How should we understand the fear and fascination elicited by accounts of communicable disease outbreaks that proliferated, following the emergence of HIV, in scientific publications and the mainstream media? The repetition of particular characters, images, and story lines - of Patients Zero and superspreaders, hot zones and tenacious microbes - produced a formulaic narrative as they circulated through the media and were amplified in popular fiction and film. The 'outbreak narrative' begins with the identification of an emerging infection, follows it through the global networks of contact and contagion, and ends with the epidemiological work that contains it. Priscilla Wald argues that we need to understand the appeal and persistence of the outbreak narrative because the stories we tell about disease emergence have consequences. As they disseminate information, they affect survival rates and contagion routes. They upset economies. They promote or mitigate the stigmatizing of individuals, groups, locales, behaviors, and lifestyles. Wald traces how changing ideas about disease emergence and social interaction coalesced in the outbreak narrative. She returns to the early years of microbiology - to the identification of microbes and 'Typhoid Mary', the first known healthy human carrier of typhoid in the United States - to highlight the intertwined production of sociological theories of group formation ('social contagion') and medical theories of bacteriological infection at the turn of the twentieth century. Following the evolution of these ideas, Wald shows how they were affected by - or reflected in - the advent of virology, Cold War ideas about 'alien' infiltration, science-fiction stories of brainwashing and body snatchers, and the HIV/AIDS pandemic. "Contagious" is a cautionary tale about how the stories we tell circumscribe our thinking about global health and human interactions as the world imagines - or refuses to imagine - the next Great Plague.

我不僅從麻風患者身上學到生命的韌性，也從醫師與救助者身上學到可貴的人性。在漫長的研究與書寫過程中，我發展出了一種信仰，我不知道它與宗教是否相似。我將自己當成一座橋梁，練習彎腰、承擔與跨越，因緣際會扮演起連結過去與現在、隱微與清晰、底層與公眾之間的研究書寫者角色。我有幸被人接納、聽其述說、見識歷史、體驗生活。既然幸運如我，無論有再多困難，我都得負重盡責地把這本書寫出來。
──摘自本書〈跋：黑暗中的熒熒燭光〉
人類學者劉紹華繼《我的涼山兄弟》，再次以廣受歧視誤解的疾病為鑿，敲開一段被遮蔽的歷史。
一般人聽到麻風，少有不覺駭然，此疾在患者外觀上造成的損害，有時令人怵目驚心，因此即使傳染力很低，卻仍長期背負沉重汙名。
一九四九年中共建政前，中國原是麻風流行之地，卻在三十年後達成世界衛生組織的防治標準，擺脫疫情威脅。這項成就得來不易，彼時苦難叢生的社會主義中國，究竟是如何辦到？這是作者試圖解開的謎團。
劉紹華的漫長解謎旅程，始自二○○三年，她在四川進行《我的涼山兄弟》時，第一次踏入麻風村。此後十餘年，她走訪中國各地的麻風聚落和防治機構，一共正式訪問四十五位不同世代的麻風醫生。麻風醫生的身影穿梭全書，如同當年他們奔忙於國家政治與底層苦痛之間。他們的生命故事，交織出社會主義中國麻風防疫運動的後臺樣貌、乃至人道理想與革命現實難以兩全的矛盾掙扎。
單數、大寫的歷史敘事，往往充滿虛構和流失真相。何況，從一九五○年代毛澤東展開極權統治，到一九八○年代鄧小平實施改革開放，其間巨變中國傷痕累累，官方對這段過往諱莫如深，更是緊控論述的詮釋權。本書以人類學民族誌方法為主，文獻爬梳為輔，勉力將歷史還諸沉默眾人，為時代留下複數的重要證言。