Ways of transmission of pathogens of infectious diseases are:

a set of natural habitats of pathogens infectious diseases
a set of transmission factors providing circulation of the parasite between infected and susceptible organisms
abiotic environmental factors involved in transmission of pathogens from the source to the susceptible organism
abiotic objects of the environment containing pathogens of infectious disease

К сожалению, у нас пока нет статистики ответов на данный вопрос, но мы работаем над этим.