BCG vaccination in India and tuberculosis in children: newer facets.

With the extended programme of immunisation and since 1985 the universal programme of immunisation and the coverage status of BCG vaccination in India has been very good, although it is still unsatisfactory in the eastern states. It is emphasized that BCG vaccination cannot prevent natural tuberculous infection of the lungs and its local complications, although it reduces the haematogenous complications of primary infection. However, this is not true for malnourished children who, inspite of BCG vaccination, develop serious, and often fatal types of tuberculosis such as miliary, meningitic and disseminated tuberculosis. The tuberculin anergy in malnourished children, is mainly responsible for high morbidity and mortality. BCG vaccinated, well-nourished children manifest modified patterns of tuberculous disease, following infection. The most important manifestation is the increased incidence of intrathoracic tuberculosis, specially enlargement of the various groups of mediastinal nodes and their local complications. Localisation of the disease by T cell immunity, due to BCG vaccination is responsible for this and the much lower incidence of haemotological complications such as neurotuberculosis and disseminated disease. In these children, the clinical picture of neurotuberculosis is also modified, with a tendency for more localised involvement of the brain and meninges. Similarly, vaccinated children may present with hepatomegaly, splenomegaly or isolated organ disease. It is important to relearn the new patterns of tuberculosis disease seen in vaccinated, non-malnourished children, and to a lesser extent in children with grade 1 to 2 protein energy malnutrition (PEM). With these limitations of BCG vaccination, other strategies like chemoprophylaxis need multicentric trials in high risk children, in different parts of the country.

Protein energy malnutrition (PEM), brain and various facets of child development.

Protein energy malnutrition (PEM) is a global problem. Nearly 150 million children under 5 years in the world and 70-80 million in India suffer from PEM, nearly 20 million in the world and 4 million in India suffer from severe forms of PEM, viz., marasmus, kwashiorkor and marasmic kwashiorkor. The studies in experimental animals in the west and children in developing countries have revealed the adverse effects of PEM on the biochemistry of developing brain which leads to tissue damage and tissue contents, growth arrest, developmental differentiation, myelination, reduction of synapses, synaptic transmitters and overall development of dendritic activity. Many of these adverse effects have been described in children in clinical data, biochemical studies, reduction in brain size, histology of the spinal cord, quantitative studies and electron microscopy of sural nerve, neuro -CT scan, magnetic resonance imaging (MRI) and morphological changes in the cerebellar cells. Longer the PEM, younger the child, poorer the maternal health and literacy, more adverse are the effects of PEM on the nervous system. Just like the importance of nutrients on the developing brain, so are the adverse effects on the child development of lack of environmental stimulation, emotional support and love and affection to the child. When both the adverse factors are combined, the impact is severe. Hence prevention of PEM in pregnant and lactating mothers, breast feeding, adequate home based supplements, family support and love will improve the physical growth, mental development, social competence and academic performance of the child. Hence nutritional rehabilitation, psychosocial and psychomotor development of the child should begin in infancy and continue throughout. It should be at all levels, most important being in family, school, community and various intervention programmes, local, regional and national. Moreover medical students, health personnel, all medical disciplines concerned with total health care and school teachers should learn and concentrate on the developmental stimulation and enrichment of the child.

Pediatric tuberculosis pyramid and its fate with and without chemotherapy/chemoprophylaxis.

The latest available information on total and infectious cases of tuberculosis in the country and also large number of sputum positive cases being detected annually, particularly after the involvement of multipurpose workers in the primary health care programme for the control of tuberculosis, is presented. The consequences of the large pool of infectious cases in the population lead to spread of bacilli to children with development of primary infection in them. These children with primary infection, specially high risk group in infancy and early childhood, get serious complications of the disease. It may be emphasized that BCG vaccination cannot prevent the lodgement of tubercle bacilli in the lung but can only contain or restrict haematogenous spread. Inspite of increasing coverage of infants with BCG vaccination there are an increasing number of cases of intrathoracic tuberculosis, particularly various groups of mediastinal nodes. However, to a lesser extent haematogenous complications do occur in malnourished children, as BCG has a limited value in preventing serious complications in children with malnutrition. The clinical pattern of pediatric tuberculosis has also changed in vaccinated and partly or inadequately drug treated children. Hence, chemoprophylaxis/chemotherapy to prevent complications of primary infection has been tried. Even relatively privileged children in developed countries are reported to have complications of primary infection to an extent of 10 to 15%, as per the studies all over world. So preventive chemoprophylaxis, preferably with two bactericidal drugs, should be considered as the main strategy for controlling primary infection. Chemoprophylaxis with two drugs should be used as incidence of isoniazid resistant bacilli has increased. All concerned with child health should consider the strategy of treatment of primary infection in high risk children by chemoprophylaxis by starting a large multicentric trial both in urban and rural areas, as a part and parcel of primary health care intervention already in practice for cases of sputum positive pulmonary tuberculosis.