Two top Bush administration officials are beginning a 17-day trip to seven African countries in search of ways to alleviate health problems affecting millions of children.

Health and Human Services Secretary Louis W. Sullivan and Ronald W. Roskens, administrator of the Agency for International Development, left Wednesday on a mission to Mali, Nigeria, Uganda, Malawi, South Africa, Zimbabwe and Senegal.Ambitious programs designed to eradicate communicable diseases and reverse dehydration from acute diarrhea have saved the lives of many African children over the past decade.

But some of these gains have been offset by a dramatic increase in acquired immune deficiency syndrome, or AIDS. The World Health Organization estimates that 10 million or more African children will be infected at birth with the AIDS virus by the year 2000.

According to government statistics, child mortality rates in Africa may increase by as much as 50 percent during the 1990s as a result of AIDS.

Another growing problem is the number of children orphaned by parents who die of AIDS. According to U.S. estimates, the infection rate among urban women in Malawi of reproductive age is 23 percent. AIDS is a particularly acute problem in Uganda as well.

Sullivan and Roskens also will focus on other child survival problems. In Malawi, the principle cause of sickness and disease among children is malaria.

Even in the Ivory Coast, one of Africa's most prosperous countries, 16 percent of schoolchildren are stunted, an indicator of chronic malnutrition, according to a World Bank study. In Mali, one child in six dies in infancy, the highest ratio in Africa, according to a World Bank study.

Congress generally has been wary of administration foreign assistance requests, but Africa is an exception because of its great needs. Congress approved $800 million for an African development fund, $240 million more than the administration's request. Of that figure, $80 million is earmarked for child survival.

In an interview, Roskens said he and Sullivan, a medical doctor, will concentrate on recommending long-term programs to combat child mortality in Africa. Of the estimated 40,000 children who die daily worldwide, he said a substantial percentage are African.