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472-PA10 Molecular epidemiology of TB in South African gold mines
50
Tubercle and Lung Disease: Supplement 2
435-PA10 en 1995
Le RAI ~ P h n o m Penh et au Cambodge
Phuong, K.*, Norval, P-Y.**, Bakhim, T.*, San, K.K.*, Sovann, N.* *Ministkre de la Santg du Cambodge; **OMS
La premiere enquSte tuberculinique nationale du Cambodge a d6but6 en 1995, 1 an apr~s l'introduction progressive du traitement court. Une enqu&e tuberculinique compl6mentaire ~ Phnom Penh est compar6e h l'enquSte de 1968. Pr6s de 9.000 enfants ont 6t6 test6 en milieu scolaire par une IDR h la tuberculine (0,1 ml RT 23, 1 UI) avec lecture au 3 ° jour. L'6chantillonnage comprenait 30 grappes de 160 enfants h Phnom Penh et 30 grappes de 130 dans le reste du pays. 3 Provinces (6,5% de la population) ont 6t6 ot6es de la base de sondage pour raison de s6curit6. Le taux de scolarisation ~ 5 ans est de 85% en ville et 80% pour le pays. Le RAI est de 0,99% h Phnom Penh et pour le Cambodge. La courbe des r6actions chez les enfants non vaccin6s indique un premier mode ?a 2-3 mm, un antimode h 9 m m compatible avec l'6tude chez les tuberculoses positives et un second mode ~t 15 mm 7t Phnom Penh et 13 mm pour le pays. 4.251 enfants de 5 h 9 ans ont 6t6 test6s ~t Phnom Penh et 3.800 darts le reste du pays. Le sexe ratio est de 0,88 dans les 2 enqu~tes contre 1,01 en population de cet age. 26,7% des enfants de Phnom Penh n'avaient pas de cicatrice vaccinale BCG contre 44% dans le pays. 4.4% des enfants etaient absents au 3 ° jour h Phnom Penh contre 10% pour le pays. Le taux de notification des tuberculose BK+ en 1994 au Cambodge est 131 BK+/100.000 habitants, la tranche d'age 60-69 ans est la plus atteinte avec 696 BK+/100.000 habitants de 60 h 69 ans. La relation habituelle entre RAI et incidence tuberculose (1% = 50 nouveaux cas par 100.000 habitants) n'est pas applicable au Cambodge. L'atteinte anormalement 61ev6e des populations ag6es, pourrait expliquer la modification de cette relation. Le taux de d6pistage de la tuberculose ne peut 8tre calcul6. Dans une enquSte par sondange en population g6n6rale effectu6e en 1968 Phnom Penh parmi 3600 personnes (RT23 1 U1), le RAI etait de 2,7% chez les enfants non vaccin6s de 5-9 ans (85/461 IDR > 9mm). Le renouvellement total de la population de Phnom Penh aprSs la p6riode Khmer Rouge (1975-1979) rend difficile la comparaison du RAI de 1968 et de 1995.
439-PA10 La situation 6pid6miologique de la tuberculose au Tchad Baptiste, J.P., Morin, E., Norval, P.-Y., De Mane Nana, Mission Frangaise de Coopgration, N'Djamena, Tchad
La situation 6pid6miologique de la tuberculose au Tchad est mieux connue depuis que le Programme National Tuberculose (PNT) a mis en place un Registre de la Tuberculose par District en 1992. Avant 1988, on ne connaissait que les tuberculoses toutes formes pour l'ensemble du pays.
Le poster montre d'abord le taux de d6pistage des tuberculoses toutes formes depuis 1960. Apr~s l'effondremerit de la p6riode de guerre (1979 ?~ 1982), le taux de d6pistage rejoint progressivement le niveau de 1975 h 1978: sup6rieur h 50 tuberculoses toutes formes par 100 000 habitants par an. Le poster montre que 80% des mises en traitement sont faites darts six h6pitaux. Le poster compare le pourcentage des TPM+ mises au traitement et le taux de gudrison dans les districts avec ou sans chimioth6rapie de courte dur6e (CCD).
Conclusion: La lutte contre la tuberculose est revenue un niveau honorable au Tchad en 1995. Mais l'am61ioration du taux de d6pistage et du taux de gu6rison directement due au PNT n'est pas encore ddmontrable. Cependant l'analyse 6pid6miologique permet un choix de priorit6 pour le programme: la relance des activit6s potentiellement la plus efficace et rentable commence par les 6 grands h6pitaux du pays - correspondant aux 5 villes principales du pays.
472-PA10 Molecular epidemiology of TB in South African Gold Mines Godfrey-Faussett, P., Murray, J., Shearer, S., Bruce, M., Sonnenberg, P., Kambashi, B., Mee, C. Zambart Project, UTH, Lusaka; National Centre for Occupational Health, Johannesburg; Goldfields West Hospital, Westonaria, South Africa
Background: The incidence of TB in South African gold miners is among the highest recorded in any population (> l%/yr). Silicosis, crowding, migrant labour from areas of high prevalence and HIV infection are among the causes. Although a TB control policy is in place with adequate diagnostic and therapeutic resources and a directly observed treatment regimen, recurrent disease is common. In order to develop interventions to improve control, we are studying the molecular epidemiology of TB in the four mines served by one hospital. Methods: All isolates of M. tuberculosis from the mines between September and December 1994 have been DNA fingerprinted by standard methods. Prints have been scanned into a personal computer and compared using GelCompar software. Clusters of identical and closely related isolates have been reported back to the mine where employment and medical records have been reviewed to investigate epidemiological links between miners. Results: Among the first 100 isolates, 11 families of related isolates containing 8 clusters of identical isolates have been found. The largest cluster represents more than 10% of TB cases arising in the four mines and 11/ 13 individuals in the cluster worked together on a particular mine up to three years ago. In the next cluster, all 5 miners work in the same mine. Clustering is associated with employment history rather than with regional origin but more immediate risk factors have not yet been identified. At present, 35% of individuals have "clus-
Abstracts
tered" isolates but this proportion may rise as the study continues since the period of collection is short relative to the incubation period of TB.
Conclusions: A substantial amount of TB seen in the gold mines is caused by ongoing transmission. An infectious source (or sources) at an individual mine over the past few years has contributed significantly to the current burden of disease. Establishing the relative importance of ongoing transmission rather than reactivation of disease imported with migrant labour will allow more rational control measures to be developed.
471-PAl0
Genetic diversity among M. tuberculosis
in Zambia Bruce, M., Kambashi B., de Haas, P., Kahenya, G., GodfreyFaussett, P. Zambart Project, UTH, Lusaka and RIVM, Bilthoven
Background: DNA fingerprinting of M. tuberculosis has enhanced our understanding of the epidemiology of tuberculosis in Europe and the USA. In countries with a high prevalence of TB and little immigration, particular isolates may be expected to predominate. In order to explore the potential of DNA fingerprinting to address epidemiological questions in such a situation we have studied the diversity of strains within and between individuals in Zambia.
442-PA10
51
Tuberculosis morbidity in Lithuania
Gaidamoniene, D., Butkiene, P., Daniene, J., Slapkauskaite, D. Centre of Pulmonology and Tuberculosis, Vilnius, Lithuania
Till 1986 TB morbidity [MB] had a tendency to decrease, but from 1989 there was a progressive increase. If in 1989 morbidity was 37.4 per 100000 population, then in 1994 it had already increased up to 63.0 per 100000 population. TB MB in 1994 among adults, teenagers and children was 67.0/25.7/16.8 per 100000 according to the age groups. MB among countryside population is always higher than among the city population, and MB is twice higher among males than females. According to the age, the highest MB during year 1994 was: 30 to 39 years - 72.4, 40 to 49 years - 100.9, 50 to 59 years of age - 84.2 per 100000 population° The most commonly met TB form is TB of respiratory system. In 1994 it made 88.1%, while extrapulmonal TB was 11.9%. New TB cases of respiratory system in structure of clinical forms were as follows: infiltrative TB made 53.6%, disseminated lung TB 20.5%, focus forms 14.4%. New sputum positive cases among adults were 56.2%. Prevalence [Pr] of all TB forms in 1994 made 240.1 per 100000 population. Pr was 314.1 among adults, 39.8 among teenagers and 31.5 among children per 100000 population. Mortality from TB - 11.2 per 100000 population. Moreover, it was more common in the countryside than in the city.
Methods: DNA fingerprints were made in Lusaka using standard methods from three groups of specimens: I. Multiple individual colonies picked from the periphery of primary sputum isolates and subcultured; II. Multiple isolates from one episode in an individual; III. Isolates from different individuals. Fingerprints from groups I and II were compared in sets by visual inspection. Those from group III were scanned into a computer and analysed using GelCompar Software. Identical and nearly identical matches were reinspected visually to confirm the validity of the software's matching.
454-PA10 Tuberculin conversion among health care workers in a general hospital of Rio de Janeiro, Brasil. Preliminary results Bodchat, N., Muz~ de Souza, G., Cravo, R., Mellow, F., Viana, A., Nunes, Z., Oliveira, 0., Kritski, A. Rio de Janeiro, Brazil
Objective: To assess the tuberculin test (TT) conversion rate in a general hospital of Rio de Janeiro.
Methods: In February 1994 the two step TT was pro-
isolates - only one set showed mixed infection. II. 173 isolates from 83 patients were fingerprinted - one set showed mixed infection. III. Isolates from 115 individuals were fingerprinted. Three quarters of the isolates fall within one large family (which may represent a clade). However, two thirds of isolates are unique with no identical match among those so far examined. Almost all the isolates have had more than six copies of IS6110.
posed to the HCWs in our hospital. PPDRT23/Serum Institute- Denmark were performed by Ministry of Health trained nurse practitioners. Number of HCWs = 432:221 or 51% reactors, 1 lost and 210 nonreactors. In the last group, one week later another test was done. Booster phenomena occurred in 7 or 5% and 79 or 37% were lost. Those who failed to achieve at least 6 mm of increment over the initial reading sere considered as negatives ones, n = 124 or 59%. Among those 80 or 65% were retested 12 to 14 months thereafter.
Conclusions: It is surprisingly rare to find mixed infections within an individual in Zambia, despite the high prevalence of both TB and HIV. DNA fingerprinting with IS6110 is a robust tool and the copy number is high enough to draw reliable conclusions about relatedness in Zambia. Although there is much less heterogeneity between individuals than in Europe or the USA, it is still possible to define small clusters of identical fingerprints that may represent ongoing transmission.
Results: 74 or 92% of HCWs have persistent negative tests and 6 or 8% showed the conversion of TT, i.e. 10 mm of increase over the highest previous reading. The relationships between conversion and HCWs grouped by age (< 50 and > 50), occupation (contact with Tb patients x administrative personnel), work settings (wards and offices with Tb patients x administrative and services areas), community exposure to Tb (household contacts x no household contacts) were
Results: I. 293 colonies were picked from 81 primary
Tubercle and Lung Disease: Supplement 2
435-PA10 en 1995
Le RAI ~ P h n o m Penh et au Cambodge
Phuong, K.*, Norval, P-Y.**, Bakhim, T.*, San, K.K.*, Sovann, N.* *Ministkre de la Santg du Cambodge; **OMS
La premiere enquSte tuberculinique nationale du Cambodge a d6but6 en 1995, 1 an apr~s l'introduction progressive du traitement court. Une enqu&e tuberculinique compl6mentaire ~ Phnom Penh est compar6e h l'enquSte de 1968. Pr6s de 9.000 enfants ont 6t6 test6 en milieu scolaire par une IDR h la tuberculine (0,1 ml RT 23, 1 UI) avec lecture au 3 ° jour. L'6chantillonnage comprenait 30 grappes de 160 enfants h Phnom Penh et 30 grappes de 130 dans le reste du pays. 3 Provinces (6,5% de la population) ont 6t6 ot6es de la base de sondage pour raison de s6curit6. Le taux de scolarisation ~ 5 ans est de 85% en ville et 80% pour le pays. Le RAI est de 0,99% h Phnom Penh et pour le Cambodge. La courbe des r6actions chez les enfants non vaccin6s indique un premier mode ?a 2-3 mm, un antimode h 9 m m compatible avec l'6tude chez les tuberculoses positives et un second mode ~t 15 mm 7t Phnom Penh et 13 mm pour le pays. 4.251 enfants de 5 h 9 ans ont 6t6 test6s ~t Phnom Penh et 3.800 darts le reste du pays. Le sexe ratio est de 0,88 dans les 2 enqu~tes contre 1,01 en population de cet age. 26,7% des enfants de Phnom Penh n'avaient pas de cicatrice vaccinale BCG contre 44% dans le pays. 4.4% des enfants etaient absents au 3 ° jour h Phnom Penh contre 10% pour le pays. Le taux de notification des tuberculose BK+ en 1994 au Cambodge est 131 BK+/100.000 habitants, la tranche d'age 60-69 ans est la plus atteinte avec 696 BK+/100.000 habitants de 60 h 69 ans. La relation habituelle entre RAI et incidence tuberculose (1% = 50 nouveaux cas par 100.000 habitants) n'est pas applicable au Cambodge. L'atteinte anormalement 61ev6e des populations ag6es, pourrait expliquer la modification de cette relation. Le taux de d6pistage de la tuberculose ne peut 8tre calcul6. Dans une enquSte par sondange en population g6n6rale effectu6e en 1968 Phnom Penh parmi 3600 personnes (RT23 1 U1), le RAI etait de 2,7% chez les enfants non vaccin6s de 5-9 ans (85/461 IDR > 9mm). Le renouvellement total de la population de Phnom Penh aprSs la p6riode Khmer Rouge (1975-1979) rend difficile la comparaison du RAI de 1968 et de 1995.
439-PA10 La situation 6pid6miologique de la tuberculose au Tchad Baptiste, J.P., Morin, E., Norval, P.-Y., De Mane Nana, Mission Frangaise de Coopgration, N'Djamena, Tchad
La situation 6pid6miologique de la tuberculose au Tchad est mieux connue depuis que le Programme National Tuberculose (PNT) a mis en place un Registre de la Tuberculose par District en 1992. Avant 1988, on ne connaissait que les tuberculoses toutes formes pour l'ensemble du pays.
Le poster montre d'abord le taux de d6pistage des tuberculoses toutes formes depuis 1960. Apr~s l'effondremerit de la p6riode de guerre (1979 ?~ 1982), le taux de d6pistage rejoint progressivement le niveau de 1975 h 1978: sup6rieur h 50 tuberculoses toutes formes par 100 000 habitants par an. Le poster montre que 80% des mises en traitement sont faites darts six h6pitaux. Le poster compare le pourcentage des TPM+ mises au traitement et le taux de gudrison dans les districts avec ou sans chimioth6rapie de courte dur6e (CCD).
Conclusion: La lutte contre la tuberculose est revenue un niveau honorable au Tchad en 1995. Mais l'am61ioration du taux de d6pistage et du taux de gu6rison directement due au PNT n'est pas encore ddmontrable. Cependant l'analyse 6pid6miologique permet un choix de priorit6 pour le programme: la relance des activit6s potentiellement la plus efficace et rentable commence par les 6 grands h6pitaux du pays - correspondant aux 5 villes principales du pays.
472-PA10 Molecular epidemiology of TB in South African Gold Mines Godfrey-Faussett, P., Murray, J., Shearer, S., Bruce, M., Sonnenberg, P., Kambashi, B., Mee, C. Zambart Project, UTH, Lusaka; National Centre for Occupational Health, Johannesburg; Goldfields West Hospital, Westonaria, South Africa
Background: The incidence of TB in South African gold miners is among the highest recorded in any population (> l%/yr). Silicosis, crowding, migrant labour from areas of high prevalence and HIV infection are among the causes. Although a TB control policy is in place with adequate diagnostic and therapeutic resources and a directly observed treatment regimen, recurrent disease is common. In order to develop interventions to improve control, we are studying the molecular epidemiology of TB in the four mines served by one hospital. Methods: All isolates of M. tuberculosis from the mines between September and December 1994 have been DNA fingerprinted by standard methods. Prints have been scanned into a personal computer and compared using GelCompar software. Clusters of identical and closely related isolates have been reported back to the mine where employment and medical records have been reviewed to investigate epidemiological links between miners. Results: Among the first 100 isolates, 11 families of related isolates containing 8 clusters of identical isolates have been found. The largest cluster represents more than 10% of TB cases arising in the four mines and 11/ 13 individuals in the cluster worked together on a particular mine up to three years ago. In the next cluster, all 5 miners work in the same mine. Clustering is associated with employment history rather than with regional origin but more immediate risk factors have not yet been identified. At present, 35% of individuals have "clus-
Abstracts
tered" isolates but this proportion may rise as the study continues since the period of collection is short relative to the incubation period of TB.
Conclusions: A substantial amount of TB seen in the gold mines is caused by ongoing transmission. An infectious source (or sources) at an individual mine over the past few years has contributed significantly to the current burden of disease. Establishing the relative importance of ongoing transmission rather than reactivation of disease imported with migrant labour will allow more rational control measures to be developed.
471-PAl0
Genetic diversity among M. tuberculosis
in Zambia Bruce, M., Kambashi B., de Haas, P., Kahenya, G., GodfreyFaussett, P. Zambart Project, UTH, Lusaka and RIVM, Bilthoven
Background: DNA fingerprinting of M. tuberculosis has enhanced our understanding of the epidemiology of tuberculosis in Europe and the USA. In countries with a high prevalence of TB and little immigration, particular isolates may be expected to predominate. In order to explore the potential of DNA fingerprinting to address epidemiological questions in such a situation we have studied the diversity of strains within and between individuals in Zambia.
442-PA10
51
Tuberculosis morbidity in Lithuania
Gaidamoniene, D., Butkiene, P., Daniene, J., Slapkauskaite, D. Centre of Pulmonology and Tuberculosis, Vilnius, Lithuania
Till 1986 TB morbidity [MB] had a tendency to decrease, but from 1989 there was a progressive increase. If in 1989 morbidity was 37.4 per 100000 population, then in 1994 it had already increased up to 63.0 per 100000 population. TB MB in 1994 among adults, teenagers and children was 67.0/25.7/16.8 per 100000 according to the age groups. MB among countryside population is always higher than among the city population, and MB is twice higher among males than females. According to the age, the highest MB during year 1994 was: 30 to 39 years - 72.4, 40 to 49 years - 100.9, 50 to 59 years of age - 84.2 per 100000 population° The most commonly met TB form is TB of respiratory system. In 1994 it made 88.1%, while extrapulmonal TB was 11.9%. New TB cases of respiratory system in structure of clinical forms were as follows: infiltrative TB made 53.6%, disseminated lung TB 20.5%, focus forms 14.4%. New sputum positive cases among adults were 56.2%. Prevalence [Pr] of all TB forms in 1994 made 240.1 per 100000 population. Pr was 314.1 among adults, 39.8 among teenagers and 31.5 among children per 100000 population. Mortality from TB - 11.2 per 100000 population. Moreover, it was more common in the countryside than in the city.
Methods: DNA fingerprints were made in Lusaka using standard methods from three groups of specimens: I. Multiple individual colonies picked from the periphery of primary sputum isolates and subcultured; II. Multiple isolates from one episode in an individual; III. Isolates from different individuals. Fingerprints from groups I and II were compared in sets by visual inspection. Those from group III were scanned into a computer and analysed using GelCompar Software. Identical and nearly identical matches were reinspected visually to confirm the validity of the software's matching.
454-PA10 Tuberculin conversion among health care workers in a general hospital of Rio de Janeiro, Brasil. Preliminary results Bodchat, N., Muz~ de Souza, G., Cravo, R., Mellow, F., Viana, A., Nunes, Z., Oliveira, 0., Kritski, A. Rio de Janeiro, Brazil
Objective: To assess the tuberculin test (TT) conversion rate in a general hospital of Rio de Janeiro.
Methods: In February 1994 the two step TT was pro-
isolates - only one set showed mixed infection. II. 173 isolates from 83 patients were fingerprinted - one set showed mixed infection. III. Isolates from 115 individuals were fingerprinted. Three quarters of the isolates fall within one large family (which may represent a clade). However, two thirds of isolates are unique with no identical match among those so far examined. Almost all the isolates have had more than six copies of IS6110.
posed to the HCWs in our hospital. PPDRT23/Serum Institute- Denmark were performed by Ministry of Health trained nurse practitioners. Number of HCWs = 432:221 or 51% reactors, 1 lost and 210 nonreactors. In the last group, one week later another test was done. Booster phenomena occurred in 7 or 5% and 79 or 37% were lost. Those who failed to achieve at least 6 mm of increment over the initial reading sere considered as negatives ones, n = 124 or 59%. Among those 80 or 65% were retested 12 to 14 months thereafter.
Conclusions: It is surprisingly rare to find mixed infections within an individual in Zambia, despite the high prevalence of both TB and HIV. DNA fingerprinting with IS6110 is a robust tool and the copy number is high enough to draw reliable conclusions about relatedness in Zambia. Although there is much less heterogeneity between individuals than in Europe or the USA, it is still possible to define small clusters of identical fingerprints that may represent ongoing transmission.
Results: 74 or 92% of HCWs have persistent negative tests and 6 or 8% showed the conversion of TT, i.e. 10 mm of increase over the highest previous reading. The relationships between conversion and HCWs grouped by age (< 50 and > 50), occupation (contact with Tb patients x administrative personnel), work settings (wards and offices with Tb patients x administrative and services areas), community exposure to Tb (household contacts x no household contacts) were
Results: I. 293 colonies were picked from 81 primary