Mononucleosis

Mononucleosis, also known as infectious mononucleosis (IM), mono, or glandular fever is a contagious disease most common in teenagers and young adults.

Causative agents
Epstein-Barr virus is the most common cause of infectious mononucleosis (IM), making up approximately 90% of those diagnosed, but other infectious agents, such as cytomegalovirus, toxoplasmosis gondii parasite, HIV (human immunodeficiency virus), rubella virus, hepatitis A, B, or C viruses, and adenovirus can cause this disease.

Although Epstein-Barr virus is the most common cause of infectious mononucleosis, the majority of people infected with Epstein-Barr virus never develop mononucleosis. It is estimated that 80% - 90% of the worldwide population is infected with the Epstein-Barr virus.

Symptomology
Symptoms vary from several weeks to several months and may include:
 * extreme fatigue and malaise
 * fever, sweating and chills
 * sore throat,
 * head and body aches
 * swollen lymph nodes in the neck and armpits
 * swollen liver or spleen or both
 * rash, usually resolving in several days

Treatment
Treatment is mainly supportive: rest, plenty of fluids, analgesics, and antipyretics. A vaccine for the prevention of Epstein-Barr virus is being explored.

Trigger for CFS
A minority of infectious mononucleosis patients develop postviral fatigue syndrome and meet the criteria for chronic fatigue syndrome.

Studies relating to infectious mononucleosis and CFS

 * 2017, A Prospective Study of Infectious Mononucleosis in College Students"'Abstract - Background: The present study aims to prospectively investigate possible biological and psychological factors present in college students who will go on to develop chronic fatigue syndrome (CFS) following Infectious Mononucleosis (IM). Identification of risk factors predisposing patients towards developing CFS may help to understand the underlying mechanisms and ultimately prevent its occurrence. Our study is enrolling healthy college students over the age of 18. Enrollment began in March of 2013 and is ongoing. Methods: Biological and psychological data are collected when students are well (Stage 1), when they develop IM (Stage 2), and approximately 6 months after IM diagnosis (Stage 3). Results: Two case studies demonstrate the progression of student symptomology across all three stages. Conclusion: The Case Studies presented illustrate the usefulness of a prospective research design that tracks healthy.'"
 * 2006, Post-infective and chronic fatigue syndromes precipitated by viral and non-viral pathogens: Prospective cohort study"'Abstract -To delineate the risk factors, symptom patterns, and longitudinal course of prolonged illnesses after a variety of acute infections. Prospective cohort study following patients from the time of acute infection with Epstein-Barr virus (glandular fever), Coxiella burnetii (Q fever), or Ross River virus (epidemic polyarthritis). The region surrounding the township of Dubbo in rural Australia, encompassing a 200 km geographical radius and 104,400 residents. 253 patients enrolled and followed at regular intervals over 12 months by self report, structured interview, and clinical assessment. Detailed medical, psychiatric, and laboratory evaluations at six months to apply diagnostic criteria for chronic fatigue syndrome. Premorbid and intercurrent illness characteristics recorded to define risk factors for chronic fatigue syndrome. Self reported illness phenotypes compared between infective groups. Prolonged illness characterised by disabling fatigue, musculoskeletal pain, neurocognitive difficulties, and mood disturbance was evident in 29 (12%) of 253 participants at six months, of whom 28 (11%) met the diagnostic criteria for chronic fatigue syndrome. This post-infective fatigue syndrome phenotype was stereotyped and occurred at a similar incidence after each infection. The syndrome was predicted largely by the severity of the acute illness rather than by demographic, psychological, or microbiological factors. A relatively uniform post-infective fatigue syndrome persists in a significant minority of patients for six months or more after clinical infection with several different viral and non-viral micro-organisms. Post-infective fatigue syndrome is a valid illness model for investigating one pathophysiological pathway to chronic fatigue syndrome.'"
 * 2000, infectious mononucleosis: Characteristics of patients who report failure to recover "'Abstract - We sought to determine how often acute mononucleosis precipitates chronic illness, and to describe the demographic, clinical, and psychosocial features that characterize patients who report failure to recover. We enrolled 150 patients with infectious mononucleosis during the acute illness and asked them to assess their recovery at 2 and 6 months. At baseline, we performed physical and laboratory examinations; obtained measures of psychological and somatic functioning, social support, and life events; and administered a structured psychiatric interview. Self-assessed failure to recover was reported by 38% of patients (55 of 144) at 2 months and by 12% (17 of 142) at 6 months. Those who had not recovered reported a persistent illness characterized by fatigue and poor functional status. No objective measures of disease, including physical examination findings or serologic or laboratory markers, distinguished patients who failed to recover from those who reported recovery. Baseline predictors for failure to recover at 2 months were older age (odds ratio [OR] = 1.4, 95% confidence interval [CI]: 1.1 to 1.8, per 5-year increase), higher temperature (OR = 1.5, 95% CI: 1.1 to 2.2, per 0.5 degrees C increase), and greater role limitation due to physical functioning (OR = 1.5, 95% CI: 1.2 to 1.9, per 20-point decrease in Short Form-36 score). At 6 months, baseline predictors for failure to recover included female sex (OR = 3.3, 95% CI: 1.0 to 12), a greater number of life events more than 6 months before the disease began (OR = 1.7, 95% CI: 1.1 to 2.5, per each additional life event), and greater family support (OR = 1.9, 95% CI: 1.1 to 4.2, per 7-point increase in social support score). We were not able to identify objective measures that characterized self-reported failure to recover from acute infectious mononucleosis. The baseline factors associated with self-reported failure to recover at 2 months differed from those associated with failure to recover at 6 months. Future studies should assess the generalizability of these findings and determine whether interventions can hasten recovery."