Glandular fever syndromes:
These includes infectious mononucleosis, acute
cytomegalovirus and acquired toxoplasmosis.
The common features of these infections are:
1-Rarely spread between infected cases.
2- Most infections are subclinical.
3- Chronic infection may occur.
4- Activation of latent infection may occur.
5- Occasionally transmitted through blood or leucocyte
transfusion.
6- Atypical lymphocyte appear during acute infection.
7- Cytomegalovirus and toxoplasma can cause intrauterine
infection and congenital disease.
Infectious mononucleosis
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Learning objectives
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Epidemiology
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2
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Clinical features
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3
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Laboratory tests
Infectious mononucleosis (IM):
Epidemiology:
1- The disease is caused by Epstein –Barr virus which is a
herpes virus.
2- In developing countries it is a subclinical childhood
infection while in upper socioeconomic group, primary
infection may be delayed until adolescence or early adult life.
3- 50% of infections result in typical IM.
4- Virus is usually acquired from asymptomatic excretors.
5- The main source of transmission is the mouth, pharynx
and urogenital tract.
Clinical features:
1- Lymphadenopathy especially posterior cervical.
2- Pharangitis.
3- Fever.
4- Splenomegaly.
5- Palatal petechiae.
6- Periorbital oedema.
7- Hepatitis.
8- Non specific skin rash.
Laboratory tests;
1- Atypical lymphocyte (more than 20% of the peripheral
lymphocyte).
2- Heterophil antibody in the serum example paul-Bunnel or
monospot test.
3- Specific EBV serology (immune fluorescence).
Cytomegalovirus infection
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Learning objectives
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Clinical features of acquired and gestational
CMV
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Investigations
Clinical features:
1- Hepatosplenomegaly might be seen just like IM .
2- Lymphadenopathy,Pharangitis and tonsilitis are less
common.
3- Jaundice is uncommon.
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Unusual complications include neurological involvement,
haemolytic anaemia, pericardtis, pneuonitis and arthropathy
Investigations:
1- Atypical lymphocytosis is not as prominent as in IM and
heterophil antibody test are negative.
2- Liver function test are often abnormal with raised alkaline
phosphatase.
3- Serological diagnosis (CMV specific IgM antibody).
Gestational CMV infection
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1- Most cases are subclinical.
2-Suspension arise by detection of heterophil antibody
negative glandular fever in pregnancy.
3- Congenital infection can occur at any stage of gestation.
4-The risk of spread to the fetus is around 40%.
5-The most important sequelae is the CNS involvement of the
fetus.
Toxoplasmosis
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Learning objectives
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1
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Epidemiology
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2
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Clinical features
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3
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Laboratory tests
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4
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Management
Acquired toxoplasmosis:
Epidemiology:
Toxoplasma gondii is an intracellular parasite the sexual
phase of the parasites life cycle occur in the small intestinal
epithelium of the domestic cast, oocyte shead in cat feaces and
are spread to intermediat hosts, including humans. Oocyte may
survive in moist conditions for weeks or months.
Oocyte undergo asexual multiplication to form a cyst in the
tissues which persist for the life-time of the host.
Clinical features:
1- The peak incidence is between 25-35 years.
2-Painless enlargement of the lymph nodes is the most
common features.
3-The spleen is seldom palpable.
4- Most patients have no systemic symptoms. But some
complain of malaise, fatigue, muscle pain, fever, headache and
sore throat.
5- Complete resolution usually occurs within a few months.
6- Other site other than lymph nodes seldom involved such as,
brain, heart, lung, liver or skeletal muscle.
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Retinochoroiditis is the result of congenital infection
Laboratory tests:
1- The heterophil antibody test is negative and atypical
lymphocyte may be scanty or abscent.
2- The sabin-feldman dye test detect IgG Ab.
3- The IgM antibody by indirect immunoflurescence or Eliza is
useful in confirming acute infection.
4- Lymph nose biopsy can detect the toxoplasma organism
through antiserum or PCR.
Management:
1- Usually toxoplasmosis is self limiting.
2- Pyrimethamine and sulfadiazine is reserved for rare cases of
severe or progressive disease and for infection in immune
compromised patient.
3- A few individual develop the chronic fatigue syndrome after
acute toxoplasmosis but there is no evidence that their immune
response is other than normal and antimicrobial therapy is
unnecessary.
4- In pregnant women with recent infection, spiramycin (3g
daily in divided doses until term).
Congenital toxoplasmosis:
1- It is acute in nature, mostly subclinical, affect 0.3-1% of
pregnancies with a 60% transmission to the fetus.
2- The incidence of congenital disease (40%) is greatest in the
first trimester but may extend into the third trimester.
3- Many fetal infection are subclinical at birth but long-term
sequelae occur in almost all cases.
4- The main features are retinochoroiditis, microcephaly and
hydrocephalus.
5- Routine use of toxoplasma screen and treatment in
pregnancy are being debated.