all thing about CMV

1. IN THE NAME OF GOD

2. • Family: Herpesviridae.
• Subfamily: β-herpesviridae.
• The viral genome is ds-DNA.
• Genome: Double stranded DNA, linear, 238
kbp, reiterated sequences
• Replication: Nucleus, bud from nuclear
membrane
• Nucleocapsid 105nm in diameter, 162
capsomers
• The largest in Herpesvirus
• Genome code more than 200 proteins
VIROLOGY

3. CYTOMEGALOVIRUS HISTORY
• First isolated in 1956 from 2 dying infants from salivary gland and kidneys with
demonstration of inclusion bodies
• “Salivary Gland Virus”
• 1960 Wellar et al proposed name ‘cytomegalovirus’
• CMV first isolated from renal transplant patient in 1965

4. Double-stranded DNA core
Icosahedral nucleocapsid
Tegument
(proteinaceous matrix)
Lipid bilayer envelope contains
Glycoproteins
CMV STRUCTURE

6. HUMAN CYTOMEGALOVIRUS VIRION STRUCTURE

7. OTHER PROPERTIES
• Virus glycoprotein: gC / gCL or gB / gcll (gM &gN)
gC in attachment gCL & gCLL in disulfide bond
• CMV genome coded 200 proteins & 25 glycoprotein by 238 genes.
• Because of mutation proteins not recognize but all CMV have tow glycoprotein (gB & gL or gH) that
are necessary to enters host.
• CMV enters host by glycoprotein B (gB)-mediated membrane fusion upon receptor-binding to gH/gL-
related complexes, causing devastating diseases such as birth defects.
• CMV infectious particles, or virions, possess a lipid envelope that contains viral surface glycoproteins
and encases the tegument compartment and the viral capsid
• The capsid is composed of four integral protein species (for HCMV, pUL46, pUL80.5, pUL85, pUL104) that
are organized into 162 capsomeres (150 hexamers plus 12 pentamers) and 320 triplexes located
between the capsomeres.
capsids protein : major capsid protein (MCP/pUL86), triplex monomer (TRI1/pUL46, also called minor
capsid binding protein [mcBP]), triplex dimer (TRI2/pUL85, also called minor capsid protein [mCP]) and
smallest capsid protein (SCP/ pUL48A)

8. • The tegument region is approximately 50 nm thick and includes seven relatively abundant
virus-encoded protein species ,at least five of which are phosphorylated
• The virion envelope is estimated to be 10 nm thick and contains at least ten abundant protein
species
• Both the tegument and envelope contain additional less abundant virus-encoded and
host-cell proteins, as well as phospholipids, polyamines, and small RNAs
• pp150 is the second most abundant constituent of HCMV tegument layer and has
been recognized as a major cytomegalovirus structural antigen since the 1980s
• The envelope is a major determinant of infectivity in cmv and it is derived from the host
membranes that have been modified by insertion of viral glycoproteins

9. Landmarks on the assembly protein and protease precursors (protocapsomer)

10. CAPSID ASSEMBLY MODEL

11. Capsids in nucleus of CMV-
infected cells

13. EGRESS OF NUCLEOCAPSID

15. • HOW IS CMV SPREAD?
• Person to person contact (kissing, sexual contact, getting saliva or urine on
hands and then touching eyes, or the inside of nose or mouth)
• Through the breast milk of an infected woman
• Infected pregnant women can pass the virus to their unborn babies
• Blood transfusions and organ transplantations

16. EPIDEMIOLOGY & PATHOGENESIS
• Once infected, the virus remains in the person for life and my be reactivated
from time to time, especially in immunocompromised individuals.
• The virus may be transmitted in utero, perinatally, or postnatally.
• Perinatal infection is acquired mainly through infected genital secretions, or
breast milk. Overall, 2 - 10% of infants are infected by the age of 6 months
worldwide. Perinatal infection is thought to be 10 times more common than
congenital infection
• Postnatal infection mainly occurs through saliva. Sexual transmission may
occur as well as through blood and blood products and transplanted organ.
• The amount of tryptophan and nitric acid are important in virus replication
• Cmv can remain latent In Saliva and retina) Low level of immunity(

17. • It infects 85% of adults
• The main non-genetic cause of hearing loss in children
• HCMV infection represents a significant risk for the development of cardiovascular
diseases such as atherosclerosis and neoplasm such as human brain tumor and
colon cancer
• While several FDA-approved drugs have been shown to be effective in suppressing
viral replication and lytic infection, they do not affect viral latent infection and
therefore, cannot completely eliminate this viral infection
• In developed countries, HCMV sero-positivity in child bearing-age women ranges
from less than 45% to 85%. In developing countries, the sero-positivity can reach
almost 100%
• cmv infection estimated incidence is around 0.5% of all live births and there are
more than 60, 000 newborns with HCMV congenital infection annually in the US and
the European Union
• In developing countries, the estimated incidence of congenital HCMV infection is
higher, ranging from 1% to 5% of all live births

18. • more than 85% of infected newborns are asymptomatic at birth
• Congenital CMV infection is the leading viral cause of mental retardation. routine
physical examination of newborns fails to identify more than 90% of children with CMV
congenital infection
• Cytomegalovirus (CMV) is the most common perinatal viral infection leading to
neonatal and childhood sequelae
• CMV infection affecting nearly 40,000 infants each year in the United States
• diagnosis of primary CMV infection in pregnancy congenital infection is 30-50%, on
average, and that the severity of infection varies widely
• CMV can engage in lytic infection to produce viral progeny as well as establish latent
infection that can co-exist with the host during the lifetime of the host
• In developed countries with a high standard of hygiene, 40% of adolescents are
infected and ultimately 70% of the population is infected. In developing countries, over
90% of people are ultimately infected

19. • WBCs and CD13 + are reservoir cells
• Detected in most tissues of body and remains latent
• Enter host cell by fusion or phagocytosis
• Viral particles are made and assembled in nucleus , attain envelope by budding
through inner nuclear membrane
• Replication produces immediate early (IE), Early (cytoplasm) and late antigens
• IE (nucleus) : direct production of viral and cellular genes
• Early (cytoplasm) : directs viral DNA synthesis
• Late ( Nucleus + Cytoplasm) : directs production of structural nucleocapsid proteins

20. • Generally, CMV infection is held in check by the host’s immune response.
• Primary CMV infection in an immunocompetent host is normally
asymptomatic.
• → CMV disease is generally restricted to the immunocompromised host
• CMV has the ability of lifelong persistent, latent infection, and can reactivate
under certain conditions.
• → In transplant recipients, infection with CMV from the donor organ or the
reactivation of CMV in the recipient can lead to disease development.
• Immunocompromised patients such as transplant recipients and AIDS
patients are prone to severe CMV disease such as pneumonitis, retinitis,
colitis, and encephalopathy.

21.  Ubiquitous virus most populations infections in early childhood often
asymptomatic
 Clinical disease increasing due to increasing number of
immunocompromised patients
 In the absence of any form of antiviral prophylaxis, CMV disease
occurs in 20–30% of transplant recipients, with a vast majority of the
episodes developing within 90 days post-transplant
 A major complication of hematopoietic stem cell
transplantation(HSCT).
 CMV is a major cause of morbidity in transplant recipients.

22. HUMAN CYTOMEGALOVIRUS
• A complex β-herpesvirus
• Large genome (238kb)- Slow replicating- Restricted host
range
• Infects 60-90% of the population worldwide, typically asymptomatic infection
• Infection in immunocompromised individuals life threatening -Stem cell and solid
organ transplant recipients -HIV infected individuals- Cancer patients receiving
intensive chemotherapy regimens
• Infection in utero: Leading cause of infectious disease related birth defects
• 1 in 100 infected & 1 in 1000 present symptoms/pathology
• Mild to severe hearing loss
• Cognitive deficits
• Physical abnormalities

23. • Viral factors
– replication dynamics
– immune evasion
– viral heterogeneity
– viral co-infections
• Host factors
– CD4+, CD8+ T-cell
– NK cell, B-cell
– exogenous
immunosuppression
–
CMV PATHOGENESI
Disease associated with CMV
In immunocompetent host.
In immunocompromoized.
Congenital infection

24. Cmv
infection
cycle

25. INFECTION IN IMMUNOCOMPETENT HOSTS
• CMV is an opportunistic virus that rarely causes diseases in healthy people,
particularly when infection occurs in childhood.
• About 70-90% of adults have antibody to CMV.
• In adolescence and early adulthood primary CMV infection is usually
asymptomatic, but may cause infectious mononucleosis like syndrome
• (CMVs) encode a mitochondria-localized inhibitor of apoptosis, vMIA, and a
viral inhibitor of caspase activation
• in cmv ,proteins including pUL38, IE1 491aa, and IE2 579aa, can prevent
apoptosis induced by various stimuliintrinsic stresses as well as extrinsic,
immune-regulated signals

26. • CMV causes disease in almost every organ of the body, e.g., pneumonia,
hepatitis, colitis, retinitis, and neuropathy.
• The most obvious cause of reactivation of cmv is immunosuppression and
patients receiving immunosuppressive medications after transplantation or
who have immune compromising diseases such as HIV are prone to CMV
reactivation and disease
• To date, vMIA is the most broadly antiapoptotic CMV protein known and
analogous to the cellular Bcl-2 proteins, is highly effective against a myriad
of stimuli including

27. INFECTIOUS MONONUCLEOSIS LIKE SYNDROME
• Mild hepatitis and pneumonia may observed in patients with primary CMV-infection
and infectious mononucleosis like syndrome.
• Duration; 2-4 weeks.
• prognosis: recovery is usual.
• Treatment: Infectious mononucleosis like syndrome is a fairly mild illness, requires no
antiviral drug treatment.
• It is a disease of adolescent and young adults.
• Symptoms include: fever, loss of appetite, malaise, splenomegaly, impaired liver
function, lymphocytosis with atypical lymphocytes, but without characteristic
pharyngitis and lymphadenopathy.
• Patients are negative for heterophil antibody to sheep red blood cell (SRBC).

28. • Defined as the isolation of CMV from the saliva or urine within 3 weeks of birth
• Commonest congenital viral infection, affects 0.3 - 1% of all live births. The
second most common cause of mental handicap after Down's syndrome
and is responsible for more cases of congenital damage than rubella
• Transmission to the fetus may occur following primary or recurrent CMV
infection. 40% chance of transmission to the fetus following a primary
infection
• May be transmitted to the fetes during all stages of pregnancy
• No evidence of teratogenicity, damage to the fetus results from destruction
of target cells once they are formed
CONGENITAL INFECTION

29. • Seroprevalence of CMV in the human population:
• 30~90% in developed countries and may be higher in developing countries,
increasing with age.
• Contact with the saliva or urine of young children is a major cause of CMV infection
among pregnant women.
• Risk of CMV infection is likely to be reduced by careful attention to good personal
hygiene, such as hand washing.
Transmitted via:
• Sexual contact
• soliva
• Placental transfer
• Breastfeeding
• Blood transfusion
• Solid-organ transplantation
• Hematopoietic stem cell transplantation
PREGNANT WOMEN AND CMV

30. • Temporary Symptoms
• Liver problems
• Jaundice (yellow skin and eyes)
• Lung problems
• Spleen problems
• Purple skin splotches
• Small size at birth
• Seizures
• Permanent Symptoms or Disabilities
• Hearing loss
• Vision loss
• Mental disability
• Small head
• Lack of coordination
• Seizures
• Death
SYMPTOMS OF CONGENITAL CMV

31. • CYTOMEGALIC INCLUSION DISEASE
• CNS – abnormalities- microcephaly- mental- retardation- spasticity- epilepsy,-
periventricular- calcification
• Eye -choroidoretinitis and optic atrophy
• Ear -sensorineural deafness
• Liver -hepatosplenomegaly and jaundice which is due to hepatitis
• Lung -pneumonitis
• Heart -myocarditis
• Thrombocytopenic purpura, Haemolytic anaemia
• Late sequelae in individuals asymptomatic at birth -hearing defects and reduced
intelligence.

32. Characterized by intra-nuclear inclusion with enlargement of both cell
& nucleus. Cytoplasmic inclusions are also seen in the infected cells.

33. There are foci of
concentrated inflammatory
infiltrate in renal
parenchyma
Enlarged CMV-infected renal tubular
epithelial cells with prominent
intranuclear inclusion surrounded by
a clear halo (bull-eye appearance).
CMV-infected renal tubular epithelial cell
with typical bull-eye appearance. Note the
rather enlarged CMV-infected cell as
compared to adjacent normal renal tubular
epithelial cells.

34. CMV - DIAGNOSIS
• a fourfold increase in preexisting anti-CMV IgG titers
• isolation of the virus by culture of the throat & saliva, buffy coat, or urine, plasma &
blood
Tissue culture: delay diagnosis
• CMV disease: aazcute symptomatic + evidence of CMV infection
• Quantitative CMV DNA by PCR diagnosis and monitor response.
CMV-DNAemia by molecular techniques
• Qualitative CMV DNA detection by PCR extremely sensitive, can’t diff active or
latent
• CMV pp65 antigen: in peripheral lymphocyte semiquantitative fluorescent assay
more rapid > C/S
• Serum CMV IgM ,IgG Ab: good for screening before KT but not sensitive for
diagnosis
• Histopathology: delay diagnosis and inadequate specimen collection

36. • CMV Diagnosis in other way
presence of virus or antibody to CMV does not indicate that current disease is due to CMV
Different strategies used in different clinical situations
Congenital CMV within 30 days of birth isolation of virus from urine
Immunocompromised patient * antigen detection in buffy coat indicates
LABORATORY DIAGNOSIS
-biopsy specimens may be examined histologically for CMV inclusion antibodies or for the presence of CMV
antigens. However, the sensitivity may be low
-The pp65 CMV antigenemia test is now routinely used for the rapid diagnosis of CMV infection in
immunocompromised patients
-PCR for CMV-DNA is used in some centers but there may be problems with interpretation

37. LABORATORY DIAGNOSIS
Virus Isolation
 -Conventional cell culture is regarded as gold standard but requires up to 4 weeks for result
 -more useful are rapid culture methods such as the DEAFF test which can provide a result in
24-48 hours
 Serology
 Paired antibody titers (4-fold increase in convalescent phase compared to acute phase)
 ELISA to determine if acute infection, prior infection, or passively acquired maternal antibody
in an infant is present
 CMV IgM titers for congenital infection
 Other tests include CF test, fluorescence assays (CMV pp65 antigenemia test, IFA, ACIF),
indirect haemagglutination & PCR
 CMV should be suspected if a patient has symptoms of infectious mononucleosis but has
negative test results for mononucleosis and Epstein Barr virus, or if they show signs of hepatitis,
but has negative test results for hepatitis A, B, and C

38. • PCR is more sensitive than shell vial or antigenemia assays
• Some patients may be pre emptively treated
• unnecessarily using PCR strategies
• Quantitative PCR may be more sensitive than qualitative PCR
• No criteria for standard treatment threshold exist for quantitative CMV PCR
• PCR is the best method for diagnosis of CMV especially before organ transplantation
PCR BASED SCREENING METHODS

39. TREATMENT
Congenital infections - it is not usually possible to detect congenital infection unless
the mother has symptoms of primary infection. If so, then the mother should be told
of the chances of her baby having cytomegalic inclusion disease and perhaps
offered the choice of an abortion
Perinatal and postnatal infection - it is usually not necessary to treat such patients.
Immunocompromised patients - it is necessary to make a diagnosis of CMV
infection early and give prompt antiviral therapy. Anti-CMV agents in current use
are ganciclovir, forscarnet, and cidofovir

40. CMV TREATMENT
• In immunocompetent hosts the disease may be asymptomatic and no treatment may
be required
• Tapering of immunosuppresants may be required
• mononucleosis-like syndrome may resolve without the administration of antiviral drugs
• Invasive disease need anti-viral drugs
• azathioprine or mycophenolate mofetil should be given in reduced dosage or
discontinued.
• Reduced immunotherapy is necessary when there is evidence of tissue invasive
disease and organ involvement (including chorioretinitis).
• cyclosporine or tacrolimus should be discontinued in this setting remains controversial.
• We usually do not discontinue cyclosporine or tacrolimus unless there is evidence of
lifethreatening infection
• Corticosteroids are generally continued to prevent possible adrenal insufficiency.

41. ANTI-CMV THERAPY
• Ganciclovir: (Cytovene® and Cymevene®) is a synthetic analogue of 2-
deoxyguanosine, that competitively inhibits the incorporation of dGTP by viral DNA
polymerase–intravenous or oral
• Valganciclovir: (Valcyte®) a prodrug form of ganciclovir with improved oral
bioavailability
• Foscarnet: (Foscavir ) is an inhibitor CMV DNA polymerase (UL54)
• ‒ Useful for ganciclovir resistant CMV
• ‒ Major limitation is nephrotoxicity
• Cidofovir: (Vistide ) inhibits viral DNA polymerase
• ‒ May be useful for ganciclovir resistant CMV but not well studied in organ transplant
recipients
• Maribavir: is an investigational agent that prevents viral encapsidation and nuclear
egress . the most promising treatment for cmv was Maribavir,

42. ANTIVIRALS INTERUPT DNA SYNTHESIS
• IE gene upregulates transcription and expression of IL - 2 and IL- 2 receptor
• IE gene prevents inhibitory effect of cyclosporine on IL – 2 gene transcription
• IE and early antigens also upregulate adhesion molecules such as ICAM –1
and LFA – 3, further increased by antiviral agents
• CMV has ability to down regulate MHC class 1 molecules

43. •REDUCE CHANCES OF CONTRACTING CMV
• Wash hands often with soap and water for 15-20 seconds, especially after wiping
runny noses, changing diapers, picking up toys, etc. If soap and water are not
available, use alcohol-based hand gel.
• Use soap and water or a disinfectant to clean hard surfaces that have been
contaminated by secretions
• Don’t share food, drinks, or eating utensils with young children
• Don’t kiss young children on the lips—give them a big hug and a kiss on top of the
head If you work in a day care center, limit close contact with children younger than
2½ years of age, especially
• if you've never been infected with CMV or don't know if you've been infected

44. • Every hour, congenital CMV causes one child to become disabled
• Each year, about 30,000 children are born with congenital CMV infection
• About 8,000 children each year suffer permanent disabilities caused by CMV
• About 1 in 150 children is born with congenital CMV infection
• About 1 in 750 children is born with or develops permanent disabilities due to CMV
• CMV is still among the most important infectious complications after transplant
• In the absence of prophylaxis, CMV reactivation can occur in over 75% of solid
organ transplant recipients depending on other risk factors
• Once CMV infection is established, then its replication is highly dynamic with
rapid increases in viral load
• CMV infection may lead to tissue invasive disease
Some things about CMV

45. CYTOMEGALOVIRUS & CANCER THERAPY
HCMV has recently been implicated in different cancer forms where it may provide
mechanisms for oncogenic transformation, oncomodulation and tumour cell immune evasion
antiviral treatment against HCMV has been shown to inhibit tumour growth in preclinical models
One essential immune evasion strategy that can be induced or applied by tumour cells is the
formation of an inflammatory microenvironment & CMV help it.
 Indeed, tumour-related inflammation is regarded as one enabling characteristic crucial for the
tumour cell to sustain a proliferative state, evade apoptosis, increase angiogenesis, invasion,
metastasis and suppression of immune responses
 20% of the global cancer burden can be linked to infectious agents including viruses, bacteria
and parasites
CMV is not currently causally implicated in human cancer, a number of recent evidence
suggests that HCMV may be specifically associated with some human malignancies
HCMV nucleic acids and proteins have been detected in 90-100% of glioblastomas and
medulloblastomas, prostate, breast and colon cancers and in mucoepidermoid carcinomas of
salivary glands
 HCMV proteins are not detected in healthy tissues surrounding HCMV positive tumors but HCMV
protein expression is restricted to the tumour; mainly in tumour cells, but virus proteins are
sometimes found in endothelial cells and inflammatory cells within the tumour

46. • They demonstrated cell specific localization of HCMV in 97% of mucoepidermoid
carcinomas of salivary glands. HCMV IE and pp65 were expressed in tumour cells, but
not in non- tumor cells and positively correlated with severity
• HCMV infection inhibit apoptosis and induce drug resistance by induction of the p53
tumor suppressor homologue gene product ΔN-p73α, resulting in abnormal neural cell
survival & inhibit the expression of the potent anti-angiogenic protein thrombospondin-
1
• Treatment of neuroblastoma cells with the anti-viral drug ganciclovir in vitro or in vivo
inhibits tumor growth
• As of today HCMV has been detected in glioma, medulloblastoma, neuroblastoma,
breast, prostate and colon cancer and mucoepidermoid tumors of the salivary gland

47. Thank you
CDC STATS: WWW.CDC.GOV/CMV help you to know more about CMV