Urbanization does not stop in front of the African continent. Here there are megacities, i.e. agglomerations with very large populations. Incredible 72 percent of the African urban population, about 300 million people, live in the slums of these cities.

There catastrophic hygienic conditions prevail. Health risks, which are enormous, take the form of dangerous diseases, such as Ebola, cholera and tuberculosis. This is where our aid project begins.

Some pathogens exude a very characteristic odour that is only detected by humans at high concentrations. Trained animals, however, are very sensitive to it.

Our aid project is now concerned with decrypting the "scent code" of pathogens and training sniffer animals for rapid reaction in infected areas.

Dogs and rats can learn to identify reliably the scent codes of pathogens and thus save lives. This is due to their excellent sense of smell. Moreover, they are highly intelligent, social, playful animals.

Using specially trained dogs and rats, we want to track down pathogens, such as those responsible for cholera and tuberculosis, in African conurbations. Ideally this would permit containment of disease risk and assurance of food and drinking water safety.

Clicker training is a highly effective operant conditioning method. The sniffer animals learn that the clicking noise means "food."

As a first step they only receive the reward if they respond to the positive sample.

Pathogens, such as Mycobacterium tuberculosis, exude a very characteristic odour. Sniffer dogs or rats can choose from three different scents in the next step.

Only when the animal pauses at the desired TBC scent does clicking occur and the animal gets food as a reward. The sniffer animals thereby learn that this was the correct response.

Now it goes one step further. Awaiting the sniffer dogs and rats in the next training module are ten samples. In this training phase they learn to examine a large number of samples and to detect pathogens.

The epidemic sniffer dogs and rats must pass a rigorous internal accreditation examination before they work in the field. This is a double-blind test, and to pass, all positive samples must be identified.