night soil sure can be used as fertiliser (and has been for millenia), but it has many germs we should try to avoid, such as coliform bacteria and the eggs of intestinal worms. these can be minimised (except for the spore forming bacterial species) by heating or fermenting the ‘manure’. there is less risk to health if one uses animal manure such as horse or cow dung, but the same principles apply: age or heat to kill most bacteria first.
probably one third to one third of the market gardens in the world rely on human sewage for irrigation, especially now that water is becoming scarce.
(new scientist article on the topic)
wash your vegies well, folks, in soapy water if possible.