Respiratory tract infections are the most important cause of morbidity and mortality among children less than 5 years of age in developing countries-most poor population live. The highest incidence of RTI is among children under one year of age. These diseases are also the major reason for irrational use of antibiotics. Most epidemiological studies in the literature have focused on the more serious forms of RTI, namely pneumonia, and little accurate information exists of the less severe forms of RTI. The respiratory infections are also a major factor promoting nasopharyngeal carriage of potential respiratory pathogenic bacteria, the pneumococcus and haemophilus influenza. The role of these bacteria in the less severe infections is not well known. In the context of the ARIVAC studies focusing on pneumococcal carriage and infant morbidity pattern, a set of 99 children from 98 families (1 twin) living in a semi-rural area of Bangladesh were closely observed throughout the first year of life. This gave us an opportunity to collect information on morbidity of these children in relation to their carriage of pneumococci and ask questions about morbidity pattern and burden of morbidity, health care seeking behaviour of parents and vice versa if any association between pneumococcal carriage with respiratory disease. Health care providers need adequate information about the nature, distribution, quantity and determinants of illness in populations for effective planning, development and efficient primary health care and thus to reduce infant morbidity and mortality in developing countries.

ARIVAC Bangla study is a collaborative study between Institute of National public health (KTL) Helsinki, Finland and Gonoshasthaya Kendra (Peoples’ health centre), Bangladesh.  Study villages were in Savar, a semi rural area situated 35 kilometres north-west from the capital city Dhaka, Bangladesh .There were total 98 families enrolled to the study (99 infants, 1 twin) from May 2000 to May 2001 and then one year follow-up period until the child was one year old ended May 2002. The field work consisted of collecting nasal swab from the infant, all siblings of index child and other family members present during every home visit by paramedics. In addition the recall Morbidity and treatment data, present child health status and household data of index child were collected by full filling two questionnaires. According to study protocol the first visit took place at the age of 2 weeks of the new born, then 2 weeks interval up to the age of 4 months and then after 1month interval for the next 8 months until the child was one year old. The laboratory work portion contains growth and culture and serotyping of the nasal swab carriage. Part of the data is analysed.

Result:

Morbidity data analysis shows that number of total illness episodes during one year follow up were 254. Total person months were 1156.30. Among all illness episodes 199 RTI cases (78.34%), GE 19 (7.48%), Skin diseases 32 (12.59%) and other diseases were 4 cases (1.57).The main morbidity burden was RTI and its incidence was 0.172 (CI 95% 0.148-0.196). Among 99 children 85 had encountered RTI (85.8%) at least once in their 1st year of life (90 %) and 50% of them encounter RTI with in first 3.5 months of age (95% CI interval bound). The hazard of getting RTI steadily increased until 3 months and then decreased by the age of one year in both sex groups. Seasonal analysis indicated that RTI morbidity was bit higher in the dry and colder months from September to April and its incidence was lower during monsoon period, when humidity is relatively high. Data shows male children suffered more RTI than female children. There were 9 children who did not have any illness episodes during whole one-year observation period.