Tuberculosis, deprivation, and ethnicity in Leeds, UK, 1982-1997.

AIMS: To determine whether tuberculosis is increasing in frequency and to explore the association between deprivation, ethnicity, and tuberculosis in the city of Leeds. METHODS: Descriptive epidemiology and ecological analysis of a register of children and young people (0-18 years) diagnosed with tuberculosis from 1982 to 1997 in Leeds Health Authority. RESULTS: A total of 107 children were identified, 61 through contact tracing, to give an age and sex standardised incidence rate of 3.9 per 100 000 per year. Rates decreased over the 16 year study period by an estimated 6.6% per year. The disease was more common in girls (56%) and most frequent in 5-9 year olds, with respiratory disease accounting for the largest proportion (82%). Children of south Asian origin (35%) had a crude incidence rate of 25.7 per 100 000 per year. The female:male ratios differed notably between south Asian (1.9:1) and non-south Asian children (1.02:1). For all subjects, univariate analyses showed significant positive associations between incidence and deprivation, population density, and ethnicity. There were no significant associations between deprivation, population density, and ethnicity and incidence of tuberculosis in south Asian children. For non-south Asian, mainly white children, only deprivation was significant. The proportion of non-south Asian children in the population was the overriding factor influencing incidence of tuberculosis. CONCLUSIONS: Tuberculosis remains an uncommon disease in Leeds children. An unexpected finding was a relatively higher incidence in Asian girls compared to boys. Overall, ethnicity explains a high proportion of disease independently of deprivation and population density but for non-south Asian Leeds children the strongest risk factor is deprivation.

Drinking in snakes: kinematic cycling and water transport.

Snakes are purported to drink by sucking water into their mouths and then compressing the oral cavity to force water into the oesophagus. Video recordings of drinking behaviour in 23 snakes representing 14 species from three families, combined with simultaneous recordings of water volumes consumed, show that all the snakes vary widely in the amount of water taken in when drinking. This variation is not correlated with kinematic events. Kinematic recordings and indirect measurements of water flow suggest that moving water into the mouth can be decoupled from the processes that move water into the oesophagus and that, infrequently, water may continue flowing into the mouth during both opening (suction) and closing (presumed compression) of the mouth. Drinking in snakes is not a simple, stereotyped behaviour. Different snake species differ in both drinking kinematics and water inflow patterns. Vertical excursions of the mandible are smallest in booids and larger, but highly variable, in different viperids and colubrids. Cyclic movements of the tongue seen in booids are not evident in viperids or colubrids. All the snakes usually take in water at rates far below their potential maximum rate. Although drinking is apparently achieved by suction, a single model cannot explain all water movement patterns in snakes. At a practical level, functional morphological studies of drinking in snakes (and possibly many other animals) must demonstrate that fluid flow actually correlates with kinematic events. Without such an empirical demonstration, interpretation of other measurements (pressure, movement, etc.) is unlikely to produce meaningful models.

Effect of zidovudine on perinatal HIV-1 transmission and maternal viral load.

PIP: The International Child Health Group of the Royal College of Pediatrics and Child Health is displeased with the UNAIDS, UNICEF, and WHO policy statement endorsing the artificial feeding of infants. The statement holds that with nutritionally adequate breast milk substitutes safely prepared and fed to the infants of mothers with HIV infection, the infants are at less risk of morbidity and mortality than if they were breast-fed. This global policy has more potential to harm than help, for women in extremely poor and unsuitable settings may wrongly decide to adopt bottlefeeding. The better strategy is to promote exclusive breast-feeding for 4-6 months. Efforts should also be made to reduce the vertical transmission of HIV by increasing the use of short-course zidovudine wherever feasible. Further efforts should be made to address the factors which contribute to HIV infection and prevent social and economic development.^ieng

Silent at school--elective mutism and abuse.

A retrospective case-control study of electively mute children from one city is reported. Eight of 18 children selectively mute in school had suffered definite or probable abuse compared with only one control with a speech or language problem, and no classroom controls. The implications for management are discussed.

Childhood tuberculosis in Leeds, 1982-90: social and ethnic factors and the role of the contact clinic in diagnosis.

A retrospective analysis of childhood tuberculosis in Leeds over a nine year period (1982-90) was performed which showed that the contact clinic is important for the early detection and treatment of disease in children. Two thirds of the cases of tuberculosis in children under 15 years were diagnosed and treated at the clinic. The incidence of tuberculosis was greater in Asian than in white children and, independent of race, was greater in the most deprived area of the city.

Heaf status 12 years after infant BCG immunization.

Uncertainty exists over the long-term influence of Heaf status and immunity of infant BCG immunization. BCG is offered to all Leeds Asian infants with uptake estimated at 86%. We have examined the effect of this immunization policy on the Heaf status of all 12- to 13-year-old children tested in the city in 1988. 6363 children (431 Asians) were eligible for Heaf testing of whom 5379 (366 Asians) were tested. 90 (25%) Asians and 4596 (92%) non-Asians had a Heaf grade 0-1 with no definite previous BCG and were, using current UK Department of Health recommendations, eligible for BCG immunization. With an annual incidence of tuberculosis in Asian children in Leeds of only 6 per 100,000 it is probable that most of the 75% of Asian children who did not require immunization had persisting immunity from their infant BCG rather than as a result of primary infection. We conclude that infant BCG immunization is effective at providing appropriate immunity, avoiding repeat BCG, in most children at age 12 years.

Time of development of tuberculosis in contacts.

The British Thoracic Association has recommended that close contacts of smear-positive cases of tuberculosis be followed up for at least 2 yrs (Tubercle 1978; 59: 245-259) but Selby et al. have recently suggested that a reduction in duration of follow up may be appropriate (Respir Med 1989; 83: 353-355). We have reviewed the results of contact procedures in Leeds to determine whether our experience supports reduction in the duration of follow up of contacts of patients with tuberculosis. In the 5-yr period 1983-87 there were 555 cases of tuberculosis (135 in Asians) of whom 42 (7.6%) were identified by contact procedures. In addition, contact procedures identified 35 children who were given chemoprophylaxis for positive Heaf tests (grade 2 or more). Of the 42 contacts with tuberculosis, 30 (71%) were diagnosed at the first visit, eight (19%) were diagnosed 6 months later and four (10%) were diagnosed 16-24 months after their initial clinic attendance. Five of the 42 contacts with TB were Asian, two of whom were diagnosed late. Seven out of ten non-Asian contacts who were diagnosed late had initial Heaf reactions of grade 1 or 2. All cases diagnosed late were contacts of a sputum-positive source. Poverty, as defined by residence in the Leeds Urban Priority Area, was associated with an increased risk of 3.3-fold for tuberculosis and a sixfold risk for chemoprophylaxis diagnosed by contact procedures.(ABSTRACT TRUNCATED AT 250 WORDS)

Outbreak of tuberculosis in a poor urban community.

A woman from a poor urban community presented recently with pulmonary tuberculosis. Screening of contacts revealed 10 cases of tuberculosis, eight of whom were children. A further 10 children had grade 2-3 positive Heaf tests and were given chemoprophylaxis. Tuberculosis remains a potential problem, particularly in young unimmunized children in deprived areas.

Identical twins with idiopathic external hydrocephalus.

Monozygotic twins with idiopathic external hydrocephalus are reported. Characteristic computerised tomographic features were associated with early gross motor delay and rapid improvement. A genetic basis for the syndrome is supported by its occurrence in identical twins.

BCG immunisation of infants by percutaneous multiple puncture.

PIP: The safety, efficacy, and ease of administration of percutaneous multiple-puncture gun immunization of infants with BCG was compared with intradermal injection with a syringe. 214 consecutive infants scheduled for BCG were alternately given percutaneous or intradermal injections over the left deltoid muscle by 1 of 3 doctors. The Modified Heaf gun with 20 needles set to penetrate 1 mm, or a syringe with a 24 gauge short beveled needle was used. Doctors recorded bleeding and ease of administering the vaccine. The intradermal method was recorded as difficult in 36 cases, very difficult in 4, and the percutaneous method was deemed difficult in 1 case. Of the 200 infants remaining in contact 3-7 days later, 141 were read as positive. There were no significant differences in amount of bleeding or seroconversion. A difference in seroconversion was observed, however, between the different doctors using the intradermal technique. The percutaneous method resulted in less ulceration and scarring, gave consistent seroconversion, and was easier to administer.^ieng

Inner city tuberculosis and immunisation policy.

Asian children, excluding recently arrived immigrants, had a similar incidence of tuberculosis to white children in Leeds from 1982-6. Children living in the urban priority area were 2.6 times more likely to develop tuberculosis than those living elsewhere. Selection for infant BCG immunisation should not depend on ethnic group alone.