TORCH Profile – Part 1 – Rubella virus

The sample for the TORCH profile

1. Venous blood is collected to prepare the serum.
2. The other sample used is urine and spinal fluid for evidence of the infections for TORCH.
3. Diagnosis can be confirmed by the culture of one of the specific pathogens or by increased levels of IgM against the specific pathogen.

Purpose of the test (Indications)

1. TORCH profile is done to find the cause of premature birth or abortion.
2. TORCH is used to screen infants for infections such as toxoplasmosis, cytomegalovirus, herpes simplex, rubella, and syphilis.

Pathophysiology of TORCH profile

1. TORCH profile includes the following tests for:
   1. Toxoplasmosis antibody.
   2. Rubella antibody.
   3. Herpes Simplex.
   4. Cytomegalovirus
   5. Some people include syphilis as well.
2. These infections may lead to birth defects, growth delay, brain, and nervous system problems in the baby.
3. If TORCH screening on infants is positive, more testing will be needed to confirm the diagnosis. The mother will also need to be checked.
4. The test is ordered when a pregnant woman is suspected of having any of the TORCH infections.
5. These infections can be serious if they occur during pregnancy because they can cross the placenta from the mother to the developing fetus and can cause congenital defects in the newborn.
6. The TORCH infections cause a syndrome characterized by:
   1. Microcephaly.
   2. Sensorineural deafness.
   3. Chorioretinitis.
   4. Hepatosplenomegaly.
   5. Thrombocytopenia.
7. TORCH infection sign/symptoms are:
   1. Fever and poor feeding.
   2. The newborn is often small for gestational age.
   3. A petechial rash on the skin may be present, with small reddish or purplish spots due to bleeding from capillaries under the skin.
   4. An enlarged liver and spleen (hepatosplenomegaly) are common, and jaundice.
   5. Hearing impairment, eye problems, mental retardation, autism, and death can be caused by TORCH infections.
   6. The mother often has a mild infection with few or no symptoms.
8. The examiner may test blood, urine, and spinal fluid for evidence of the infections for TORCH.
9. Diagnosis can be confirmed by the culture of one of the specific pathogens or by increased levels of IgM against the pathogen.

Rubella  Virus

Sample

1. Blood to prepare serum.
2. The culture of the affected site.

Pathology

1. Rubella is not a serious disease and also called German measles.
   1. This is also called 3-days measles.
   2. There are fever and transient rash in the children, and adults.
2. infection during the first 16 weeks of pregnancy presents major risks for the unborn baby.
   1. When a pregnant woman has a rash and other symptoms of rubella, laboratory tests are required to make the diagnosis.
   2. This is effective in the first trimester of the pregnancy.
3. Complications:
   1. Affected infants show various pathologies like cataracts, microcephaly,  deafness, and heart defects.
   2. There is a chance of spontaneous abortion and stillbirth.
   3. In congenital infection, the virus may be isolated from CSF, urine, amniotic fluid, and other sites.

Signs and Symptoms

1. There is exposure to the patient with Rubella 14 to 21 days before the onset.
2. There is lymphadenopathy, postauricular, and cervical before the rash appears.
3. Post-natal Rubella is usually asymptomatic in 50% of the cases.
   1. The post-natal infection has a fever and malaise.
   2. There is suboccipital adenitis.
   3. Polyarthritis is seen in 25% of the cases. It subsides usually in one week but may persist for weeks. Rarely chronic arthritis develops.
   4. A fine, pink maculopapular rash appears on the face, trunk, and extremities. It fades quickly and may be lost in one day in each area.
4. Congenital Rubella, the infant may be asymptomatic at birth.
   1. Later on, these babies may have cataracts and glaucoma.
   2. There may have microphthalmia.
   3. There is a hearing defect.
   4. There is psychomotor retardation.
   5.  There may be heart anomalies like patent ductus arteriosus.
   6. The patient may have organomegaly.
   7. There are maculopapular rashes.
   8. The earlier newborn gets an infection, the severe will be signs and symptoms.
   9. Deafness is seen when a fetus gets an infection in the second trimester.
   10. IgM antibody is diagnostic in the newborn.
       1. Congenital rubella in the first trimester is associated with congenital abnormalities in a fetus like heart defects, brain damage, and deafness.
          1. There may abortion or stillbirth.
       2. Women titer greater than 1:10 to 1:20, then she is not susceptible to rubella infection.
          1. If the titer is <1:8, it indicates that she has no immunity to rubella.

Diagnosis:

1. Cultural diagnosis is time-consuming and difficult.
2. Rubella antibody :
   1. For immune status = antibody IgG is positive.
   2. For active infection = IgM (IgG) is positive. EIA can be done with only the IgM antibody.
   3. For congenital infection = IgM antibody is positive.
      1. There is a fourfold increase in acute disease titer and convalescent stage.
      2. The titer of ≥ 1:8 is considered evidence of immunity.
   4. Haemagglutination inhibition (HAI), not popular today because is time-consuming and difficult. Other serologic tests are the best options.
      1. Passive haemagglutination test where tanned RBCs are sensitized to Rubella antigens.
   5. Latex particle agglutination test.
   6. Enzyme immunoassay (EIA).

Source 2

Lab test	Result	Clinical Interpretation
HAI titer	<1:8	No immunity
	>1:20	Immune to rubella
Latex agglutination	Negative	No immunity to rubella
ELIZA                    IgM	<0.9 IU/mL	No infection
IgM	>1.1 IU/mL	Active infection
IgG	<7 IU/mL	No immunity to rubella
IgG	>10 IU/mL	Immune to rubella

Treatment

• Treatment is symptomatic.

Prognosis

• Rubella is usually a mild disease and may last for 3 to 4 days.
• Congenital Rubella has a high mortality.

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