healt

Epidemiology and aetiology of community-acquired pneumonia in children : South African Thoracic Society guidelines (part 1)

BACKGROUND. Pneumonia remains a major cause of morbidity and mortality among South African (SA) children. Improved immunisation regimens, strengthening of HIV programmes, better socioeconomic conditions and new preventive strategies have influenced the epidemiology of pneumonia. Furthermore, sensitive diagnostic tests and better sampling methods in young children improve aetiological diagnosis. OBJECTIVES. To summarise current information on childhood community-acquired pneumonia (CAP) epidemiology and aetiology in children as part of the revised South African Thoracic Society guidelines. METHODS. The Paediatric Assembly of the South African Thoracic Society and the National Institute for Communicable Diseases expert subgroup on epidemiology and aetiology revised the existing SA guidelines.The subgroup reviewed the published evidence in their area; in the absence of evidence, expert opinion was accepted. Evidence was graded using the British Thoracic Society (BTS) grading system, and the relevant section underwent peer review. RESULTS. Respiratory viruses, particularly respiratory syncytial virus, are the key pathogens associated with hospitalisation for radiologically confirmed pneumonia in HIV-uninfected children. Opportunistic organisms, including Pneumocystis jirovecii, are important pathogens in HIV-infected infants, while non-typable Haemophilus influenzae and Staphylococcus aureus are important in older HIV-infected children. Co-infections with bacteria or other respiratory viruses are common in hospitalised children. Mycobacterium tuberculosis is common in children hospitalised with CAP in SA. CONCLUSIONS. Numerous public health measures, including changes in immunisation schedules and expansion of HIV prevention and treatment programmes, have influenced the epidemiology and aetiology of CAP in SA children. These changes have necessitated a revision of the South African Paediatric CAP guidelines, further sections of which will be published as part of a CME series in SAMJ.The SA Medical Research Councilhttp://www.samj.org.zaam2021Paediatrics and Child Healt

Measurement of the Bs0→J/ψKS0B_s^0\to J/\psi K_S^0 branching fraction

The $B_s^0\to J/\psi K_S^0$ branching fraction is measured in a data sample corresponding to 0.41$fb^{-1}$ of integrated luminosity collected with the LHCb detector at the LHC. This channel is sensitive to the penguin contributions affecting the sin2$\beta$ measurement from $B^0\to J/\psi K_S^0$ The time-integrated branching fraction is measured to be $BF(B_s^0\to J/\psi K_S^0)=(1.83\pm0.28)\times10^{-5}$. This is the most precise measurement to date

Model-independent search for CP violation in D0→K−K+π−π+ and D0→π−π+π+π− decays

A search for CP violation in the phase-space structures of D0 and View the MathML source decays to the final states K−K+π−π+ and π−π+π+π− is presented. The search is carried out with a data set corresponding to an integrated luminosity of 1.0 fb−1 collected in 2011 by the LHCb experiment in pp collisions at a centre-of-mass energy of 7 TeV. For the K−K+π−π+ final state, the four-body phase space is divided into 32 bins, each bin with approximately 1800 decays. The p-value under the hypothesis of no CP violation is 9.1%, and in no bin is a CP asymmetry greater than 6.5% observed. The phase space of the π−π+π+π− final state is partitioned into 128 bins, each bin with approximately 2500 decays. The p-value under the hypothesis of no CP violation is 41%, and in no bin is a CP asymmetry greater than 5.5% observed. All results are consistent with the hypothesis of no CP violation at the current sensitivity

Measurement of the CP-violating phase \phi s in Bs->J/\psi\pi+\pi- decays

Measurement of the mixing-induced CP-violating phase phi_s in Bs decays is of prime importance in probing new physics. Here 7421 +/- 105 signal events from the dominantly CP-odd final state J/\psi pi+ pi- are selected in 1/fb of pp collision data collected at sqrt{s} = 7 TeV with the LHCb detector. A time-dependent fit to the data yields a value of phi_s=-0.019^{+0.173+0.004}_{-0.174-0.003} rad, consistent with the Standard Model expectation. No evidence of direct CP violation is found.Comment: 15 pages, 10 figures; minor revisions on May 23, 201

Search for the lepton-flavor-violating decays Bs0→e±μ∓ and B0→e±μ∓

A search for the lepton-flavor-violating decays Bs0→e±μ∓ and B0→e±μ∓ is performed with a data sample, corresponding to an integrated luminosity of 1.0  fb-1 of pp collisions at √s=7  TeV, collected by the LHCb experiment. The observed number of Bs0→e±μ∓ and B0→e±μ∓ candidates is consistent with background expectations. Upper limits on the branching fractions of both decays are determined to be B(Bs0→e±μ∓)101  TeV/c2 and MLQ(B0→e±μ∓)>126  TeV/c2 at 95% C.L., and are a factor of 2 higher than the previous bounds

Absolute luminosity measurements with the LHCb detector at the LHC

Absolute luminosity measurements are of general interest for colliding-beam experiments at storage rings. These measurements are necessary to determine the absolute cross-sections of reaction processes and are valuable to quantify the performance of the accelerator. Using data taken in 2010, LHCb has applied two methods to determine the absolute scale of its luminosity measurements for proton-proton collisions at the LHC with a centre-of-mass energy of 7 TeV. In addition to the classic "van der Meer scan" method a novel technique has been developed which makes use of direct imaging of the individual beams using beam-gas and beam-beam interactions. This beam imaging method is made possible by the high resolution of the LHCb vertex detector and the close proximity of the detector to the beams, and allows beam parameters such as positions, angles and widths to be determined. The results of the two methods have comparable precision and are in good agreement. Combining the two methods, an overall precision of 3.5% in the absolute luminosity determination is reached. The techniques used to transport the absolute luminosity calibration to the full 2010 data-taking period are presented.Comment: 48 pages, 19 figures. Results unchanged, improved clarity of Table 6, 9 and 10 and corresponding explanation in the tex

Measurement of the ratio of branching fractions BR(B0 -> K*0 gamma)/BR(Bs0 -> phi gamma) and the direct CP asymmetry in B0 -> K*0 gamma

The ratio of branching fractions of the radiative B decays B0 -> K*0 gamma and Bs0 phi gamma has been measured using an integrated luminosity of 1.0 fb-1 of pp collision data collected by the LHCb experiment at a centre-of-mass energy of sqrt(s)=7 TeV. The value obtained is BR(B0 -> K*0 gamma)/BR(Bs0 -> phi gamma) = 1.23 +/- 0.06(stat.) +/- 0.04(syst.) +/- 0.10(fs/fd), where the first uncertainty is statistical, the second is the experimental systematic uncertainty and the third is associated with the ratio of fragmentation fractions fs/fd. Using the world average value for BR(B0 -> K*0 gamma), the branching fraction BR(Bs0 -> phi gamma) is measured to be (3.5 +/- 0.4) x 10^{-5}. The direct CP asymmetry in B0 -> K*0 gamma decays has also been measured with the same data and found to be A(CP)(B0 -> K*0 gamma) = (0.8 +/- 1.7(stat.) +/- 0.9(syst.))%. Both measurements are the most precise to date and are in agreement with the previous experimental results and theoretical expectations.Comment: 21 pages, 3 figues, 4 table