Aia nā maʻi maʻi ma nā wahi āpau a ua laha ʻia no nā miliona mau makahiki. ʻAʻohe ʻano ola i mālama ʻia, ʻaʻole hoʻi ke kanaka. Mai ka maʻi AIDS a i ka SARS (= maʻi ʻeha ʻeha ʻeha), ma o ka liʻiliʻi a i ʻole ka maʻi hepa C, ua hoʻopau nā maʻi maʻi viral i ka heluna kanaka a hoʻoulu mau i ka ʻike o ka pōʻino olakino. ʻO nā mea ʻē aʻe, ʻoi aku ka maʻamau a emi ʻole ka pōʻino i ke olakino.

ʻO nā "hōkū" maoli o ka hoʻoilo, ka maʻi maʻi, gastroenteritis a me ke anu maʻamau e kamaʻilio e pili ana iā lākou i kēia manawa o ka makahiki. ʻO kā lākou paepae maʻi maʻi i hoʻopaʻa ʻia i kēia kau, hōʻailona ʻia e ke anuanu a me ka haʻahaʻa o ka lā. Akā he aha ke kuleana o ke aniau i ka puka ʻana mai o kēia mau maʻi ahulau? He mau maʻi ʻē aʻe i ka lewa? ʻOi aku ka palupalu o ko mākou kino?

Ma mua o ka pane ʻana i kēia mau nīnau āpau, pono mākou e hoʻomanaʻo i ka nui o ka honua o nā virus. ʻAʻole ʻike ʻia a hiki i ka hopena o XIX^stkenekulia, ʻaʻole i ʻike nui ʻia i kēia lā, no ka nele o nā kumuwaiwai ʻenehana. ʻO ka ʻoiaʻiʻo, ua hana ʻia kahi noiʻi liʻiliʻi e pili ana i ka ecology viral o ka lewa, a me ke ʻano o kēia mau mea e launa pū me ke kaiapuni. Eia nō naʻe, ʻike mākou ua hoʻouna ʻia kekahi mau maʻi ma o ka lewa, aʻo nā mea ʻē aʻe, ʻo ka hoʻopili ka mea e hoʻoholo ai. Ua wehewehe ʻia kēia e morphology virus.

ʻO ke kumu, he ʻano hana like nā mea a pau: komo ka maʻi i loko o ke kino, komo i loko o kahi kelepona, a laila hoʻokuʻu i kāna ʻano genetic i loko. A laila hoʻoikaika kēia mea i ka cell parasitized e hana i nā haneli o nā kope o ka maʻi e hōʻiliʻili i loko o ka cell. Ke lawa nā maʻi maʻi, haʻalele lākou i ke kelepona no ka ʻimi ʻana i nā mea pio ʻē aʻe. Ma ʻaneʻi hiki iā mākou ke ʻike i kahi ʻokoʻa nui ma waena o nā ʻano ʻelua o nā maʻi virus.