| dc.description.abstract | Parasitic worms of the genus Schistosoma cause schistosomiasis. It has been shown that pregnancy has no effect on schistosome infection and that infection during pregnancy confers protection to offsprings born to infected mothers in human beings and C57BL/6 mice. However, the pathological effect of Schistosoma mansoni infection in pregnant BALB/c mice and the subsequent immunological implications on the offsprings has not been studied. This work therefore sought to compare pathology in experimentally infected pregnant BALB/c mice and the subsequent immunological implications on the offsprings. A pilot experiment (1) was done to determine the appropriate time when to mate the mice after infecting them (group A), and of infecting offsprings from infected mothers (group E) and those from uninfected mothers (group F). Mice, six weeks old, were randomly placed into four groups W, X, Y and Z. They were all infected at week 1 but mated at one week interval i.e. week 1, 2, 3, and 4 for W, X, Y, and Z respectively. Perfusion was done at week 7 to recover adult worms. Gross pathology and histopathology of the liver tissue were studied at week 4 and 7. Results for mice in group Wand Z consistently conformed to the expected disease pattern with regard to presence of adult worms at week five and mild pathology by week 7. However mating was done at week 1post infection as for W instead of week 4 post infection as for Z so that perfusion is done when mice have given birth after the gestation period of 21 days.
Mice born to infected mothers were weaned at 3 weeks post delivery and bled for
serum at two week intervals between week 4 and 16 post delivery. ELISA results failed
to show a specific downward trend in schistosome antibody levels with time as
expected. However, week 12 was set for infecting mice in group E and F because the
antibody level was lower than that at week 10, and week 16. In the second (IT)
experiment, mice in group A were infected and mated (the pregnant group) while those
in group B were infected and not mated (positive control). Mice in group C were not
infected (negative control). but were mated. The in vitro proliferative responses to
schistosome antigens, IgG antibody levels, gross pathology as well as histopathology
were studied. Antigen-stiinulated 'proliferative responses showed that pregnancy
suppressed' cellular immune responses butt not humoral responses. Lymph node and
spleen cells responses were lower in group A than B while ELISA showed higher
antibody levels in group B than A. More worms were recovered from group A than
group B at week 6 and 7. Granuloma diameter in A was smaller than that in B. In the
third (III) experiment, infants born to infected mothers in group A were used as group E
and their pathology compared with those born to uninfected mice in group C of
experiment II (as group F). Infection was done at week 12 after birth in both groups.
Results showed that mice born to infected mothers were better protected from S.
mansoni infection than those born to naive mothers with regard to the adult worm | en |
