Rotavirus specific, serum
IgM/
IgA/
IgG levels among hospitalized children and their respective mothers were determined. Children were grouped as having rotavirus diarrhoea (RVD) and non-rotavirus diarrhoea (NRVD) on the basis of fecal excretion measured by ELISA and RT-PCR. Although
IgM seropositivity was observed among children of both the groups, it was significantly higher in the acute as well as convalescent phase serum samples (P < 0.05 for both) of RVD group. Five out of ten acute sera from the NRVD group were positive for
IgM and seven showed
IgA/
IgG seroconversion indicating
rotavirus infection among these children in the past. It was noted that, three out of 24 mothers' sera from RVD group, showed presence of
IgM in the serum collected during
convalescence of their children. The observation suggests, subclinical
rotavirus infection among mothers probably contacted from their children. This is supported by the seroconversion for
IgA/
IgG among these three mothers. Such a phenomenon was not noticed among the mothers from NRVD group. In general,
IgA positivity did not vary significantly among the children from both the groups.
IgA seropositivity was significantly higher (P < 0.001) from children of RVD group as compared to healthy group of children following
rotavirus infection. From RVD group, all the child patients and 12 mothers out of 24 (50%) showed
IgA/
IgG seroconversion. None of the mothers from NRVD group showed seroconversion. Serum samples of healthy children and adults, showed
IgM positivity at equal level (10%), but a significant difference (P < 0.01) was observed in
IgA positivity. In conclusion, subclinical transmission of
rotavirus infection from children to their mothers may occur. Seroconversion alone cannot be considered as a marker of rotavirus diarrhoea in children. Moreover, about 40-50% of subjects lacked rotavirus specific
IgA at protective levels, making them susceptible to
rotavirus infection.