|LETTER TO EDITOR
|Year : 1996 | Volume
| Issue : 3 | Page : 196-197
Infectivity of varicella and herpes zoster
RR Mittal, Shivali
R R Mittal
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Mittal R R, Shivali. Infectivity of varicella and herpes zoster. Indian J Dermatol Venereol Leprol 1996;62:196-7
| To the Editor,|| |
Varicella is transmitted by droplet infection from nasopharynx. Susceptible people may contract varicella from patients of either varicella or herpes zoster (HZ) as vesicular fluid of HZ is also infectious. Importance of vesicular fluid of varicella in transmission is not known although it contains great deal of virus. Herpes zoster usually occurs as sporadic affliction of individual or rarely in clustered or localized epidemics. These clustered epidemics show that herpes zoster is occasionally temporally related to exposure to varicella zoster virus (VZV).
A 29-year-old woman had attack of herpes zoster in relation to trigeminal nerve 20 days back and she was put on laser treatment as pain persisted after clearance of lesions. After 2 days she brought her 4-year-old son who had crop of polymorphic eruptions which were centrepetal in distribution. The child was diagnosed as a case of varicella. There was no history of similar lesions at home or in neighbourhood. One day later his 7-year-old sister also showed similar features.
In another case, an old man of 50 years had been suffering from pain and burning sensation in distribution of C5-6 segments on right side for 3 days which was followed one day later by appearance of grouped papulovesicular lesions. His 3 grandchildren who stay with him had already taken treatment for varicella 12-14 days prior to appearance of herpes zoster symptoms in him.
Events described above clearly show development of varicella following herpes zoster and reciprocally development of herpes zoster following varicella. Illnesses followed appropriate incubation periods. Herpes zoster to varicella is not uncomman and Seiler found the incidence of 15.5% amongst susceptible children who had not previously had varicella. We believe that this mode of transmission is more frequent than observed and is common especially when index case is young and children in same family had not yet suffered from varicella or if grandparents suffer from herpes zoster then grandchildren get varicella form them.
The explanation for second case is that reactivation of latent virus in ganglion may be due to reinfection with VZV as is also evident from appearance of herpes zoster in clusters. Similar cases have also been reported in past. Defences that are responsible for preventing recrudescent VZV infection are reliant on continual boost of immunity consequent upon subclinical reinfectin. It is possilbe that at times reinfection may stimulate humoral immunity which interferes with cell mediated defences and leads to reactivation of VZV with clinical lesions of herpes zoster. Some immunity is present in such cases and therefore they develop segmental herpes zoster rather than disseminated disease which is rare. Thus exposure to VZV may also be considered another factor for reactivating latent virus in herpes zoster in addition to other established precipitation factors such as trauma, irradiation etc. So herpes zoster should be considered a potentially infectious or contagious disease.
| References|| |
|1.||Palmer SR, Caul EO, Donald DE, et al. An outbreak of singles? Lancet 1985;ii:1108-11. |
|2.||Thomas M, Robertson WS. Dermal transmission of virus as a cause of shingles. Lancet 1971;ii:1347-50. |
|3.||Berlin BS, Campbell T. Hospital acquired herpes zoster following exposure to chickenpox. JAMA 1970;24:1831-3. |