Association of maternal salivary streptococcus mutans and other factors with child's salivary strepcoccus mutans in rehri goth Karach : an analytical cross-sectional study

Date of Award


Document Type


Degree Name

Master of Science in Epidemiology & Biostatistics (MSc Epidemiology & Biostats)


Community Health Sciences


Streptococcus mutans (S. mutans) are the principal etiological agents of early childhood caries (ECC) and its early acquisition is found to be an important predictor for ECC. Since mothers share an intimate contact with their children during first 2 to 3 years of life, the risk of transmission should increase with high maternal salivary S. mutans counts. Hence, evaluating and studying the maternal S. mutans and other maternal factors associated with the colonization of S. mutans causing ECC in 6-30 months old will therefore facilitate the implementation of ECC preventive measures for ensuring a better oral health outcomes in children. Objectives: Primary objective: • To determine the association of maternal Streptococcus mutans counts with Streptococcus mutans counts among children of 6-30 months old at Rehri Goth, Karachi Pakistan. Secondary objectives: • To determine the frequency of dmft/DMFT among 6-30 months old children and their mothers of Rehri Goth, Karachi Pakistan • To determine the association of maternal related and other factors with streptococcus mutans counts among children of 6-30 months old at Rehri Goth, Karachi Pakistan. Methodology: A community based analytical cross-sectional study design was selected. Rehri Goth, a rural community was selected as the source population. The sample consists of 193 dyads of mother and children of 6-30 months of age were recruited via purposive sampling technique during February and March 2015. As primary outcome and main exposure variable were S. mutans counts of children and their mothers respectively, saliva samples were collected from both and microbiological analysis was performed. Secondly caries assessment was performed according to WHO caries assessment criteria using DMFT index for mothers and dmft index for children. To assess the association of other maternal related and other factors which include breast feeding and bottle feeding practices; and oral hygiene measures with S. mutans counts of children a pretested questionnaire was used. The data was analyzed using zero inflated negative binomial regression model. Results: Out of 193 children recruited for the study, 109 (56.47%) were male. Mean age of mothers was 29.39 years (SD 6.2 years) and mean age of children was 19.54 months (SD 6.8 months). In our study, S. mutans colonization was found in 43.5% of children and 18.6% of mothers. Total number of children with carious teeth (i.e. dmft > 0) were 12 (6.2%) whereas total number of mothers with carious teeth (DMFT > 0) were 130 (67.4%). For both mothers and their children decayed component of DMFT/ dmft score contributed greatest part. Maternal S. mutan counts were not statistically associated with child's S. mutans counts (Mean child's S. mutans count ratio: 1, 95% CI: 1, 1.01), however we did find that increase in age of mother, use of bottle for feeding, use of pacifier, habit of mouthbreathing, age at which child's oral cavity/ teeth cleaning was started and presence of caries in mother's oral cavity were associated with increase in child's S.mutans count; whereas breastfeeding while complimentary feeding were associated with decrease in child's S.mutans count at 5% level of significance. Conclusion: Mothers do play a crucial role in the foundation years of a child. And hence should be made more aware about correct feeding practices and oral hygiene measures that should be adopted. Also mothers should be taught on maintaining better oral health of themselves which will prevent their children as well from bacterial colonization.

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