Actinos and CIRS: how to know when mold is not the whole story

A r/CIRS poster had done the part that was supposed to make things clearer. Her latest HERTSMI-2 came back at a 6. She had spent three months on the Shoemaker path. She still felt worse at home.

Her question was the real question behind this page: "Test for Actinos? go back on CSM and just grin and bear it?" A few lines later came the part that matters as much as the lab number: "Cannot go through another remediation."

Actinobacteria, often called actinos or actinomycetes among people dealing with CIRS (Chronic Inflammatory Response Syndrome, the mold-related illness this guide is about), are gram-positive bacteria, not fungi. That category distinction matters operationally. HERTSMI-2 only tests for fungi; a clean number cannot tell you whether actinos are present.

The useful question is not whether actinos are worse than mold. If you already handled mold and still are not improving, what can actually tell you whether actinos are part of your picture?

Actinos are bacteria, and the test has to match the question

MoldCo's Mold Home Test Kit is a HERTSMI-2 dust qPCR for five fungal species: Aspergillus penicillioides, Aspergillus versicolor, Chaetomium globosum, Stachybotrys chartarum, and Wallemia sebi. It does not detect actinobacteria. Neither do MoldCo's blood panels. Starter, CIRS, and Complete are inflammatory and hormone biomarker draws through LabCorp; they measure how the body is reacting, not what is in the dust.

The musty smell people associate with mold is a useful tell. It comes from a VOC called geosmin, produced by actinomycetes as well as some molds. The smell that made the building feel sick is not, by itself, a fungal signal.

WHO's indoor air guidance describes microbial pollution from hundreds of species of bacteria and fungi when persistent moisture is present. A large epidemiologic review found consistent links between damp buildings and respiratory or allergic illness, with no single causal agent isolated in every case (Mendell et al., 2011). In a NIOSH-led investigation of one water-damaged office building, thermophilic actinomycetes in dust were associated with reduced lung function on spirometry and greater odds of granulomatous-disease-like symptoms, while fungi were not associated with the measured outcomes (Park et al., 2017). One study does not prove CIRS or your case. It does make one point hard to ignore: bacterial exposure in a damp building is not a fringe concern.

In the CIRS framework developed by Shoemaker, actinos are treated as a separate exposure axis alongside fungi, endotoxins, mycotoxins, and other inflammagens. Shoemaker's 2021 paper studied dust-based Dominance and Prevalence Indices and their relationship to GENIE gene-expression patterns in a small observational cohort (Shoemaker et al., 2021). That does not make actinos the answer in every case. It makes them a separate question.

What each test can and cannot tell you

A better way to think about this is: every test has a job. The mistake is expecting one test to do all of them.

HERTSMI-2. What this can tell you is whether five CIRS-relevant fungi show up in dust above threshold. What it cannot tell you is whether actinos, endotoxins, beta-glucans, or other bacterial markers are present. MoldCo's Mold Home Test Kit is a HERTSMI-2 dust qPCR; it is not an actino test. For help with the number, see the guide to interpreting HERTSMI-2 or ERMI and the mold illness testing overview.

ERMI. ERMI is a wider 36-species fungal qPCR panel that can characterize fungal burden in dust. It still does not answer the actino, endotoxin, or beta-glucan question on its own.

An extended commercial dust panel with actino measurement. Some dust panels add actinobacteria measurement through Dominance and Prevalence Indices, which separate skin-derived (Human Habitat) from soil-derived (Soil Habitat) actinos. What this can tell you is whether the dust profile appears weighted toward one of those categories in the Shoemaker framework. These indices are not widely used in current CIRS practice. There is also a timing problem: actinos run high in almost any water-damaged building, so measuring environmental actinos is not useful until remediation, if it is needed, is finished. What it cannot tell you is fungal contamination or endotoxin exposure; Shoemaker's physician guide says the Actino Index "will not indicate fungal contamination or growth of bacteria making endotoxins" (SurvivingMold physician guide). MoldCo does not perform extended actino dust-panel testing.

GENIE. GENIE is a host-response transcriptomic blood test ordered through some CIRS-aware clinicians. In the Shoemaker observational cohort, it can help separate which exposure category appears to be driving the inflammatory response, including mold, actinos, endotoxins, and related pathways. What it cannot tell you on its own is where the exposure is coming from or what your treatment plan should be. MoldCo does not run GENIE.

Multi-site actino swab. Some CIRS practitioners outside MoldCo use body-site swabs for actinos, including nose, mouth, and (in females) vaginal sites. Dr. Scott McMahon's caveat from the AMA travels with this topic: the science is very new, and the therapies have been tested on relatively small populations. What this can tell you is whether actinos are recovered from the sampled site. What it cannot tell you, on its own, is the full clinical meaning; that takes clinical history read alongside the testing. MoldCo does not offer this testing.

MARCoNS nasal swab. A MARCoNS swab asks about multi-antibiotic-resistant coag-negative Staph in the nose. It is a recognized step in the Shoemaker Protocol, and MoldCo can address suspected MARCoNS for members when clinically appropriate. The swab does not target actinos, though very occasionally actinos do show up on one.

Endotoxin and beta-glucan dust testing. These tests answer different exposure questions: bacterial endotoxin and fungal cell-wall beta-glucan. They do not answer whether actinos are present. They can matter when the remaining driver is some combination of mold, actinos, and endotoxin. MoldCo does not offer them.

MoldCo blood panels. Starter ($56), CIRS ($299), and Complete ($799) measure inflammatory and hormone biomarkers (TGF-beta1, MMP-9, MSH, C4a, and others) through LabCorp. They can help show how the body is responding. They do not test for actinobacteria. That is why the Complete Health Panel is the wrong call to action for an actino-specific question, even though it can be useful elsewhere in the mold-toxicity picture.

What changes when actinos are actually in the picture

If actinos are confirmed, named in outside testing, or clinician-interpreted as part of the case, the conversation changes. It still should not become a self-treatment checklist.

In a Reddit AMA, not in published or independently verified work, Dr. Shoemaker described daily medicated shampoo for a positive actino skin test, named Selsun Blue as his personal choice, and noted that more abrasive soaps such as Lava may remove more skin actinos but may be too rough for daily use. The conditional and the caution are the point. Independent dermatology trials of selenium sulfide, the active ingredient in Selsun Blue, study fungal skin conditions like Malassezia and pityriasis versicolor, not skin actinos. The recommendation is also tied to a positive test in the first place. Treating Selsun Blue as a blanket self-care step for anyone worried about actinos skips the testing and clinician judgment that should come first.

The environmental side changes too. Shoemaker has described ongoing air filtration, more intensive drywall cleaning when actinos are present, and, in a Reddit AMA rather than published work, "for the worst cases" that did not respond to binders, MARCoNS treatment, or immune support alone, a combination of vacuum cleaning, air filtration, small particle cleaning, and a surfactant cleaner. For someone who is chemically sensitive, a plain dish-soap surfactant solution is gentler than a branded spray cleaner. Those are clinician-attributed steps from an unpublished discussion. They are not MoldCo telling every reader to buy specific products.

The wider public-health baseline is still source control. EPA guidance says the key to mold control is moisture control and that larger or extensively damaged areas should involve experienced professionals (EPA mold guide). Per the SurvivingMold IEP consensus statement, which is meant as an adjunct to standard IICRC remediation, CIRS-aware cleanup adds steps both inside the containment area and beyond it, since IICRC cleanup does not cover the area outside containment (IEP consensus PDF). For drywall, contents, HVAC, or persistent dust questions, the right next person is often an independent environmental professional. MoldCo does not perform remediation; see the separate guide to remediation for CIRS patients.

When actinos travel with the body

Some readers ask the harder version of the question. They left the moldy building, completed the protocol, and still test positive for actinos on a body-site swab. What now? On r/CIRS, a patient writing as baffledcheesecake described getting rid of a car that tested high for what she called "pathogenic human habitat actinos," only to watch the new car re-contaminate from her own skin shedding. One AMA participant put it more bluntly: "How can you get out of exposure when YOU ARE the exposure?"

Current evidence supports a narrower, less frightening answer. Shoemaker has stated that Corynebacterium tuberculostearicum has been found in sinuses. Whether the skin seeds the sinuses or the sinuses seed the skin is not actually known. Naik and colleagues showed in 2018 that skin Corynebacterium can promote an IL-17A inflammatory response that depends on the bacterial cell wall's mycolic acid; under metabolic stress, the same species can shift from a non-inflammatory commensal into a driver of skin inflammation, in mouse models (Naik et al., 2018). That makes the body-as-source question biologically plausible. It does not prove every persistent CIRS case is driven by colonization, and it does not prove a settled treatment endpoint.

This is where clinician interpretation matters. If you have a GENIE result, an extended dust-panel result, or a body-site swab naming actinos, the result needs to be read alongside symptoms, building history, HERTSMI or ERMI context, MARCoNS status, and other exposure data. Symptoms alone cannot sort those categories.

Actinos are not every incomplete responder's answer

One recovered r/CIRS poster wrote, "I had no issues with ticks or actinos or any other toxin." That line belongs near the end of this article because it keeps the premise honest.

Some people do improve on a mold-focused path. Some need MARCoNS addressed. Some need the building source found. When treatment stalls, endotoxin exposure is worth ruling out before anyone jumps to actinos. Some need a clinician to question whether mold toxicity is the right frame at all. Actinos are worth discussing when the evidence points there: a relevant outside result, a clean fungal panel that does not match the clinical picture, a body-site question, or persistent symptoms after the mold-only path has been taken seriously.

They are not a shortcut around careful testing.

Where MoldCo fits

MoldCo Care is a Detox / Clear / Repair telehealth pathway for adults, guided by the Shoemaker Protocol. It does not run GENIE. It does not perform extended actino dust-panel testing. It does not perform environmental remediation. MoldCo's HERTSMI-2 home test does not detect actinos, and MoldCo's Starter, CIRS, and Complete blood panels do not detect actinos either.

That boundary is what makes the bridge useful. If you already have an outside GENIE result, an extended dust-panel result, or a body-site swab mentioning actinos, MoldCo Care can help interpret that result inside the wider mold-toxicity care plan. See supported states for current coverage and the CIRS treatment protocol overview for how the pathway works in practice.

If you are earlier in the process and still trying to understand whether mold toxicity belongs in the conversation, start with the symptom questionnaire. The next step depends on what you already know. A clean HERTSMI-2, by itself, does not answer the actino question. A symptom list, by itself, does not either.

Any health-related claims made on this site have not been evaluated by the Food and Drug Administration (FDA). The information provided on this site is not intended as a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. MoldCo assumes no responsibility or liability for any errors or omissions in the content of the references, nor for any actions taken in reliance thereon.