Steamed & boiled food is ok, but raw foods whenever possible
is even better. Starchy (eg. rice, potato) foods are better
consumed boiled, but everything else (ie. fats and proteins) must
be consumed raw.
Raw sashimi, raw eggs, raw coconut, raw nuts, raw oils, raw
vegetables (and raw juices), raw fruits, etc.
As for bacteria and virus :
1) Don't forget there are beneficial bacteria too (google
"probiotics"). Indiscriminate killing of all bacteria is unwise and
insufficient beneficial bacteria can cause disease as well.
2) Most 'harmful' bacteria and viruses cause disease and death only
because the human body is already toxic and polluted, due to eating
cooked, processed and polluted food for years. If you're on a 100%
raw healthy diet, no virus or bacteria can cause disease in
you.
3) Regardless of viruses and bacteria, the FACT is cooking of foods
is a severe and irreversible chemical process that harms the human
body.
4) Conclusion : obtain and consume fresh, clean, raw, organic foods
that are safe and healthy to eat. These foods are possible to
obtain (especially in a fortunate society like Singapore), it's
just a matter of whether you're willing to make the extra effort,
or not.