Measles, mumps, and rubella are acute viral diseases. Measles causes respiratory symptoms and rash, spreading via respiratory routes. Mumps primarily causes parotid gland swelling but can also cause orchitis and meningitis, spreading through respiratory droplets. Rubella spreads similarly and can cause birth defects if acquired during pregnancy. Laboratory diagnosis for all three involves virus detection by cell culture isolation or nucleic acid testing, as well as antibody detection by techniques like ELISA.

1. MEASLES,
MUMPS,
RUBELLA

2. MEASLES
• Measles is an acute, highly contagious childhood
disease, characterized by fever and respiratory
symptoms, followed by typical maculopapular
rash.

3. Pathogenesis
• Transmission occurs predominantly via the respiratory
route.
• Spread: The virus multiplies locally in the respiratory
• tract; then spreads to the regional lymph nodes → enters
into the bloodstream in infected monocytes (primary
viremia) → further multiplies in reticuloendothelial
system → spills over into blood (secondary viremia) →
disseminates to various sites.

5. Lab diagnosis
 Specimen: Nasopharyngeal swab
 Antigen detection: By using anti-nucleoprotein
antibodies.
 Virus isolation:
 Monkey or human kidney CPE as multinucleated
giant cells
 Antibody detection: Against nucleoprotein antigen
by ELISA or neutralization tests.
 Reverse-transcription PCR--detects viral RNA.

6. MUMPS VIRUS
• Mumps virus is the most common cause of
parotid gland enlargement in children.
• In severe cases, it can also cause orchitis and
aseptic meningitis.

7. Pathogenesis
• Transmission is through the respiratory route via droplets,
saliva, and fomites.
• Primary replication occurs in the nasal mucosa or upper
respiratory mucosa → infects mononuclear cells and
regional lymph nodes → spills over to blood stream
resulting in viremia → dissemination.
• Target sites: Mumps virus has a special affinity for
glandular epithelium. The classic sites include the salivary
glands, testes, pancreas, ovaries., mammary glands and
central nervous system.

9. Laboratory diagnosis
• Specimen: Buccal or oral swab
• Antigen detection by direct IF test
• Viral isolation
• Primary monkey kidney cell lines
• Shell vial technique
• Serum antibodies by ELISA, neutralization test,
hemagglutination inhibition test
• RT PCR: detects viral RNA

10. Rubella virus
• Rubella belongs to Togaviridae family, and is the
only member under genus Rubivirus
• It is enveloped, single-stranded RNA virus
measuring 50-70 nm in size.
• Its envelope contains a lipid layer from which
two types of spike-like glycoproteins (El and E2)
are projected.
• There is only one serotype and humans are its
only known reservoir.

12. Types of rubella infections
• Rubella may present as postnatal infection or congenital
infection.
• Postnatal Rubella
• Postnatal rubella may occur during neonatal age,
childhood, and adult life.
• Transmission
• Rubella virus spreads from person to person by
respiratory droplets via upper respiratory mucosa.

13. Spread
• Rubella virus replicates locally in the nasopharynx, and
then spreads to the lymph nodes.
• Subsequently, viremia develops after 7-9 days, and lasts
until 14th day by which time both antibody and rashes
appear almost simultaneously suggesting an immunologic
basis for the appearance of rash.

14. Congenital Rubella Syndrome
• The most serious consequence of rubella virus infection
is Congenital Rubella Syndrome.
• Rubella is highlyI teratogenic and is included in the list
of the agents causing congenital infection known as
'TORCH complex [Toxoplasma, Others (e.g. varicella,
agenr of syphilis), Rubella virus, Cytomegalovirus and
Herpes simplex virus].

15. Transmission
• Both die risk of transmission to fetus and severity of
congenital infection are maximum if the mother
acquires the virus during first trimester of pregnancy.
• • Risk after 5th month of pregnancy is almost
negligible
• (90% risk ar 11 weeks vs 20% risk ar 20 weeks of
gestation).

16. Laboratory diagnosis
• Specimen: Nasopharyngeal or throat swabs
• Virus isolation:
• In monkey or rabbit origin cell lines and then growth
detected by viral interference
• Antibody detection: By HAI or ELISA