slurred speech may have been explicable by an osmotic disturbance but this is a most unlikely explanation for her persisting paraplegia. Our report and that of Noda et al raise two important questions. What is the incidence of prolonged paraplegia after myelography with water soluble contrast? Does the development of paraplegia imply an underlying neurological lesion (eg, an arteriovenous malformation or disseminated sclerosis)? These questions deserve further evaluation since MRI now provides, in certain clinical situations, an alternative to myelography. If subsequent data suggest that the risk of post-myelography paraparesis is anything other than exceedingly remote, it will become mandatory to advise patients of this risk because a patient rendered paraplegic by this procedure may well seek compensation. Department of Neurology, London SE1 9RT, UK


Department of Radiology, William Harvey Hospital, Ashford, Kent


Guy’s Hospital,

*Present address. MRC Human Movement and Balance Unit, Institute of Neurology, London WC1 N 3BG, UK

Borrelia burgdorferi in urban


SiR,—The causative agent of Lyme disease, the spirochaete Borrelia burgdorferi, is transmitted to man in the UK by the tick Ixodes ricinus. Early treatment may prevent progression to serious neurological and arthritic complications, but many early symptoms are non-specific and the antibody response in the first weeks of infection is often poor. Identification of potential foci of B burgdorferi infection can be helpful since a knowledge of exposure to the risk of tick bite in a known endemic area can assist clinical diagnosis. In the UK, Lyme disease has been associated principally with forested areas such as the New Forest (Hampshire), Thetford Forest (Norfolk), and parts of Scotland. We report B burgdorferi in ticks collected from an enclosed urban park visited by an estimated 3 million people annually. In 1988, a 9-year-old poodle was brought to a veterinary practice in Richmond (a borough in south-west London, on the River Thames) with a 2 week history of multiple joint stiffness, pyrexia, and general malaise. Before the onset of symptoms the owner had noted several major tick infestations on the dog after walks to Richmond Park and in Bushey Park, which is close by Hampton Court. Both these parks have large numbers of deer roaming free. Lyme disease was suspected, and serum sent to Southampton Public Health Laboratory was found positive for antibodies to B burgdorferi by western blot. Oxytetracycline 20 mg/kg thrice daily was prescribed and the dog was much improved within a week. Ticks were collected from vegetation in the two parks and tested for B burgdorferi by polymerase chain reaction (PCR). Adult female I ricinus were each crushed in 100 pl ammonium hydroxide (0-5 mol/1) and heated to 100°C for 5 min in a sealed 0-5 ml microfuge tube followed by 10 min at 100°C with the tube open. 10 ul of each sample were added to a standard PCR reaction mix (’Amplitaq’ kit, Perkin-Elmer Cetus) and B burgdorferi DNA was amplified.3 B burgdorferi was found in 2 of 40 Richmond Park ticks and in 3 of 25 ticks from Bushey Park. Ticks can pose a significant threat to public health in parks and other recreational areas.’ This study shows that Richmond Park and Bushey Park are foci of B burgdorferi infection and indicates the possibility of acquiring Lyme disease in urban parklands where I ricinus is found. Further investigation will be required in order to assess the potential risk of Lyme disease to the general public and park employees in these and similar areas. In the New Forest 25% of Forestry Commission employees5 and 2-4-5% of local inhabitants (unpublished) show evidence of infection by B burgdorferi, but serious clinical complications are rare. The identification of the New Forest as a focus of B burgdorferi infection in 19866 led to an intensive campaign by physicians and the local public health laboratory to alert doctors to the risk of Lyme disease following tick bites. As a result, many local general practitioners now recognise and treat the early symptoms of Lyme disease. Environmental health officers have taken steps to try to

reduce the incidence of Lyme disease by providing advice to visitors methods of avoiding tick bites and in recognising and removing attached ticks.7 The PCR method greatly facilitates the rapid identification of new foci of infection, such’as Richmond Park and Bushey Park. These areas can then be targeted with campaigns aimed at increasing public awareness of Lyme disease. on

Public Health Laboratory, Southampton General Hospital, Southampton SO9 4XY, UK


Veterinary Surgery,


161 Kew Road, Richmond

1. Steere AC, Hutchinson GJ, Rahn DW, et al. Treatment of the early manifestations of Lyme disease. Ann Intern Med 1983; 99: 22-26. 2. Editorial. Diagnosis of Lyme disease. Lancet 1989; ii: 198-99. 3. Guy EC, Stanek G. Detection of Borrelia burgdorferi in Lyme disease patients’ sera by PCR. J Clin Pathol 1991; 44: 611. 4. Newson HD. Arthropod problems in recreational areas. Annu Rev Entomol 1977; 22: 333-53. 5. Guy EC, Bateman DE, Martyn CN, Heckels JE, Lawton NF. Lyme disease: prevalence and clinical significance of Borrelia burgdorferi-specific IgG in forestry workers. Lancet 1989; i: 484-86. 6. Williams D, Rolles CJ, White JE. Lyme disease in a Hampshire child: medical curiosity or beginning of an epidemic? Br Med J 1986; 292: 1560-61. 7. Anon. Just a tick?: tick bites and Lyme disease. Lyndhurst, Hampshire: New Forest District Council, Environmental Health Office, 1991.

Isolation of Helicobacter pylori from frozen

gastric biopsy specimens SIR,-Dr Assous and colleagues (June 8, p 1412) state that culture of Helicobacter pylori from gastric biopsy specimens is the reference method for detection of the organism and suggest that freezing of the specimens before culture will lead to a substantially lower isolation rate. There is no commonly accepted "gold standard" method for diagnosis of colonisation by H pylori. 1 The sensitivity of culture techniques depends on many factors, including the number of biopsy specimens, transport conditions, culture medium, and experience of laboratory workers.1,;! Assous et al do not provide the numbers of patients with gastritis in the two groups (biopsy specimens cultured fresh or after freezing) so the comparison made between the two heterogeneous groups is not

helpful. There is

loss of bacterial

cells, of any species, on study, fractions of 52 gastric biopsy specimens homogenised in glucose transport medium, were



recovery after frozen storage. In


stored at - 70°C.3 When cultured at 2,4, and 6 months after storage, H pylori was isolated from 87%, 93%, and 91 %, respectively, of fractions positive on initial culture, with bacterial counts (colonyforming units) down to 20-80% of the original numbers. Goodwin and Armstrong2 suggested that biopsy specimens are stored at - 70°C in a broth or 1 % peptone water and 25% glycerol. We have received 39 gastric biopsy specimens from Venezuela for antibiotic sensitivity studies. The specimens were frozen in nutrient broth and transported in dry ice to England. H pylori was isolated from 35 specimens (90%) with a selective medium,4 and we were not surprised that 29 isolates (83%) were resistant to metronidazole.5 Freezing specimens before culture will lower the sensitivity of detection of H pylori, but, with care, the organism should be isolated from well over 90% of colonised gastric biopsy specimens. Bradford

Royal Infirmary,

Bradford, West Yorkshire BD9 6RJ, UK


1. Morris A, Ali MR, Brown P, Lane M, Patton K. Campylobacter pylori infection m biopsy specimens of gastric antrum: laboratory diagnosis and estimation of sampling error. J Clin Pathol 1989; 42: 727-32. 2. Goodwin CS, Armstrong JA. Microbiological aspects of Helicobacter pylori. (Campylobacter pylori). Eur J Clin Microbiol Infect Dis 1990; 9: 1-13. 3. Abdalla S, Marco F, Perez RM, Pique JM. Reproducible test for detecting Helicobacter pylori in frozen samples. J Clin Pathol 1990; 43: 519. 4. Dent JC, McNulty CAM. Evaluation of a new selective medium for Campylobacter pylori. Eur J Clin Microbiol Infect Dis 1988; 7: 555-68. 5. Glupczynski Y, Burette A, de Koster E, et al. Metronidazole resistance in Helicobacter pylori. Lancet 1990; 335: 976-77.

Isolation of Helicobacter pylori from frozen gastric biopsy specimens.

253 slurred speech may have been explicable by an osmotic disturbance but this is a most unlikely explanation for her persisting paraplegia. Our repo...
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