From the onset of the statistical era (which began around 1840 in Britain and the United States) until the present time, roughly half the world's population were (and are) infants and children under the age of fifteen. This must also have been the situation among all humankind before 1840. In the eighteenth century in the West, in those regions for which some crude figures exist, such as Massachusetts, Britain, the core lands of modern France, Sweden, and the German lands, it can be said with some confidence that life expectancy at birth occasionally touched forty years but even there it was generally less. Given that measles and several other epidemic diseases tended to target people under fifteen–half of the population–it follows that they had a very large clientele to work on.

An endemic disease is one that is continuously present in any given population in nascent form. Its rate of occurrence as an illness–which is to say, its prevalence–may differ according to the season of the year and other variables, but its causal agent is almost always found within the locality. Heading the list of today's endemic, or always present, child killers are the water-borne ailments collectively known as dysentery and the diarrheal diseases. In contrast, an epidemic disease, such as smallpox in its most virulent forms (extinct since 1977 in its free-ranging state) or measles (which still exists), only occasionally attacked any given human population. The disease agents, or pathogens, which had the potential to periodically set this sort of epidemic in motion almost always came in from outside the place in which victims lived.


Unlike a dread disease such as bubonic plague (essentially a disease of rats and other rodents), smallpox had no nonhuman host. Thus, over time it was vital to the perpetuation of the smallpox variola that it not kill off all its child hosts. If it did, the children would not be there in a few years, in their capacity as sexually mature adults, producing children of their own, who in turn could host the variola. Without hosts, the variola would become extinct.

It is essential to understand that the causal agents of infectious disease are living things that have the potential to change their forms over time. These mutations make their presence felt in the altered way the disease makes its presence felt among humankind.

In the case of smallpox as it affected populations in western Europe and the Middle East before around 1650, it was most commonly a benign endemic disease that did not kill its victims. Aside from sickly infants, who in any case could not be expected to live, pre-1650s smallpox neither killed nor scarred nor blinded nor neutered its victims. It was in this benign form that smallpox first entered the medical record.

Writing in Baghdad before 925 C.E., the Persian physician-philosopher Abu-Bakr al-Razi reported that smallpox was a common disease which most Middle Eastern children underwent with no ill effects. Al-Razi noticed that the illness never struck the same person twice. Nearly 700 years later, this was apparently still the situation in the British Isles. William Shakespeare, who died in 1616, in his many sonnets in praise of beautiful young men and women nowhere mentioned the threat of disfigurement or death from the disease. Thus, before 1616, it would appear that rampaging lethal smallpox was still unknown in England.

Opinions are divided about when and where the variola virus of smallpox first changed into its violently nasty forms. On the one hand, many historians argue that the Spanish, Genoese, and other European adventurers who went to the Caribbean Islands in the New World in and after 1518 were responsible. Having acquired smallpox immunity by hosting a benign case of the disease in their infancy at home, they brought forms of smallpox with them that, when let loose, quickly changed into lethal forms that killed millions of non-immune Native Americans who had never before been exposed to smallpox. If these events–so catastrophic from the First Nation point of view–actually happened, it can be suggested that disease mutation may have first occurred in the New World.

Or it may have already happened in parts of sub-Saharan Africa, or in Bengal, in northeastern India. In both regions, sometime before medically aware European observers came on the scene in the late seventeenth century, village curers recognized that some cases of smallpox were now lethal. They also observed that little children who survived a bout of the disease in any of its forms were immune to further attacks. Putting two and two together, they devised the control technique known as inoculation.

In this process, a curer took a bit of a smallpox scab from a moderately sick child, diluted it, and then scratched it into the skin of the child being inoculated. The curer and the parents realized that this process was not risk free, yet they continued to use it. In the 1870s it was found that more than eighty percent of the Bengali men who were imprisoned in government jails in that province had already been inoculated.

The processes of inoculation first described by Western observers in Bengal in the late seventeenth century were also being commonly used at that time in parts of West Africa, from whence they were brought to the New World. In 1706, the slave Onesimus taught his master, the Reverend Cotton Mather of Old North Church, Boston, the mysteries of smallpox prevention through inoculation. In earlier years, between 1620 and 1700, Massachusetts had been blessed by an exceptionally benign disease environment and a low infant mortality rate that had allowed far more babies to survive to adulthood than was the case in the middle colonies and in Europe. However, in the years just before 1706, Old World diseases, including smallpox, had begun to strike youthful New Englanders. For this reason, Mather was atypically willing to listen to what his African dependent said and to put it into practice. He had the children in his immediate circle inoculated and encouraged his friends to follow suit.

Massachusetts-style inoculation against smallpox caught on in the New England colonies and in some of the more smallpox-prone parts of Europe. Thus in authoritarian Sweden, the central government gradually realized that if smallpox were allowed to rage among its infants unchecked the country would be in danger of being depopulated. During bad periods, such as the years between 1779 and 1782, nearly a fifth of all deaths were from smallpox; most of the victims were children under the age of nine. Aware of this, the Swedish government strongly encouraged parents to have their offspring inoculated.

Among western Europeans and European-Americans, inoculation processes may have turned the tide against smallpox, even before the immunization process known as VACCINATION was devised by Edward Jenner in the late 1790s and put into common use early in the next century.


At the opening of the twenty-first century, twenty-five years after smallpox was abolished in its free-ranging state worldwide, measles–an air-borne virus–continues to kill one million children each year and to make an additional 42 million seriously ill. First tentatively identified as a separate disease by the Persian philosopher-physician al-Razi in the tenth century, measles today is most common among the third of the world's children who are chronically malnourished and who live in the non-West.

In addition to children with an unfavorable nutritional status, young children living in large families are also much more prone to being infected with measles than are children living in families with one or two siblings. Nowadays, when the total population of most western European countries is rapidly shrinking due to the limitation of family size, and at a time when most European and European-American parents have their children immunized against all common infectious diseases, measles has become rare in the West. This means that it has become one of the many infectious diseases most commonly found in the non-West. Its non-Western survivors, their immune systems weakened through a bout with the disease, often fall prey to pneumonia.

Bubonic Plague

From 1348 through 1351, western Europe and Egypt were ravaged by a terrible disease, which killed between a quarter and a third of the population. The first great onslaught was called the Black Death. In Europe visitations of what used to be regarded as the same disease (at the time there were no means for identifying disease agents) recurred until the late seventeenth century. In western Europe, the last major out-break was imported into Marseilles, France, in 1721 by a rogue ship coming from the Orient.

Conventional scholarship once held that humans who survived one attack of the bubonic plague did not develop immunity against a subsequent attack. Conventional scholarship also held that bubonic plague did not necessarily target children. Given that roughly half of the population in any place was under the age of fifteen, one could expect that roughly half the victims of the disease would be non-adults. However, according to Samuel K. Cohn Jr. (2002), the late medieval plagues that repeatedly hit western Europe after 1351 directed their attention primarily against children; children who survived acquired life-time immunity.

Given that these events happened before the advent of modern laboratory medical science and before the statistical age, we have no sure way of knowing just what disease agents were actually at work in Europe between 1347 and 1721. In time, new scholarship may permit the writing of comparative studies based on findings from the non-West. It is already clear, however, that the Bubonic plague that continued to kill people in Egypt until 1844 was the same as, or closely related to, modern laboratory-certified Bubonic plague.


Much more certain is our knowledge of the so-called summer plague, more usually known as poliomyelitis or infantile paralysis. In the summer of 1916, several thousand middle-class children in New York City and the surrounding region were struck with a strange new disease. Although outright death was rare–because hospital care was available–many survivors were left severely crippled in their legs and unable to walk. Other less fortunate survivors suffered impairment of their breathing apparatus and had to be placed in an iron lung.

Caused by viruses (there are three main viral strains), POLIO spreads from one person to another by a fecal-oral route and in the East Coast of the United States was very often contracted by middle-class young people who had access to public swimming pools. Polio was a high-profile disease–its victims included President Franklin Delano Roosevelt. Accordingly, it attracted the attention of highly qualified American scientists. In the development of a preventive vaccine suitable for mass distribution, the first great breakthrough was by Dr. Jonas Salk in the 1950s. In most areas of the world, Salk's techniques, which were based on the use of an injection, have now been replaced by an orally administered vaccine by Dr. Albert Sabin that was released in 1961.

Thanks to preventive immunization, polio has all but disappeared in the United States and elsewhere in the West. Yet in India, Nigeria, and some other parts of the non-West, young children and infants over the age of six months are still at risk from the disease. As of 1998, more than 18,000 fatalities were reported. Given that the quality of hospital care found in most non-Western countries is far below the standard found even half a century ago in the United States, cases that in the United States might have been successfully treated are left all but unattended and commonly result in death.


Human Immunodeficiency Virus (HIV) and Acquired Immuno-Deficiency Syndrome (AIDS) was first reported in 1981 and has become the world's fourth most common cause of death. As of 2002, 40 million people bore the lethal virus, 70 percent of them in sub-Saharan Africa.

According to the conventional wisdom of leading funding agencies as expressed by the World Health Organization (WHO), "99 percent of the HIV infections found in Africa in 2001 are attributable to unsafe sex." (WHO 2002, p. xv). However, four years earlier, the same organization admitted that half a million victims were under the age of fifteen (WHO 1998, p. 93).

An alternative assessment of the situation was found in the International Journal of STDs and AIDS in October 2002. Here, David Gisselquist and his colleagues found that a sizeable percentage of Africans suffering from HIV had not yet reached the age of puberty. Though none of these children had engaged in sexual activity involving a partner, all of them had been the recipients of clinically administered injections which were intended to prevent communicable diseases, fevers, or other childhood illnesses. On-site study showed that the cash-strapped clinics often reused syringes simply because no other instruments were available; more than half of all HIV and AIDS victims in Africa may have been infected in this way. In many cases, newborn infants may have been infected in utero by infected mothers who had made use of the disease-prevention services of clinics.

The current AIDS epidemic affects infants and young children under the age of fifteen in financially hard-pressed sub-Saharan regions in two ways. First, many of them will die of pneumonia and the other killers that strike down people whose immune systems have been rendered useless. Very often their deaths will be recorded as having been caused by something other than AIDS.

Second, and more difficult to capture statistically, millions of young Africans are becoming ORPHANS through the AIDS deaths of their parents, aunts and uncles, and other potential care-givers. In several countries in southern Africa, where nearly half the adult population is HIV-positive, orphans have little chance of survival. For this reason, many of these who do survive do not acquire the veneer of civilization and instead become teenaged mercenary soldiers, drug-dealers, extortionists, or all-purpose terrorists.

As of 2003, the AIDS epidemic continues, and in the next two or three years is expected to make its presence heavily felt in China and in India, nations which between them are the home of half the world's population. Because many non-Western countries are burdened with debt repayment to financial institutions based in the West and are thus unable to fully fund proper health services, the AIDS epidemic may well become the non-Western world's principal childhood killer. The prognosis is not good.

See also: AIDS; Contagious Diseases; Infant Mortality.


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De Waal, Alex. 2003. "How Will HIV/AIDS Transform African Governance?" African Affairs 102: 1–23.

Gisselquist, David, Richard Rothenberg, John Potterat, et al. 2002. "HIV Infections in Sub-Saharan Africa Not Explained by Sexual or Vertical Transmission." International Journal of STDS and AIDS 13, no. 10: 657–666.

Gisselquist, David, John Potterat, Paul Epstein, et al. 2002. "AIDS in Africa." The Lancet 360, no. 9343L: 1422–1423.

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