Characterization of Escherichia coli strains causing urinary tract infections in patients with transposed intestinal segments

PURPOSE

Transposition of intestinal segments into the urinary tract predisposes to urinary tract infections. We characterized bacterial infections in these patients and examined the virulence genotype and persistence of Escherichia coli isolates.

MATERIALS AND METHODS

We followed 26 patients who underwent bladder reconstructive surgery using transposed intestinal segments. E. coli strains isolated from the urine of these patients were genotyped for established virulence determinants and the frequency of carriage was compared with E. coli strains isolated from community acquired urinary infections and the fecal flora of anonymous volunteers. A longitudinal study of E. coli strains in 9 patients was also done using pulsed field gel electrophoresis.

RESULTS

E. coli was the most frequently isolated organism, responsible for 59% (62 of 105) of monobacterial infections. Other bacteria isolated included Klebsiella species, Proteus species and Enterococcus faecalis. Community acquired E. coli strains were more likely to carry multiple determinants for particular adhesins (P and S fimbriae) and toxins (alpha-hemolysin and cytotoxic necrotizing factor) than fecal strains. Carriage frequency for bladder reconstruction strains was intermediary and not significantly different. The key finding was that E. coli strains persisted for prolonged periods, including 2 years in certain patients, often despite various antimicrobial treatments.

CONCLUSIONS

This study highlights that further steps must be taken to prevent and treat urinary tract infections in this susceptible group. Particular attention should be given to the treatment of persistent infections.

Crystal structure of eta-crystallin: adaptation of a class 1 aldehyde dehydrogenase for a new role in the eye lens

Eta-crystallin is a retinal dehydrogenase that has acquired a role as a structural protein in the eye lens of elephant shrews, members of an ancient order of mammals. While it retains some activity toward retinal, which is oxidized to retinoic acid, the protein has acquired a number of specific sequence changes that have presumably been selected to enhance the lens role. The crystal structure of eta-crystallin, in common with class 1 and 2 ALDHs, is a dimer of dimers. It has a better-defined NAD binding site than those of related mammalian ALDH1 enzymes with the cofactor bound in the "hydride transfer" position in all four monomers with small differences about the dimer dyads. Although the active site is well conserved, the substrate-binding site is larger in eta-crystallin, and there are some mutations to the substrate access tunnel that might affect binding or release of substrate and product. It is possible that eta-crystallin has lost flexibility to improve its role in the lens. Enhanced binding of cofactor could enable it to act as a UV/blue light filter in the lens, improving visual acuity. The structure not only gives a view of a "natural mutant" of ALDH1 illustrating the adaptive conflict that can arise in multifunctional proteins, but also provides a well-ordered NAD binding site structure for this class of enzymes with important roles in development and health.

A national outbreak of multi-resistant Salmonella enterica serovar Typhimurium definitive phage type (DT) 104 associated with consumption of lettuce

Between 1 August and 15 September 2000, 361 cases of Salmonella enterica serotype Typhimurium definitive phage type (DT) 104, resistant to ampicillin, chloramphenicol, streptomycin, sulphonamides, spectinomycin and tetracycline (R-type ACSSuSpT), were identified in England and Wales residents. Molecular typing of 258 isolates of S. Typhimurium DT104 R-type ACSSuSpT showed that, although isolates were indistinguishable by pulsed-field gel electrophoresis, 67% (174/258) were characterized by a particular plasmid profile. A statistically significant association between illness and consumption of lettuce away from home was demonstrated (OR = 7.28; 95% CI=2.25-23.57; P=0.0006) in an unmatched case-control study. Environmental investigations revealed that a number of food outlets implicated in the outbreak had common suppliers of salad vegetables. No implicated foods were available for microbiological testing. An environmental audit of three farms that might have supplied salad vegetables to the implicated outlets did not reveal any unsafe agricultural practices. The complexity of the food supply chain and the lack of identifying markers on salad stuffs made tracking salad vegetables back to their origin extremely difficult in most instances. This has implications for public health since food hazard warnings and product withdrawal are contingent on accurate identification of the suspect product.

Characterization of a type IIb sodium-phosphate cotransporter from zebrafish (Danio rerio) kidney

Zebrafish (Danio rerio) express two isoforms of the type IIb Na-dependent P(i) cotransporter (NaPi). Type NaPi-IIb1 has previously been cloned and characterized. Here, we report the cloning of the NaPi-IIb2 transcript from zebrafish kidney, its localization, and its functional characterization. RT-PCR with renal RNA and degenerate NaPi-IIb-specific primers resulted in a specific fragment. 3'-Rapid amplification of cDNA ends yielded a product that contained typical NaPi-IIb characteristics such as a cysteine-rich COOH terminus and a PDZ (PSD95- Dlg-zona occludens-1) binding motif. Several approaches were unsuccessful at cloning the 5' end of the transcript; products lacked an in-frame start codon. The missing information was obtained from an EST (GenBank accession number ). The combined clone displayed a high degree of homology with published type IIb cotransporter sequences. Specific antibodies were raised against a COOH-terminal epitope of both NaPi-IIb1 and NaPi-IIb2 isoforms. Immunohistochemical mapping revealed apical expression of both isoforms in zebrafish renal and intestinal epithelia, as well as in bile ducts. The novel clone was expressed in oocytes, and function was assayed by the two-electrode voltage-clamp technique. The function of the new NaPi-IIb2 clone was found to be significantly different from NaPi-IIb1 despite strong structural similarities. NaPi-IIb2 was found to be strongly voltage sensitive, with higher affinities for both sodium and phosphate than NaPi-IIb1. Also, NaPi-IIb2 was significantly less sensitive to external pH than NaPi-IIb1. The strong structural similarity but divergent function makes these zebrafish transporters ideal models for the molecular mapping of functionally important regions in the type II NaPi-cotransporter family.

Series of incidents of Listeria monocytogenes non-invasive febrile gastroenteritis involving ready-to-eat meats

AIMS

A series of cases and outbreaks of febrile noninvasive gastrointestinal disease involving 31 identified cases was investigated in terms of the numbers and types of Listeria monocytogenes present in the suspect foods (ready-to-eat meats) and clinical samples from cases.

METHODS AND RESULTS

Foods and faecal samples involved in the incidents were tested for the presence and number of L. monocytogenes. Isolates were typed by macrorestriction analysis using pulsed-field gel electrophoresis. The foods contained high levels of L. monocytogenes, in one case 1.8 x 10(7) g-1. Faecal samples contained L. monocytogenes for up to 15 d after the contaminated food was consumed. All isolates from the food and faecal samples were of serotype 1/2 and were indistinguishable from one another by macrorestriction typing.

CONCLUSIONS

It is likely that the meats were contaminated either during their manufacture after they had been cooked or by underprocessing. The long shelf lives on these products would have allowed the contaminating L. monocytogenes to grow to the high numbers measured in this study, causing food poisoning as described.

SIGNIFICANCE AND IMPACT OF THE STUDY

Outbreaks of febrile noninvasive listeriosis are relatively rare. This report adds ready-to-eat meats to the range of foods that have acted as vehicles for such outbreaks.

Repeatability of long and short echo-time in vivo proton chemical-shift imaging

We carried out long (145 ms) and short (25 ms) echo time spectroscopic imaging of the brain (chemical-shift imaging, CSI) on two occasions 1 week apart on 15 healthy individuals. We found coefficients of variation (CVs) generally in the range 10-25% for long and 15-30% for short echo-time measurements. The CVs of metabolite ratios were higher by about 5-10%. Limits of agreement (defined as mean+/-2 SD of the week 1-week 2 differences) were wider at the shorter echo time. The modest repeatability may be due in part to the difficulty of repositioning spectroscopic voxels at a scale of 1 mm. The generally higher CVs and wider limits of agreement at TE25 ms suggest that the increased spectral complexity more than offsets the theoretical advantage of increased signal at short echo-times. Analysis of variance general linear modelling of metabolites and metabolite ratios showed that, in general, the subject, region of the brain and hemisphere were more important than the occasion in explaining the variability of results. Unless information on short-T2 metabolites is specifically required, better results can probably be achieved with longer echo-times. The magnitude of the CVs needs to be taken into account in the calculation of sample size for cross-sectional or linear studies.

Linkage disequilibrium analysis of chromosome 12q14-15 in multiple sclerosis: delineation of a 118-kb interval around interferon-gamma (IFNG) that is involved in male versus female differential susceptibility

We have recently reported the association of a polymorphic intronic CA-repeat in the interferon-gamma gene (IFNG) with gender bias in susceptibility to multiple sclerosis (MS) in a Sardinian population. This association could refer to a functional polymorphism within IFNG or could be due to linkage disequilibrium between the IFNG marker and a neighbouring susceptibility locus. Within the average reach of linkage disequilibrium, various other candidate genes are located. Among these the most striking ones are the genes coding for the cytokines interleukin-22 (IL-22) and interleukin-26 (IL-26) that constitute together with IFNG a cytokine cluster on chromosome 12q14. To determine more precisely the location of this gender-associated susceptibility locus, we have now performed a more extensive linkage disequilibrium screen of this region using nine additional microsatellite markers. This locus appeared to be confined to a 118-kb interval that is bordered by the markers D12S313 and D12S2511, in which IFNG itself remains the main candidate gene. Haplotype analysis confirmed that this MS-associated locus protects males from developing MS according to a recessive or allele-dosage model. Our results indicate that the well-documented gender differences in susceptibility to MS are at least partially caused by genetic factors in the region surrounding IFNG.

A national study of clinical and laboratory factors affecting the survival of patients with multiple drug resistant tuberculosis in the UK

BACKGROUND

This study aimed to describe the clinical, microbiological, molecular epidemiology and treatment of multidrug resistant tuberculosis (MDRTB) cases in the UK and to determine factors associated with survival.

METHODS

Ninety MDRTB cases were identified from 1 January 1996 to 30 June 1997; 69 were DNA fingerprinted. Date of diagnosis was determined and data were collated on key demographic factors, clinical, radiological and treatment details. Variables associated with survival were included in a Cox proportional hazards model.

RESULTS

Most of the patients (72.4%) were male, born outside the UK (57.1%), were sputum smear positive (82.2%), and had entered the UK more than 5 years previously (61.9%). Thirty eight of 78 cases (48.7%) had prior TB. Sufficient data on 82 patients were available for survival analysis; 20/27 (74.1%) known to be dead at the end of the observation period had died of tuberculosis. Median survival time overall was 1379 days (95% CI 1336 to 2515) or 3.78 (95% CI 3.66 to 6.89) years (858 days (95% CI 530 to 2515) in immunocompromised individuals (n=32) and 1554 (95% CI 1336 to 2066) days in immunocompetent cases (n=48)). Median survival in patients treated with three drugs to which the bacterium was susceptible on in vitro testing (n=62) was 2066 days (95% CI 1336 to 2515) or 5.66 years, whereas in those not so treated (n=13) survival was 599 days (95% CI 190 to 969) or 1.64 years.

CONCLUSIONS

Immunocompromised status, failure to culture the bacterium in 30 days or to apply appropriate three drug treatment, and age were significant factors in mortality. An immunocompromised patient was nearly nine times more likely to die, while application of appropriate treatment reduced the risk (risk ratio 0.06). Increasing age was associated with increasing risk of death (risk ratio 2.079; 95% CI 1.269 to 3.402)-that is, for every 10 year increase in age the risk almost doubled. Overall survival was lower than that reported in previous studies.

The social functioning of older adults with schizophrenia

A cross-sectional survey of the social functioning of community dwelling older adults was undertaken. Older adults with no psychiatric morbidity, depressed older adults and older adults with schizophrenia were surveyed to see if there were differences in the level of social functioning of the three groups. The setting was two old age psychiatric services, one in an urban area of London and the other in a semi-rural area of Leicestershire. Participants consisted of depressed (n = 81) or normal (n = 101) older persons identified as part of a general practice over 75 years check and clients over 65 years with schizophrenia (n = 30) known to mental health teams for older adults. All participants were interviewed by one of two trained researchers and completed the Mini-Mental State Examination questionnaire, the 15-item Geriatric Depression Scale, a social functioning questionnaire, and the Schedules for Clinical Assessment in Neuropsychiatry or the Brief Psychiatric Rating Scale. In our sample population, community dwelling older persons without any psychiatric diagnosis were the least isolated from their local community, reported more private leisure activities, and had the least contact with professional community services. Clients with schizophrenia reported more isolation from their local community and fewer private leisure activities than clients with a diagnosis of depression.

An evaluation of the performance of XLD, DCA, MLCB, and ABC agars as direct plating media for the isolation of Salmonella enterica from faeces

AIMS

To compare the performance of four media, singly and in combination, as direct plating media for the isolation of Salmonella enterica from human faeces.

METHODS

Two thousand four hundred and nine routine, faecal samples received by four laboratories were inoculated on to xylose lysine desoxycholate (XLD), desoxycholate citrate (DCA), mannitol lysine crystal violet brilliant green (MLCB), and alpha-beta chromogenic (ABC) agars using standardised protocols, reagents, and data collection. Isolates of presumptive salmonellae were identified using standard laboratory techniques and the results were analysed statistically.

RESULTS

Direct plating recovered 46 of the 60 possible isolates of Salmonella spp recovered via enrichment broth. No isolates were recovered from direct plating that were not recovered via selenite enrichment. MLCB gave the highest isolation rate individually (84.8%) and amounts of competing flora (CF) did not affect the recognition of colonies. ABC proved highly specific, but insensitive, and isolation rates were adversely affected by any amount of CF. Isolation rates from XLD and DCA were only affected when the CF load was heavy. DCA was least specific, with only 9.01% of picks positive and greatest number of confirmatory tests. XLD and MLCB, in combination, gave the highest isolation rate.

CONCLUSIONS

Where the earlier results of direct plating may be advantageous, XLD and MLCB provide the optimal combination. For non-typhi salmonellae, MLCB is the best, single direct plating medium. For routine diagnostic work, XLD is most effective.

Side effects of low-dose pyridostigmine bromide are not related to cholinesterase inhibition

BACKGROUND

Pretreatment with pyridostigmine bromide (PB) has become part of standard military procedures for protection against the effects of possible chemical warfare attack. The purpose of the work reported here was to quantify the type, intensity and frequency of side effects of low-dose PB, and to examine factors that predict the intensity and frequency of side effects.

METHOD

A double-blind, cross-over, placebo (PL)-controlled design was used. Of the 67 subjects, 33 received 30 mg PB every 8 h for 13 doses, and 34 received 60 mg on the same schedule. Order of PB and PL administration was counterbalanced.

RESULTS

Overall, side effects were mild, even at the 60-mg dose level. More side effects were reported when volunteers were taking PB than when they were taking placebo. Women reported more symptoms than men. Neither cholinesterase inhibition nor plasma levels of PB predicted side effect scores during the PB week; the best predictor of side effect scores during the PB week was side effect scores during the PL week.

CONCLUSION

PB is well tolerated by healthy young people, even when twice the recommended military dose is administered.

All-night exposure to EMF does not alter urinary melatonin, 6-OHMS or immune measures in older men and women

Healthy men (n = 22) and women (n = 24), 40-60 years of age, were exposed all-night (23:00-07:00 hr) to 60-Hz magnetic fields at an intensity (resultant flux density = 28.3 microTesla [microT]) well within the occupational-exposure range, or sham exposed under equivalent, counter-balanced, no-exposure ( < or = 0.2 microT) control conditions. Concentrations of melatonin, and the major metabolite of melatonin, 6-hydroxymelatonin-sulfate (6-OHMS), in first-void morning urine were not altered in either gender by exposure to the magnetic field, compared to control conditions. Statistical analysis also failed to reveal any evidence for exposure-related alterations in blood concentrations of multiple hematologic and immune system parameters (CD3, CD4, CD8, natural killer [NK] cells). The present results replicate and extend earlier negative findings based on the exposure of young men to power-frequency magnetic fields.

Melatonin and 6-OHMS in high-intensity magnetic fields

We determined if all-night exposure to 60 Hz magnetic fields at an intensity well within the upper range of occupational exposures (resultant intensity = 127.3 microTesla [muT]) resulted in suppression of melatonin or its major metabolite 6-hydroxymelatonin-sulfate (6-OHMS) in the first-void morning urine of 24 healthy male volunteers. Measures collected after continuous and intermittent magnetic field exposure test conditions were compared to similar measures collected after an equivalent no-exposure control condition. Urinary concentrations of melatonin and 6-OHMS did not differ as a function of type of magnetic field exposure, nor did they differ between field exposure and control conditions. These results demonstrate that the nocturnal secretion and metabolism of melatonin are not altered in humans by field exposure at an intensity over 600 times higher than that typically encountered in the home.

Examination of the melatonin hypothesis in women exposed at night to EMF or bright light

It has been hypothesized that the increased incidence of breast cancer in industrial societies is related to greater exposure to power-frequency electric and magnetic fields (EMF) and/or the presence of high levels of light at night (LAN). EMF and LAN are said to reduce circulating levels of the hormone melatonin which, in turn, allows estrogen levels to rise and stimulate the turnover of breast epithelial stem cells and increase the risk for malignant transformation. Three laboratory-based studies, in which a total of 53 healthy young women were exposed at night to EMF or to LAN under controlled exposure conditions, were performed to determine whether such exposures reduce melatonin and are associated with further alterations in estrogen. All-night exposure to industrial-strength magnetic fields (60 Hz, 28.3 microT) had no effect on the blood levels of melatonin or estradiol. In contrast, nocturnal melatonin levels were profoundly suppressed, and the time of peak concentration was significantly delayed in women exposed to LAN, regardless of whether they were in the follicular or luteal phase of the menstrual cycle. These changes, however, were not associated with alterations in point-for-point matching measures of estradiol. Women who chronically secrete high or low amounts of melatonin each night (area-under-curve range: 86-1,296 pg/mL) also did not differ in their blood levels of estradiol. Taken together, these results are consistent with a growing body of evidence which generally suggests that environmental EMF exposure has little or no effect on the parameters measured in this report.

Protein kinase C theta is expressed in mast cells and is functionally involved in Fcepsilon receptor I signaling

We investigated possible expression and function in mast cells of protein kinase C (PKC) theta, a member of the PKC family with demonstrated function in a limited range of cell types. We found that PKC theta is expressed in bone marrow-derived mast cells and in the RBL-2H3 mast cell line. PKC theta underwent translocation to the membrane in response to Fcepsilon receptor I (FcepsilonR I) activation. Receptor activation induced phosphorylation of PKC theta. The tyrosine phosphorylation of PKC theta is delayed relative to PKC delta and coincides temporally with PKC theta association with c-src family members Lyn and SRC: Studies of RBL-2H3 cells transduced with PKC theta constructs indicated a role for PKC theta in receptor-induced activation of extracellular regulated kinases, interleukin-3 gene transcription, and degranulation in response to antigen stimulation. These studies extend the known functions of PKCtheta to another important immune cell type and indicate the concurrent participation of multiple PKCs in the FcepsilonR I-mediated response of mast cells.

Cloning and characterization of 13 novel transcripts and the human RGS8 gene from the 1q25 region encompassing the hereditary prostate cancer (HPC1) locus

The aim of this study was to develop a saturated transcript map of the region encompassing the HPC1 locus to identify the susceptibility genes involved in hereditary prostate cancer (OMIM 176807) and hyperparathyroidism-jaw tumor syndrome (OMIM 145001). We previously reported the generation of a 6-Mb BAC/PAC contig of the candidate region and employed various strategies, such as database searching, exon-trapping, direct cDNA hybridization, and sample sequencing of BACs, to identify all potential transcripts. These efforts led to the identification and precise localization on the BAC contig of 59 transcripts representing 22 known genes and 37 potential transcripts represented by ESTs and exon traps. Here we report the detailed characterization of these ESTs into full-length transcript sequences, their expression pattern in various tissues, their genomic organization, and their homology to known genes. We have also identified an Alu insertion polymorphism in the intron of one of the transcripts. Overall, data on 13 novel transcripts and the human RGS8 gene (homologue of the rat RGS8 gene) are presented in this paper. Ten of the 13 novel transcripts are expressed in prostate tissue and represent positional candidates for HPC1.

Test of HIV incidence shows continuing HIV transmission in homosexual/bisexual men in England and Wales

It has been suggested that HIV incidence will decrease with the increased use of antiretroviral Therapy (ART) in HIV infected homosexual/bisexual men. HIV incidence was measured using a sensitive/less sensitive assay technique, at a time when combination ART was widespread. The Serological Testing Algorithm for Recent HIV Seroconversion (STARHS)13 technique was applied to syphilis test specimens collected from homosexual/bisexual men attending 15 sexually transmitted infections (STI) clinics which participated in an unlinked anonymous serosurvey of HIV infection during 1998. The HIV incidence rate was adjusted to compensate for patients who had a repeat syphilis test within the same year. Leftover syphilis test sera from 6202 men had been unlinked and anonymised, of which 415 were HIV positive. Sera from 412 (99.3%) patients were available. The STARHS assay showed 62 to have been recently infected with HIV (approximately in the last four months), giving an incidence of 3.33% per annum (95% CI: 2.06%-5.27%). The highest incidence was seen in those aged 35-44 years. About 46% of all HIV-infected homosexual/bisexual men were probably receiving combination ART at this time. If 10% of those on treatment were misclassified as recent infections the incidence would have been 2.58% per annum (95% CI: 1.53%-4.24%). In homosexual/bisexual men having syphilis tests at STI clinics in the UK during 1998 the incidence of HIV infection was between two and three per hundred per year. Treatment with combination ART of almost a half of homosexual/bisexual men who are HIV infected in the population is compatible with appreciable continuing HIV transmission among those at high behavioural risk. Public health surveillance systems for those at high risk for HIV infection should, as soon as possible, incorporate the STARHS methodology for monitoring recent HIV incidence.

PHLS overview of communicable diseases 1999

Every other year since 1995 the Public Health Laboratory Service has undertaken a consultation exercise to identify communicable diseases of high public health priority. The purpose of identifying disease priorities is to guide rational and transparent service planning and resource allocation. Also, the process aims to ensure a customer sensitive service. This paper presents the results of the priority setting exercise undertaken in 1999. A postal questionnaire was sent to 1130 key professionals involved in communicable disease control in the United Kingdom. Respondents were asked to assess the relative priority of 61 communicable diseases and to identify priority areas of work associated with these diseases. Five criteria were used to assess relative priority. The five criteria were; present burden of ill-health, social and economic impact, potential threat to health, health gain opportunity and public concern and confidence. For each disease, respondents were asked to score the importance of each criterion. Forty six percent of participants (518/1130) returned completed questionnaires. There was no significant difference in response rate by professional group. Based on the scores assigned to each of the five criteria, the relative priority of 61 communicable diseases has been established. The top ten diseases in descending order of priority are, HIV/AIDS, meningococcal diseases, Chlamydia trachomatis, influenza, tuberculosis, E. coli O157, Methicillin resistant Staphylococcus aureus, salmonellosis, transmissible spongiform encephalopathies and Helicobacter pylori. The opinion of a large number of health care professionals has been used to establish a priority rank for a wide range of communicable diseases. This work provides planners and policy makers with a synthesis of current professional opinion that can be used as a foundation for making decisions on service developments.

Tuberculosis at the end of the 20th century in England and Wales: results of a national survey in 1998

BACKGROUND

A national survey of tuberculosis was conducted in England and Wales in 1998 to obtain detailed information on the occurrence of the disease and recent trends. This survey also piloted the methodology for enhanced tuberculosis surveillance in England and Wales and investigated the prevalence of HIV infection in adults with tuberculosis.

METHODS

Clinical and demographic data for all cases diagnosed during 1998 were obtained, together with microbiological data where available. Annual incidence rates in the population were estimated by age, sex, ethnic group, and geographical region using denominators from the 1998 Labour Force Survey. Incidence rates in different subgroups of the population were compared with the rates observed in previous surveys. The tuberculosis survey database for 1998 was matched against the Communicable Disease Surveillance Centre HIV/AIDS database to estimate the prevalence of HIV co-infection in adult patients with tuberculosis.

RESULTS

A total of 5658 patients with tuberculosis were included in the survey in England and Wales (94% of all formally notified cases during the same period), giving an annual rate of 10.93 per 100 000 population (95% CI 10.87 to 10.99). This represented an increase of 11% in the number of cases since the survey in 1993 and 21% since 1988. In many regions case numbers have remained little changed since 1988, but in London an increase of 71% was observed. The number of children with tuberculosis has decreased by 10% since 1993. Annual rates of tuberculosis per 100 000 population have continued to decline among the white population (4.38) and those from the Indian subcontinent, although the rate for the latter has remained high at 121 per 100 000. Annual rates per 100 000 have increased in all other ethnic groups, especially among those of black African (210) and Chinese (77.3) origin. Over 50% of all patients were born outside the UK. Recent entrants to the UK had higher rates of the disease than those who had been in the country for more than 5 years or who had been born in the UK. An estimated 3.3% of all adults with tuberculosis were co-infected with HIV.

CONCLUSIONS

The epidemiology of tuberculosis continues to change in England and Wales and the annual number of cases is rising. More than one third of cases now occur in young adults and rates are particularly high in those recently arrived from high prevalence areas of the world. The geographical distribution is uneven with urban centres having the highest rates. The increase in the number of cases in London is particularly large. Tuberculosis in patients co-infected with HIV makes a small but important contribution to the overall increase, particularly in London. To be most effective and to make the most efficient use of resources, tuberculosis prevention and control measures must be based on accurate and timely information on the occurrence of disease. A new system of continuous enhanced tuberculosis surveillance was introduced in 1999, based on the methodology developed in this national survey.

PHLS primary care consultation--infectious disease and primary care research and service development priorities

In 1999 for the first time the PHLS undertook a questionnaire survey of general practitioners' views of the burden of infectious disease and the priorities for research and development of infectious disease services within the PHLS. Three hundred and seventy-one (38%) of 979 questionnaires mailed to chairs of primary care groups in England, and general practitioners in research networks, were returned. Service areas: computer transfer of laboratory results was considered of greatest priority. Guidance on antibiotic usage, guidance on infectious diseases and education for general practitioners were ranked two, three and four. Burden of infectious disease in primary care: upper respiratory tract infections, tonsillitis/pharyngitis, otitis media/externa and acute cough were placed one, three, four and seven respectively. Urinary tract infections were ranked second and dyspepsia/Helicobacter pylori fifth. Leg ulcers, diarrhoea, genital chlamydia infection and vaginal discharge were other diseases considered to cause a large burden of ill-health. Genital chlamydia, tuberculosis, Helicobacter pylori and meningococci were ranked one, two, three, and five in the NHS opportunity to affect the burden of ill-health. Priorities for improvements to diagnostic tests, evidence on which to base treatment and guidance: chronic fatigue/ME was ranked top in these areas. The other top ten syndromes ranked in order were genital chlamydia infections, antibiotic resistance surveillance, vaginal discharge, leg ulcers, sinusitis, otitis media/externa, dyspepsia/Helicobacter pylori, Creutzfeld Jacob Disease, and tonsillitis. This consultation exercise has highlighted broad areas for future PHLS involvement in primary care. In order to make progress, further consultation is needed with groups of GPs, and other relevant bodies. Particularly for the areas ranked in the top ten, the type of further PHLS involvement needs to be defined. For some syndromes (chronic fatigue and leg ulcers) this may be writing guidance and for others (respiratory tract infections) more treatment trials are required. The purposes and possible methods of communicable disease surveillance in general practice should be the subject of additional consultation.

What a test for recent infection might reveal about HIV incidence in England and Wales

BACKGROUND

A laboratory method has been developed that detects recent HIV infection and allows incidence to be estimated by testing single stored antibody-positive specimens. A theoretical exploration of the method's surveillance utility was carried out.

METHODS

Using various data sources, HIV incidence rates were postulated. The confidence intervals (CI) for these postulated incidences were calculated using the expected number of recent infections for each postulated incidence, the actual number tested for HIV, and the known number of HIV-1 positives. A test for trend was used to determine when an important change in incidence could be recognized.

RESULTS

If the incidence was 5% per annum (p.a.) in homosexual/bisexual men attending sexually transmitted diseases (STD) clinics in London, 64 recent infections would be expected in the 392 HIV-seropositive specimens and, if observed, would result in a 95% CI of 3.1-7.9% p.a. for the incidence rate. An incidence of 1% p.a. in pregnant women would be most unlikely as this would require detection of 193 recent infections, 26 more than the total 167 HIV-seropositive specimens found in 1997. In African women attending STD clinics in London, 30% of prevalent infections would be classified as recent if the incidence was 5% p.a. Further, if the incidence in homosexual/bisexual men were to fall by 50% over 3 years, a decrease of this magnitude would be recognized as significant within 2 years.

CONCLUSIONS

The detuned assay will increase the information from HIV serosurveys even where prevalence and incidence are relatively low. Existing surveillance systems should be redesigned to take full advantage of the method.