The incidence of tuberculosis in Russian prisons is 20 to 60 times the rate in the Russian population at large, where it is 24 times more prevalent than in the USA. Half the prison population is thought to be infected. The spread of disease is worsened by the promiscuity encouraged by overcrowding.
In 1996, prisoners in El Salvador, who were obliged to sleep in shifts because of overcrowding, threatened to murder fellow inmates selected by lottery to force the government to deal with the crisis -- following a pattern set in Brazil. In the whole country 8,225 inmates were held in prisons with a maximum capacity of 3,800. Many had already been held for longer than the maximum time for the crimes of which they were accused.
2. Some Russian prisoners rent out their beds to others by the hour.