"Host of disease" isn't a standard scientific term. It's more of a colloquial way of saying "a lot of diseases" or "many different diseases".

For example, you might say:

* "The overcrowded living conditions in the refugee camp led to a host of diseases."

* "The doctor said the patient had a host of allergies."

It's important to note that this phrase isn't precise. It doesn't specify the nature of the diseases or their severity.

If you're looking for a more specific and scientific term, you could consider using:

* Spectrum of diseases: This refers to a range of diseases that share some common characteristics.

* Disease burden: This refers to the impact of disease on a population, including the number of cases, deaths, and disabilities.

* Comorbidities: This refers to the presence of two or more diseases in the same individual.

Using the correct term will depend on the context of your conversation or writing.