Tehrani Infectious Disease specialiST Shahid Beheshti University of Medical Sciences Infectious Mononucleosis Definition The virus is a member of the family Herpesviridae EpsteinBarr ID: 548676
Download Presentation The PPT/PDF document "DR.SHABNAM" is the property of its rightful owner. Permission is granted to download and print the materials on this web site for personal, non-commercial use only, and to display it on your personal computer provided you do not modify the materials and that you retain all copyright notices contained in the materials. By downloading content from our website, you accept the terms of this agreement.
Slide1
DR.SHABNAM Tehrani Infectious Disease specialiSTShahid Beheshti University of Medical Sciences
Infectious MononucleosisSlide2
DefinitionThe virus is a member of the family Herpesviridae.Epstein-Barr virus (EBV) is the cause of heterophile-positive infectious mononucleosis (IM)
which is characterized by
fever, sore throat,
lymphadenopathy
, and
atypical
lymphocytosis
.
EBV is also associated with several human
tumors
, including
nasopharyngeal carcinoma,
Burkitt's
lymphoma, Hodgkin's disease
, and (in patients with
immunodeficiencies
)
B cell lymphoma.Slide3
EpidemiologyEBV infections occur worldwide. These infections are most common in early childhood, with a second peak during late adolescenceBy adulthood, more than 90% of individuals have been infected and have antibodies to the virus.Slide4
In lower socioeconomic groups and in areas of the world with deficient standards of hygiene (e.g., developing regions), EBV tends to infect children at an early age, and IM is uncommon. In areas with higher standards of hygiene, infection with EBV is often delayed until adulthood, and
IM is more prevalent
.Slide5
…EBV is spread by contact with oral secretions.The virus is frequently transmitted from asymptomatic adults to infants and among young adults by transfer of saliva during kissing. More than 90% of asymptomatic seropositive individuals shed the virus in
oropharyngeal
secretions
EBV has been transmitted by blood transfusion and by bone marrow transplantation
.(rare)Slide6
PathogenesisEBV is transmitted by salivary secretions.The virus infects the epithelium of the oropharynx and the salivary glands and is shed from these cellsThe proliferation and expansion of EBV-infected B cells along with reactive T cells during IM result in enlargement of lymphoid tissue.Cellular immunity is more important than humoral immunity in controlling EBV infectionSlide7
Clinical ManifestationsSigns and Symptoms: -Most EBV infections in infants and young children either are asymptomatic or present as mild pharyngitis with or without tonsillitis. -up to 75% of infections in adolescents present as IM.
-IM
in the elderly presents relatively often as nonspecific symptoms, including
prolonged fever, fatigue,
myalgia
, and malaise.
Slide8
pharyngitis, lymphadenopathy, splenomegaly, and atypical lymphocytes are relatively rare in elderly patientsincubation period: in young adults is 4–6 weeks.Slide9
…A prodrome of fatigue, malaise, and myalgia may last for 1–2 weeks before the onset of fever, sore throat, and lymphadenopathy. Fever is usually low-grade and is most common in the first 2 weeks of the illness; however, it may persist for >1 month.Slide10
Signs Lymphadenopathy % 95 Fever %93 Pharyngitis or tonsillitis %82 Splenomegaly %51 Hepatomegaly %11 Rash %10 Periorbital edema %13 Palatal enanthem
%7
Jaundice %5Slide11
…Lymphadenopathy and pharyngitis are most prominent during the first 2 weeks of the illnesssplenomegaly is more prominent during the second and third weeks.
Lymphadenopathy
most often affects the
posterior cervical nodes
but may be generalized.
Enlarged lymph nodes are frequently
tender and symmetric
but are
not fixed
.Slide12
…Pharyngitis, often the most prominent sign, can be accompanied by enlargement of the tonsils with an exudate resembling that of streptococcal pharyngitis.A morbilliform or papular rash, usually on the arms or trunk, develops in 5% of cases .
Most patients treated with
ampicillin
develop a macular rash; this rash is
not predictive
of future adverse reactions to
penicillinsSlide13
…Slide14
…Most patients have symptoms for 2–4 weeks.malaise and difficulty concentrating can persist for monthsSlide15
Laboratory Findingswhite blood cell count is usually elevated and peaks at 10,000–20,000 during the second or third week of illness. Lymphocytosis is usually demonstrable, with >10% atypical lymphocytesatypical lymphocytes are enlarged lymphocytes that have abundant cytoplasm, vacuoles, and indentations of the cell membraneSlide16
atypical lymphocyteSlide17
…Low-grade neutropenia and thrombocytopenia are common during the first month of illness.Liver function is abnormal in >90% of cases. Serum levels of aminotransferases and alkaline
phosphatase
are usually mildly elevated.
The serum concentration of
bilirubin
is elevated in ~40% of cases.Slide18
ComplicationsMost cases of IM are self-limited.Deaths are very rare and most often are due to: central nervous system (CNS) complications, splenic rupture, upper airway obstruction, or bacterial superinfectionSlide19
CNS complications: develop usually do so during the first 2 weeks of EBV infection.Meningitis and encephalitis are the most common neurologic abnormalities, and patients may present with headache, meningismus, or cerebellar ataxiaSlide20
…Autoimmune hemolytic anemia: occurs in 2% of cases during the first 2 weeks. In most cases, the anemia is Coombs-positive, with cold agglutinins directed against the red blood cell antigen.spleen ruptures:
in <0.5% of cases which is more common among
male
than female patients
may manifest as
abdominal pain, referred shoulder pain, or hemodynamic compromiseSlide21
Hypertrophy of lymphoid tissue in the tonsils or adenoids: can result in upper airway obstruction.Slide22
…Other rare complications associated with acute EBV infection include: hepatitis (which can be fulminant)myocarditis or pericarditis pneumonia with pleural effusioninterstitial nephritis vasculitis
.Slide23
Diagnosisheterophile test : -human serum is absorbed with guinea pig kidney, and the heterophile titer is defined as the greatest serum dilution that agglutinates sheep, horse, or cow erythrocytes. -Tests for heterophile antibodies are positive in 40%
of patients with IM during the
first week
of illness
and in
80–90% during the third week
.
Slide24
-Therefore, repeated testing may be necessary, especially if the initial test is performed early.These antibodies usually are not detectable in children <5 years of age, in the elderly, or in patients presenting with symptoms not typical of IMSlide25
monospot test: The commercially available monospot test for heterophile antibodies is somewhat more sensitive than the classic heterophile test.The monospot test is 75% sensitive and 90% specific compared with EBV-specific serologiesSlide26
…EBV-specific antibody testing : used for patients with suspected acute EBV infection who lack heterophile antibodies and for patients with atypical infections .
Anti-VCA
IgM
and
IgG
antibodies
:
- elevated in the serum of more than 90% of patients at the onset of
diseaseSlide27
- Anti-VCA IgM :diagnosis of acute IM because it is present at elevated titers only during the first 2–3 months of the disease - Anti-VCA
IgG
usually
not useful for diagnosis of IM
but is often used to assess past exposure to EBV because it
persists for lifeSlide28
Seroconversion to EBNA positivity : is also useful for the diagnosis of acute infection with EBV. Antibodies to EBNA become detectable relatively late (3–6 weeks after the onset of symptoms) in nearly all cases of acute EBV infection and persist for the lifetime of the patient. Slide29
Differential DiagnosisCMV HIV Toxoplasmosis HHV-6 Streptococcal pharyngitis Viral hepatitis Rubella Lymphoma Drugs (phenytoin, carbamazepine, sulfonamides, or minocycline)Slide30
TreatmentTherapy for IM consists of supportive measures, with rest and analgesiaExcessive physical activity during the first month should be avoided to reduce the possibility of splenic ruptureAcyclovir has had
no significant
clinical impact on IM in controlled trials.
Glucocorticoid
therapy is
not indicated
for uncomplicated IM and in fact may predispose to bacterial
superinfectionSlide31
Glucocorticoid therapy: prevention of airway obstruction in patients with severe tonsillar hypertrophy autoimmune hemolytic anemia hemophagocytic
lymphohistiocytosis
severe thrombocytopenia
Glucocorticoid
therapy have also been administered to rare patients with severe malaise and fever & to patients with severe CNS or cardiac disease.Slide32
PreventionThe isolation of patients with IM is unnecessary.