A lot of people with CFS are individuals triggered by some event in the past, often with years passing since the triggering event. A flu like sickness is often cited, I suspect it was actual influenza. My conclusion is that Chronic Fatigue Syndrome and Post Infection Fatigue are the same thing. Extending it a little further Chronic Lyme is another example of Post Infection Fatigue, with the infection being Lyme.
There are several cases reported in the literature where a population got a shared infection, recovered and a percentage came down with post infection fatigue. A reader forwarded me a link today to a study that I was not aware of, so I thought it would be good to consolidate the literature.
Fatigue following Acute Q-Fever: A Systematic Literature Review, May 2016
- “it was noted in 1990 that 4% of acute Q-fever cases had prolonged fatigue”
- “In 1992, it was stated that approximately 23% of study subjects developed QFS within 12 months following acute Q-fever”
- “Ever since, several studies on fatigue following acute Q-fever reported different prevalences. It was stated that 5–10% of patients experience residual asthenia six months after acute Q-fever and only few after one year”
- “a substantial proportion of acute Q-fever patients have symptoms similar to QFS for 6–9 months after the acute infection and then recover, but 8–10% of patients exhibit symptoms for at least a year”
- “In Australia, QFS is the most common sequel of acute Q-fever reported to affect 10–15% of patients”
- ” Higher percentages were described, with up to 28% of patients meeting the Centres for Disease Control and Prevention criteria for CFS 5 to 14 years after acute Q-fever, compared to none in the control group”
- “ten years after acute Q-fever, 68% of patients reported fatigue of any duration , of whom 20% met the CFS criteria”
- “Excluding co-morbidity, 8% of patients met the CFS criteria compared to none of the controls”
- “Post-infective fatigue following Epstein-Barr virus, Ross River virus or C. burnetii infection, was reported in 35% of cases after six weeks, 27% after three months, 12% after six months, and 9% after 12 months, regardless of the infective agent”
- “In patients with a lower respiratory tract infection who were C. burnetii seropositive 10–19 months after the acute illness, 40% reported clinically relevant fatigue, compared to 64% of seronegatives, concluding that patients have long-term health problems after a lower respiratory tract infection in general”
“Treatment with either 3 months of minocycline 200mg/day (n = 18), levofloxacine 200mg/day (n = 1), or erythromycin 400mg/day (n = 1), improved performance status and reduced fatigue , concluding that minocycline was useful in treating QFS . In a pilot-study, treatment with three months of minocycline 100mg/day (n = 29), doxycycline 100mg/day (n = 26), or levofloxacin 200mg/day (n = 3), showed improvement in performance status, headache, and mean weekly temperature .”
NOTE: These are the same antibiotics with my gut bacteria model that are predicted to help shift the gut towards normal, see this page.
NOTE: the article does NOT discuss the microbiome or probiotics.
- Influenza Virus Affects Intestinal Microbiota and Secondary Salmonella Infection in the Gut through Type I Interferons. “we found that influenza pulmonary infection can significantly alter the intestinal microbiota profile through a mechanism dependent on type I interferons (IFN-Is)…. promote the depletion of obligate anaerobic bacteria and the enrichment of Proteobacteria in the gut, leading to a “dysbiotic” microenvironment. “
Bergen Norway – Post Giardiasis Fatigue
n 2004, Bergen, Norway had a major epidemic of giardiasis. Th… ey verified by lab tests that the giardiasis was successfully treated. They also found that infections of cryptosporidum parvum increased as a side effect. “One-third of the patients experienced recurring symptoms after treatment” 
So 1/3 did NOT return to normal within a year.
- At 2 years: “among 82 patients with persisting abdominal symptoms elicited by the Giardia infection…We found that 66 (80.5%) of the 82 patients had symptoms consistent with irritable bowel syndrome (IBS) and 17 (24.3%) patients had functional dyspepsia (FD)” 
- “Fatigue was reported by 41%, whereas 38% reported abdominal symptoms, and there was a highly significant association between these symptoms. Increasing age was a highly significant risk factor for fatigue. The symptoms were not due to chronic infection in this cohort.” at 2 years after the infection [1262 patients] 
- “Patients with post-giardiasis IBS suffer very little somatic comorbidity, suggesting that the aetiology of this form of postinfective IBS is predominantly biological in origin and may thus differ from the more common, non-postinfective forms of IBS.” 
- At 3 years, “The prevalence of IBS in the exposed group was 46.1%… Chronic fatigue was reported by 46.1%” 
- “A total of 58 (60%) out of 96 patients with long-lasting post-infectious fatigue after laboratory confirmedgiardiasis were diagnosed with CFS … At the time of referral (mean illness duration 2.7 years) 16% reported improvement, 28% reported no change, and 57% reported progressive course with gradual worsening. ” 
- “The study shows that Giardia duodenalis may induce CFS persisting as long as five years after the infection. Obstructive sleep apnoea/hypopnoea syndrome, depression and anxiety were important differential diagnoses, or possibly comorbidities, to post-infectious fatigue in this study. Improvement of chronic fatigue in the period from three to five years after giardiasis was found.” 
- “Giardia infection in a nonendemic setting is associated with an increased risk for irritable bowel syndrome and chronic fatigue 6 years later. The prevalences of both conditions decrease over time, indicating that this intestinal protozoan parasite may elicit very long-term, but slowly self-limiting, complications.” 
- ” In conclusion, patients with Giardia-induced gastrointestinal symptoms developed both IBS and FD. They exhibited gastric hypersensitivity with lower drinking capacity and delayed gastric emptying.” 
- “Sporadic IBS was associated with increased risk of overactive bladder syndrome (OAB), whereas post-infectious IBS was not. An apparent association between OAB and previous Giardia infection can be ascribed to comorbid functional disorders.”
This outbreak, like CFS, mainly affected females “Young women have previously been reported as the predominant group infected during a waterborne giardiasis outbreak, due to elevated water consumption. Here, the demographics of those subsequently infected are described, and young women again predominate. As secondary cases were not waterborne, this cannot be attributed to drinking habits.” 
In 2007, ” Both these findings subsided overtime. Increasingly, investigations could not determine a definite cause for the persistent symptoms. The very long-term post-giardiasis diarrhoea, bloating, nausea and abdominal pain documented here need further study.”
” Our findings indicate that Giardia induces functional changes in commensal bacteria, possibly making them opportunistic pathogens, and alters host-microbe homeostatic interactions.” 
There are many infections that follow the identical pattern after the infection is resolved. The model that I use to explain this is a simple one, the bacteria shift aka microbiome (which includes bacteria in the mouth, throat, guts and lungs) that resulted during the active infection, persists afterwards. The body was unable to restore its normal equilibrium quickly in some.
“Here, we use a large-scale text mining-based manually curated microbe-disease association data set to construct a microbe-based human disease network and investigate the relationships between microbes and disease genes, symptoms, chemical fragments and drugs. We reveal that microbe-based disease loops are significantly coherent. Microbe-based disease connections have strong overlaps with those constructed by disease genes, symptoms, chemical fragments and drugs. Moreover, we confirm that the microbe-based disease analysis is able to predict novel connections and mechanisms for disease, microbes, genes and drugs”