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SEROTYPES OF CHLAMYDIA TRACHOMATIS IN THE GAMBIA
452
positive for morphine. Of these, 349 were also positive for methadone, including 236 samples where this drug was known to have been prescribed. Thus 113 samples containing illicit heroin also contained unprescribed methadone. A separate analysis of the 5000 samples revealed 1361 records (representing about 361 patients) where methadone was known to have been prescribed, excluding patients who had been prescribed heroin and methadone together. Of these, 234 were positive for morphine, 67 for dihydrocodeine, 36 for dextropropoxyphene, 19 for cocaine, 158 for amphetamine (including 2 where this was prescribed), and 6 for pethidine. 139 of these 1361 samples were tested for benzodiazepines, and 75 were positive (only 13 of these being known prescriptions). 54 were tested for cannabis, and 19 were positive. This survey supports the contention that patients receiving prescriptions for methadone continue to abuse illicit drugs and that prescribed methadone is itself abused. It thus appears that prescribed methadone is circulated at street-level in south-east London, if not in Liverpool. We thank Dr R. Caldwell and Dr B. Widdup for providing data from New Cross Poisons Unit.
Guy’s Hospital,
M. S.
London SE1 9RT Middlesex Hospital Medical School, London W1
LIPSEDGE
C. C. H. COOK
1. Dobbs WH. Methadone treatment of heroin addicts. JAMA 1971; 218: 1536-41. 2. Hartnoll RL, Mitcheson MC, Battersby A, et al. Evaluation of heroin maintenance in
controlled trial. Arch Gen Psychiat 1980; 37: 877-84. 3. Kosten TR, Rounsaville BJ, Kleber HD. A
25-year follow-up of cocaine use among treated opioid addicts. Arch Gen Psychiat 1987; 44: 281-84. 4. Gossop M. A review of the evidence for methadone maintenance as a treatment for narcotic addiction. Lancet 1978; i: 812-15. 5. Lipsedge MS, Cook CCH. Prescribing for drug addicts. Lancet 1987; i: 1265. 6. Marks J. Prescribing for drug addicts. Lancet 1987; ii: 46.
SEROTYPES OF CHLAMYDIA TRACHOMATIS IN THE GAMBIA
SIR,-Whereas most genital and neonatal isolates of Chlamydia trachomatis belong to serotypes D-K, strains isolated from cases of trachoma are of serotypes A-C.’ Few genital isolates have been serotyped from areas in which trachoma is endemic. Do these differences reflect a distinct tropism of serotypes A-C for the eye, or merely the absence of circulating serotypes D-K in trachoma endemic areas? Trachoma is endemic in rural areas of The Gambia. Some years ago 4 Gambian trachoma isolates were serotyped; 2 were serotype B, 1 was serotype A, and interestingly 1 was serotype D. Isolates from an infant with ophthalmia and its father’s urethra 2 were also typed; both were serotype F. We report here the serotypes of 21 further chlamydial isolates from The Gambia-10 from infants with ophthalmia neonatorum, 10 from genital tract infections, and 1 from a case of trachoma. We also report the results of serology against single serotype antigens in 30 subjects from the village of Jali, in which trachoma is endemic. Isolates were serotyped according to the method of Wang et al.3 Sera from trachoma patients were tested conventionally by microimmunofluorescence against egg-grown single serotype antigens. Table i shows the serotypes of 21 isolates and table u shows the serotype specific serum antibodies in 30 village residents. These fmdings indicate that,although serotypes D-K are prevalent genital tract pathogens in The Gambia, they are not TABLE I-SEROTYPES OF GAMBIAN ISOLATES OF CHLAMYDIA
TRACHOMATIS
*U
=
uncertain
TABLE II-SERUM ANTICHLAMYDIAL ANTIBODIES IN 30 VILLAGE RESIDENTS
Antibody titres ranged from 1/32 to 1/256. *Ref 5; tU =
uncertain
associated with trachoma. It is not clear why this should be, since trachoma has been induced in volunteers by repeated inoculation with D-K serotypes.4 Further work is needed to establish the reason for the distinct tropism of the "genital" and "trachoma" serotypes of C trachomatis. MRC
Laboratories,
Fajara, The Gambia
D. C. W. MABEY
National Institute for Biological Standards and Control, London
T. FORSEY
Institute of Ophthalmology, London
J. D. TREHARNE
1. Schachter J, Dawson CR. Human chlamydial infections. Littleton, Mass: PSG, 1978. 2. Wang SP, Grayston JT. Classification of TRIC and related strains with
microimmunofluorescence. In. Nichols RL, ed. Trachoma and related disorders. Amsterdam: Excerpta Medica, 1978: 305-21. 3. Wang SP, Kuo CC, Grayston JT. A simplified method for immunological typing of trachoma- inclusion conjunctivitis-lymphogranuloma venereum organisms. Infect Immun 1973; 7: 356-60. 4. Jones BR, Collier LH. Inoculation of man with inclusion blenorrhea virus. Ann NY Acad Sci 1962; 98: 212-28. 5. Forsey T, Darougar S, Treharne JD. Prevalence in man of antibodies to an atypical chlamydial strain: Chlamydia IOL 207. J Infect 1986; 12: 145-52.
REGIONAL FINDINGS IN METSOVO LUNG
SIR,-Pleural calcification (PC), observed among inhabitants of Metsovo and three adjacent villages in northwest Greece, is causally related to the inhalation of asbestiform tremolite fibre in the environment.’ We have also found a high incidence of malignant pleural mesothelioma (MPM) in the same areaThe source of the asbestiform tremolite was found to be a soil widely used before 1950 for interior whitewashing ("luLo" soil).3 Chest X-ray of a large group (more than 800) from Metsovo shows 46% of films with evidence of pleural disease. Again there is no sex or occupational factor; rather the incidence of PC increases with age. 81 % of adults over the age of 70 show X-ray evidence of calcified pleural plaques. We had difficulties explaining the lack of PC in some elderly Metsovites who had used and presumably had been exposed to the contents of the whitewash for decades. Chest X-ray is an insensitive diagnostic technique in cases of incipient forms of disease.’ tomography was used on 16 X-ray negative subjects born in Metsovo before 1940. All the scans showed evidence ofPC. Since 1970, some 500 Metsovites have emigrated to Trikala, a town on the plains of Thessaly, distant from Metsovo. We obtained chest X-rays on 71 of these people and found PC in 50 (70%). The age distribution and prevalence character of the PC were identical to those encountered in Metsovo,6reinforcing the impression that the causative agent was asbestiform mineral fibre, with exposure taking place early in life in Metsovo. The geology of Thessaly precludes environmental exposure to asbestiform fibre, further lending support to our hypothesis. The similarity of this finding to the description of MPM among Turkish workers in Sweden, who emigrated from Karain, Turkey, is striking. In these cases, exposure was to erionite, a fibrous zeolite, which is contained in the local rocks and soils of Karain. The emigrees were exposed early in life in Karain and the disease developed elsewhere, after migration. Many villages in the mountainous areas of Greece (eg, Epirus in northwest Greece) also used similar whitewashes before about 1940. We have recently found four more areas in northwest Greece where PC occurs in the population. Examination of these populations, a search for MPM, and mineralogical evaluation of soils and whitewashes is now being done. Metsovo lung appears common in this region of Greece. We consider all the Balkan States, those which have the Dinaric Alps as mountainous highlands along the Adriatic coast, as a region
Computerised
positive for morphine. Of these, 349 were also positive for methadone, including 236 samples where this drug was known to have been prescribed. Thus 113 samples containing illicit heroin also contained unprescribed methadone. A separate analysis of the 5000 samples revealed 1361 records (representing about 361 patients) where methadone was known to have been prescribed, excluding patients who had been prescribed heroin and methadone together. Of these, 234 were positive for morphine, 67 for dihydrocodeine, 36 for dextropropoxyphene, 19 for cocaine, 158 for amphetamine (including 2 where this was prescribed), and 6 for pethidine. 139 of these 1361 samples were tested for benzodiazepines, and 75 were positive (only 13 of these being known prescriptions). 54 were tested for cannabis, and 19 were positive. This survey supports the contention that patients receiving prescriptions for methadone continue to abuse illicit drugs and that prescribed methadone is itself abused. It thus appears that prescribed methadone is circulated at street-level in south-east London, if not in Liverpool. We thank Dr R. Caldwell and Dr B. Widdup for providing data from New Cross Poisons Unit.
Guy’s Hospital,
M. S.
London SE1 9RT Middlesex Hospital Medical School, London W1
LIPSEDGE
C. C. H. COOK
1. Dobbs WH. Methadone treatment of heroin addicts. JAMA 1971; 218: 1536-41. 2. Hartnoll RL, Mitcheson MC, Battersby A, et al. Evaluation of heroin maintenance in
controlled trial. Arch Gen Psychiat 1980; 37: 877-84. 3. Kosten TR, Rounsaville BJ, Kleber HD. A
25-year follow-up of cocaine use among treated opioid addicts. Arch Gen Psychiat 1987; 44: 281-84. 4. Gossop M. A review of the evidence for methadone maintenance as a treatment for narcotic addiction. Lancet 1978; i: 812-15. 5. Lipsedge MS, Cook CCH. Prescribing for drug addicts. Lancet 1987; i: 1265. 6. Marks J. Prescribing for drug addicts. Lancet 1987; ii: 46.
SEROTYPES OF CHLAMYDIA TRACHOMATIS IN THE GAMBIA
SIR,-Whereas most genital and neonatal isolates of Chlamydia trachomatis belong to serotypes D-K, strains isolated from cases of trachoma are of serotypes A-C.’ Few genital isolates have been serotyped from areas in which trachoma is endemic. Do these differences reflect a distinct tropism of serotypes A-C for the eye, or merely the absence of circulating serotypes D-K in trachoma endemic areas? Trachoma is endemic in rural areas of The Gambia. Some years ago 4 Gambian trachoma isolates were serotyped; 2 were serotype B, 1 was serotype A, and interestingly 1 was serotype D. Isolates from an infant with ophthalmia and its father’s urethra 2 were also typed; both were serotype F. We report here the serotypes of 21 further chlamydial isolates from The Gambia-10 from infants with ophthalmia neonatorum, 10 from genital tract infections, and 1 from a case of trachoma. We also report the results of serology against single serotype antigens in 30 subjects from the village of Jali, in which trachoma is endemic. Isolates were serotyped according to the method of Wang et al.3 Sera from trachoma patients were tested conventionally by microimmunofluorescence against egg-grown single serotype antigens. Table i shows the serotypes of 21 isolates and table u shows the serotype specific serum antibodies in 30 village residents. These fmdings indicate that,although serotypes D-K are prevalent genital tract pathogens in The Gambia, they are not TABLE I-SEROTYPES OF GAMBIAN ISOLATES OF CHLAMYDIA
TRACHOMATIS
*U
=
uncertain
TABLE II-SERUM ANTICHLAMYDIAL ANTIBODIES IN 30 VILLAGE RESIDENTS
Antibody titres ranged from 1/32 to 1/256. *Ref 5; tU =
uncertain
associated with trachoma. It is not clear why this should be, since trachoma has been induced in volunteers by repeated inoculation with D-K serotypes.4 Further work is needed to establish the reason for the distinct tropism of the "genital" and "trachoma" serotypes of C trachomatis. MRC
Laboratories,
Fajara, The Gambia
D. C. W. MABEY
National Institute for Biological Standards and Control, London
T. FORSEY
Institute of Ophthalmology, London
J. D. TREHARNE
1. Schachter J, Dawson CR. Human chlamydial infections. Littleton, Mass: PSG, 1978. 2. Wang SP, Grayston JT. Classification of TRIC and related strains with
microimmunofluorescence. In. Nichols RL, ed. Trachoma and related disorders. Amsterdam: Excerpta Medica, 1978: 305-21. 3. Wang SP, Kuo CC, Grayston JT. A simplified method for immunological typing of trachoma- inclusion conjunctivitis-lymphogranuloma venereum organisms. Infect Immun 1973; 7: 356-60. 4. Jones BR, Collier LH. Inoculation of man with inclusion blenorrhea virus. Ann NY Acad Sci 1962; 98: 212-28. 5. Forsey T, Darougar S, Treharne JD. Prevalence in man of antibodies to an atypical chlamydial strain: Chlamydia IOL 207. J Infect 1986; 12: 145-52.
REGIONAL FINDINGS IN METSOVO LUNG
SIR,-Pleural calcification (PC), observed among inhabitants of Metsovo and three adjacent villages in northwest Greece, is causally related to the inhalation of asbestiform tremolite fibre in the environment.’ We have also found a high incidence of malignant pleural mesothelioma (MPM) in the same areaThe source of the asbestiform tremolite was found to be a soil widely used before 1950 for interior whitewashing ("luLo" soil).3 Chest X-ray of a large group (more than 800) from Metsovo shows 46% of films with evidence of pleural disease. Again there is no sex or occupational factor; rather the incidence of PC increases with age. 81 % of adults over the age of 70 show X-ray evidence of calcified pleural plaques. We had difficulties explaining the lack of PC in some elderly Metsovites who had used and presumably had been exposed to the contents of the whitewash for decades. Chest X-ray is an insensitive diagnostic technique in cases of incipient forms of disease.’ tomography was used on 16 X-ray negative subjects born in Metsovo before 1940. All the scans showed evidence ofPC. Since 1970, some 500 Metsovites have emigrated to Trikala, a town on the plains of Thessaly, distant from Metsovo. We obtained chest X-rays on 71 of these people and found PC in 50 (70%). The age distribution and prevalence character of the PC were identical to those encountered in Metsovo,6reinforcing the impression that the causative agent was asbestiform mineral fibre, with exposure taking place early in life in Metsovo. The geology of Thessaly precludes environmental exposure to asbestiform fibre, further lending support to our hypothesis. The similarity of this finding to the description of MPM among Turkish workers in Sweden, who emigrated from Karain, Turkey, is striking. In these cases, exposure was to erionite, a fibrous zeolite, which is contained in the local rocks and soils of Karain. The emigrees were exposed early in life in Karain and the disease developed elsewhere, after migration. Many villages in the mountainous areas of Greece (eg, Epirus in northwest Greece) also used similar whitewashes before about 1940. We have recently found four more areas in northwest Greece where PC occurs in the population. Examination of these populations, a search for MPM, and mineralogical evaluation of soils and whitewashes is now being done. Metsovo lung appears common in this region of Greece. We consider all the Balkan States, those which have the Dinaric Alps as mountainous highlands along the Adriatic coast, as a region
Computerised