Have there not been pandemics sourced from India? If not, why the contrast? "
It's fair to say that every large country historically has its share of epidemics, including the USA and India.
Diseases like Yellow Fever, Cholera & Small Pox have spread from every country in the 19th century and from many in the 20th.
Since 1900 India has actually suffered more known epidemics than secretive China, but the total numbers dying have been much smaller.
China's unique "contributions" have been viruses related to H1N1 since 1917 and more recently SARS-Coronaviruses.
Where they all came from, and how each one spread to humans is still not well understood, but the Chi-com response to the latest Coronavirus is... well... breathtaking in its contempt for the rest of the world.
That should never be forgotten.