Are there different strains of cmv

Research into a CMV vaccine is ongoing; however, there is currently no vaccine available or proven treatment for adults with a CMV infection. Although several CMV tests exist, the Centers for Disease Control and Prevention CDC does not recommend that doctors routinely test pregnant women for CMV infection because laboratory tests cannot predict which developing babies will become infected with CMV or have long-term health problems. Blood tests can check for CMV antibodies. Positive test results indicate the person currently has or previously had a CMV infection; however, this does not necessarily mean the person is infectious.

In addition, most blood tests cannot determine the CMV strain responsible for past or current infection, and there is no consensus on these tests' utility. Other lab tests e. Minus Related Pages. Signs and Symptoms. In some cases, infection in healthy people can cause mild illness that may include: Fever Sore throat Fatigue Swollen glands Occasionally, CMV can cause mononucleosis or hepatitis liver problem. CMV is spread from an infected person in the following ways: From direct contact with saliva or urine, especially from babies and young children Through sexual contact From breast milk to nursing infants Through transplanted organs and blood transfusions.

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Abstract Background. Open in new tab Download slide. Table 1. DBS, dried blood spot. Open in new tab. Longitudinal investigations of hearing disorders in children with congenital cytomegalovirus.

Google Scholar PubMed. Google Scholar Crossref. Search ADS. Mixed cytomegalovirus glycoprotein B genotypes in immunocompromised patients. Virus load dynamics of individual CMV-genotypes in lung transplant recipients with mixed-genotype infections. Dried blood spot real-time polymerase chain reaction assays to screen newborns for congenital cytomegalovirus infection. Concurrent genotyping and quantitation of cytomegalovirus gB genotypes in solid-organ-transplant recipients by use of a real-time PCR assay.

Intrauterine transmission of cytomegalovirus to infants of women with preconceptional immunity. Human cytomegalovirus reinfection is associated with intrauterine transmission in a highly cytomegalovirus-immune maternal population. CMV gB genotypes and outcome of vertical transmission: study on dried blood spots of congenitally infected babies.

Cytomegalovirus gN genotypes distribution among congenitally infected newborns and their relationship with symptoms at birth and sequelae.

Frequent coinfection of cells explains functional in vivo complementation between cytomegalovirus variants in the multiply infected host. Impact of genetic polymorphisms in cytomegalovirus glycoprotein B on outcomes in solid-organ transplant recipients with cytomegalovirus disease. Polymorphisms of the cytomegalovirus CMV -encoded tumor necrosis factor-alpha and beta-chemokine receptors in congenital CMV disease. Modification of human cytomegalovirus tropism through propagation in vitro is associated with changes in the viral genome.

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Ganciclovir-resistant cytomegalovirus disease after allogeneic stem cell transplantation: pitfalls of phenotypic diagnosis by in vitro selection of an UL97 mutant strain. Emergence of multiple cytomegalovirus strains in blood and lung of lung transplant recipients. Human cytomegalovirus UL genes are indispensable for virus growth in endothelial cells and virus transfer to leukocytes. Human cytomegalovirus UL open reading frame is required for epithelial cell tropism.

Pass receives research funding from Sanofi-Pasteur and has partial interest in a relevant patent. In addition, Dr. Pass has served as a consultant to Merck and Vical. Sequencing studies of CMV isolates have usually been limited to one or several genes often with the aim of identifying genotypes associated with virulence properties in immunocompromised patients or infants with congenital infection [6] — [8].

Most of these studies were based on genotyping cultured isolates of CMV from cross-sectional, convenience samples with limited or no longitudinal study and uncertainty as to when the study subjects acquired CMV. While infection with multiple CMV strains is frequently reported in immunocompromised hosts, data in immune competent individuals is more limited. A key question in defining infection with a new CMV strain is whether multiple strains are acquired simultaneously at the time of initial infection or whether a single CMV strain is involved.

To address this question, a cohort of healthy seronegative women who participated in a CMV glycoprotein B gB vaccine clinical trial were followed until they acquired CMV and for up to 34 months afterwards.

In addition, it was possible to compare strains sequenced directly from body fluids to those sequenced after cell culture isolation, to address whether growth in culture might select for strains that grow more efficiently and therefore mask the detection of multiple strains. Overall description of viral genomic structure based on the sum of all loci tested. Strains can be distinguished from one another by differences in one locus or multiple loci.

A combination of subtype designations based on sequence data obtained from two or more gene loci. The study population was from the Birmingham, Alabama metropolitan area.

The mean age of subjects was The time of infection was estimated to be the midpoint of the interval during which seroconversion was detected. All immunized women except one developed gB1 antibodies and neutralizing antibodies. CMV-infected women who received placebo had all developed gB1 antibodies. The median interval from time of infection to first viral cultures was 3 months. Cultures of specimens obtained within three months of infection were available in 50 women.

In 3 women cultures were available only 6momo following seroconversion. Samples were available for PCR sequencing during follow-up of up to 34 months in 43 women. The average time between the first and last sample available for PCR sequencing was 10 months Fig.

Samples available for PCR sequencing were collected from CMV-infected women at different times following seroconversion. A total of tissue culture isolates of CMV from urine, saliva and vaginal fluid, from 53 women range 1—13, average 3. Of 53 women, 23 provided more than 4 isolates over time. These isolates always had an identical strain in the same woman. A single CMV strain was detected in each of 51 women based on UL55 and UL sequencing from two or more isolates separated in time of collection by at least one month.

The interval between the earliest and last isolates tested ranged from 1 to 34 months median, 8 months. In each of these 51 women the same strain was present in each isolate tested with no evidence of acquisition of new strains or of sequence changes based on testing of multiple genetic loci as described below.

Two of 53 participants were infected with multiple strains. In one of them, saliva and urine were available only at 18 months after seroconversion.

Two different strains were detected, one in each fluid. To assess whether the two strains might occur in both fluids with one being more abundant than the other and therefore not detected by direct sequencing, PCR products obtained from saliva and urine were cloned into plasmids, and 20 independent colonies were picked from each site for sequencing.

There was no evidence for low abundance strains existing along the predominant strain based on sequencing of 20 colonies. The second participant with two strains provided oral fluid near seroconversion in which only one strain was detected.

Twelve months later a new strain was found in three urine samples while the original oral strain was unchanged. Sequencing of 20 plasmid clones from these PCR products again did not reveal minor strains coexisting along with the major strain. Our definition of CMV subtypes and genotypes is based on an extensive multilocus analysis of independent genomes obtained from a wide range of different clinical sources and of geographically diverse human populations Zong JC, Alcendor DJ, Arav-Boger R, and Hayward GS, unpublished data.

Finally, in 13 women we also examined UL09, encoding a moderately variable protein with eight subtypes that is located on the other side of the UL region from UL and UL Five subtypes of gB were found among study participants with nucleotide polymorphisms between them ranging from 28 to bp.

Subtype 1 contained three minor variants that differed from one another by 1, 4, and 5 nucleotides. Subtype 2 had two variants that differed by one nucleotide. Subtype 3 had two variants that had five nucleotide changes Fig.

There were no minor variants of subtypes 4 and 5. We judge the one nucleotide change to represent a genuine distinct variant rather than Taq polymerase error, because we have already identified this specific variant in other patient populations [4]. Amino acid alignment encompassing the proteolytic cleavage site of gB subtypes detected in the 53 CMV-infected women. The subtype distribution among the 51 women who shed one strain was as follows: 15 women shed gB1 including variants , 9 women - gB2, 10 women - gB3, 4 women - gB4 and 13 women -gB5.

Nucleotide changes between these subtypes ranged from 35— bp. There were five variants of UL subtype B B, and B6 , with 1 to14 nucleotide changes between these variants. Subtype A included two variants, A1 and A2 that differed by 17 bp.