VD tends to be concentrated in cities and to follow people's movements; it is aggravated by war, poverty, ignorance, and lack of public health and medical facilities. Being spread by sexual contact, it is increased as sexual intercourse increases in the population, with promiscuity an essential factor in the process.

The poverty factor operates in part by encouraging ignorance, in part by limiting access to treatment facilities. It is true, although it seems to be less so than in the past, that there is more VD among the poor than among the rich. But there is plenty at all levels of society. A notion advanced by some advocates of sexual freedom seems to be as mischievous as any that come from the other side that you can avoid VD by choosing sex partners from the apparently clean and well dressed members of the well heeled. The only difference between the aristocrats of today and the kings of old as far as VD is concerned is that today they have effective diagnosis and treatment available to them. And it is still true that such things are more available to the rich than to the poor.

Syphilis needs a vaccine, gonorrhea needs a blood test. And mathematical: as world population" rises at an ever, increasing (exponential) rate, contacts between people, including sex contacts, rise even faster, very much faster; this is one reason for the increase in VD.