Cavitation of the Ghon focus in an HIV-infected infant who acquired tuberculosis after the initiation of HAART

Tuberculosis immune reconstitution inflammatory syndrome (IRIS) may present as new or worsening cavitation. We present an HIV-infected infant in whom TB infection and subsequent cavitation of the Ghon focus appeared to coincide with immune reconstitution due to highly active antiretroviral therapy (HAART). TB-IRIS in response to infection that occurs after starting HAART has not previously been described

Treatment outcomes for children with multidrug-resistant tuberculosis: a systematic review and meta-analysis

BACKGROUND: Paediatric multidrug-resistant (MDR) tuberculosis is a public health challenge of growing concern, accounting for an estimated 15% of all global cases of MDR tuberculosis. Clinical management is especially challenging, and recommendations are based on restricted evidence. We aimed to assess existing evidence for the treatment of MDR tuberculosis in children. METHODS: We did a systematic review and meta-analysis of published and unpublished studies reporting treatment outcomes for children with MDR tuberculosis. We searched PubMed, Ovid, Embase, Cochrane Library, PsychINFO, and BioMedCentral databases up to Oct 31, 2011. Eligible studies included five or more children (aged ≤16 years) with MDR tuberculosis within a defined treatment cohort. The primary outcome was treatment success, defined as a composite of cure and treatment completion. RESULTS: We identified eight studies, which reported treatment outcomes for a total of 315 patients. We recorded much variation in the characteristics of patients and programmes. Time to appropriate treatment varied from 2 days to 46 months. Average duration of treatment ranged from 6 months to 34 months, and duration of follow-up ranged from 12 months to 37 months. The pooled estimate for treatment success was 81·67% (95% CI 72·54-90·80). Across all studies, 5·9% (95% CI 1·3-10·5) died, 6·2% (2·3-10·2) defaulted, and 39·1% (28·7-49·4) had an adverse event. The most common drug-related adverse events were nausea and vomiting. Other serious adverse events were hearing loss, psychiatric effects, and hypothyroidism. INTERPRETATION: The treatment of paediatric MDR tuberculosis has been neglected, but when children are treated outcomes can be achieved that are at least as good as those reported for adults. Programmes should be encouraged to report outcomes in children to improve the knowledge base for care, especially as new drugs become available. FUNDING: None

Missed opportunities in the diagnosis of pulmonary tuberculosis in children

In 52% of children with confirmed and probable tuberculosis the diagnosis could have been made earlier than it was. The main clinical clues which should have led to suspicion of tuberculosis were close adult contacts and previous recurrent respiratory tract infections

Nosocomial infections in HIV-infected and HIV-uninfected children hospitalised for tuberculosis

Background The interaction between tuberculosis and HIV-infected infection is well known and is responsible for the increase in the incidence of tuberculosis (TB) in sub-Saharan Africa over the last decade. This places a considerable extra burden on health services. The Brooklyn Hospital for Chest Diseases (BCH) is a non-acute TB hospital for the City of Cape Town, South Africa. The hospital has 60 children's beds and approximately 140 paediatric admissions annually. This study, undertaken before the availability of antiretroviral drugs in the public sector in South Africa, documents the occurrence of nosocomial infections in HIV-infected and HIV-uninfected children at BCH. Method This retrospective case-control study evaluated the occurrence of nosocomial infections in (HIV)-infected children and age- and time of admission-matched HIV-uninfected children admitted to the BCH, Cape Town, South Africa between July 1999 and December 2001 for the treatment of tuberculosis (TB). Results Forty-seven HIV-infected children (mean age 40 months) and 47 HIV-uninfected children (mean age 41 months) were studied. The HIV-infected children, who were not receiving antiretroviral therapy because it was not yet available in the public sector, experienced 109 episodes of nosocomial infections compared to 22 episodes amongst those not infected with HIV (p = 0.001). Twenty-five nosocomial infections (23%) among the HIV-infected children, but only two (9%) among the HIV-uninfected children, were serious enough to require transfer to a tertiary care hospital for management. Pneumonia was the commonest nosocomial infection and occurred in 26 (56%) HIV-infected patients, of whom three died, but in only four (9%) HIV-uninfected children, none of whom died. An outbreak of varicella affected 10 HIV-infected (21%) and 9 HIV-uninfected children (19%). One HIV-infected child died of varicella pneumonia. Other common nosocomial infections encountered in HIV-infected and HIV-uninfected children respectively were upper respiratory tract infections (pharyngitis, tonsillitis or rhinitis) affecting 21 and four, otitis media in five and one, oral candidiasis in seven and zero, urinary tract infection in four and one and acute gastroenteritis in five and zero children. Five HIV-infected children (11%) died and four of the deaths were known to be due to nosocomial infection; only one HIV-uninfected child died from severe miliary TB. Conclusion Nosocomial infections occurring in HIV-infected children are a serious cause of morbidity and mortality in children hospitalised for the treatment of tuberculosis. Their impact could be reduced by the earlier introduction of antiretroviral treatment and by immunisation against certain of the infecting agents. Post-exposure prophylaxis for varicella could prevent or alleviate disease. South African Family Practice Vol. 49 (7) 2007: pp. 1

Polarization Evolution in Strong Magnetic Fields

Extremely strong magnetic fields change the vacuum index of refraction. Although this polarization dependent effect is small for typical neutron stars, it is large enough to decouple the polarization states of photons traveling within the field. The photon states evolve adiabatically and follow the changing magnetic field direction. The combination of a rotating magnetosphere and a frequency dependent state decoupling predicts polarization phase lags between different wave bands, if the emission process takes place well within the light cylinder. This QED effect may allow observations to distinguish between different pulsar emission mechanisms and to reconstruct the structure of the magnetosphere.Comment: 22 pages, 10 figures, accepted for publication in MNRA

Quantum Drag Forces on a Sphere Moving Through a Rarefied Gas

As an application of quantum fluid mechanics, we consider the drag force exerted on a sphere by an ultra-dilute gas. Quantum mechanical diffraction scattering theory enters in that regime wherein the mean free path of a molecule in the gas is large compared with the sphere radius. The drag force is computed in a model specified by the ``sticking fraction'' of events in which a gaseous molecule is adsorbed by the spherical surface. Classical inelastic scattering theory is shown to be inadequate for physically reasonable sticking fraction values. The quantum mechanical scattering drag force is exhibited theoretically and compared with experimental data.Comment: 5 pages no figure

Unexplained HIV-1 infection in children — documenting cases and assessing for possible risk factors

Background. In the year 2000 we reported possible horizontal transmission of HIV-1 infection between two siblings. An investigation of three families, each with an HIV-infected child but seronegative parents, permitted this finding. Sexual abuse and surrogate breast-feeding were thought unlikely. The children had overlapping hospitalisation in a regional hospital. Since then several cases of unexplained HIV infection in children have been reported. A registry was established at Tygerberg Children’s Hospital for collection of data on the extent of horizontal or unexplained transmission of HIV in children. Study design. Retrospective chart review. Results. Fourteen children were identified, 12 from the Western Cape and 1 each from the Eastern Cape and KwaZulu-Natal. Thirteen (92%) had been hospitalised previously. In the Western Cape, children had been hospitalised in 8 hospitals. Ten of 13 (77%) were admitted as neonates and 9 of 13 (69%) had 2 or more admissions. Intravascular cannulation and intravenous drug administration occurred in all but 2 children before HIV diagnosis. Conclusion. We have confirmed HIV infection in a number of cases where the source of infection has been inadequately explained. Circumstantial evidence supports but does not prove nosocomial transmission. Further studies and identification of medical procedures conducive to the spread of HIV are urgently needed

Basis States for Relativistic, Dynamically-Entangled Particles

In several recent papers on entanglement in relativistic quantum systems and relativistic Bell's inequalities, relativistic Bell-type two-particle states have been constructed in analogy to non-relativistic states. These constructions do not have the form suggested by relativistic invariance of the dynamics. Two relativistic formulations of Bell-type states are shown for massive particles, one using the standard Wigner spin basis and one using the helicity basis. The construction hinges on the use of Clebsch-Gordan coefficients of the Poincar\'e group to reduce the direct product of two unitary irreducible representations (UIRs) into a direct sum of UIRs.Comment: 19 pages, three tables, revte