“THE BIGGEST, best story in development.” That is how Michael Clemens, a senior fellow at the Center for Global Development, described swiftly declining child mortality rates across Africa in an interview with the Economist.

Of the 20 African countries that track nationwide living standards, 16 have recorded marked declines in the rate of deaths of children younger than 5, reported World Bank economists Karina Trommlerova and Gabriel Demombynes. Senegal, Rwanda and Kenya have reported drops of more than 8 percent a year, a rate that, if sustained, would cut child mortality in half within a decade. Nine more countries have seen decreases of more than 4.4 percent a year, which would meet the target established by the Millennium Development Goal to reduce child mortality by two-thirds between 1990 and 2015.

This news is terrific, and these countries’ feats are virtually unheard of. Rates of child mortality in many African countries are dropping twice as fast as during the past two decades. A handful of countries’ declining rates — namely those of Senegal, Rwanda and Kenya — dwarf comparable figures reported in China in the 1980s and Vietnam at the end of the 20th century, periods of rapid growth brought on by market reforms.

This success story calls, first, for humility and flexibility, because it has no single explanation. In certain countries, economic growth has correlated with lower mortality rates. Ethiopia, Ghana, Rwanda and Uganda — countries that experienced an average annual rise in gross domestic product of more than 6.5 percent between 2005 and 2010 — have been at the forefront of reducing child mortality. Yet economics alone appears to be an insufficient indicator, given that Senegal, with a stagnating economy, has seen the sharpest declines in child mortality, while Liberia, with a growing economy, continues to suffer from high rates. International aid has played a role — for example, with agricultural assistance in some countries and the distribution of inexpensive bed-nets that protect children from malaria-transmitting mosquitoes.

The other takeaway is hope, which is essential, given the necessity for future progress. There are still 7.5 million children younger than 5 dying every year, 6 million of them from preventable diseases, according to Rajiv Shah, administrator of the Agency for International Development (USAID). The challenge is to replicate and broaden the successes of Senegal, Rwanda and Kenya.

To that end, USAID will join with India and Ethi­o­pia in convening a Child Survival Effort on June 14 with the goal of eliminating preventable childhood death. The initiative will reach beyond Africa to other high-mortality countries, including India and Pakistan, which, along with Nigeria, Ethiopia and the Democratic Republic of Congo, account for half of global child deaths. It will use an array of techniques rather than seeking one magic bullet: introducing new means of immunizations and vaccines, aiding pregnant women with micronutrients and revamping nutrition standards.

The slogan of this effort reads: “Every Child Deserves a 5th Birthday.” We hope that Congress embraces this goal, recognizing a legitimate opportunity to prevent child deaths.