Sam Walters

Comparison of interferon-{gamma} release assays and tuberculin skin test in predicting active tuberculosis (TB) in children in the UK: a paediatric TB network study

Background The value of interferon-γ release assays (IGRA) to diagnose active tuberculosis (TB) in children is not established, but these assays are being widely used for this purpose. The authors examined the sensitivity of commercially available IGRA to diagnose active TB in children in the UK compared with the tuberculin skin test (TST). Methods The authors established a paediatric tuberculosis network and conducted a retrospective analysis of data from children investigated for active TB at six large UK paediatric centres. All centres had used TST and at least one of the commercially available IGRA (T-Spot.TB or Quantiferon-Gold in Tube) in the diagnostic work-up for active TB. Data were available from 333 children aged 2 months to 16 years. The authors measured the sensitivity of TST and IGRA in definite (culture confirmed) and probable TB in children, agreement between TST and either IGRA, and their combined sensitivity. Results Of 333 children, 49 fulfilled the criteria of definite TB, and 146 had probable TB. Within the definite cohort, TST had a sensitivity of 82%, Quantiferon-Gold in tube (QFT-IT) had a sensitivity of 78% and T-Spot.TB of 66%. Neither IGRA performed significantly better than a TST with a cut-off of 15 mm. Combining the results of TST and IGRA increased the sensitivity to 96% for TST plus T-Spot.TB and 91% for TST plus QFG-IT in the definite TB cohort. Conclusions A negative IGRA does not exclude active TB disease, but a combination of TST and IGRA increases the sensitivity for identifying children with active TB.

Chickenpox in childhood: A review prepared for the UK Advisory Group on Chickenpox on behalf of the British Society for the Study of Infection

Chickenpox in childhood is a milder condition than in older patients, but serious and even fatal complications may occur. These occur especially in immunosuppressed individuals, but can also be seen in normal children. The commonest of these is secondary bacterial infection with staphylococci or streptococci. Reyes syndrome is now rare in chickenpox, since aspirin no longer used in treatment. Aciclovir and VZIG (varicella zoster immune globulin) have a role in the management of chickenpox in the immunosuppressed or immunodeficient child, and aciclovir may be valuable in managing some normal children. Chickenpox should not always be considered a trivial illness.

Potentially lethal bacterial infection associated with varicella zoster virus.

Chickenpox is generally considered to be a benign self limiting illness in children. Indeed, mild secondary bacterial infection of the skin, of little clinical importance, is the most common complication of varicella virus infection.1 2 There has been a recent increase in reports of serious bacterial infections, however, both during or after chickenpox. We reviewed the case notes of 13 children (mean age 30 months; seven boys, six girls) who presented to our unit over 12 months (1994-5) with bacterial sepsis associated with chickenpox. We also included one case (case 1) who died of group A streptococcal septicaemia at another hospital. Occult bacterial infection with group A streptococcus or Staphylococcus aureus may complicate chickenpox and cause potentially lethal disease An 11 month old girl was admitted with fever, poor feeding, and diarrhoea on the fourth day after the onset of chickenpox. She had a fever of 40°C and a haemorrhagic pustular rash. There was periorbital oedema and conjunctival injection with oral erythema and a 1 cm diameter black necrotic lesion around a vesicle on the dorsum of her left hand. There was no neurological or cardiovascular compromise at presentation. Twenty four hours later she became shocked with a capillary refill time of four seconds, peripheral core temperature difference of 8°C, blood pressure of 75/40 mm Hg, and a pulse of 150 beats/min. She developed increasing oedema and required supplementary oxygen. Despite resuscitation with colloid and a course of antibiotics she continued to deteriorate and was intubated and mechanically ventilated. Inotropic support and large volumes of colloid were required to correct the shock. Initial laboratory investigations indicated a haemoglobin concentration of 103 g/l, a white cell count of 7.2 × 109/l, and a platelet count of 119 x109/l with normal clotting. There was hyponatraemia with a …

Systemic complications associated with bacterial tracheitis.

The toxic shock syndrome, septic shock, pulmonary oedema, and the acute respiratory distress syndrome (ARDS) were recognised in four children with bacterial tracheitis. ARDS has not previously been reported in association with bacterial tracheitis. Prompt recognition of the severe systemic complications of bacterial tracheitis could lead to a decrease in the morbidity and mortality of this condition.

Pneumonia associated with infection with pneumocystis, respiratory syncytial virus, chlamydia, mycoplasma, and cytomegalovirus in children in Papua New Guinea.

Paired serum samples were collected from 94 children with pneumonia admitted to Goroka Hospital, Papua New Guinea. All but three of the children were aged 1-24 months. Only nine children were malnourished, with weight for age less than 70% of the Harvard median (three had weight for age less than 60% of the Harvard median). Pneumocystis carinii antigen was detected in the serum of 23 children. Twenty two children had serological evidence of recent infection with respiratory syncytial virus. Five children were probably infected with Chlamydia trachomatis at the time of the study, and there was less convincing serological evidence of current infection in a further 11 children. Five children showed a fourfold rise in antibody to Mycoplasma pneumoniae. Although only one child showed a fourfold rise in antibody to cytomegalovirus, 86 children had this antibody. No child showed a fourfold rise in antibody to Ureaplasma urealyticum or Legionella pneumophila. P carinii, respiratory syncytial virus, C trachomatis, M pneumoniae, and cytomegalovirus may be important causes of pneumonia in children in developing countries.

Presentation, diagnosis and management of tuberculosis in HIV-infected children in the UK

Management of HIV‐infected children with tuberculosis (TB) is challenging. The objective of this study was to assess current treatment and outcomes in a resource‐rich setting in the era of highly active antiretroviral therapy (HAART).

Bacterial tracheitis: a multi-centre perspective.

The published literature on bacterial tracheitis is limited. We report the first multi-centre study of bacterial tracheitis together with a concise review of the literature. We conducted a retrospective study of cases admitted during the period 1993–2007 to 3 tertiary paediatric centres in the United Kingdom and 1 in Australia. A total of 34 cases were identified. 31 patients (91%) required intubation. Complications included cardiorespiratory arrest in 1, ARDS in 1, hypotension in 10, toxic shock syndrome in 1 and renal failure in 1 patient(s). Staphylococcus aureus was the most commonly implicated bacterial organism, isolated from the respiratory tract in 55.8% of the cases overall. Other pathogens commonly isolated from the respiratory tract included Streptococcus pyogenes (5.9%), Streptococcus pneumoniae (11.8%) and Haemophilus influenzae (11.8%). Viral coinfection was identified in 9 (31%) of the 29 cases in whom immunofluorescence testing was performed (influenza A in 4 cases; parainfluenza 1 in 2 cases; parainfluenza 3 in 2 cases; adenovirus in 1 case). The combined experience from 4 major paediatric intensive care units suggests that bacterial tracheitis remains a rare condition with an estimated incidence of approximately 0.1/100,000 children per year. Short-term complications were common but long-term sequelae were rare. There were no fatal outcomes, which contrasts with the high historical mortality rates and likely reflects improvements in intensive care management.

Endocarditis Due to Group A β-Hemolytic Streptococcus in Children with Potentially Lethal Sequelae: 2 Cases and Review

Bacterial endocarditis affecting the normal heart is rare in childhood. Here we describe 2 children who developed endocarditis due to group A b-hemolytic Streptococcus (GABHS) that required emergency cardiac surgery. These cases emphasize the importance of considering this diagnosis in children presenting with signs of embolism, for whom urgent intervention may avert catastrophe. Case 1. A 4-year-old boy presented with a 10-day history of fever and pain in his left foot. On examination he was feverish with purpuric lesions on his left thigh and dusky discoloration of his toes. The cardiovascular system was normal on the basis of clinical examination, but echocardiography revealed a large flailing vegetation attached to a mitral valve leaflet with severe associated regurgitation. He underwent urgent cardiac surgery to excise the vegetation and thrombus and repair the mitral valve. Two cultures of blood and a culture of a scraping from the left foot taken on admission yielded (untyped) GABHS. Culture of a throat swab taken earlier yielded no growth. Ischemia of the forefoot progressed to necrosis and amputation of 2 toes, leaving a residual deformity that required plastic and orthopedic surgery. He completed a 6-week course of antibiotics and has subsequently remained well. Case 2. A 33-month-old boy presented with hot, tender, painful swelling in his ankles and right knee 4 weeks after varicella. On examination he was pyrexial, tachycardic, and had splenomegaly. The remainder of the examination, including auscultation of the heart, was normal. He was treated with ibuprofen. Two days later his left leg suddenly became cold with impalpable pulses. A gallop rhythm and an ejection systolic murmur were heard over the precordium. Echocardiography showed perforation of the aortic valve with vegetation

Paediatric HIV infection

Globally paediatric HIV infection represents a major setback to child health. The World Health Organisation estimates that over 20 million adults and 1.5 million children have been infected with HIV since the pandemic began 20 years ago. World wide over a thousand children a day are born with HIV. The highest incidence rates are in sub-Saharan Africa and South Asia, particularly now in urban India.1 The Day report recently published projections for the incidence and prevalence of AIDS in England and Wales for 1995–9. Although a fall is expected in new AIDS cases among homo/bisexual males, a 25% rise in the heterosexual acquisition category, and a 60% increase in the incidence of AIDS in children of HIV infected mothers are projected.2 Absolute numbers of known infected children are still small in the UK, with 380 vertically infected children reported by October 1996 (table 1). Around 80% of the children with confirmed HIV infection reside in the Thames regions (predominantly in London) with about 7% resident in Scotland. View this table: Table 1 Infection status of children born to HIV positive mothers reported to the British Paediatric Surveillance Unit or Royal College of Obstetricians and Gynaecologists by 31 October 1996 (from Newsletter 29) The most exciting advance in preventing paediatric HIV infection for countries that can afford it, has been the report from the AIDS Clinical Trials Group (ACTG) protocol 076 that zidovudine (AZT) given perinatally to a selected group of HIV infected pregnant women and their infants reduced the risk of vertical transmission by two thirds (25% to 8%).3 The mothers received AZT in the second and third trimester, followed by intrapartum intravenous AZT, and AZT was given to infants for the first six weeks of life. Vertical transmission rates vary world wide, with reports from prospective studies ranging from 15–20% in …

Infectious Diseases and the Kidney

The kidney is involved in a wide range of bacterial, viral, fungal, and parasitic diseases. In most systemic infections, renal involvement is a minor component of the illness, but in some, renal failure may be the presenting feature and the major problem in management. Although individual infectious processes may have a predilection to involve the renal vasculature, glomeruli, interstitium, or collecting systems, a purely anatomic approach to the classification of infectious diseases affecting the kidney is rarely helpful because most infections may involve several different aspects of renal function.