Infectious mononucleosis: psychological symptoms during acute and subacute phases of illness

Inflammatory cytokine-associated depression

Inflammatory cytokines can sometimes trigger depression in humans, are often associated with depression, and can elicit some behaviors in animals that are homologous to major depression. Moreover, these cytokines can affect monoaminergic and glutamatergic systems, supporting an overlapping pathoetiology with major depression. This suggests that there could be a specific major depression subtype, inflammatory cytokine-associated depression (ICAD), which may require different therapeutic approaches. However, most people do not develop depression, even when exposed to sustained elevations in inflammatory cytokines. Thus several vulnerabilities and sources of resilience to inflammation-associated depression have been identified. These range from genetic differences in neurotrophic and serotonergic systems to sleep quality and omega-3 fatty acid levels. Replicating these sources of resilience as treatments could be one approach for preventing "ICAD". This article is part of a Special Issue entitled SI: Neuroimmunology in Health And Disease.

Health anxiety--an indicator of higher interoceptive sensitivity?

BACKGROUND AND OBJECTIVES

According to cognitive-behavioral models, health anxiety arises from the misattribution of normal bodily sensations as signs of a severe illness. Consequently, higher levels of interoceptive accuracy might be critically involved in the development of health anxiety.

METHODS

To test this central assumption of cognitive behavioral models of health anxiety, we assessed interoceptive accuracy in a sample of college students (N = 100). Two interoceptive tasks (detection of one's own heartbeat using the Schandry paradigm and detection of nonspecific skin conductance fluctuations, NSCFs) were used.

RESULTS

We found no indication for a positive association between facets of health anxiety and a higher interoceptive accuracy in the two tasks. In fact, worse heartbeat perception was associated with higher health anxiety as measured by two questionnaires whereas perception of NSCFs was not significantly related to any facet of health anxiety. In addition, we found a bias to overestimate NSCFs in people with heightened health anxiety.

LIMITATIONS

Because a sample of college students served as participants, the generalization of the findings is limited and further studies in patients with the diagnosis of hypochondriasis are necessary.

CONCLUSIONS

The findings of both interoceptive paradigms suggest that health anxiety is not associated with better but rather with less accurate and biased interoceptive sensitivity. Probably, not a heightened interoceptive sensitivity but rather the bias in overestimating harmless somatic cues is more relevant for the maintenance of health anxiety. Our results are in line with recent research in other somatoform disorders.

Immunostimulation in the treatment for chronic fatigue syndrome/myalgic encephalomyelitis

Chronic fatigue syndrome (CFS)/myalgic encephalomyelitis (ME) has long been associated with the presence of infectious agents, but no single pathogen has been reliably identified in all patients with the disease. Recent studies using metagenomic techniques have demonstrated the presence of thousands of microbes in the human body that were previously undetected and unknown to science. More importantly, such species interact together by sharing genes and genetic function within communities. It follows that searching for a singular pathogen may greatly underestimate the microbial complexity potentially driving a complex disease like CFS/ME. Intracellular microbes alter the expression of human genes in order to facilitate their survival. We have put forth a model describing how multiple species-bacterial, viral, and fungal-can cumulatively dysregulate expression by the VDR nuclear receptor in order to survive and thus drive a disease process. Based on this model, we have developed an immunostimulatory therapy that is showing promise inducing both subjective and objective improvement in patients suffering from CFS/ME.

Mood disturbance after infection

OBJECTIVE

An aetiological link between acute infection and major depression has long been hypothesized, and is increasingly gaining recognition within contemporary literature. This review aims to examine the evidence for such a link, specifically between acute, self-limiting infection and major depression, and to summarize the current understanding of pathophysiological mechanisms underlying this link.

METHODS

Relevant articles were sourced via an online search of published literature from Embase, MEDLINE, PsycINFO and PubMed using a variety of search terms including mood disorder, depression, infection and inflammation. Additionally, a search for articles from the bibliographies of retrieved papers was conducted.

RESULTS

Findings from retrospective studies suggest an association between infection and subsequent mood disturbance, including major depression. This association has been confirmed by studies employing prospective observational or experimental challenge designs. The available evidence supports a multifactorial basis of vulnerability towards major depression in the context of acute infection. Genetic, neuroendocrine, autonomic and psychosocial factors may interact to potentiate the likelihood of a severe and prolonged depressive response to an immunological stressor in some individuals.

CONCLUSION

Mood disturbance is likely to have a host-protective role in the context of an acute sickness response to infection. However, this usually adaptive and reversible response may progress in some vulnerable individuals into a more sustained and severe pattern of behavioural and physiological changes of major depression. Further research is needed to delineate the factors that predispose, precipitate and perpetuate depression in the context of acute infective illness. Such insights will inform effective prevention and treatment strategies.

A taxometric analysis of health anxiety

BACKGROUND

A long-standing issue in the health anxiety literature is the extent to which health anxiety is a dimensional or a categorical construct. This study explores this question directly using taxometric procedures.

METHOD

Seven hundred and eleven working adults completed an index of health anxiety [the Whiteley Index (WI)] and indicated their current health status. Data from those who were currently healthy (n=501) and receiving no medical treatment were examined using three taxometric procedures: mean above minus below a cut (MAMBAC), maximum eigenvalue (MAXEIGEN) and L-mode factor analysis (L-MODE).

RESULTS

Graphical representations (comparing actual to simulated data) and fit indices indicate that health anxiety is more accurately represented as a dimensional rather than a categorical construct.

CONCLUSIONS

Health anxiety is better represented as a dimensional construct. Implications for theory development and clinical practice are examined.

Is human herpesvirus-6 a trigger for chronic fatigue syndrome?

Chronic fatigue syndrome (CFS) is an illness currently defined entirely by a combination of non-specific symptoms. Despite this subjective definition, CFS is associated with objective underlying biological abnormalities, particularly involving the nervous system and immune system. Most studies have found that active infection with human herpesvirus-6 (HHV-6)--a neurotropic, gliotropic and immunotropic virus--is present more often in patients with CFS than in healthy control and disease comparison subjects, yet it is not found in all patients at the time of testing. Moreover, HHV-6 has been associated with many of the neurological and immunological findings in patients with CFS. Finally, CFS, multiple sclerosis and seizure disorders share some clinical and laboratory features and, like CFS, the latter two disorders also are being associated increasingly with active HHV-6 infection. Therefore, it is plausible that active infection with HHV-6 may trigger and perpetuate CFS in a subset of patients.

Epstein-Barr virus hepatitis associated withicterus: A case report

Introduction. Primary Epstein-Barr virus infection (EBVI) in children is usually asymptomatic with seroconversion. If primary infection occurs in adolescents or in adulthood, the most common manifestation is acute infectious mononucleosis. The diagnosis of acute infectious mononucleosis is made by virus and serologic tests. The most important evidence of primary EBV infection includes IgM class antibodies detected by using EBV virus-capsidantigen (EBV VCA) which appears at the beginning of illness and usually lasts 1 to 2 months. Paul Bunnell Davidson test, although non-specific, is still in use today in diagnosis of infectious mononucleosis and for detection of heterophile antibodies. Case report. Acute hepatitis with icterus is a rare clinical manifestation in primary EBV infection. However, sometimes it is the only manifestation of the disease. This is a case report of a patient with EBV hepatitis and icterus associated with long-lasting fever without pharyngitis and lymphadenopathy, which are characteristics of infectious mononucleosis. The etiologic diagnosis was confirmed by positive Paul Bunnell Davidson test and by detection of specific antibodies (class IgM) to EBV VCA in patient's serum. Discussion. The pathogenetic mechanism which causes destruction of hepatic cells and provokes cholestasis during EBV infection, has not been cleared yet. It is supposed that EBV has no direct cytocide effects on hepatic cells, yet destruction of these cells is caused by toxic action of free radicals through lipid peroxidation. Patients with infectious mononucleosis have autoantibodies directed against enzyme superoxide-dismutase which neutralizes enzyme's antioxidant action. As a result of this action, free radicals accumulate in hepatic cells and cause their damage. Conclusion. Icteric forms of EBV infection are rare. In differential diagnosis of icterus caused by infectious agents, one should not forget EBV. .

Infecções virais e depressão

OBJETIVO: A associação entre depressão e viroses é estudada há quase dois séculos, com resultados conflitantes. O objetivo deste trabalho é fazer uma análise crítica dos estudos existentes na literatura sobre essa relação. MÉTODOS: A pesquisa bibliográfica utilizou as fontes eletrônicas de busca MEDLINE e LILACS (1966 a agosto 2005). As referências dos artigos foram utilizadas como fonte adicional de consulta. RESULTADOS: Foram abordados os trabalhos que trataram da associação entre depressão e os vírus HIV, HCV, EBV, influenza, HSV, HBV, HAV, BDV e HTLV. A relação entre HIV e depressão mostrou-se bem documentada na literatura. Existem indícios de que a prevalência desse transtorno nos indivíduos infectados pelo HIV seja maior que a encontrada nos soronegativos. Além disso, estudos constataram que a depressão está associada a pior prognóstico da infecção. Quanto à associação entre HCV e depressão, os trabalhos sugeriram maior prevalência desse transtorno psiquiátrico nos portadores do HCV comparados à população geral. Não existem evidências científicas suficientes para dar suporte à relação entre os demais vírus e depressão. CONCLUSÃO: As associações mais bem fundamentadas foram aquelas entre depressão e os vírus HIV e HCV. A relação entre as demais viroses e depressão precisa ser mais bem estudada, e trabalhos com delineamento adequado se fazem necessários.

Risk and predictors of fatigue after infectious mononucleosis in a large primary-care cohort

BACKGROUND

Fatigue has been found to complicate infectious mononucleosis (IM) when patients are directly asked about it. We do not know whether such fatigue is clinically significant, nor whether IM is a specific risk for fatigue (or whether it can follow other common infections). Various risk markers for post-infectious fatigue have been identified, but findings are inconsistent.

AIM

To determine the risk of clinically reported fatigue (compared with depression) after IM (compared with both influenza and tonsillitis) in patients attending primary care, and to examine risk markers for post-IM fatigue.

DESIGN

Comparison of matched primary-care cohorts.

METHODS

We identified 1438 adult patients with a positive heterophil antibody test for IM from the UK General Practice Research Database. These patients were individually matched on age, sex and practice to two comparison groups; one with a clinical diagnosis of influenza and the other of tonsillitis.

RESULTS

The odds ratios (ORs) (95%CI) for reported fatigue after IM vs. influenza and tonsillitis were 4.4 (2.9-6.9) and 6.6 (4.2-10.4), respectively. Risk markers for post-IM fatigue included female sex and premorbid mood disorder. By comparison, the ORs for depression after IM vs. influenza and tonsillitis were 1.6 (0.9-2.6) and 2.3 (1.4-3.9), respectively.

DISCUSSION

IM is a specific and significant risk for clinically reported fatigue, which is both separate from, and more common than, depression. Female sex and premorbid mood disorder are risk markers for fatigue. These can be used both to target prevention strategies and to explore aetiological mechanisms.

Infectious mononucleosis: return to play

Infectious mononucleosis most commonly affects adolescents and young adults with a febrile illness accompanied by pharyngitis,lymph node enlargement, and transient fatigue. The diagnosis is usually confirmed with demonstration of heterophile antibodies. Typical signs and symptoms are reviewed, along with pitfalls in diagnosis and management. The rare complication of splenic rupture serves to focus recommendations for returning athletes to strenuous physical activities. Because careful prospective studies of infectious mononucleosis in athletes are lacking, review of available literature suggests that clinicians may recommend a return to all sports in those without spleen enlargement 4 weeks after the onset of illness.

Infectious mononucleosis in active patients: definitive answers to common questions

Infectious mononucleosis may account for considerable illness, especially among adolescents and young adults. Although the disorder was well described more than 70 years ago as involving fever, sore throat, and lymphadenopathy, questions often arise about diagnosis and management. Because primary infection with the Epstein-Barr virus (EBV) can lead to diverse disease manifestation and complications, physicians must be well-versed in the disorder's epidemiology and pathophysiology. New information assesses the reliability of heterophil antibody testing and the role of EBV-specific antibody testing, and addresses issues of management, including corticosteroids, antiviral drugs, and restriction from athletic participation. Most athletes can return to sports after a minimum of 4 weeks, provided the spleen is not palpable.

The association between asthma, asthma, therapeutic classes and hepatic enzyme elevation among adult HMO members

The results of this case-control study conducted at a large HMO support the notion that severe asthma may be associated with transient hepatic enzyme elevation. Conversely, we found no evidence of associations between asthma therapeutic classes and hepatic enzyme elevation.

Predictions and associations of fatigue syndromes and mood disorders that occur after infectious mononucleosis

BACKGROUND

Certain infections can trigger chronic fatigue syndromes (CFS) in a minority of people infected, but the reason is unknown. We describe some factors that predict or are associated with prolonged fatigue after infectious mononucleosis and contrast these factors with those that predicted mood disorders after the same infection.

METHODS

We prospectively studied a cohort of 250 primary-care patients with infectious mononucleosis or ordinary upper-respiratory-tract infections until 6 months after clinical onset. We sought predictors of both acute and chronic fatigue syndromes and mood disorders from clinical, laboratory, and psychosocial measures.

FINDINGS

An empirically defined fatigue syndrome 6 months after onset, which excluded comorbid psychiatric disorders, was most reliably predicted by a positive Monospot test at onset (odds ratio 2.1 [95% CI 1.4-3.3]) and lower physical fitness (0.35 [0.15-0.8]). Cervical lymphadenopathy and initial bed rest were associated with, or predicted, a fatigue syndrome up to 2 months after onset. By contrast, mood disorders were predicted by a premorbid psychiatric history (2.3 [1.4-3.9]), an emotional personality score (1.21 [1.11-1.35]), and social adversity (1.7 [1.0-2.9]). Definitions of CFS that included comorbid mood disorders were predicted by a mixture of those factors that predicted either the empirically defined fatigue syndrome or mood disorders.

INTERPRETATION

The predictors of a prolonged fatigue syndrome after an infection differ with both definition and time, depending particularly on the presence or absence of comorbid mood disorders. The particular infection and its consequent immune reaction may have an early role, but physical deconditioning may also be important. By contrast, mood disorders are predicted by factors that predict mood disorders in general.

Acute complications of Epstein-Barr virus infectious mononucleosis

Infectious mononucleosis caused by Epstein-Barr virus (EBV) usually resolves over a period of weeks or months without sequelae but may occasionally be complicated by a wide variety of neurologic, hematologic, hepatic, respiratory, and psychological complications. The strength of association of EBV with many of these complications remains based on scattered case reports, often using unsophisticated diagnostic tests, and the evidence for causation in many instances is unconvincing. There is little benefit of antiviral treatment of uncomplicated or complicated infectious mononucleosis. Corticosteroids may have a role in hastening resolution of some complications, especially upper airway obstruction and possibly immune-mediated anemia and thrombocytopenia, but should be used judiciously.