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"For decades Algeria has had one of the highest population growth rates in the world, arising directly from a steady gap between deathrates and birthrates. The reasons are of a complex social, economic and cultural kind, such as high infant mortality, traditionally early marriage, family models largely determined by religion, the common practice of child labour and other factors. As a consequence of the mismatch between economic and demographic growth the society is confronted by growing mass unemployment, underemployment, food supply problems, housing shortages and ecological crises. The critical economic situation in the eighties reduced the prospects for constraining the population explosion by quickly conquering socioeconomic underdevelopment. Nowadays Algeria is deliberately following a programme for family planning, which is also supported to a certain extent by the Islamic clergy." (SUMMARY IN ENG), (excerpt)

Neuraminidase may play a role as a pathogenic factor in Erysipelothrix rhusiopathiae infection. The protective effect of active immunization with purified neuraminidase was therefore tested in an infection experiment in white mice. Mice were immunized 2, 4, 6, 8 or 10 times i.p. with Erysipelothrix neuraminidase. A control group received 10 injections with physiological saline. The infective dose varied between 7 and 7 x 10(7) cells. While all control animals infected with 7 x 10(1) germs died, the lethal effect could be reduced to 50% and 25% in animals immunized twice and 4 times, respectively. Only animals immunized 8 and 10 times were still partly protected against germ numbers of 10(3)-10(4). Germ numbers of 10(5) and more were almost always fatal even in highly immunized animals. Even a high immunization with neuraminidase could only lower the lethal by a maximum factor of 10(4) germs used.

The activity of neuraminidases of two strains of Haemophilus avium and three strains of H. paragallinarum were examined using serum of 1-day-old, 8-week-old and 2-year-old chickens as well as human serum, N-acetyl neuraminosyl-D-lactose (NL), N-acyl neuraminic acid glycoproteid (BSM) and colominic acid (Col) as substrates. Further the N-acetyl neuraminate (NAN) content in chicken and human serum was determined. No significant differences were found between the content of NAN in human serum and 1-day-old chickens serum. However, three and ten times less NAN could be determined in serum of 8-week-old and 2-year-old chickens, respectively. This suggests that NAN containing glycoproteins may be a factor of the non specific host defence mechanisms in young chickens. The neuraminidases of both Haemophilus species differ by their activity spectrum.H. avium cleaves the alpha-ketosidic linkage of NAN in its 2 --> 3, 2 --> 6 and 2 --> 8 position. Neuraminidase of H. paragallinarum was less active and cleaves mainly the 2 --> 6 linkage of NAN. Neuraminidases of H. avium and H. paragallinarum were three and ten times more active against chicken serum than human serum. This selective activity may be explained by the specific adaptation of H. avium and especially of H. paragallinarum to their natural host.