occasions.2,3 The sensitivity of this test on re-use was 96% and the
99%; the positive and negative predictive values were 98 9% and 97-2%, respectively.
data suggest that if more than 2 assays per
device are done the test time is longer, and therefore this use should be restricted to 2 samples per device. HIV-check is presently used many African countries in an effort to reduce the transmission of a deadly disease. From experience in Tanzania at least 40% of all previously used HIV-check devices can be re-used. Thus, for 50 000 HIV-checks purchased 20 000 can be re-used and about$US80 000 can be saved. Cost savings of 30-50% per sample
tested, if achievable, will help to ensure that all transfused blood is screened for HIV-1in developing countries, as is recommended by many AIDS control programmes. Department of Infectious and Tropical Diseases, 7440 University Hospital,
2200 Copenhagen N, Denmark
Department of Microbiology and Immunology, Muhimbili Medical Centre,
S. Y. MASELLE
Dar es Salaam, Tanzania
1 World Health Organisation. Report of the WHO-meeting on criteria for evaluation and standardisation of diagnostic tests for HIV antibody. Geneva: WHO,
nitrate and did not hydrolyse urea. In all patients, the Elek test and guineapig inoculation were negative. The four initial isolates of C diphtheriae were not distinguishable by electrophoresis of intracellular proteinss or with a ribosomal RNA gene probe
(unpublished results). Beta-haemolytic streptococci (group C) were isolated from only 1 of the 8 throat swabs. Two further, unconnected, patients were identified in the same period. One man was found to carry C diphtheriae variant belfanti and had been treated as an outpatient for persistent pharyngitis. Toxigenic C diphtheriae variant mitis was isolated from another patient, who had probably acquired it when travelling in India. He had presented with a mild pharyngitis and lymphadenopathy and had not been admitted to hospital. With the exception of the toxigenic strain, whether the C diphtheriae was responsible for pharyngitis or was a mere coloniser is not clear. However, its presence poses a potential risk to the population. We suggest that routine culture for the organism should still be done, especially for those who could be immunocompromised.
London WC1 E 6AU, UK
A. P. R. WILSON G. L. RIDGWAY R. N. GRUNEBERG
Streptococcal and Diphtheria Reference Unit, Central Public Health Laboratory, London
A. EFSTRATIOU G. COLMAN B. COOKSON
Department of Clinical Microbiology, University College and Middlesex Hospitals,
WHO/GPA/BMR./88.1. 2. Svendsen J, Faber V, Maselle SY, et al. Usefulness of simple tests for HIV-1 antibody in small hospitals in East Africa: Danish Department of International Development Cooperation. Report file no 104, Dan 8/432 (in press). 3. Spielberg F, Kabeya CM, Ryder RW, et al. Field testing and comparative evaluation of rapid, visually read screening assays for antibody to human immunodeficiency virus. Lancet 1989; i: 580-84.
EJ. Recognition of diphtheria. Lancet 1975; i: 1235-36. Pappenheimer AM. Diphtheria: studies on the biology of an infectious disease Harvey
1. Stokes 2
Lect 1982; 76: 45-73.
Routine screening for
SIR,—In the UK, there has been much debate over the need for routine cultures of throat swabs for diphtheria from patients with pharyngitis.Lack of staff and resources has led some laboratories to discontinue such routine screening. Of eleven London teaching hospital laboratories we telephoned, five cultured most or all throat swabs for Corynebacterinna diphtheriae, one only routinely screened children, and five looked for the organism only if the diagnosis was suspected clinically. Mass immunisation has resulted in the virtual disappearance of toxigenic C diphtheriae from the population, but might not have affected carriage of non-toxigenic strains.2 An outbreak of diphtheria has occurred lately in Scandinavia, where rates of immunisation are high but 19% of children and 50-70% of adults did not have protective levels of antitoxin.3Lysogenic conversion to toxin production might occur in vivo.’ In a susceptible population introduction of a toxigenic strain could result in direct spread by droplet infection or indirect spread by conversion of non-toxigenic C diphtheriae already carried in the pharyngeal flora.’ We report here the detection in eight patients of a non-toxin producing C diphtheriae among about 10 000 throat swabs cultured at University College Hospital between December, 1988, and September, 1990. The eight isolates were of an unusual type and possibly had a common source. All but one patient were homosexual, aged 19-44. Three were HIV positive. Presenting symptoms and signs were 1 week of mild to severe sore throat, and malaise and pharyngitis. The five patients treated responded to antibiotics. The first patient had a tonsillar exudate and cervical lymphadenopathy and was admitted to an infectious diseases unit until the strain was found not to produce toxin. The next three cases presented during two months but no connection could be found between them. Another patient was detected on routine culture and forty-eight of his respiratory contacts were negative on screening. However, his partner proved to carry the organism. He had noticed a sore throat 4 days previously; his urethral and rectal cultures were negative. Two other patients presented with symptoms related to oral/genital sex. The corynebacteria produced small domed colonies with a smooth edge on tellurite agar, were non-haemolytic on blood agar, and showed a brown halo on ’I’insdale’s medium. They were unusual in that they produced acid from glucose, glycogen, dextrin, and starch but not from maltose. They reduced
3. Rappuoli R, Perugini M, Falsen E. Molecular epidemiology of the 1984-1986 outbreak of diphthena in Sweden. N Engl JMed 1988; 318: 12-14. 4 Pappenheimer AM, Murphy JR Studies on the molecular epidemiology of diphtheria. Lancet 1983; ii: 923-26. 5. Hallas G. The use of SDS-polyacrylamide gel electrophoresis in epidemiological studies of Corynebacterium diphtheriae Epidemiol Infect 1988; 100: 83-90
Sudden infant death
SIR,-My interest in sudden infant death syndrome (SIDS) has focused on apparent variations in incidence among different ethnic groups. It is well known that North American Chinese have the lowest incidence and North American native Indians the highest. An unusually high incidence of SIDS occurs amongst the native Indians of Alberta, Canada, who recorded 55 deaths from SIDS between 1982 and 1986 (out of a provincial total of 430 SIDS deaths), while there was only 1 Chinese SIDS death. Native Indians and Chinese each make up just under 2% of the provincial population. While Albertan Indians have had major changes in life-style, Albertan Chinese have maintained many of their traditions, particularly with respect to infant care. During the summer of 1989, I visited the Chinese city of Guangzhou (Canton) to determine if, indeed, North American Chinese were using traditional infant care practices. Guangzhou is the ancestral home of many North American Chinese. I also wanted to gather data on the incidence of SIDS in the People’s Republic of China, since this information is not available. The records of 1100 births showed the virtual absence of risk factors for SIDS, such as underweight or premature infants and teenaged mothers. Smoking among women (another significant risk factor) appears virtually non-existent (it is regarded as culturally unacceptable for women of reproductive age in China). Interviews with 40 mothers showed that mother, father, and baby sleeping in the same bed is the norm. Further, there is a high level of tactile contact with the baby. Babies are usually carried in the mother’s arms or in a sling. At seminars attended by some 250 clinicians, including paediatricians and gynaecologists, it became apparent that doctors in south China were virtually unaware of SIDS. A handful of physicians suggested that they may have seen cases that fitted the syndrome. However, it was clear that, after an exhaustive description of the syndrome, SIDS was not widespread in Guangzhou. One could argue that SIDS exists, but goes undiagnosed through ignorance. However, the fact that a few physicians acknowledged seeing cases that might fit the
syndrome, suggests that the mainland Chinese incidence of SID S is similar to the low rate in North American Chinese. Clearly, more work is needed to explain the lack of awareness of the syndrome in China, and confirm that the Chinese do have the lowest incidence of SIDS.
Funding for field work in China was provided by the International Health Exchange Program, under the sponsorship of the Canadian Public Health Association and the Canadian Society for International Health, and supported by the International Development Research Centre. Department of Anthropology, University of Calgary,
Calgary, Alberta, Canada T2N
Electrocardiogram changes in localised myocardial injury by bullet SIR,-Fox et aP reported electrocardiograms (ECG) of several patients with old non-penetrating injuries to the chest that affected the heart. We describe here the ECG findings in a patient whose heart continued to beat for 15 h after a gunshot wound to the heart. A 41 -year-old man was shot from the back through the chest by a pistol (Colt, 0-38 in, 1 cm). He was immediately taken to hospital, where he remained conscious for 4 h. He died from massive
haemorrhage 15 h after admission. Necropsy revealed nonpenetrating localised myocardial laceration. The bullet had entered from the left 11 th intercostal area and exited from the left anterior chest. The diaphragm, stomach, transverse colon, pericardium, and left lung were also damaged, and there was 800 ml of fresh blood in the left thorax. The injury, on the anterolateral site of the left ventricle, measured 53 by 26 cm, 4-5 cm above the apex and at the distal end of the obtuse marginal branch of the circumflex artery (left coronary artery) (fig 1). The damaged myocardium weighed 3-4 g. The entire thickness of the myocardium proved to be damaged, with moderate bleeding around the injury (8-5 by 7-5 cm), muscle necrosis, and black gunshot powder. Thus the injury seemed transmural but non-penetrating. Microscopy revealed diffuse and severe acute necrosis of the muscle cells, with bleeding and lead powder. Neutrophil, lymphocyte, and macrophage infiltration occurred mainly at the margins of the necrotic tissue. No other findings suggestive of arteriosclerosis of the coronary artery, old infarction, or acute infection were demonstrated. The muscle layer in the right ventricle was histologically normal. ECGs (fig 2), obtained 1’5,2, and 4 h after the shooting, showed an acute left anterolateral myocardial infarction-like pattern with a
Fig 2-ECG of patient with localised myocardial injury lacerated by bullet (1’5 h after injury).
regular sinus rhythm (ST elevation in I, II, aVL, and V3 Vb leads, reciprocal ST depression in III, aVR, and Vi, and pathological Q waves in I, aVL, and V4). Most bullet injuries of the heart are penetrating and account for most of the early deaths. In this patient, however, the heart continued to beat for 15 h despite the massive myocardial damage. In sudden death due to myocardial infarction there are no visible changes, whereas remarkable changes were seen in our patient. The ST segment elevation was assumed to be due to the injury to the myocardial surface rather than secondary myocardial ischaemia because of injury to the coronary artery. Kurume
Department of Legal Medicine, University School of Medicine, Kurume, Fukuoka 830, Japan
HIROSHI KIMURA YOHKO ITO
Department of Surgery, Omuta City Hospital, Fukuoka
Department of Medical Information Science, Osaka
Medical School, Osaka
KM, Rowland E, Krikler DM, Bentall HH, Goodwin JF. Electrophysiological manifestations of non-penetrating cardiac trauma. Br Heart J 1980; 43: 458-62.
Self-experimentation SIR,-Dr Forrester’s excellent article (Sept 29, p 798) calls to mind the time when Prof Giles Brindley entered the pantheon of US urological folk heroes. At the 1983 meeting of the American Urological Association in the naughty city of Las Vegas, he lectured on pharmacological erection. The audience was hardly prepared for him to step out from behind the lectern to demonstrate personally the effect such injections have. This is not his only self-experiment. He has implanted sensors into the scrota of paraplegic patients to measure testis temperature. Since he wished to learn what happens under conditions of running exercise, something he could not ask of the patients, he had himself implanted.1 The back-to-back juxtapostion in the same issue of the Klinische Wochenschrift of Forssmann’s cardiac catheterisation article with von Lichtenberg and Swick’s paper describing the clinical testing of the first practical intravenous contrast mediumz seems to me extraordinary. The moral seems to be that self-experimentation does not guarantee a Nobel prize, although it worked for Forssmann. 33 East 74th Street, New York, NY 10021, USA
Fig 1-Heart with localised injury lacerated by bullet.
ADRIAN W. ZORGNIOTTI
Brindley GS. Deep scrotal temperature and the effect of it on clothing,airtemperature, activity, posture and paraplegia. Br J Urol 1982; 54: 49-55. 2. von Lichtenberg A, Swick M. Klinische prufung des uroselectans. Klin Wochenschr 1929; 45: 2089-91.