Perspectives in Biology and Medicine

Congregation and Infection

Although infection has long been understood as central to the progression of CF, historians and sociologists have mostly focused on CF as a paradigmatic genetic disease, albeit one in which secondary infection has been central to disease management (Kerr 2000, 2005; Lindee and Mueller 2011; Solomon 2015; Wailoo and Pemberton 2006). Several sociologists have theorized how infectious risk is perceived and managed by people with CF and their providers in British CF clinics, yet none have captured the dynamic and interconnected history of this issue (Brown et al. 2020, 2021a, 2021b; Lowton and Gabe 2006). In her recent historical review of the shifting scientific debates about cross-infection in CF, Michelle LaBonte (2022) emphasizes that CF came to be seen as both genetic and infectious, focusing on how taxonomic complexities and diagnostic uncertainty [End Page 90] informed CF infection control policies with significant consequences for the CF community. While important for understanding the impact of cepacia on infection control guidelines and community, existing work largely ignores the interconnected agricultural, industrial, and medical histories of cepacia and the myriad downstream consequences of evolving microbial knowledge. At once a genetic and infectious disease, CF is informative for thinking about what happens when the ethical, legal, and social implications of genetic and microbial risk intersect.

CF was first described as a clinical entity in the late 1930s. American pathologist Dorothy Andersen correlated the cystic fibrosis of the pancreas with the pulmonary and digestive sequalae of the disease in 1938 (Lindee and Mueller 2011). The etiology of CF was unclear, with early researchers proposing nutritional, infectious, and hereditary causes, but by the 1950s, CF was generally accepted as a recessive condition (Andersen 1958; LaBonte 2022). Starting in the 1950s, parents of children with CF mobilized to establish what is now the CF Foundation (CFF), marking the start of a biosocial community that coalesced as CF families congregated first to promote research and better care, and later for social support, connection, and advocacy (Doershuk 2002). Early on, the CFF helped support the development of specialized CF centers that directed innovative comprehensive treatment programs that extended the lives of children with CF (di Sant'Agnese 2002). These CF centers and CFF activities gathered people with CF and their parents for the purposes of medical care, research, social support, and fundraising. As more children with CF were diagnosed and as more survived to adulthood, specialized CF summer camps, shared hospital rooms and wards, fundraisers, and patient conferences formed the basis of a robust CF community. Yet these sites of congregation unknowingly established the conditions for bacterial transmission between people with CF.

Infection has long been understood as central to the progression of CF. Accordingly research and treatment innovations often aimed to understand and address lung congestion and infection. Research revealed that bacterial colonization progressed as individuals aged, from more easily treatable Staphylococcus aureus to increasingly antibiotic resistant forms of Pseudomonas aeruginosa and a growing a number of gram-negative microorganisms, though there were significant debates regarding the pathogenicity of organisms involved (Christie and Tansey 2004; Iacocca, Sibing, and Barbero 1963). Developments in antibiotic therapy have been vital in CF care, with both novel agents and new routes of delivery playing critical roles in delaying and managing chronic infection, thereby reducing morbidity and mortality in CF patients (Solomon 2015; Stern 2002). As historians Keith Wailoo and Stephen Pemberton (2006) illustrate, antibiotic therapy in CF was initially more ritualistic than scientific. Through the 1970s, there were few studies to guide prescribing practices alongside signs of increasingly antibiotic resistant microorganisms within the CF population. Accordingly, CF clinicians began to grapple with questions about whether antibiotics were a "double-edged [End Page 91] sword" or "the magic sword of CF care" (82). Although CF clinicians were increasingly concerned about how to effectively manage chronic infection, they were less focused upon questions of how people with CF became infected in the first place. Then in the 1980s, increasing rates of a novel bacteria called cepacia gained the attention of CF clinicians and researchers. As CF researchers performed studies to better understand bacterial transmission, the CF community was reconfigured by infectious risk.

From Bacteria to Ribotypes

In the 1980s, CF clinics began to identify an increasing number of CF patients with a lesser-known pathogen, then called Pseudomonas cepacia. Cepacia was known primarily as a plant pathogen that sometimes infected hospitalized patients. The microbe was especially troubling because it was innately resistant to many antibiotics, whereas Pseudomonas aeruginosa acquired antibiotic resistance over time with treatment and therefore generally had a more attenuated impact on disease progression. Cepacia was also different because it could instigate a lethal syndrome of fulminant pneumonia, sepsis, and respiratory failure (Isles et. al 1984). With heightened concern about this new microbe, CF clinics began to study the distribution of cepacia in their patient populations. Using the standard epidemiologic methods of bacterial phenotyping and contact tracing, researchers at Rainbow Babies Hospital in Cleveland and Toronto Sick Kids clinics hypothesized clinic-based spread of the microbe (Isles et al. 1984; Thomassen et al. 1986). A third clinic at St. Christopher's Hospital for Children in Philadelphia published data concluding that cepacia was endemic rather than epidemic at their center (Tablan et al. 1985). Despite disagreements about the transmissibility of cepacia, the Cleveland CF Center elected to segregate cepacia and non-cepacia patients alongside other hygiene measures. This move led to decreasing rates of infection, confirming their suspicion of nosocomial or patient-to-patient transmission (Thomassen et al. 1986).

Amidst controversy regarding whether cepacia was transmissible, a physician named John Lipuma joined the team at St. Christopher's Hospital for Children in the mid-1980s. A pediatrician with advanced training in pediatric infectious diseases, Lipuma would go on to become a leading CF researcher whose lab serves as a national reference laboratory for the CFF. For Lipuma, genetics were the true test of bacterial identity and transmission patterns, as microbes could have the same genes yet look different in petri dishes.

Lipuma brought a new molecular method called ribotyping to the study of cepacia in CF (Lipuma et al. 1988). Ribosomal DNA was known to have a low rate of mutation which made it ideal for studying the relationship between bacterial strains. Accordingly, Lipuma ribotyped cepacia specimens from CF patients across several CF clinics and established that a single ribotypic strain of cepacia [End Page 92] predominated. Each clinic's predominant strain differed significantly from that of other CF centers, and each strain was distinct from geographically associated environmental isolates of cepacia. Though highly suggestive of patient-to-patient spread or nosocomial transmission, Lipuma and colleagues ultimately called for more studies employing the novel and critically informative molecular methods.

Cultures of CF Camp

As the scientific community mobilized to study the transmission of cepacia in the late 1980s and early 1990s, people with CF were increasingly mobile, a quality that became important to epidemiological investigations. Indeed, children and adults with CF were traversing states and even continents to meet others with the disease at North American CF Summer Camps. The CF Camps were specialized summer programs that were funded in part by the CFF. They brought children together for one to four weeks each summer to give them a sense of normalcy, community, and fun. Unlike regional CF centers or local fundraisers, CF camps sometimes attracted patients from afar (Berkman 1969; Stadnyk and Bindschadler 1970). Heralded for their favorable impact on the quality of life for youngsters with CF, the CF summer camps inadvertently supplied the perfect experimental conditions for Lipuma's continued investigation of cepacia.

One former CF camper, "Raina," was able to detail how CF camps were at once sites of social enrichment and epidemiological investigation (interview with author, 2020). Raina traveled from her home in Great Britain to attend a Canadian CF camp in 1990. To Raina, camp was a "magical place" that promoted rigorous CF management and self-esteem. But CF camp also facilitated a research study whose significance did not register with her at the time. "Before we went, we were asked to take part in a research study," Raina explained. "So, you sign the consent forms and things and send phlegms off, because there was some kind of hypothesis that, you know, they were just interested to see what you grow before and after this trip." Raina even remembered how her father asked if camp was "a bit risky" but that "it didn't register as important." Just a few months after Raina returned from camp, Lipuma and colleagues (1990) published a study indicating that at a CF camp held the previous year, Patient A had transmitted cepacia to patient B. Through ribotyping and contact tracing, the authors illustrated how a combination of close interactions and shared spaces led to bacterial transmission between the two people.

For Raina and her camp compatriots, this conclusion did not come soon enough. Raina recalls acquiring Pseudomonas aeruginosa while away but she ultimately felt lucky as some peers got cepacia at CF camp. In 1993, a more extensive study of cepacia transmission at CF camps was published in the Morbidity and Mortality Weekly Report, an epidemiological digest published by the US Centers for Disease Control and Prevention (Honicky et al. 1993). The authors reported [End Page 93] 16 cases of cepacia acquisition at camp, 14 of which exhibited a ribotype that was identical to that of a camper to whom each of the newly infected subjects had been exposed. In addition, data regarding campers' behaviors and contacts revealed that campers who spent more time together or slept together in the same cabin, and those who hugged, kissed, shared toothpaste, finger food, or eating utensils were more likely to later culture cepacia. Looking back at camp, Raina seemed somewhat bewildered, reflecting on what she called "an experimental design" in which a camp with cepacia positive patients was "the intervention."

The 1993 study was only the beginning of epidemiologic work leveraging increasingly sophisticated molecular methods to study CF microbes. But looking back, the report did mark the beginning of the end of a certain version of CF sociality, one that was unfettered by the knowledge of infectious risk. The CFF's support of CF camps was pulled right away (Walters and Smith 1993). Then in 1995, the Foundation issued a guideline about infectious disease in CF that emphasized the importance of accurate bacterial typing in clinical laboratories. While CF camps thus provide a kind of origin story of cross-infection, centered on the mighty microbe cepacia, a longer and broader look at the history of CF reveals that Danish CF clinics had hypothesized cross-infection before 1980 (Bergan and Høiby 1975). In response, the Danish segregated CF patients by bacterial strain in order to maintain community contact while reducing the risk of cross-infection of the more common CF microbe, Pseudomonas aeruginosa (Høiby and Rosendal 1980). Yet it took the scourge of cepacia to inspire broader North American and European efforts to understand bacterial transmission in CF, work that gradually helped focus attention on the potential transmission of other more common CF microbes like Pseudomonas aeruginosa.

Despite the accumulation of evidence of cross-infection, it took 10 years for a standard set of infection control guidelines to be developed in the US (Saiman et al. 2003). During the intervening decade, clinics and CF camps, retreats, and conferences established their own rules for mitigating risk, with CF adults and families sometimes even advocating more nuanced and careful management of cross-infection within CF clinics. While it took time for policymakers to standardize infection control practices across US CF centers, CF clinicians and scientists in this period performed highly coordinated work across continents to develop a deeper understanding of cepacia.

A Microbial Jekyll and Hyde

Founded in 1996, the International Burkholderia Cepacia Working Group (IBCWG) gathered scientists from around the US, Canada, and Europe to further knowledge of the highly deleterious CF pathogen. By then cepacia had been reclassified from Pseudomonas to a new genus, called Burkholderia, after the plant pathologist Walter H. Burkholder who had originally described the microbe in [End Page 94] 1950 (Yabuuchi et al. 1992). The IBCWG established laboratory typing standards for the species, while studying the transmission of cepacia between CF patients and looking far and wide for environmental reservoirs of the microbe. Investigators itemized cepacia strains in diverse locations ranging from patient lungs and hospitals, to soils and waters, to velvet beans and donkeys (Lipuma 1998). This broad survey of potential sources of cepacia implicated scientists working in industry and agriculture (Govan, Hughes, and Vandamme 1996). Among them was the industrial microbiologist Ananda Chakrabarty of the pivotal Diamond vs. Chakrabarty Supreme Court case. While Chakrabarty's infamous "patent on life" involved a genetically modified strain of Pseudomonas aeruginosa (Doll 1998), he later patented a strain of cepacia that was capable of degrading Agent Orange (Chakrabarty and Kellogg 1985). Chakrabarty's well-publicized research buoyed hopes that hazardous wastes might be mitigated by special microbes. Chakrabarty even bolstered this enthusiasm by telling reporters that he predicted a day when farmers could spray the toxin to clean out weeds and then "root out" toxins by spraying cepacia (Lowenstein 1981).

Cepacia was therefore what some CF researchers called "a microbial Jekyll and Hyde" (Govan, Hughes, and Vandamme 1996). It was harmful to CF patients and other immunocompromised hosts, yet it was also capable of degrading environmental toxins and protecting certain crops. While soil treatment with Chakrabarty's genetically modified cepacia never gained traction, cepacia was applied in other bioremedial and agricultural contexts. In the 1990s, companies with names like "Stine Microbial" and "Good Bugs, Inc." registered different strains of cepacia with the Environmental Protection Agency (EPA) for use as a biopesticide (Federal Register 1997a, 1997b). Given the potentially abundant applications of cepacia, the IBCWG worked to educate these other cepacia scientists about the risks of human infection. This was especially important because taxonomic understandings of, and names for, cepacia strains were evolving rapidly (Govan, Hughes, and Vandamme 1996). Members of the IBCWG published CF data in broader microbiology journals and the group sponsored a conference in collaboration with the American Phytopathological Society (APS) and the EPA. Entitled "Burkholderia cepacia: Friend or Foe?" the day-long event gave CF researchers an opportunity to convey their concerns to an audience of plant pathologists and microbiologists working in agriculture (APS 1998).

In bridging scientific silos, the IBCWG researchers pushed other scientists to defend their assertions that certain strains of cepacia were safe. This required researchers to clarify both how they were characterizing cepacia strains and how they were determining the human pathogenicity of the microbes. The year after the "Friend or Foe" conference, IBCWG researchers in collaboration with the CFF also got the EPA to hold a hearing on the risks that agricultural use of cepacia posed to people with CF (Lewis and Kendall 1999). This mix of robust research and political savvy was successful in motivating the EPA in 2003 to pass [End Page 95] a significant new use rule restricting use of cepacia (Federal Register 2003a). Meanwhile, the IBCWG's efforts to engage the broader scientific community had resulted in the voluntary withdrawal of registrations on existing cepacia products, greatly decreasing the chance of environmental deployment of the microbe (Federal Register 2000, 2002).

What is particularly fascinating about the EPA hearing on cepacia is how the IBCWG promoted the adoption of genetic methods to assess cepacia strains. Michelle LaBonte's (2022) work on this period details the taxonomic complexity of cepacia whereby five strains of the microbe were categorized into genomovars, a newly coined term used to denote strains that are phenotypically similar but genotypically distinct from one another. Whereas industrial and agricultural microbiologists had often relied on phenotypic methods of classification, the hearing resulted in recommendations that more complex genetic methods also be used to assess and monitor biopesticidal strains of cepacia (Lewis and Kendall 1999). By convening previously siloed groups of scientists with varied expertise on cepacia, the IBCWG brought scientific and regulatory attention to the potential relationship between land and health, soil and lungs, arguing that the instability of bacterial genomes gave all cepacia strains the potential to impact the medically vulnerable.

Risks and Rules

This relationship between environment, ecology, and bacteria was not lost on Mallory Smith, a woman with CF who was infected with cepacia at age 11. Smith recounts her decade-plus battle with cepacia in a podcast called Biome, featured on Green Grid Radio, Stanford University's sustainability-focused station (Smith 2014). Smith compares cepacia infection to broader ecological catastrophe by narrating the story of two parallel landscapes, her tattered lungs and the damaged lands of Hawaii. Smith's vivid metaphor helps her teach others about the fragility of ecosystems, but Smith's story is also a testament to shifts in the shape of CF community. Smith was born in 1992, just as news of cross-infection was mounting and the opportunities to meet other people with CF began to diminish. Smith faced the disease in isolation until her early 20s, when she met other people with CF while hospitalized. Masked and at a distance, through outdoor chats and Facebook messages, Smith eventually found friends who satisfied her need to confide in people who understood her day-to-day life (Smith 2019).

Had Smith been born earlier, she might have connected with other children with CF at CF camp or fundraisers. But in the course of the 1990s, CF community gatherings diminished in response to infectious risks. Organizations that continued to hold CF gatherings worked hard to establish infection control rules that enabled community while also reducing the risk of infection (Cystic-L 1997). Their efforts ranged from excluding or cohorting cepacia patients to detailed hygiene [End Page 96] measures. Community organizers associated with Cystic Fibrosis Research, Inc. (CFRI) even lobbied clinics to adopt many of their personal hygiene measures, to monitor and document infection control routines within wards, clinics, and pulmonary function laboratories, and to communicate to patients whether microbiological testing was performed according to recently developed standards. Since the safety of CFRI gatherings depended upon accurate cepacia screens and quality infection control measures at CF clinics, patient advocates were vocal that the clinics needed to keep patients informed and do more to help prevent spread.

In 2003, the CFF published updated guidelines (Saiman et al. 2003). Whereas the 1995 guidelines on "Infectious Disease in Cystic Fibrosis" included only a few pages on bacterial surveillance and infection control and prevention, the new 2003 guidelines were devoted entirely to the challenge of preventing infection and transmission. Among other things, the guidelines called for people with CF to maintain three feet of distance from one another. The guidelines were further updated in 2013, with even more rigorous recommendations (Saiman et al. 2014). The 2013 guidelines called on CF centers to implement contact precautions for all people with CF whereas previously precautions were dependent on sputum culture. People with CF were also advised to maintain six feet of distance, wear masks in CF clinics and wards, and adhere to hygiene guidelines. Lastly, only one person with CF was deemed permissible at any given CFF-sponsored indoor event to limit chance encounters in these settings. Both the 2003 and 2013 guidelines made only brief reference to the psychosocial impact of infection control recommendations, largely as a potential impediment to adherence. Though many people with CF appreciated the CFF's efforts to make clinics and hospitals safe, the one-person-rule at indoor Foundation events raised concerns, especially among older people with CF.

Paul Quinton, a preeminent scientist who himself has CF, is among the one-person-rule's most vocal and vehement critics. Quinton diagnosed himself with CF at age 19 and made the critical scientific contribution of describing the chloride transport problem that underlies CF (Quinton 2002). Quinton and other vocal CF adults feel that the Foundation's rules are based on an outdated paradigm of CF as a pediatric disease, with the CFF and protective parents making decisions for people with CF. In the medical journal Chest, Quinton and colleagues Steven Shepherd, Eric Goodrich, and Julie Desch, all of whom also have CF and expertise in either public health or medicine, argued that the ban on conference attendance failed to quantify and weigh risk of infection against the benefits of community, social interaction, and the opportunities to acquire and contribute disease-specific knowledge (Shepherd et al. 2014). Noting that evidence of cross-infection came from studies of nosocomial transmission and CF camps that lacked basic hygiene measures, the authors were adamant that the rule excluding people with CF from CF conferences was based on feelings rather than evidence. [End Page 97]

In addition, Quinton and colleagues claimed that the rule was harmful, especially to adults. By rendering people with CF as sources of contagion and danger to one another, Quinton and colleagues argued that the rule could even damage "what for many patients is an already fragile sense of self-worth" (Shepherd et al. 2014, 682). Furthermore, they argued that by making a blanket rule for pediatric and adult patients, the Foundation implied that CF adults were incompetent to make their own decisions. To Quinton and colleagues, the CFF's job was to promote policies that effectively balanced safety and the opportunity to participate in Foundation events—in their words, "not just to add to an accountant's tally of tomorrows," but rather "to help young people use their tomorrows to becoming healthy, functioning adults" capable of making responsible choices (682).

When I interviewed Quinton, he described the goal of health in much broader terms as a state that factored in mental health, and agency, but also complex microbiology (interviews with author, 2015 and 2017). The "absence of bacteria is not health," he explained, referencing the microbial interactions within CF lungs. In keeping with more sophisticated understandings of CF lung disease, he explained how specific microbes often do the most damage when disrupted by other microbes. Quinton even nodded to fecal transplants as an instance when cross-infection with good microbes is clinically warranted. But Quinton's concerns extended beyond questions of mental health and microbiology. When it came to the potential impact of the CFF's banning people with CF from indoor events, he worried that it was perhaps a slippery slope, and that he might one day be declined entry to an airplane. Quinton's lungs often raised concerns that he might have tuberculosis, and he lived through tuberculosis screenings before he diagnosed himself with CF in college (Quinton 2002).

While Quinton's concerns might seem personal, they came to life in 2012, when a boy named Coleman Chadam was excluded from a Palo Alto–area public school.

Chadam v. Palo Alto School District

In October 2012, Coleman Chadam was pulled from his Palo Alto School District classroom and directed to attend another area school in order to protect Chadam and two siblings with CF who were already in attendance. But Coleman Chadam did not have CF. Legal records indicate he had "the genetic marker for, but not the disease of, cystic fibrosis," meaning that he was likely just a CF carrier or had a more complex genotype but lacked signs of CF (Kadvany 2018; Wagner 2016). CF carriers are relatively common, and in adults carrier status is generally revealed via carrier screening for reproductive purposes; carrier status may also be revealed incidentally via newborn screening, which is how Coleman Chadam's CFTR genotype made it into his medical records (Broder 2012). The school's misinterpretation of this result ultimately led to the family's legal case, Chadam v. [End Page 98] Palo Alto School District (No. C 13–4129 CW (N.D. Cal. Jan. 29, 2014); Kadvany 2018).

The case grabbed the attention of legal experts because it highlighted shortcomings of the 2008 Federal Genetic Information Non-Discrimination Act (GINA). GINA covers discrimination based upon genetic information in the realms of health insurance and employment, but it fails to extend to public services or accommodations like education. California State has a more inclusive genetic discrimination law called CalGINA that does cover education. Yet the Chadams' lawyer ultimately elected to argue the case under section 504 of the Americans with Disability Act (ADA). Under the powerful and familiar federal mandate Coleman Chadam's genetic status was argued to be a perceived disability that led to discrimination by the school district (Wagner 2016). After moving between the district court and the Court of Appeals, the case was ultimately settled out of court (Kadvany 2018; Wagner 2017). But Chadam raised crucial questions for the legal community about how genetic discrimination is covered in different settings like public education.

In addition to gaining attention from legal scholars, the case also garnered substantial media attention. With articles like one in Wired magazine entitled, "DNA Got a Kid Kicked Out of School—and It'll Happen Again," the Chadams' story resonated with broader concerns about privacy and the potential misuses of genetic information (Zhang 2016). Given genetic screening often gets applied in prenatal and newborn contexts, the misinterpretation and misuse of genetic information in this case raises questions about the disclosure and communication of this type of information for patients, families, providers, and policymakers. Similarly, the case raises questions about the appropriate use of such information in the event genetic markers do significantly increase the risks of infection and transmission, as for people with CF. For example, Geller and colleagues (2020) delineate the ethical questions raised by the application of genomics to COVID-19 management decisions, given ongoing research on the genomic basis of host susceptibility to infection and responses to vaccination and treatment. Querying the ethics of using genomic information to make public health decisions, they note the role genomics might play in balancing the benefits and harms of school closures by allowing attendance of individuals whose genetics suggest a lower risk of infection. Thus, while some of the coverage of Chadam v. Palo Alto School District was sensationalistic, the case is a critical example of the unintended consequences of our expanding knowledge of the relationship between genetics and infectious disease. That Coleman Chadam was excluded from school also confirmed the worst fears of a few CF advocates, making Paul Quinton's 2015 declaration to me that "If I have to be the Rosa Parks of this, I will" much more understandable.

While many CF adults are supportive of policies that mitigate infectious risk, in interviewing nearly 50 adults with CF for a project on CF community, I found [End Page 99] that even supporters of the CFF's policies raised concerns about how the guidelines were devised and shared with the community. The CFF committee charged with updating the infection control guidelines consisted of a single adult with CF (who happened to be trained in law), along with three parents of CF children and 17 health-care personnel with expertise in CF (Saiman et al. 2014). Although the 2013 policy was first posted for public comment, the initial dissemination of the final recommendations revealed minimal consideration of the psychosocial ramifications for a tight-knit community that was used to weighing evidence, gathering socially, and working collectively to combat CF. This history of infectious disease in CF reveals that people with CF anticipated many of the necessary measures for mitigating infection and foresaw the potential consequence of discrimination based upon such policies, illustrating the importance of involving varied stakeholders early in the development and dissemination of guidelines.

When Genetic and Microbial Risk Collide

While Mallory Smith saw in her battle with cepacia a metaphor or lesson about environmental degradation, I see this story of CF pathogens as a case study that unites the ethical, legal, and social implications of genomic and microbial research. The CF story raises numerous ethical questions about iatrogenic harms, patient autonomy, and balancing risks of infection against psychosocial benefits. It also entails marked social implications for the CF community, which largely disbanded and then reconfigured in response to infectious risk. Importantly, CF highlights the regulatory challenge of useful substances that harm a minority, and the potential for discrimination based on microbial and genetic information. CF is therefore an illustrative case study for contemporary efforts to anticipate the potential implications of microbial and genomic information.

Both the Human Genome Project and the Human Microbiome Project have made concerted efforts to address the ethical, legal, and social implications of newfound scientific knowledge (Dolan, Lee, and Cho 2022; Geller et al. 2014), a tradition that was largely absent in the scientific research on cross-infection in CF. Although the informatic and molecular methods employed in contemporary studies of the genome, infectious diseases, and the microbiome differ significantly from those used to study cross-infection, the CF story illustrates the watershed impact of introducing novel molecular methods to study microbes within a group defined by a shared genetic diagnosis.

CF raises important questions and considerations for contemporary researchers contemplating the potential consequences of scientific knowledge. The CF community's work to address the threat of infection highlights how microbes connect diverse stakeholders. Indeed, the organized efforts to limit environmental deployment of cepacia call attention to the myriad factors that may be necessary to make vulnerability visible and to inspire protective action. CF is an unusually [End Page 100] well-resourced disease with funding from the highly effective CFF, the pharmaceutical industry, and governmental institutions (Farooq et al. 2020). Through CF clinics, research funding, and lobbying efforts, the CFF has been able to set research agendas, establish guidelines, impact behavior, and influence policymakers to mitigate infectious risks. The influence of the CF community on the EPA's regulation of cepacia demonstrates how a well-resourced, well-organized interest group can make headway on a threat that, in fact, affects a broader (though largely unidentified) at-risk population. After all, cepacia does not harm people with CF exclusively. Anyone with a compromised immune system may be more susceptible to infection; for example, cepacia infections have been repeatedly observed in patients with chronic granulomatous disease, and even hearty US soldiers proved vulnerable to cepacia infection after extensive exposure in the swampy training and fighting conditions of the Vietnam war (Greenberg et al. 2009; Taplin, Bassett, and Mertz 1971). In 2020, a case of Burkholderia cepacia pneumonia and bacteremia was even reported in an immunocompetent patient compromised by COVID-19 infection (Osman and Nguyen 2020).

In a way, given the scientific acumen of researchers and the political savvy of the CFF, the vulnerability of CF patients ultimately may have protected other vulnerable populations. At the same time, the tight regulation of cepacia may have foreclosed important opportunities for mitigating environmental toxins like trichloroethylene that are implicated in cancer and ecological destruction (Vial et al. 2011). Indeed, biotechnologists continued to hope that genomic sequencing of cepacia isolates might clearly distinguish pathogenic and ecological strains or reveal specific virulence genes that could be silenced to allow environmental use of manufactured strains (Chiarini et al. 2006).

The story of how the CF community worked to address the threat of infection also shows how insights about infectious risk can disband and reconfigure community, altering the experiences of disease and sociality. While epidemiological evidence initially raised concerns about infectious risk in CF, the application of a growing array of molecular methods to microbial CF research were pivotal in proving transmission, first with cepacia and later with respect to Pseudomonas aeruginosa and other bacteria (Cheng et al. 1996; LiPuma et al. 1990). Today, advances in genomics are impacting microbial diagnostics, studies of transmission, and knowledge of microbial diversity and host genetic factors related to microbial colonization. Increasingly, this work reveals that genetic diseases have an infectious component, while infectious diseases often have a genetic component (Casanova and Abel 2013; Duggal, Geller, and Sutherland 2019). Within CF research, ongoing investigations of CF pathogens have expanded to investigate the CF lung and gut microbiomes (Caverly, Zhao, and LiPuma 2015; Madan et al. 2012). For the CF community, the social implications of infectious risk remain an enduring consequence of cross-infection, one that has pushed people with CF to become pioneers of virtual socialization (Nowakowski et al. 2022). As the [End Page 101] boundaries between genetic and infectious diseases become increasingly porous, the CF story provides a clear example of this blurring while offering examples of the ethical, legal, and social implications of newfound microbial knowledge. With decades of experience with both microbial surveillance and social distancing, CF offers vital lessons for a time a when we are all becoming acutely aware of our microbes.