United States Court of Appeals

for the Fifth Circuit ____________

No. 22-40728

____________

Lisa Torrey; Kathryn Kocurek, Individually and on behalf of the 

Estate of J. David Kocurek, Ph.D.; Amy Hanneken; Jane 

Powell; Carol Fisch; John Valerio, Individually and as Next 

Friend of Christopher Valerio; Randy Sykes; Brienna 

Reed; Rosetta Fuller; Adriana Monteiro Moreira; 

Jessica McKinnie; Kristine Woodard; Gayle Clarke; 

Allison Lynn Caruana; Chloe Lohmeyer; Tawnya Dawn 

Smith, Individually and as Next Friend of Monet Pitre; Mike 

Peacher, Individually and as Next Friend of Ashleigh Peacher; 

Alarie Bowerman, Individually and as Next Friend of Elisa 

Bowerman, Emory Bowerman and Anais Bowerman, 

Plaintiffs—Appellants,

versus

Infectious Diseases Society of America, 

Defendant—Appellee.

______________________________

Appeal from the United States District Court 

for the Eastern District of Texas

USDC No. 5:17-CV-190

______________________________

Before Jones, Stewart, and Duncan, Circuit Judges.

Stuart Kyle Duncan, Circuit Judge:

United States Court of Appeals

Fifth Circuit

FILED

November 16, 2023

Lyle W. Cayce

Clerk

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A professional society specializing in the study and treatment of 

infectious diseases published guidelines in a peer-reviewed medical journal 

for treating Lyme disease. Individuals who claim to suffer from persistent 

Lyme disease symptoms sued the society, alleging the guidelines harmed 

them by casting doubt on how chronic Lyme disease should be treated and 

even whether the condition exists. The district court dismissed the claims 

because it concluded that the statements at issue were non-actionable 

medical opinions, not factual assertions that could support a claim for 

fraudulent or negligent misrepresentation. We AFFIRM.

I.

A.

Plaintiffs are people who claim to suffer from chronic Lyme disease. 

A person contracts Lyme disease from ticks carrying the bacterium Borrelia 

burgdorferi. See generally Robert L. Bratton et al., Diagnosis and Treatment of 

Lyme Disease, 83 Mayo Clinic Proc. 566 (2008). Typical symptoms are

fever, headache, swollen joints, fatigue, and rashes. Many patients respond 

to short-term antibiotics, but some do not. This latter group is said by some 

to experience “post-Lyme disease syndrome,” “posttreatment chronic 

Lyme disease,” or “chronic Lyme disease.”

The nature of chronic Lyme disease, and how to properly treat the 

condition, are matters of scientific dispute. Plaintiffs allege that some 

doctors, accepting the phenomenon’s existence, recommend a holistic 

approach that may include long-term antibiotics. Others take a different 

view—like the Defendant here, the Infectious Diseases Society of America 

(“IDSA”), a professional society of doctors, scientists, and other healthcare 

professionals.

In 2006, IDSA published The Clinical Assessment, Treatment, and 

Prevention of Lyme Disease, Human Granulocytic Anaplasmosis, and Babesiosis: 

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Clinical Practice Guidelines by the Infectious Diseases Society of America

(“the Guidelines”). The Guidelines appeared in the peer-reviewed medical 

journal Clinical Infectious Diseases, one of IDSA’s publications. The 

Guidelines extensively discuss how to diagnose and treat Lyme disease.1

Throughout, they express doubt about the causes, frequency, and even the 

existence of chronic Lyme disease. Moreover, the Guidelines do not 

recommend long-term antibiotic therapy for persons with persistent Lyme 

symptoms who have already received recommended treatments.

B.

In November 2017, Plaintiffs sued IDSA, six health insurance 

companies and a health insurance trade association (collectively, the 

“Insurance Defendants”), and seven doctors (“the Doctors”) who were 

among the fourteen authors of IDSA’s 2006 Guidelines. Plaintiffs alleged 

that the Insurance Defendants paid the Doctors “large consulting fees” to

include baseless treatment recommendations in the Guidelines, which, in 

turn, would allow the Insurance Defendants to deny coverage for chronic 

Lyme disease. Plaintiffs asserted claims under the Racketeer Influenced and 

Corrupt Organizations Act (RICO), 18 U.S.C. § 1962(a)–(d), as well the 

Sherman Act.

From 2019 to 2021, Plaintiffs settled with all Insurance Defendants. 

They also conducted full discovery on their RICO and antitrust claims. In 

January 2021, on the last day of fact discovery, Plaintiffs filed a Second 

Amended Complaint, adding for the first time fraudulent and negligent 

misrepresentation claims against IDSA. IDSA and the Doctors moved to 

_____________________

1 We discuss specific statements from the Guidelines below, as necessary to 

address Plaintiffs’ arguments.

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dismiss Plaintiffs’ Second Amended Complaint and also moved for summary 

judgment on the RICO and antitrust claims.

In March 2021, Plaintiffs filed a Third Amended Complaint, adding

allegations supporting their misrepresentation claims. IDSA and the 

Doctors again moved to dismiss. Plaintiffs later voluntarily dismissed with 

prejudice their RICO claims against IDSA and the Doctors and likewise

dismissed their antitrust claim against the Doctors (but not against IDSA). 

In September 2021, the district court granted IDSA’s motion for summary 

judgment on the antitrust claims.

All that remained were Plaintiffs’ misrepresentation claims against 

IDSA, which the district court dismissed shortly thereafter. The court 

reasoned that “the statements in the IDSA Guidelines are not the type of 

statements that Plaintiffs can recover for based on misrepresentation, as they 

are medical opinions, not factual representations.” At best, the court 

observed, “Plaintiffs cite other studies or statements that have reached 

different conclusions or formed different opinions than those expressed in 

the IDSA Guidelines.”

Subsequently, IDSA moved to recover $43,940.06 in costs for 

defending against Plaintiffs’ RICO and antitrust claims. Plaintiffs filed a 

notice stating they agreed with IDSA’s proposed bill of costs. Accordingly, 

the district court granted IDSA $43,940.06 in costs and entered final 

judgment against Plaintiffs.

Plaintiffs timely appealed.

II.

We review de novo a Rule 12(b)(6) dismissal for failure to state a claim. 

See Norsworthy v. Hous. Indep. Sch. Dist., 70 F.4th 332, 336 (5th Cir. 2023). A 

complaint that fails to state a facially plausible claim must be dismissed. Bell 

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Atl. Corp. v. Twombly, 550 U.S. 544, 570 (2007). “[F]acial plausibility” 

means “factual content that allows the court to draw the reasonable inference 

that the defendant is liable for the misconduct alleged.” Ashcroft v. Iqbal, 556 

U.S. 662, 678 (2009). We accept well-pled facts as true and view them in the 

light most favorable to the plaintiff. PHI Grp., Inc. v. Zurich Am. Ins. Co., 58 

F.4th 838, 841 (5th Cir. 2023). But we disregard “conclusory allegations, 

unwarranted factual inferences, or legal conclusions.” Heinze v. Tesco Corp., 

971 F.3d 475, 479 (5th Cir. 2020) (citation omitted).

III.

Plaintiffs argue the district court erred in dismissing their 

misrepresentation claims against IDSA. They contend that the Guidelines, 

properly read, do not merely report medical opinions but instead make

factual representations about the proper treatment for, and indeed the very 

existence of, chronic Lyme disease. We disagree. Instead, as explained below, 

we agree with the district court that the Guidelines “are medical opinions, 

not factual representations,” and cannot form the basis for a claim of 

fraudulent or negligent misrepresentation.

Before beginning our analysis, we say a brief word about the applicable 

law. Plaintiffs’ misrepresentation claims might be governed by the laws of 

three different States—Texas, New York, or Virginia. See generally

Restatement (Second) of Conflict of Laws §§ 6, 145 (Am. L. 

Inst. 1971). The parties spar over this choice-of-law question, but their 

disagreement does not touch the key issue on which we resolve this appeal—

i.e., whether the Guidelines constitute non-actionable medical opinions or 

actionable factual representations.2 As to that issue, the parties appear to 

_____________________

2 The parties’ disagreement about applicable state law instead centers on the issue 

of “derivative” reliance—specifically, whether Plaintiffs may maintain a claim based on 

the allegation that their doctors relied on IDSA’s alleged misrepresentations. Because we 

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agree that those States’ laws do not meaningfully differ.3 Accordingly, we 

need not resolve the choice-of-law question. See LHC Nashua P’ship, Ltd. v. 

PDNED Sagamore Nashua, L.L.C., 659 F.3d 450, 456–57 (5th Cir. 2011) 

(explaining we need not decide governing State law “if our conclusions 

would be the same”). We therefore turn to Plaintiffs’ arguments.

Plaintiffs appear to agree that merely publishing a medical opinion—

even a hotly debated one—in a peer-reviewed journal cannot give rise to a 

misrepresentation claim. Some of our sister circuits have adopted that 

proposition in analogous contexts, relying on both the First Amendment and 

commonsense observations about the nature of scientific debate. See Pacira 

Biosci., Inc. v. Am. Soc’y of Anesthesiologists, Inc., 63 F.4th 240, 249 (3d Cir. 

2023) (holding that “content, verifiability, and context” all support 

conclusion that statements in peer-reviewed medical journal are 

“nonactionable opinions” for trade libel claims); ONY, Inc. v. Cornerstone 

Therapeutics, Inc., 720 F.3d 490, 498 (2d Cir. 2013) (holding that contents of 

article published in peer-reviewed medical journal are “non-actionable 

scientific conclusions” for false advertising claim under Lanham Act). Our 

circuit has discussed one of those precedents favorably, albeit in dicta. See 

Eastman Chem. Co. v. Plastipure, Inc., 775 F.3d 230, 235 (5th Cir. 2014) 

(“After a thorough analysis, the Second Circuit concluded that the First 

Amendment places scientific debates unfolding within the scientific 

community beyond the reach of the Lanham Act.” (citing ONY, 720 F.3d at 

496–97)). We discuss those cases in greater detail below. For their part, 

_____________________

do not address this issue, we need not address the antecedent choice-of-law question posed 

by the parties. 

3 Indeed, Plaintiffs’ brief concedes there is no substantive difference on this issue 

among the laws of Texas, New York, or Virginia and that, consequently, “the Court need 

not resolve the choice-of-law question with regards to this issue.”

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Plaintiffs do not contest the principle and, in any event, cite no decision 

casting any doubt on it.4

What Plaintiffs do argue, however, is that the district court failed to 

read the Guidelines’ statements about chronic Lyme disease “in context.”

Had it done so, they contend, the court would have seen that the Guidelines 

do not merely report opinions but, rather, make factual assertions intended 

to influence doctors and insurance companies. These arguments miss the 

mark.

Plaintiffs contend the district court “literally” read the Guidelines 

without considering “the perception of them as applied by medical 

practitioners, other researchers, and influential players within the medical 

community.” We disagree. Plaintiffs cite no authority instructing courts to 

read the Guidelines in that way. Instead, Plaintiffs cite cases merely saying

courts must consider “a reasonable person’s perception of the entirety of a 

publication,” In re Lipsky, 460 S.W.3d 579, 594 (Tex. 2015), and must avoid

“literalism.” Immuno AG. v. Moor-Jankowski, 567 N.E.2d 1270, 1273 (N.Y. 

1991). These are everyday interpretive rules, but Plaintiffs fail to show how 

the district court violated them. To the contrary, the district court explicitly 

recognized the Guidelines’ context: it noted that the Guidelines “set forth 

explanations of medical research, experiments and knowledge based on 

citations to other published studies and clinical trials, not naked assertions of 

fact.” Indeed, if anyone has taken the Guidelines out of context, it is

Plaintiffs. Asthe district court observed, the statementstargeted by Plaintiffs

_____________________

4 Accordingly, we need not determine when, if ever, the mere publication of a 

medical or other scientific opinion might form the basis for a cause of action for 

misrepresentation or any other tort.

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“are isolated portions of complex documents and reading the IDSA

Guidelines in their entirety undermines Plaintiffs’ pleadings.”

Plaintiffs also contend the Guidelines show that IDSA tried to 

“bury” or “explain away” treatment failures, which Plaintiffs interpret as 

the organization’s “skepticism and overall disapproval of the studies relating 

to instances of chronic Lyme disease.” This argument is unavailing. Contrary 

to Plaintiffs’ view, the Guidelines do not become actionable factual 

representations merely because they disapprove of studies Plaintiffs prefer. 

As the district court concluded, “[a]t best, Plaintiffs cite other studies or 

statements that have reached different conclusions or formed different 

opinions than those expressed in the IDSA Guidelines.” See Am. Sch. Of 

Magnetic Healing v. McAnnulty, 187 U.S. 94, 106 (1902)) (“[D]ifferent

schools of medicine have their followers, and many who believe in the one 

will pronounce the other wholly devoid of merit. But there is no precise 

standard by which to measure the claims of either . . . .”).

Plaintiffs next argue that the district court erred by relying on a 

Guidelines disclaimer which “contradicts” the Guidelines’ opening 

sentence. We again disagree. The disclaimer states that the “[G]uidelines 

cannot always account for individual variation among patients,” and that 

“the ultimate determination” to apply them should “be made by the 

physician in the light of each patient’s individual circumstances.” The 

Guidelines’ introductory sentence states that they “are intended for use by 

health care providers who care for patients who either have these infections 

or may be at risk for them.” We see no contradiction between the two 

statements. It is perfectly consistent (1) to offer general guidance to 

physicians about treating Lyme disease, while (2) recognizing the final 

decision should be left up to the treating physician given inevitable variation 

in individual cases. In any event, even if Plaintiffs were correct that some 

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tension existed between the two statements (although we see none), they cite 

no authority that this amounts to an actionable misrepresentation.

As to specific statements in the Guidelines, Plaintiffs emphasize two. 

They take issue with IDSA’s positions that (1) “[t]here is no convincing 

biological evidence for the existence of symptomatic chronic B. burgdorferi

infection among patients after receipt of recommended treatment regimens 

for Lyme disease,” and (2) “[a]ntibiotic therapy has not proven to be useful 

and is not recommended for patients with chronic (>6 months) subjective 

symptoms after recommended treatment regimens for Lyme disease.”5 On 

their face, however, these statements are medical opinions. In this context (a 

scientific debate over treatment options for persistent Lyme symptoms), to 

say that evidence is not “convincing” or that some treatment is “not 

recommended” is plainly to express a medical opinion. Just because Plaintiffs 

disagree with those opinions does not mean that IDSA is somehow liable 

because their doctors or insurance providers found the opinions persuasive.

Not only do Plaintiffs misread the Guidelines, but accepting their 

arguments would risk putting us at odds with other circuits. For instance, in 

the Second Circuit’s ONY case, the plaintiff claimed an article in a peerreviewed medical journal made false statements about the effectiveness of 

treatments to help lung function in premature infants. 720 F.3d at 492–95. 

The Second Circuit recognized that scientific discourse “poses several 

problems for the fact-opinion paradigm of First Amendment jurisprudence.” 

Id. at 496. On the one hand, “[m]ost conclusions contained in a scientific 

journal article are, in principle, capable of verification or refutation by means 

of objective proof.” Ibid. (internal quotation marks and citation omitted). On 

_____________________

5 Plaintiffs raise similar objections to IDSA’s not recommending long-term 

antibiotic therapy “[b]ecause of a lack of biological plausibility, lack of efficacy, absence of 

supporting data, or the potential for harm to the patient.”

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the other hand, “it is the essence of the scientific method that the conclusions 

of empirical research are tentative and subject to revision, because they 

represent inferences about the nature of reality based on the results of 

experimentation and observation.” Ibid. Accordingly, the court concluded 

that the statements at issue were “more closely akin to matters of opinion, 

and [were] so understood by the relevant scientific communities.” Id. at 497. 

It therefore held that “the contents of the article [were] non-actionable 

scientific conclusions.” Id. at 498.

Similarly, the Third Circuit’s Pacira case involved a dispute over the 

efficacy of an anesthetic to control post-surgical pain. 63 F.4th at 243. The 

manufacturer plaintiff sued defendants for trade libel for publishing 

statements in a medical journal criticizing the anesthetic. Ibid. Citing ONY, 

the Third Circuit examined the content of the publication, the verifiability of 

the assertions, and the context in which they were written. Id. at 245–49. The 

court concluded that a “fair and natural reading of these statements shows 

that these are nonactionable subjective expressions.” Id. at 246 (internal 

quotation marks and citation omitted). 

Plaintiffs rely on our opinion in Eastman Chemical Co. v. Plastipure, 

Inc., but it does not help them. That case involved a plaintiff who

manufactured a plastic resin used in drinking containers. 775 F.3d at 233. 

Defendants, who were plaintiff’s competitors, published an article in a peerreviewed journal “summarizing the results of its testing of more than 500 

commercially available plastic products.” Ibid. They also distributed a threepage brochure depicting plaintiff’s resin as containing harmful chemicals. Id. 

at 233–34. We allowed plaintiff’s Lanham Act suit to go forward, but only 

after emphasizing that “[plaintiff] did not sue [defendants] for publishing an 

article in a scientific journal.” Id. at 236. Rather, we stated, “[plaintiff] 

sought to enjoin statements made in commercial advertisements and directed 

at customers.” Ibid. Accordingly, we affirmed the injunction, which applied

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only to defendants’ statements “in connection with any advertising, 

promotion, offering for sale, or sale of goods or services,” but not to the 

journal article. Id. at 237. As this description of Eastman confirms, the case 

helps IDSA, not Plaintiffs.

In sum, the district court did not err in holding that IDSA’s 

Guidelines statements about chronic Lyme disease constitute nonactionable 

medical opinions.6

IV.

The district court’s judgment is AFFIRMED.

_____________________

6 Alternatively, Plaintiffs argue that—even if the Guidelines are nonactionable 

medical opinions—they can still sue for misrepresentation because IDSA knew the

opinions were false. We need not address this argument because, as IDSA points out, 

Plaintiffs did not raise it in the district court. Plaintiffs’ reply brief does not even attempt 

to argue to the contrary. Accordingly, the argument is forfeited. See Moore v. LaSalle Mgmt. 

Co., L.L.C., 41 F.4th 493, 509 (5th Cir. 2022) (“We do not consider arguments raised for 

the first time on appeal.” (internal quotation marks and citation omitted)).

Finally, Plaintiffs argue the district court erred by granting IDSA’s bill of costs as 

the prevailing party. But the only basis on which Plaintiffs argue for reversal is that the 

district court erred in dismissing their misrepresentation claims. Because we affirm the 

dismissal of those claims, we necessarily affirm the bill of costs.

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