Infectious diseases of economic importance: Molecular biological characteristics of foot-and-mouth disease viruses collected in Tanzania from 1967 to 2009

Foot-and-mouth disease (FMD) is endemic in Tanzania. Since the first reports in 1954, FMD has caused significant economic losses in the country due to mortality and morbidity of livestock and costs associated with controlling the disease. The aim of this study was to review the serotype and genetic relationships of the FMD virus (FMDV) recovered from outbreaks in Tanzania, and compare them with viruses detected from elsewhere in the sub-Saharan region. At the World Reference Laboratory for foot-and-mouth disease (WRLFMD), a total of 106 FMD viruses have been isolated from samples collected between 1967 and 2009 from northern, southern, eastern and central parts of Tanzania. The presence of FMDV was determined by laboratory methods such as VI, CF, antigen ELISA and RT-PCR. Phylogenies of VP1 sequences were determined by the Neighbour-joining method. Foot-and-mouth disease virus SAT1 was the most frequent serotype (46.2%; n = 49) isolated in Tanzania followed by O (26.4%; n = 27), A (14.1%; n = 15) and SAT 2 (11.3%; n = 13). Genotyping showed that type O viruses fell into either the EAST AFRICA 1 (EA-1) or EA-2 topotypes, type A’s into the AFRICA topotype (genotype I), type SAT 1’s into topotype I and type SAT 2’s into topotype IV. This study reveals that serotypes A, O, SAT1 and SAT2 cause FMD outbreaks in Tanzania. Recent samples from outbreaks in 2008, 2009 and 2010 have been typed as serotypes A, O, SAT1 and SAT2. Phylogenetic analysis of FMDV isolates from Tanzania showed that they are genetically related to lineages and topotypes from West and East Africa. In Tanzania, lack of comprehensive animal movement records and inconsistent vaccination programs make it difficult to determine the exact source of FMD outbreaks or to trace the transmission of the disease over time. Therefore, further collection and analysis of samples from domestic and wild animals, together with improved local epidemiological investigation of FMD outbreaks is required to elucidate the complex epidemiology of FMD in the sub-Saharan region.

New technologies to diagnose and monitor infectious diseases of livestock: challenges for sub-Saharan Africa

Using foot-and-mouth disease (FMD) as an example, this review describes new tools that can be used to detect and characterise livestock diseases. In recent years, molecular tests that can detect and characterise pathogens in a diverse range of sample types have revolutionised laboratory diagnostics. In addition to use in centralised laboratories, there are opportunities to locate diagnostic technologies close to the animals with suspected clinical signs. Work in this area has developed simple-to-use lateral-flow devices for the detection of FMD virus (FMDV), as well as new hardware platforms to allow molecular testing to be deployed into the field for use by non-specialists. Once FMDV has been detected, nucleotide sequencing is used to compare field strains with reference viruses. Transboundary movements of FMDV are routinely monitored using VP1 sequence data, while higher resolution transmission trees (at the farm-to-farm level) can be reconstructed using full-genome sequencing approaches. New technologies such as next-generation sequencing technologies are now being applied to dissect the viral sequence populations that exist within single samples. The driving force for the use of these technologies has largely been influenced by the priorities of developed countries with FMD-free (without vaccination) status. However, it is important to recognise that these approaches also show considerable promise for use in countries where FMD is endemic, although further modifications (such as sample archiving and strain and serotype characterisation) may be required to tailor these tests for use in these regions. Access to these new diagnostic and sequencing technologies in sub-Saharan Africa have the potential to provide novel insights into FMD epidemiology and will impact upon improved strategies for disease control.Effective control of infectious diseases is reliant upon accurate diagnosis of clinical cases using laboratory tests, together with an understanding of factors that impact upon the epidemiology of the infectious agent. A wide range of new diagnostic tools and nucleotide sequencing methods are used by international reference laboratories to detect and characterise the agents causing outbreaks of infectious diseases. In the past, high costs (initial capital expenses, as well as day-to-day maintenance and running costs) and complexity of the protocols used to perform some of these tests have limited the use of these methods in smaller laboratories. However, simpler and more cost-effective formats are now being developed that offer the prospect that these technologies will be even more widely deployed into laboratories particularly those in developing regions of the world such as sub-Saharan Africa.

Molecular characterization of foot-and-mouth disease virus: implications for disease control in Bangladesh

Foot-and-mouth disease (FMD) is endemic in Bangladesh, and to implement an effective FMD control programme, it is essential to understand the complex epidemiology of the disease. Here, we report on the characterization of FMD virus (FMDV) recovered from FMD outbreaks in Bangladesh in late 2009. All isolated viruses belonged to the FMDV serotype O. The phylogenetic reconstruction showed that all isolates belonged to the Middle East-South Asia (ME-SA) topotype, but fell into two distinct sublineages, one named Ind-2001 (the other has not been named). Within both sublineages, the 2009 Bangladesh isolates were most closely related to viruses from Nepal collected during 2008 and 2009. Additionally, both sublineages contained older viruses from India collected in 2000 and 2001. In South Asia, there is extensive cross-border cattle movement from Nepal and India to Bangladesh. Both these findings have implications for the control of FMD in Bangladesh. Because of the porous borders, a regional FMD control strategy should be developed. Further, animal identification and monitoring animal movements are necessary to identify the cross-border movements and market chain interactions of ruminants, leading to improved border and movement controls. Additionally, a vaccination strategy should be developed with the initial objective of protecting small-scale dairy herds from disease. For any successful FMD control programme, long-term Government commitment and adequate resources are necessary. A sustainable programme will also need farmer education, commitment and financial contributions.

Phylogeography of foot-and-mouth disease virus types O and A in Malaysia and surrounding countries

Foot-and-mouth disease (FMD) is endemic in the countries of mainland Southeast Asia where it represents a major obstacle to the development of productive animal industries. The aim of this study was to use genetic data to determine the distribution of FMD virus (FMDV) lineages in the Southeast Asia region, and in particular identify possible sources of FMDV causing outbreaks in Malaysia. Complete VP1 sequences, obtained from 214 samples collected between 2000 and 2009, from FMD outbreaks in six Southeast Asian countries, were compared with sequences previously reported. Phylogenetic analysis of these sequences showed that there were two patterns of FMDV distribution in Malaysia. Firstly, for some lineages (O/SEA/Mya98 and serotype A), outbreaks occurred every year in the country and did not appear to persist, suggesting that these incursions were quickly eradicated. Furthermore, for these lineages FMD viruses in Malaysia were closely related to those from neighbouring countries, demonstrating the close epidemiological links between countries in the region. In contrast, for O/ME-SA/PanAsia lineage, viruses were introduced and remained to cause outbreaks in subsequent years. In particular, the recent incursion and maintenance of the PanAsia-2 sublineage into Malaysia appears to be unique and independent from other outbreaks in the region. This study is the first characterisation of FMDV in Malaysia and provides evidence for different epidemiological sources of virus introduction into the country.

Genetic characterization of foot-and-mouth disease viruses, Ethiopia, 1981-2007

Foot-and-mouth disease (FMD) is endemic to sub-Saharan Africa. To further understand its complex epidemiology, which involves multiple virus serotypes and host species, we characterized the viruses recovered from FMD outbreaks in Ethiopia during 1981-2007. We detected 5 of the 7 FMDV serotypes (O, A, C, Southern African Territories [SAT] 1, and SAT 2). Serotype O predominated, followed by serotype A; type C was not recognized after 1983. Phylogenetic analysis of virus protein 1 sequences indicated emergence of a new topotype within serotype O, East Africa 4. In 2007, serotype SAT 1 was detected in Ethiopia and formed a new distinct topotype (IX), and serotype SAT 2 reappeared after an apparent gap of 16 years. The diversity of viruses highlights the role of this region as a reservoir for FMD virus, and their continuing emergence in Ethiopia will greatly affect spread and consequent control strategy of the disease on this continent.

Integrating genetic and epidemiological data to determine transmission pathways of foot-and-mouth disease virus

Estimating detailed transmission trees that reflect the relationships between infected individuals or populations during a disease outbreak often provides valuable insights into both the nature of disease transmission and the overall dynamics of the underlying epidemiological process. These trees may be based on epidemiological data that relate to the timing of infection and infectiousness, or genetic data that show the genetic relatedness of pathogens isolated from infected individuals. Genetic data are becoming increasingly important in the estimation of transmission trees of viral pathogens due to their inherently high mutation rate. Here, we propose a maximum-likelihood approach that allows epidemiological and genetic data to be combined within the same analysis to infer probable transmission trees. We apply this approach to data from 20 farms infected during the 2001 UK foot-and-mouth disease outbreak, using complete viral genome sequences from each infected farm and information on when farms were first estimated to have developed clinical disease and when livestock on these farms were culled. Incorporating known infection links due to animal movement prior to imposition of the national movement ban results in the reduction of the number of trees from 41472 that are consistent with the genetic data to 1728, of which just 4 represent more than 95% of the total likelihood calculated using a model that accounts for the epidemiological data. These trees differ in several ways from those constructed prior to the availability of genetic data.

Foot-and-mouth disease virus serotype A in Egypt

We describe the characterization of a foot-and-mouth disease (FMD) serotype A virus responsible for recent outbreaks of disease in Egypt. Phylogenetic analysis of VP1 nucleotide sequences demonstrated a close relationship to recent FMD virus isolates from East Africa, rather than to viruses currently circulating in the Middle East.

Transmission pathways of foot-and-mouth disease virus in the United Kingdom in 2007

Foot-and-mouth disease (FMD) virus causes an acute vesicular disease of domesticated and wild ruminants and pigs. Identifying sources of FMD outbreaks is often confounded by incomplete epidemiological evidence and the numerous routes by which virus can spread (movements of infected animals or their products, contaminated persons, objects, and aerosols). Here, we show that the outbreaks of FMD in the United Kingdom in August 2007 were caused by a derivative of FMDV O₁ BFS 1860, a virus strain handled at two FMD laboratories located on a single site at Pirbright in Surrey. Genetic analysis of complete viral genomes generated in real-time reveals a probable chain of transmission events, predicting undisclosed infected premises, and connecting the second cluster of outbreaks in September to those in August. Complete genome sequence analysis of FMD viruses conducted in real-time have identified the initial and intermediate sources of these outbreaks and demonstrate the value of such techniques in providing information useful to contemporary disease control programmes.

Foot-and-mouth disease (FMD) outbreaks in the United Kingdom during August and September 2007 have caused severe disruption to the farming sector and cost hundreds of millions of pounds. Investigating and determining the source of these outbreaks is imperative for their effective management and future prevention. Foot-and-mouth disease virus (FMDV) has a high mutation rate, resulting in rapid evolution. We show how complete genome sequences (acquired within 24–48 h of sample receipt) can be used to track FMDV movement from farm to farm in real time. This helped to determine the most likely source of the outbreak, assisted ongoing epidemiological investigations as to whether these field cases were linked to single or multiple releases from the source, and predicted the existence of undetected intermediate infected premises.

The impact of pasture development and grazing on water-yielding catchments in the Murray - Darling Basin in south-eastern Australia

Experiments conducted from November 1996 to June 2002 in adjacent small catchments near Wagga Wagga, New South Wales, compared the productivity and hydrology of a heavily fertilised (about 30 kg phosphorus/ha.year) Phalaris aquatica (phalaris) pasture with that of a lightly fertilised (about 14 kg phosphorus/ha every second year) native grassland that contained a mixture of C3 and C4 perennial grasses, dominantly C4 Bothriochloa macra (redgrass).In summer, the native catchment was dominated by C4 perennial grasses while the phalaris catchment was dominated by annual C4 weedy species. During the cooler months, the phalaris pasture contained higher proportions of Vulpia spp., and other less-desirable annual grasses. Throughout the experiment, the native catchment was dominated by redgrass, whereas in the phalaris catchment the persistence of phalaris declined. Redgrass became prominent on the more arid aspects of the phalaris catchment as the experiment progressed.Pasture production in the phalaris catchment was higher in most seasons than the native catchment, which resulted in an overall stocking rate advantage of about 80%. The productivity gain per unit of P input was 0.4 for the phalaris catchment compared with 1 for the native catchment, implying that phosphorus was applied to the phalaris catchment at an excessive rate.During wet periods the native catchment produced substantially more runoff than the phalaris catchment, while in dry times it developed substantially larger soil water deficits. Runoff from the phalaris catchment was higher in suspended and dissolved nitrogen and phosphorus than for the native catchment. Higher runoff from the native catchment combined with its drier soil profile in summer indicated that its deep drainage potential was less than in the phalaris catchment.

Maternal obesity and pregnancy outcome: a study of 287,213 pregnancies in London

OBJECTIVE

To examine the maternal and foetal risks of adverse pregnancy outcome in relation to maternal obesity, expressed as body mass index (BMI, kg/m(2)) in a large unselected geographical population.

DESIGN

Retrospective analysis of data from a validated maternity database system which includes all but one of the maternity units in the North West Thames Region. A comparison of pregnancy outcomes was made on the basis of maternal BMI at booking.

SUBJECTS

A total of 287,213 completed singleton pregnancies were studied including 176,923 (61.6%) normal weight (BMI 20--24.9), 79 014 (27.5%) moderately obese (BMI 25--29.9) and 31,276 (10.9%) very obese (BMI> or =30) women.

MEASUREMENTS

Ante-natal complications, intervention in labour, maternal morbidity and neonatal outcome were examined and data presented as raw frequencies and adjusted odds ratios with 99% confidence intervals following logistic regression analysis to account for confounding variables.

RESULTS

Compared to women with normal BMI, the following outcomes were significantly more common in obese pregnant women (odds ratio (99% confidence interval) for BMI 25--30 and BMI> or =30 respectively): gestational diabetes mellitus (1.68 (1.53--1.84), 3.6 (3.25--3.98)); proteinuric pre-eclampsia (1.44 (1.28--1.62), 2.14 (1.85--2.47)); induction of labour (2.14 (1.85--2.47), 1.70 (1.64--1.76)); delivery by emergency caesarian section (1.30 (1.25--1.34), 1.83 (1.74--1.93)); postpartum haemorrhage (1.16 (1.12--1.21), 1.39 (1.32--1.46)); genital tract infection (1.24 (1.09--1.41), 1.30 (1.07--1.56)); urinary tract infection (1.17 (1.04-1.33), 1.39 (1.18--1.63)); wound infection (1.27 (1.09--1.48), 2.24 (1.91--2.64)); birthweight above the 90th centile (1.57 (1.50--1.64), 2.36 (2.23--2.50)), and intrauterine death (1.10 (0.94--1.28), 1.40 (1.14--1.71)). However, delivery before 32 weeks' gestation (0.73 (0.65--0.82), 0.81 (0.69--0.95)) and breastfeeding at discharge (0.86 (0.84--0.88), 0.58 (0.56--0.60)) were significantly less likely in the overweight groups. In all cases, increasing maternal BMI was associated with increased magnitude of risk.

CONCLUSION

Maternal obesity carries significant risks for the mother and foetus. The risk increases with the degree of obesity and persists after accounting for other confounding demographic factors. The basis of many of the complications is likely to be related to the altered metabolic state associated with morbid obesity.

Risk factors for community-acquired pneumonia diagnosed upon hospital admission. British Thoracic Society Pneumonia Study Group

A case-control study of risk factors for community-acquired pneumonia in adults admitted to hospital is reported. Cases were surviving patients (n = 178) admitted to 14 hospitals in England. Controls were individuals (n = 385) randomly selected from the electoral registers of the areas served by the hospitals. The two groups were compared with regard to risk factors for pneumonia using a standardized postal questionnaire. Independent risk factors associated with cases in log-linear regression analysis were age, heart disease (as indicated by congestive heart failure and/or digitalis treatment), lifetime smoking history, chronic airway disease (chronic bronchitis and/or asthma), occupational dust exposure, pneumonia as a child, single marital status and unemployment. Corticosteroid and bronchodilator therapy were also independent risk factors in the log-linear regression analysis, but may reflect the severity of underlying lung disease for which these drugs were prescribed. These data suggest that cigarette smoking is the major avoidable risk factor for acute pneumonia in adults.

Risk factors for community-acquired pneumonia diagnosed by general practitioners in the community

The purpose of this study was to identify risk factors for pneumonia diagnosed in the community by general practitioners, using a case control study in 29 general practices in Nottingham, U.K. Patients with radiographically confirmed pneumonia were compared with adults randomly selected from electoral registers corresponding to the catchment areas of the general practices taking part in the study. Sixty-six cases and 489 controls participated. Significant risk factors in univariate analysis included age, chronic obstructive pulmonary disease, congestive heart failure and lifetime consumption of cigarettes. Multiple logistic regression analysis of these four variables showed that age [adjusted odds ratio = 2.69 (for 30 year increment), 95%CI = 1.66-4.35] and chronic obstructive pulmonary disease (adjusted odds ratio= 1.99, 95%CI = 1.15-3.45) were independent risk factors. Only age and chronic obstructive pulmonary disease were independent risk factors for pneumonia in this study. Since cigarette smoking is the major cause of chronic obstructive pulmonary disease, these data suggest that cigarette smoking is the main avoidable risk factor for community-acquired pneumonia in adults.

Vocal control of acoustic information for sonar discriminations by the echolocating bat, Eptesicus fuscus

This study aimed to determine whether bats using frequency modulated (FM) echolocation signals adapt the features of their vocalizations to the perceptual demands of a particular sonar task. Quantitative measures were obtained from the vocal signals produced by echolocating bats (Eptesicus fuscus) that were trained to perform in two distinct perceptual tasks, echo delay and Doppler-shift discriminations. In both perceptual tasks, the bats learned to discriminate electronically manipulated playback signals of their own echolocation sounds, which simulated echoes from sonar targets. Both tasks utilized a single-channel electronic target simulator and tested the bat's in a two-alternative forced choice procedure. The results of this study demonstrate changes in the features of the FM bats' sonar sounds with echolocation task demands, lending support to the notion that this animal actively controls the echo information that guides its behavior.

Teenage fertility and life chances

Teenage mothers and their children face poorer prospects in life than do women who delay motherhood until later in life. Moreover, patterns of early childbearing tend to be repeated in subsequent generations. Therefore, an understanding of the factors associated with early fertility is important for the prevention of adverse consequences. This paper uses data from the National Survey of Sexual Attitudes and Lifestyles to explore these associations. Early sexual intercourse is an important predictor of early fertility, as is poor educational attainment, although it is not clear to what extent pregnancy acts to thwart academic ambitions, or to what extent poor educational performance leads to a need to seek personal fulfilment in other than academic goals. Thus, interventions designed to influence age at first intercourse and to improve educational performance both have potential in terms of impacting on teenage pregnancy rates. Family background also exerts a powerful influence on teenage fertility. Young people for whom one or both parents are absent are more likely to become parents early in life. However, the most important factor of family life determining the chances of teenage motherhood appear to be the quality of communication about sexual matters with the home. In terms of outcomes, teenage mothers are more likely to live in social housing, are less likely to be in paid employment and have larger than average sized families. Certain areas of the country, notably the older, run-down industrial areas, have higher rates of teenage motherhood than the newer, more prosperous areas. Because most of these effects are independent of one another, there is potential merit in intervening to prevent unintended conception at several points in a young woman's life. Primary preventive efforts are needed to reduce the rates at which teenage pregnancy occurs in this country. Yet, if the cycle of deprivation that means the children of young mothers themselves enter parenthood early is to be broken, then efforts must also be made to mitigate the effects of teenage fertility for both mother and child.

Private sexual behavior, public opinion, and public health policy related to sexually transmitted diseases: a US-British comparison

OBJECTIVES

The purpose of this study was to characterize sexual behavior and opinions about sex in the United States and Britain; implications are discussed for effective public health policy regarding sexually transmitted diseases (STDs) in the United States.

METHODS

Large-scale national probability surveys conducted in the 2 countries detailed sexual behavior, opinions, and the prevalence of STDs.

RESULTS

In comparison with that of Britain, the US population has greater variability in sexual behavior, less tolerant opinions about sexual behavior, and a higher STD prevalence and lower condom usage among men.

CONCLUSIONS

The survey data show compelling evidence from both countries of a strong association between number of sex partners and STD risk. In the United States relative to Britain, there is both greater dispersion in sexual behavior and a greater incidence of unconditional opposition to certain sexual practices. The former implies a need for strong public health policy to address the risks of STDs, but the latter implies strong opposition to that policy. This disjuncture between public health need and feasibility may contribute to the high US rate of STDs.

Fluorescence in situ hybridization assessment of the telomeric regions of jumping translocations in a case of aggressive B-cell non-Hodgkin lymphoma

We report a jumping translocation involving a donor chromosome 1 long arm in a case of aggressive B-cell non-Hodgkin lymphoma (NHL). Conventional cytogenetic banding studies demonstrated a breakpoint distal to the heterochromatic region of the donor 1q chromosome. Characterization by fluorescence in situ hybridization (FISH) of the jumping translocation demonstrated an apparent telomeric sequence loss of the recipient chromosomes. Additional cytogenetic aberrations, including the t(18;22) translocation associated with non-Hodgkin lymphoma, were also observed in this case. Cytogenetically similar cases of jumping translocations reported in the literature have implicated a preferential involvement of the donor chromosomes' heterochromatic regions and the telomeric regions of the recipient chromosomes. Jumping translocations are still considered rare and their appearance is associated with a poor prognosis. The presence of these specific findings for this case are discussed and compared with those previously reported in other hematologic disorders.

Assessing participation bias in a sexual behaviour survey: implications for measuring HIV risk

OBJECTIVES

To assess the likelihood of participation bias in a large population-based sex survey, and its possible effect on estimates of HIV risk behaviours.

DESIGN

Construction of general hypotheses about non-participants through comparisons of willing and unwilling participants.

METHODS

British adults aged 16-59 years were surveyed in 1990-1991. Interviews consisted of a face-to-face section combined with a self-completion booklet (n = 18876). Interviewers recorded interviewee embarrassment. Homosexual experience and number of lifetime heterosexual partners (grouped 0, 1, 2 or more) were recorded prior to booklet offer. Logistic regression was performed, with embarrassment and booklet refusal as outcome variables, assessing their association with sexual behaviour after controlling for demographic variables. Assuming that, in sexual behaviour, non-participants are closer to the embarrased and the booklet refusers ('unwilling' participants) than to others, these analyses provide an indication of the nature of participation bias.

RESULTS

Higher refusal an embarrassment rates were associated with both reporting no homosexual experience and fewer heterosexual partners.

CONCLUSIONS

Under our untestable assumption, these results are consistent with non-participants being generally at lower risk of HIV infection. Methods need to be developed both to reduce participation bias in sex surveys, and to incorporate it in analysis.

An evaluation of 'rapid review' as a method of quality control of cervical smears using the AxioHOME microscope

One method of quality control which has recently been recommended by professional bodies in the UK is the 'rapid review' method. This involves the microscopic 30 s review of all negative cervical smears with the intention of flagging potential missed abnormalities. Although it has been suggested that rapid review is better than 10% random rescreening of negative smears, the efficiency and efficacy of this method of quality control have not been thoroughly evaluated. We have used the AxioHOME system, which can record the area of a slide covered and the screening time, to investigate slide coverage during rapid review quality control, as performed by 15 cytoscreeners and MLSOs reviewing a test set of 22 slides each. The test set comprised 18 negative slides, three positive slides, and one unsatisfactory slide. We have recorded two distinct methods of rapid review in use amongst cytotechnologists, the step method and the whole slide method. The data show that rapid review takes longer on average than the recommended 30 s, the mean screening times being 76 s and 82 s for the step and whole slide methods, respectively. Abnormal smears were missed on three of 15 occasions by the step method (sensitivity 80%, positive predictive value 85%), and on seven of 30 occasions by the whole slide method (sensitivity 76.6%, positive predictive value 45%). However, the 95% confidence intervals were wide (57.7-90.7% for the step method, and 51.9-95.7% for the whole slide method). Analysis of scanning tracks and screening rates shows significant flaws in the methodology of rapid review. Abnormal cells were not identified, although dyskaryotic cells were included in the scanning track on nine occasions, seven using the whole slide method and two using the step method. On one occasion (using the step method) abnormal cells were not identified because they were not included in the scanning track. Further research is in progress to determine optimal methods of rapid review, and whether the rapid review technique is as effective as automated screening systems for quality assurance in cytology.

The use and cost of hospital services by London AIDS patients with different AIDS defining conditions

BACKGROUND

Contracting for HIV service provision is now an established part of the National Health Service commissioning process. AIDS is a heterogeneous condition, comprising various opportunistic illnesses which require different services and which have different resource implications. This study describes the use of hospital services and associated costs for the management of different AIDS defining conditions.

METHOD

A retrospective case-notes analysis was performed, of 335 AIDS patients treated at St Mary's Hospital, London, between 1 January 1983 and 30 September 1989, as well as a costing exercise of 37 clinical departments to calculate HIV-related costs.

RESULTS

Mean age at time of AIDS diagnosis for these predominantly homosexual men was 38 years. Use of services varied, as did associated costs-from 8163 pounds per patient-year for patients with Constitutional Disease to 42,124 pounds for those with Cytomegalovirus Disease Most diagnostic categories showed a shift over the study period from an in-patient- to an out-patient-based service. Patients diagnosed after 1987 had overall lower costs per patient-year compared with those diagnosed before 1987: whereas out-patient costs for most groups had increased, in-patient expenditure decreased. For most categories, in-patient care costs and out-patient drugs prescribed provided the greatest proportion of total costs. Average costs per in-patient day ranged from 334 pounds to 433 pounds, and average costs per out-patient visit ranged from 99 pounds to 411 pounds for different AIDS defining conditions.

CONCLUSIONS

Different opportunistic illnesses of symptomatic HIV disease have different treatment and resource implications. Casemix will need to be taken into consideration when contracting for HIV services, including extra-contractual referrals.

Survival and the use and costs of hospital services for London AIDS patients treated with AZT

The aim of this study was to evaluate the survival patterns and use and cost of hospital services of AIDS patients treated with azidothymidine (AZT) at St Mary's Hospital, London. A retrospective analysis of inpatient and outpatient case notes was performed, as was a survey of HIV-related care costs in 37 clinical departments. Of the 183 AIDS patients managed between 1 January 1987 and 30 September 1989, 132 were treated with AZt and 51 without AZT. Mean age at time of AIDS diagnosis for these predominantly homosexual men was 37.5 years for those treated with AZT compared with 40.7 years for those not on AZT. Median survival time from date of AIDS diagnosis was significantly longer for patients treated with AZT compared with those not treated with AZT (23 vs 13.5 months, P = 0.0004). The interval from diagnosis of HIV infection to date of AIDS diagnosis did not differ significantly between groups. Inpatients and outpatients use of services was greater for those receiving AZT than for those who did not. Costs reflected this increase use of services and the costs for those treated with AZT were pounds 3061 per AIDS patient-year higher compared with AIDS patients not receiving AZT; 36% of this cost was directly attributable to the cost of AZT itself. The introduction of AZT into routine clinical practice seems to have been a cost-effective intervention though it has been associated with an increased use of hospital services and associated costs per AIDS patient-year as well as increases survival time from AIDS diagnosis.

Community service needs of people with HIV infection in London

The objectives of this study were to describe the expressed needs for community services of HIV-infected individuals by disease stage, gender and transmission category and the barriers which prevent the receipt of such services. Structured interviewer-administered questionnaires concerning a 6-month retrospective period were used to obtain information on need for community services and problems which prevented the receipt of services. The study sample included 70 homosexual men with asymptomatic HIV disease, 42 homosexual men with symptomatic non-AIDS, 53 homosexual men with AIDS, 23 heterosexual men, 29 heterosexual women, 9 male and 9 female injecting drug users. The main outcome measures were the extent to which needs for community services were met and person/service combinations for which problems or barriers prevented the receipt of community services. On average, subjects expressed a need for 10 categories of community services over the 6-month period: homosexuals expressed a mean of 10, heterosexuals 10, injecting drug users 11, subjects with asymptomatic HIV infection 9, subjects with symptomatic non-AIDS 11, subjects with AIDS 13, men 9 and women 14. A total of 58% of community service needs were always met, 6% were rarely not met, 16% were sometimes not met, 6% were often not met and 14% were not met at all. The extent to which subjects felt that their needs were met was similar for the different study groups, but the needs of women were met somewhat less frequently than those of men. Similarly, people with AIDS felt that their needs were met slightly less often. Reported levels of unmet need were high for a wide range of services. The most common reason subjects gave for not having received a community service for which they expressed a need was ignorance of where or how to obtain the service. This was mentioned in one-third of all such cases. Anxieties over the competence with which a service would be rendered was mentioned in 13% of cases and long waiting times in 11%. The frequencies of unmet need for many community services were high and often seemed to arise either from a lack of awareness on the part of subjects on how and where services could be obtained or from doubts about the relevance of services offered. Both of these barriers should be surmountable through the provision of better information to patients, extending user involvement in service development and the better co-ordination of service delivery through care management approaches.

Who goes to sexually transmitted disease clinics? Results from a national population survey

OBJECTIVES

To examine the pattern of attendance at sexually transmitted disease (STD) clinics in Britain. To compare the demographic characteristics, behaviours and attitudes of STD clinic attenders with those of non-attenders, and to assess the extent to which STD clinics are used by those with high-risk sexual lifestyles.

DESIGN

Random sample general population survey of sexual attitudes and lifestyle.

SUBJECTS

18,876 randomly selected men and women resident in Britain aged 16-59 years.

MAIN OUTCOME MEASURES

Demographic characteristics, pattern of homosexual partnerships, heterosexual partnerships, payment for sex, abortion, drug injection in the last five years, and attitudes to sexual behaviours amongst 512 respondents who had attended STD clinic in the last five years compared with those who had not.

RESULTS

8.3% of men and 5.6% of women had attended a clinic in their lifetime and 3.4% and 2.6% respectively in the last five years. Attendance rates varied substantially with area of residence. 11% of Inner London residents had attended in the last five years. In multivariate analysis, STD clinic attendance for men was most strongly associated with increased numbers of heterosexual partners, (OR = 6.01 (4.44-8.15) and homosexual partnerships (OR = 9.59 (5.83-15.8)) and more weakly associated with payment for sex, non-manual social class, age 25-44, unmarried status and smoking. Clinic attendance for women was most strongly associated with numbers of heterosexual partners (OR = 3.74 (2.76-5.08) and injecting drug use (OR = 4.39 (1.73-11.1)). A weaker independent association was found with a history of abortion, anal sex, non-manual social class, non-married status and age 16-24. From the total population, 1 in 6 men and 1 in 7 women in the top 5% of the distribution for numbers of heterosexual partners and 1 in 5 men paying for sex and 1 in 4 of those with a homosexual partner had attended a clinic in the last five years. The probability of attendance increased with multiple risk behaviours. Of women 64.2% and of men 69.7% attending clinics reported major risk markers for STD transmission.

CONCLUSIONS

STD clinics in Britain are used by a wide demographic spectrum of the population. The behaviours, but not the attitudes, of attenders differed markedly from those of non-attenders. Clinics are relatively efficient in attracting only those with high-risk lifestyles, but, at a population level, the minority of those reporting risk-markers for STD transmission attend clinics. These findings suggest that STD clinics are an important focus for sexual health promotion, but that community programmes are also important for reaching non-attenders.

The economic costs of caring for people with HIV infection and AIDS in England and Wales

The objectives of this study were firstly to estimate total lifetime care costs for an individual with HIV/AIDS, and secondly to estimate the total costs of caring people with HIV infection and AIDS in England and Wales between 1992 and 1997 inclusive. Questionnaires and monthly diaries were used to collate data on healthcare utilisation from patients with HIV infection over a 6-month period. These data were then used to estimate the annual total direct costs of care (stratified by disease stage), total lifetime costs of care, and present and future total national care costs for England and Wales. Costing data were obtained from providers of services throughout Greater London. In total, 235 patients with HIV infection were recruited from 2 clinics in Greater London. All costs were calculated in 1992-93 pounds sterling (pound; 1 pound = $US1.58, December 1995). Annual care costs were estimated at 4515 pounds ($US7134) for a person with asymptomatic HIV disease, 8836 pounds ($US13,961) for a person with symptomatic non-AIDS and 15 268 pounds ($US24,123) for a person with AIDS. Lifetime care costs were estimated at 84,522 pounds ($US133,545) per patient. The total costs of care for England and Wales were forecast to increase from 116,627,400 pounds ($US184,271,300) in 1992 to 162,638,100 pounds ($US256,968,200) in 1997. In conclusion, our study further emphasises the continued shift in hospital services from the inpatient sector to the outpatient sector. The importance of community care and informal care, in terms of the associated direct economic costs, is also highlighted. This emphasises the need for close collaboration between different agencies and strategic coordination of services. Finally, the study forecasts an increase in care costs in England and Wales during the 1990s.

Behavioural risk factors for HIV infection amongst blood donors in London

This paper compares the prevalence of risk factors for sexual acquisition of human immunodeficiency virus infection (HIV-1) among blood donors with the risk in the general population. Sexual behaviour data collected as part of a cross-sectional survey of central London blood donors were compared, after indirect standardization for age and sex, with those collected among Greater London participants of the National Survey of Sexual Attitudes and Lifestyles (NATSSAL). Overall, male blood donors had lower risk sexual lifestyles than age-matched NATSSAL participants in that they had had fewer lifetime female sexual partners, were more likely to have had first sexual intercourse after 16 years and were less likely to have had a homosexual partner. Men who have had sex with men since 1977 were asked not to donate blood. Despite this, 3.6% of male donors had had some sexual experience with another man and 1.9% had had sexual intercourse with at least one male partner. In contrast, female donors had had more sexual partners, were more likely to have had first sexual intercourse before 16 years and had probable higher rates of sexually transmitted disease (STD) clinic attendance than NATSSAL participants, explained by the much higher proportion of single rather than married female blood donors at each age. In conclusion, male donors had lower risk sexual lifestyles than age-matched NATSSAL participants, although even low levels of homosexual contact give some cause for concern. Female donors appeared to have higher risk sexual lifestyles than the general population because a much higher proportion of the female blood donors were single. The results provide important insights for those defining blood donor referral criteria.

Geographic variation in sexual behaviour in Britain: implications for sexually transmitted disease epidemiology and sexual health promotion

OBJECTIVES

To explore geographical variation in sexual behaviour in Great Britain with reference to the prevalence of HIV infection.

DESIGN

The National Survey of Sexual Attitudes and Lifestyles comprises a randomly selected, representative sample of almost 19,000 men and women aged 16-59 years living in Great Britain.

METHODS

The survey was carried out using a combination of face-to-face interview and self-completion questionnaires and a wide range of data was collected. In this study, data on numbers and sex of sexual partners, condom use, injecting drug use, perception of risk of AIDS and lifestyle change were analysed, and comparisons were made between the different geographical areas in Great Britain.

RESULTS

In the last 5 years, men living in Inner London were more likely to have a male partner [odds ratio (OR), 5.6; 95% confidence interval (CI), 3.1-10.0] or to have had 10 or more female partners (OR, 2.4; 95% CI, 1.6-3.6) than men living in other parts of the country. Similar results were observed for women living in Inner London: OR for a female partner in the last 5 years was 4.1 (95% CI, 1.6-10.2) and for five or more male partners in the last 5 years was 2.1 (95% CI, 1.5-2.8). More complex, but less striking patterns of behaviour were seen in different parts of the country. Both men and women living in Inner London were more likely to recognize that they were at some risk of acquiring HIV and were also more likely to report a change in sexual lifestyle.

CONCLUSIONS

These analyses highlight the difficulties inherent in extrapolating from sexual behaviour data gathered using purposive samples to the population as a whole. The results are consistent with the known epidemiology of HIV and sexually transmitted diseases in Britain. The data suggest that cases of HIV will continue to be concentrated in Inner London, but Londoners are particularly aware of their risk. Reported behaviour change in response to perception of risk of AIDS underlines the importance of effective health promotion.

Provision of sex education and early sexual experience: the relation examined

OBJECTIVES

To explore the relation between receipt of sex education and experience of first intercourse.

SUBJECTS AND DESIGN

The national survey of sexual attitudes and lifestyles is based on a sample of 18,876 respondents aged 16-59, randomly selected from the Post Office's small-user postcode address file. Data were collected between May 1990 and November 1991 by personal interviews combining a self administered questionnaire with a face to face interview.

MAIN OUTCOME MEASURES

Age at first intercourse, use of contraception at first intercourse, actual and preferred source of sex education (including school based lessons).

RESULTS

Median age at first intercourse fell by four years for women and three years for men over the past four decades, to 17 for both men and women aged 16-19 at the time of interview. Of those respondents for whom school was the main source of information about sexual matters, men were less likely, and women no more likely, to have had intercourse before the age of 16 than were those citing other main sources, such as friends and the media. Both men and women were more likely to have used some method of contraception. In multivariate analysis, these effects remained after controlling for the effect of current age, educational attainment, and religious affiliation.

CONCLUSIONS

These data provide no evidence to support the concern that provision of school sex education might hasten the onset of sexual experience. These findings have important implications for the provision of sexual health education and highlight the need to carry out prospective and randomised studies of the impact of sex education.

Sexual behaviour and HIV epidemiology: comparative analysis in France and Britain. The ACSF Group

OBJECTIVE

France and Britain have similar size populations, yet the incidence of AIDS is threefold higher in France. The objective of this study was to compare data from two surveys recently performed in the two countries, in order to determine whether differences in sexual and drug-use behaviour could explain the different epidemiological patterns.

DESIGN

Cross-sectional random sample surveys of France and Britain.

RESPONDENTS

In France, 20,055 persons aged 18-69 years and in Britain, 18,876 persons aged 16-59 years were interviewed in 1990-1991. The following indicators were compared in the respondents aged 18-59 years: prevalence of homosexual experience and injecting drug use, number of sexual partners, prevalence of sexual practices, condom use and sex with prostitutes, age of sexual partners.

RESULTS

Very similar results were found for the prevalence of male homosexual partnerships. Slightly higher numbers of lifetime partners were reported by French than British men, but no difference was found for recent periods. Anal intercourse and sex with prostitutes was more frequent among heterosexual French people than British people. Condom use was more systematic in Britain than in France.

CONCLUSION

Only small differences were found between the two countries, although prevalence of risk indicators were higher in France. These differences combined with early development of prevention policies in Britain, together with the timing of virus introduction, may contribute to differences between the epidemics in the two countries.

Management of women presenting to the accident and emergency department with lower abdominal pain

The diagnosis and management of lower abdominal pain is difficult, particularly for the inexperienced accident and emergency (A&E) or surgical trainee. In women, potential gynaecological causes may further confuse the picture. We analysed the incidence, spectrum of presentation and immediate management of 322 women presenting consecutively to an inner city A&E department over a 6-month period with lower abdominal pain. A standard questionnaire relating to history, examination, immediate investigations and preliminary diagnosis was completed by the attending A&E doctor. The cause of abdominal pain, according to the A&E doctor's diagnosis, was gynaecological in 61%, gastroenterological in 23%, urological in 7% and non-specific in 9% of cases. Of the women, 39% (124/322) were referred to a duty specialist, of whom 86% (107/124) required admission for investigation and/or treatment. Women initially diagnosed as having pain of gynaecological origin formed the largest group of patients to be referred. In 69% (67/97) of these cases, the A&E doctor's initial diagnosis was confirmed by the gynaecologist. This study shows that pain of gynaecological origin was the largest single cause of lower abdominal pain in women presenting to our A&E department and that, in the majority of cases, these women needed to be referred to the duty gynaecologist for immediate treatment. Although overall diagnostic accuracy rate was relatively high, the management of potentially life-threatening gynaecological conditions such as ectopic pregnancy was poor. These results emphasise the need to improve in-service gynaecological training in A&E departments.

Estimating the sexual mixing patterns in the general population from those in people acquiring gonorrhoea infection: theoretical foundation and empirical findings

STUDY OBJECTIVES

To describe mathematically the relationship between patterns of sexual mixing in the general population and those of people with gonorrhoea infection, and hence to estimate the sexual mixing matrix for the general population.

DESIGN

Integration of data describing sexual behaviour in the general population, with data describing sexual behaviour and mixing among individuals infected with gonorrhoea. Use of these data in a simple mathematical model of the transmission dynamics of gonorrhoea infection.

SETTING

The general population of London and a genitourinary medicine (GUM) clinic in west London.

PARTICIPANT

These comprised 1520 men and women living in London who were randomly selected for the national survey of sexual attitudes and lifestyles and 2414 heterosexual men and women who presented to the GUM clinic with gonorrhoea.

MAIN RESULTS

The relationship between sexual mixing among people with gonorrhoea and sexual mixing in the general population is derived mathematically. An empirical estimate of the sexual mixing matrix for the general population is presented. The results provide tentative evidence that individuals with high rates of acquisition of sexual partners preferentially select other individuals with high rates as partners (assortative mixing).

CONCLUSIONS

Reliable estimates of sexual mixing have been shown to be important for understanding the evolution of the epidemics of HIV infection and other sexually transmitted diseases. The possibility of estimating patterns of sexual mixing in the general population from information routinely collected in gonorrhoea contact tracing programmes is demonstrated. Furthermore, the approach we describe could, in principle, be used to estimate the same patterns of mixing, using contact tracing data for other sexually transmitted diseases, thus providing a way of validating our results.

Relation between maternal haemoglobin concentration and birth weight in different ethnic groups

OBJECTIVE

To assess the relation of the lowest haemoglobin concentration in pregnancy with birth weight and the rates of low birth weight and preterm delivery in different ethnic groups.

DESIGN

Retrospective analysis of 153,602 pregnancies with ethnic group and birth weight recorded on a regional pregnancy database during 1988-91. The haemoglobin measurement used was the lowest recorded during pregnancy.

SETTING

North West Thames region.

SUBJECTS

115,262 white women, 22,206 Indo-Pakistanis, 4570 Afro-Caribbeans, 2642 mediterraneans, 3905 black Africans, 2351 orientals, and 2666 others.

MAIN OUTCOME MEASURES

Birth weight and rates of low birth weight (< 2500 g) and preterm delivery (< 37 completed weeks).

RESULTS

Maximum mean birth weight in white women was achieved with a lowest haemoglobin concentration in pregnancy of 85-95 g/l; the lowest incidence of low birth weight and preterm labour occurred with a lowest haemoglobin of 95-105 g/l. A similar pattern occurred in all ethnic groups.

CONCLUSIONS

The magnitude of the fall in haemoglobin concentration in pregnancy is related to birth weight; failure of the haemoglobin concentration to fall below 105 g/l indicates an increased risk of low birth weight and preterm delivery. This phenomenon is seen in all ethnic groups. Some ethnic groups have higher rates of low birth weight and preterm delivery than white women, and they also have higher rates of low haemoglobin concentrations. This increased rate of "anaemia," however, does not account for their higher rates of low birth weight, which occurs at all haemoglobin concentrations.

Cost and utilisation of community services for people with HIV infection in London

This study aimed to describe the use and costs of community services for HIV-infected people by disease stage, sex and transmission category (homosexual, heterosexual, injecting drug use) by use of a prospective cohort study in which people were followed up for six months. There were two major components; gathering quantitative information on service utilisation from people with HIV infection using two interviewer-administered questionnaires and six self-completed monthly diaries; and estimating the costs of the services provided. People were recruited from two London clinics: the Jefferiss Wing Genito-urinary Medicine (GUM) clinic at St. Mary's Hospital, Paddington, and the Patrick Clements GUM clinic at the Central Middlesex Hospital, Harlesden. Costing data was obtained from providers of community services throughout Greater London. The main outcome measures were contacts per person-year, and costs per person-year, for all community services stratified by service sector. The people studied each made, on average, 139 community service contacts per year at a cost of 2,806 pounds; there was little difference in average utilisation between the three transmission categories. There were differences in both the utilisation of services and costs within the formal and informal sectors for subjects from different disease stages. Although the average number of contacts per person-year were similar for women and men, the total cost of community services was higher for women than for men, reflecting the differences in types of services used. The results indicated a high proportion of total care costs for people with HIV and AIDS is incurred through community-based social care.(ABSTRACT TRUNCATED AT 250 WORDS)

Sexual behaviour among London GUM clinic attenders: implications for HIV education

The aim of this study was to describe the sexual behaviour of a sample of genitourinary medicine (GUM) clinic attenders, 5 years after the launch of the UK government HIV media campaigns. A gender-specific and anonymous cross-sectional self-completion questionnaire was modified from the National Survey of Sexual Attitudes and Lifestyle and completed by 250 men and 250 women. The majority of the respondents were in their twenties, lived in London and were employed or students. Sixty-eight per cent of the men reported that one or more of their last 3 partners was not a regular partner. For those men whose last sexual encounter was with a new partner, 27% of heterosexuals and 33% of homosexuals reported using a condom. Fifty-one per cent of women reported one or more non-regular partners among their last 3 partners. For those women whose last sexual encounter was with a new partner, 43% of heterosexuals and 75% of bisexuals used a condom. Seventy-eight per cent of men and 75% of women had had a previous sexually transmitted disease (STD). These findings highlight the persistence of practices associated with the risk of contracting or transmitting HIV infection and which needs to be addressed in future educational campaigns. The GUM clinic population is an important population to monitor over time, either by longitudinal or serial cross-sectional studies. The results of this study provide a baseline against which to gauge the effects of future educational interventions.

Pneumocystis carinii pneumonia: relationship between cyst size and response to treatment

Pneumocystis carinii pneumonia is a common cause of death in patients with AIDS. Diagnosis is based on cytological examination of smears prepared from induced sputum samples and bronchoalveolar lavage (BAL) specimens which have been stained with methenamine silver. We have examined 46 BAL/induced sputum specimens from patients who had clinical symptoms and signs suggestive of P. carinii pneumonia and measured the diameter of a minimum 100 cysts in each specimen. We found that cyst size correlated with response to treatment with co-trimoxazole. This observation has implications for the therapeutic management of patients with this infection.

Changing use of hospital services and costs at a London AIDS referral centre, 1983-1989

OBJECTIVE

To describe the use of hospital-based services and associated costs over time for HIV-infected individuals by disease stage and year of treatment.

METHODS

Data on service use were abstracted from inpatient and outpatient case-notes of 459 HIV-infected patients (121 asymptomatic and 338 AIDS patients) treated at St Mary's Hospital, London between 1983 and 1989. Cost estimates were derived from a survey of the 37 departments involved with HIV-related care. The number and type of admissions and outpatient visits, referral and discharge venues, number and type of tests and procedures performed, drugs prescribed and associated costs for the study period were the outcome measures used.

RESULTS

Most patients were homosexual men. At the time of first HIV-related visit, 80.7% lived in London. Most day cases and planned admissions were organized through the outpatient clinic; 31% of emergency admissions were initiated by patients themselves. For people with AIDS the number of day case admissions increased while planned admissions decreased. There was a marked reduction in the duration of inpatient stays, especially for AIDS patients. Costs associated with inpatient care decreased concomitantly. The number of outpatient visits for patients with symptomatic disease increased, resulting in increased outpatient expenditure. Asymptomatic patients had fewer inpatient tests, while outpatient tests did not change over time; costs followed similar patterns. Mean inpatient and outpatient drug-days prescribed did not change nor did average inpatient drug-costs although outpatient drug-costs increased. Inpatient tests performed on symptomatic non-AIDS patients decreased, while mean outpatient tests increased; average costs followed similar patterns. Inpatient drug-days prescribed and costs remained the same, while outpatient drug-days and average drug-costs increased during the study period. For AIDS patients, the number of inpatient tests performed and their average costs decreased but outpatient tests performed increased, though their average costs remained the same. Mean inpatient drug-days prescribed and average drug-costs decreased, while number of outpatient drug-days prescribed and average drug-costs increased markedly over time. For each disease category, expenditure on admissions and related tests decreased over time, while expenditure on outpatient visits and drug-costs increased.

CONCLUSIONS

The shift from an inpatient- to an outpatient-based service has resulted in fewer patients being investigated and treated in hospital and more as outpatients. This has resulted in a reduction of inpatient-related costs, while outpatient-related costs have increased. The overall contribution of drug-costs to the total cost has increased greatly over time. With the anticipated advent of new antiviral compounds, the importance of ascertaining their effectiveness as well as their efficacy will become crucial.

Changing presentation and survival, service utilization and costs for AIDS patients: insights from a London referral centre

OBJECTIVE

To describe the use of services and associated costs for HIV-infected patients by stage of infection in the context of changing patterns of presentation and survival.

METHODS

A retrospective analysis of inpatient and outpatient case-notes of 335 AIDS patients and a survey of HIV-related care provided by 37 departments at St Mary's Hospital, London. Survival from time of diagnosis of AIDS, time from diagnosis of HIV infection to AIDS, and use and costs of services per patient-year were outcome measures.

RESULTS

During the study period 1 January 1982 to 30 September 1989, 152 AIDS patients were diagnosed before 1987 (group 1) and 183 since 1987 (group 2), most of whom were homosexual men. The median interval of first HIV-related visit to diagnosis of AIDS increased from 0 (group 1) to 264 days (group 2; P < 0.0001). Median survival from AIDS diagnosis increased from 14.6 (group 1) to 21.0 months (group 2; P < 0.02). Group 2 patients used fewer inpatient services than group 1 patients irrespective of disease stage. Symptomatic patients in group 2 used more outpatient services than group 1 patients. Total HIV-related expenditure was lower for patients without AIDS in group 2 than in group 1, while expenditure for AIDS patients remained similar.

CONCLUSION

Earlier patient presentation, a shift from inpatient- to outpatient-based clinical care and increased survival from time of AIDS diagnosis has occurred. Increased drug expenditure was offset by reduced inpatient expenditure. Total expenditure per patient-year was stable; increased survival and introduction of new drugs will increase future lifetime use of resources.

Pertussis immunisation and serious acute neurological illnesses in children

OBJECTIVE

To determine long term outcome in children who had a severe acute neurological illness in early childhood associated with pertussis immunisation.

DESIGN

Follow up study of cases and matched controls.

SETTING

Assessment of children at home and at school throughout Britain.

SUBJECTS

Children recruited into the national childhood encephalopathy study in 1976-9 were followed up, with one of their two original matched controls, in 1986-9.

MAIN OUTCOME MEASURES

Performance in educational attainment tests; behaviour problems reported by teachers and parents; continuing convulsions; evidence of other neurological or physical dysfunction.

RESULTS

Over 80% of cases and controls were traced. Case children were significantly more likely than controls to have died or to have some form of educational, behavioural, neurological, or physical dysfunction a decade after their illness. The prevalence of one or more of these adverse outcomes in case children who had been immunised with diphtheria, tetanus, and pertussis vaccine within seven days before onset of their original illness was similar to that in case children who had not been immunised recently. The relative risk for recent diphtheria, tetanus, and pertussis immunisation in children who had died or had any dysfunction in comparison with controls was 5.5 (95% confidence interval 1.6 to 23.7). However, the number of cases associated with vaccine (12) was extremely small and statistically vulnerable, and other possible agents or predisposing factors could not be excluded.

CONCLUSIONS

Diphtheria, tetanus, and pertussis vaccine may on rare occasions be associated with the development of severe acute neurological illnesses that can have serious sequelae. Some cases may occur by chance or have other causes. The role of pertussis vaccine as a prime or concomitant factor in the aetiology of these illnesses cannot be determined in any individual case. The balance of possible risk against known benefits from pertussis immunisation supports continued use of the vaccine.