Tuberculin response two years after BCG vaccination at birth.

Grindulis, H; Baynham, M. I. D.; Scott, Peter; Thompson, R. A.; Wharton, B A

doi:10.1136/adc.59.7.614

Cited by 60 publications

(42 citation statements)

References 12 publications

(1 reference statement)

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“…36 Some discrepancy between effective BCG vaccination and presence of a scar is to be expected, as scars are not invariably present among all vaccinees. 37 Thus, in The Gambia, a scar was found in only 71% of children aged 0 to 9 years with a health-card record of a vaccination. 18 In the Canadian study, 17% of subjects with a record of past BCG vaccination showed no visible scar.…”

Section: Discussionmentioning

confidence: 99%

Risk Factors for Tuberculosis Infection in Children in Contact With Infectious Tuberculosis Cases in The Gambia, West Africa

et al. 2003

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ABSTRACT. Objective. Tuberculosis (TB) infection is highly prevalent in developing countries. As infected children represent a large proportion of the pool from which TB cases will arise, knowledge of the factors that influence TB infection in children are of importance to evaluate transmission of infection in the community and adapt TB control activities. There are limited data on the risk of infection in child populations in developing countries.Methods. We performed a household contact study in The Gambia (West Africa), in which children who were living in contact with individuals who had proven smearpositive pulmonary TB cases were investigated. A questionnaire was addressed to the mother or caregiver of the child to investigate the presence of various risk factors and assess the degree of exposure of the child to the individual with TB within the household. A tuberculin skin test (TST) was performed on each child. TST sizes >5 and 10 mm, respectively, were considered positive.Results. Households of 206 TB cases were visited, and 384 children aged <5 years were examined. The median age was 2, and 48% were girls. The distribution of TST responses followed a bimodal pattern, with 135 (35%) children presenting a palpable induration. Random effects logistic regression analysis demonstrated that the risk of positive TST response in the child increased with the geographic proximity of the child to the individual with TB within the household and with the degree of activities shared with the individual with TB. It was also associated with the clinical severity of the disease in the index case. Nutritional status and presence of a bacille Calmette-Guérin (BCG) scar were not independent risk factors for TST positivity in this population. On multivariate analysis, the effect of geographic proximity to the individual with TB, household size, and duration of cough in the index case persisted for TST responses >5 mm.Conclusions. In a highly endemic country with high BCG vaccination coverage in Africa, TB infection in children who were in contact with individual with infectious TB was directly related to the intensity of exposure of the child to the individual with TB. Our data suggest that a positive TST in a child reflects most probably TB infection rather than previous BCG vaccination. Contact I n 1995, the World Health Organization estimated that at least 180 million children under the age of 15 years were infected with Mycobacterium tuberculosis worldwide and that nearly 170 000 children died of tuberculosis (TB). 1,2 TB infection and disease among children are much more prevalent in developing countries, where resources for TB control are scarce, than in industrialized countries. 3 However, despite the public health importance of the disease, TB is rarely investigated in children, as the diagnosis is difficult in the young age groups and children are usually not infectious. 4 In addition, contact tracing is rarely done in nonindustrialized countries because of lack of resources, and Isoniazid prophylaxis is not sys...

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Section: Discussionmentioning

confidence: 99%

Risk Factors for Tuberculosis Infection in Children in Contact With Infectious Tuberculosis Cases in The Gambia, West Africa

et al. 2003

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“…7 However, the sensitivity of the BCG scar as an index of vaccination status is still the subject of controversy. 6 Failure to form a scar may be related to factors such as lack of maturation of the immune system, 8 faulty technique, or use of a nonpotent vaccine. 9 In Peru, intradermal administration of BCG is given at birth at any health facility, such as a hospital or health post.…”

mentioning

confidence: 99%

A Prospective Study of Bacillus Calmette-Guérin Scar Formation and Tuberculin Skin Test Reactivity in Infants in Lima, Peru

Santiago¹,

Lawson²,

Gillenwater³

et al. 2003

Pediatrics

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ABSTRACT. Objectives. To determine the sensitivity of the bacillus Calmette-Guérin (BCG) scar as an indicator of previous vaccination and to ascertain the tuberculin skin test (TST) response in infancy after vaccination in a community from an area hyperendemic for tuberculosis (TB).Methods. In a birth cohort of healthy term infants from Lima, Peru, a single dose of BCG vaccine was administered within the first month of life. Scar formation was assessed biweekly during the first 6 months and again at 3 years after vaccination. TST response was evaluated 6 months after vaccination.Results. Six months after vaccination, 99% (68) of the newborns exhibited a BCG scar (>2 mm). Scar size did not differ by sex, birth weight, age at vaccination, or nutritional status in the first 2 months. Eighty percent of the participants were found 3 years after vaccination, and all of them had a BCG scar. Mean TST reaction size 6 months after vaccination was 2.9 ؎ 0.3 mm. No association was found between sex or age at BCG vaccination and TST size. Only 3 children had a TST >10 mm, and the 3 had a TB contact at home.Conclusions. The BCG scar was a sensitive indicator of vaccination status up to 3 years after the administration of the vaccine in the first month of life. Although nearly a quarter of the children had a TST response >5 mm 6 months after vaccination, TST reactions >10 mm did not occur in the absence of exposure to a person with tuberculosis. A cutoff of 10 mm should be used for disease control purposes in people who are born in countries where TB is endemic. The presence or absence of a BCG scar is often used as an indicator of previous vaccination in clinical settings as well as surveys performed by health institutions such as the Expanded Program on Immunization to assess vaccine uptake. 7 However, the sensitivity of the BCG scar as an index of vaccination status is still the subject of controversy. 6 Failure to form a scar may be related to factors such as lack of maturation of the immune system, 8 faulty technique, or use of a nonpotent vaccine. 9 In Peru, intradermal administration of BCG is given at birth at any health facility, such as a hospital or health post. This is part of the regular immunization program following WHO guidelines. 10 Since 1991, the same strain of BCG has been used across the country. In 2000, the estimated incidence of active pulmonary TB in Peru was 111 cases per 100 000, 11 but in one area, it has been reported to be 364 per 100 000 12 despite 95% coverage of BCG vaccination at birth and a human immunodeficiency virus prevalence of Ͻ0.5%. 11 In countries with such a high TB incidence, diagnostic algorithms include the tuberculin skin test (TST) as a screening tool, particularly in children. 13,14 It has been shown that the BCG may affect the TST by factors such as strain and dose, 15 number of vaccines administered, 16,17 time since vaccination, 18 age and nutritional status, 19 and method of vaccine administration. 20 However, the scope of these effects is unclear. Therefore, for the TST to...

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“…5,6,16 No entanto, devemos, ainda, considerar que em uma população como a nossa, com elevada prevalência de tuberculose, a efetividade da vacina BCG, no período neonatal, pode ser questionada, uma vez que pode sofrer influência da imunidade passiva adquirida por via transplacentária. 8,17,18 Este trabalho reforça, pelos resultados encontrados, a idéia de que a utilização da vacina BCG nos primeiros meses de vida não prejudica a utilidade do teste de Mantoux, em maiores de 2 anos de idade, no diagnóstico de tuberculoseinfeccção. Dessa forma, o teste tuberculínico pode ser válido para o diagnóstico de tuberculose-infecção em crianças maiores de 2 anos de idade, mesmo que tenham recebido vacina BCG no período neonatal.…”

Section: Discussionunclassified

“…É um método bastante questionado, pois acredita-se que a hipersensibilidade cutânea por vacina BCG seja fugaz, enquanto a possí-vel imunidade conferida seja de caráter duradouro 5 . Trabalhos que avaliam o teste tuberculínico pós-vacinal utilizando PPD derivado do Mycobacterium tuberculosis na dose de 2 a 5 UT demonstram uma positividade de 50% a 90% três a seis meses após a aplicação da vacina BCG, viragem esta que diminui progressivamente em função do tempo 6,7,8 .…”

Section: Introductionunclassified

Can the Mantoux test be used in BCG vaccined children?

Sarinho

Filho²,

Silva³

1994

J Pediatr (Rio J)

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ResumoO estudo prospectivo foi realizado com teste tuberculínico de Mantoux em 371 crianças eutróficas que haviam sido vacinadas com BCG no primeiro mês de vida, e realizada a leitura entre 48 e 72 horas após a aplicação.Não houve diferença significante (x 2 = 2,174 p>0,05) de resposta ao teste tuberculíneo entre as 59 crianças sem vacina BCG (grupo de controle) e as 180 crianças vacinadas, considerando-se as menores de 6 anos.Quando a avaliação foi feita por faixa etária, verificou-se que aos 2 anos de idade apenas 36,36% das crianças vacinadas foram reatoras. J. Pediatr. (Rio AbstractThis prospective trial was realized in 371 children previously vaccinated with BCG in the first month of life in whom the Mantoux tuberculin test was done and read 48-72 hours afterwards. Among 371 BCG-vaccinated children, 106 (28,57%) were Mantoux reactive, 10 of whom with clinical tuberculosis.There was no statistically significant difference in the tuberculin test between the control group (59 non-BCG-vaccinated children) and 180 vaccinated children, considering those under 6 years old.When we compared by age, we verified that just 36,36% of the children at the age 2 reacted positively to PPD. J. Pediatr. (Rio). 1994; 70(2):91-94: tuberculosis, Mantoux test, BCG.Emanuel S. C. Sarinho, Antônio S. Aguiar Filho, Almerinda M. R. Silva Introdução A tuberculose continua sendo um grave problema de saúde pública. Anualmente, aparecem 4 milhões de novos casos de bacilíferos no mundo e 2 a 3 milhões de pacientes existentes evoluem para o óbito 1 . Na Holanda o risco de infecção diminuiu 14% anualmente entre 1958 e 1965, enquanto que em Uganda, no mesmo período, essa diminuição foi de apenas 1,4%. Em 5 anos a tuberculose deixou de ser problema de saúde pública na Holanda, ao passo que em Uganda, se persistir com este decréscimo anual, a doença só será erradicada após meio século 1 .A tuberculose se comporta de maneira diferente em países pobres e ricos. Entre as inúmeras características do subdesenvolvimento, podem-se citar algumas relacionadas à doença, tais como menor diminuição dos coeficientes de mortalidade apesar de quimioterapia eficaz, pico representativo da curva de mortalidade em faixa etária mais jovem, primeira exposição ao bacilo de Koch em idade precoce, elevada prevalência, além de maior falha de diagnóstico e abandono de tratamento 1,2 .Estima-se que a prevalência de casos de tuberculose ativa no Brasil alcance 120.000 doentes, e que, atualmente, descobrem-se apenas 75% dos casos esperados da doença, dos quais apenas 80% são curados 3 .As crianças são mais vulneráveis e apresentam maior probabilidade de adquirir formas graves, como a miliar e a meningoencefalia, tendo maior risco de seqüelas e êxito letal. Infelizmente, como contraponto, na infância, a tuberculose freqüentemente é paucibacilar e, por conta disso, a bacterioscopia e a cultura do espécimen obtido geralmente são negativas. Em decorrência desse fato, um método adicional de grande valor, por fornecer subsídios para o reconhecimento de tuberculose-infecção, é o...

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Tuberculin response two years after BCG vaccination at birth.

Cited by 60 publications

References 12 publications

Risk Factors for Tuberculosis Infection in Children in Contact With Infectious Tuberculosis Cases in The Gambia, West Africa

Risk Factors for Tuberculosis Infection in Children in Contact With Infectious Tuberculosis Cases in The Gambia, West Africa

A Prospective Study of Bacillus Calmette-Guérin Scar Formation and Tuberculin Skin Test Reactivity in Infants in Lima, Peru

Can the Mantoux test be used in BCG vaccined children?

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