Amagciwane agcwele yonke indawo futhi abegcwele izigidi zeminyaka. Alukho uhlobo lokuphila olusindiwe, ikakhulukazi umuntu. Kusukela ku-AIDS kuye ku-SARS (= i-acute acute respiratory syndrome), nge-smallpox noma i-hepatitis C, izifo ezibangelwa amagciwane ziye zaqeda isibalo sabantu futhi zilokhu zivusa umcabango wenhlekelele yezempilo. Ezinye, nokho, zivame kakhulu futhi aziyingozi kangako empilweni.

"Izinkanyezi" zangempela zasebusika, umkhuhlane, i-gastroenteritis kanye nomkhuhlane ovamile zikhuluma ngazo ngalesi sikhathi sonyaka. Umkhawulo wabo wobhubhane ufinyelelwa ngokuhlelekile ngalesi sikhathi sonyaka, okuphawulwa amakhaza nezinga eliphansi lokukhanya kwelanga. Kodwa iliphi iqhaza esinalo isimo sezulu ekuqubukeni kwalezi ziqongo zobhubhane? Ingabe akhona amagciwane amaningi emoyeni? Ingabe umzimba wethu untekenteke kakhudlwana?

Ngaphambi kokuba siphendule yonke le mibuzo, kufanele sikhumbule ukuthi umhlaba wamagciwane ungakanani. Akwaziwa kuze kube sekupheleni kwe-XIX^stekhulwini leminyaka, kusengakahlolisiswa nanamuhla, ngenxa yokuntuleka kwezinsiza zobuchwepheshe ezanele. Eqinisweni, luncane ucwaningo olwenziwe nge-viral ecology yomoya, kanye nokuthi lezi zinhlangano zisebenzisana kanjani nemvelo. Kodwa-ke, siyazi ukuthi amanye amagciwane asakazwa kakhulu emoyeni, kanti kwamanye, ukuxhumana okunqumayo. Lokhu empeleni kuchazwa ngu i-virus morphology.

Ngokuyisisekelo, zonke zinendlela efanayo yokusebenza: igciwane lingena emzimbeni, lingene engqamuzaneni, bese likhipha ufuzo lwalo ngaphakathi kwalo. Lesi sici sibe sesiphoqa iseli elifakwe igciwane ukuthi lenze amakhulukhulu amakhophi egciwane azonqwabelana ngaphakathi kweseli. Uma kunamagciwane anele, ashiya ingqamuzana ayofuna ezinye izisulu. Kulapha lapho singabona khona umehluko omkhulu phakathi kwezigaba ezimbili zamagciwane.