Shingles Transmission: Exploring Genetics, Risks, and Other Factors
Shingles, a painful and potentially debilitating condition, is caused by the reactivation of the varicella-zoster virus (VZV) in people who have previously had chickenpox. Here's what we know about the genetics and transmission of shingles.
People with HIV have a higher risk of developing shingles due to weakened immune systems. However, when it comes to the genetics of shingles, the picture is not as clear-cut. Current understanding supports that certain host genetic factors can influence the severity and susceptibility to VZV infections, particularly in severe or central nervous system (CNS)-related cases. For instance, a newly identified genetic variant in the host gene NPHP4 (S862N) was shown to impair the protein's interaction with regulatory proteins, potentially contributing to severe VZV CNS pathology. This indicates that host genetics can affect shingles pathology by altering the immune response or viral control.
However, direct evidence linking genetics to shingles development risk in the general population is more limited. Most known risk factors remain related to immune status, age, and comorbidities rather than specific genetic predisposition.
Regarding the risk of shingles transmission to infants during pregnancy, the concern is principally about exposure to the live VZV virus. Pregnant individuals with shingles can potentially transmit the virus to the fetus or newborn, but this generally requires direct contact with infectious rash fluid or lesions and is rare. Newborns, especially if premature or with low birth weight, and pregnant people are considered vulnerable and should avoid direct exposure to shingles lesions.
It's important to note that the genetic link discussed primarily pertains to VZV severity or severe manifestations, not increased vertical transmission risk. The main preventive measures for transmission during pregnancy focus on avoiding exposure, vaccination of non-immune individuals, and early medical intervention.
In summary, genetics appear to influence susceptibility and severity of shingles through host immune factors, but are not yet established as major risk factors for shingles development broadly. Transmission risk to infants during pregnancy relates to viral exposure, not genetics; avoiding contact with shingles lesions and vaccination are key preventive strategies. No strong or direct evidence was found linking genetic factors to increased transmission risk to infants in utero.
The exact mechanism by which genetics may cause shingles is still unclear. However, one study suggested an association between shingles development and variations in the HLA-B gene, which contains instructions for making a protein important to a person's immune system. Another study found a similar weak link between shingles and genetics, with a family history of the condition possibly associated with a higher risk of painful symptoms and postherpetic neuralgia.
Limited research suggests that children may inherit a genetic risk of shingles depending on whether they get chickenpox. If a person has shingles lesions on or near the nipple, they should pump breast milk from the affected breast and feed the infant with the unaffected breast to avoid direct contact with the infant's mouth.
Certain types of cancer, such as leukemia and lymphoma, can increase the risk of shingles. People taking medications to avoid rejection of a new organ, suppress psoriasis, reduce psoriatic arthritis symptoms, or receiving chemotherapy to treat cancer may also have a greater risk of shingles.
Shingles is only transmitted through direct contact with the fluid in skin lesions and blisters. Contrary to common belief, shingles cannot be transmitted to an infant through breast milk or during pregnancy or closer to delivery through transplacental transmission. Even if a person contracts VZV from blister fluid, they risk contracting chickenpox, not shingles.
There are vaccines available in the United States that can reduce a person's risk of developing shingles. People can consider talking with a doctor about whether either vaccine may be suitable for them.
- In some severe or central nervous system cases of shingles, host genetics can influence the severity and susceptibility to VZV infections, particularly via a genetic variant in the NPHP4 (S862N) gene.
- Pregnant individuals with shingles can transmit the varicella-zoster virus (VZV) to the fetus or newborn, but the risk is usually rare and requires direct contact with infectious rash fluid or lesions.
- Studies suggest an association between shingles development and variations in the HLA-B gene, which codes for a protein important to the immune system. A family history of shingles may also potentially increase the risk of painful symptoms and postherpetic neuralgia.
- Children may inherit a genetic risk of shingles depending on whether they get chickenpox. In such cases, one should pump breast milk from the affected breast and feed the infant with the unaffected breast to avoid direct contact with the infant's mouth.
- There are vaccines available in the United States that can reduce a person's risk of developing shingles. These vaccines are suitable options to explore in consultation with a healthcare provider.
