Survival Of Herpes Simplex Virus Research Articles

Investigating the survival of herpes simplex virus on toothbrushes and surrogate phallic devices.

Herpes simplex virus-1 (HSV-1) is a member of the alphaherpesvirus (alphaherpesvirinae) subfamily, allowing it to affect a wide range of hosts. Herpes simplex virus-1 affects 3.7 billion people, or 67% of the population, under the age of 50. With a vast number of people infected by the virus, everyday objects are often contaminated with this agent. In this study we determined how long HSV-1 can remain viable on contaminated fomites. Fomites were selected for their use near potentially contaminated orifices and variable frequency of sanitization. Toothbrushes and surrogate phallic devices (SPDs) were cut, sterilized, and contaminated. After contaminating the fomites, we collected samples over a 24h period, then used plaque assays to determine viral titers at prescribed time points. The quantity of replication-competent virus present appears to decrease significantly 2h post-contamination, then steadily declines over time, nearing zero at 24h. Our findings suggest that different surfaces influence HSV-1 survival. Proper cleaning must be performed for these types of fomites, especially if shared in an environment where someone with active genital or oral herpes lesions uses one of these fomites shortly after someone else.

Photodynamische Therapie bei infektiöser Keratitis

Photodynamic therapy (PDT) has been used in ophthalmology for the last 10 years particularly for disorders of the posterior pole. In recent years PDT has been increasingly applied for corneal cross-linking in progressive keratoconus. The classical PDT is performed with porphyrins as photosensitizers and illumination with visible light of 630-635nm wavelength and cross-linking with the photosensitizer riboflavin and ultraviolet illumination at 370nm. Illumination of photosensitizers generates free oxygen radicals, which damage the cell membrane or nucleic acids of eukaryotic cells or even microorganisms. By cross-linking a stronger network of collagen fibers can additionally be achieved. Experimental studies have shown that PDT with higher concentrations of photosensitizers may induce necrosis and apoptosis of corneal cells and that survival of herpes simplex virus will be reduced on a LogMar scale by 4-5 lines, of Staphylococcus aureus, Pseudomonas aeruginosa or Candida albicans strains by 1-2 lines. Previous clinical studies have shown that PDT may heal bacterial or even acanthamoeba keratitis. Thus, some authors claim that photodynamic therapy may be a potential alternative in therapy resistant infectious keratitis. However, the limitations of this therapeutic option in particular need further investigation.

The Survival of Herpes Simplex Virus in Preserved Murine Corneas

Background/Aims: This study investigates the survival of HSV in infected mouse corneas, in the conditions of normal human eye bank preservation. Methods: Hundred seventy-two BALB/C mice infected with herpes simplex virus 1 (HSV-1) (KOS) were randomly assigned to either: no preservation in group 1 (n = 62), 31°C preservation for 3 weeks in group 2 (n = 70) or 4°C preservation for 8 days in group 3 (n = 40). The presence of HSV-1 was thereafter detected by viral culture and PCR. Results: In groups 1, 2 and 3, HSV-1 was detected by culture in 22 (35.5%), 1 (1.4%) and 0 (0.0%) of the corneas, and by PCR in 27 (43.7%), 3 (4.2%) and 7 (17.5%) of the corneas respectively. When compared to group 1, HSV was detected significantly less often in groups 2 (p < 0.0001) and 3 (p < 0.0001). Conclusions: HSV-1 DNA undergoes a degradation during corneal preservation.

The Survival of Human Immunodeficiency Virus in Water, Sewage and Sea Water

Drinking water treatment serves as an effective barrier against the transmission by water of enteric viruses. Current practices achieve a standard of less than 1 culturable enterovirus per 1,000 litres of treated water. The likely susceptibilty of HIV to water treatment processes has been assessed in the laboratory by comparing its resistance to environmental stress with that of poliovirus 2 for which quantitative information already exists. HIV cultured in a human T-cell line was added to samples of dechlorinated drinking water, settled raw sewage, and sea water. These were incubated at 16°C and sampled over 11 days. HIV was detected by serial dilution and subculture followed by fluorescent antibody tests for infected cells and by enzyme immune assay for p24 antigen. The survival of herpes simplex virus and poliovirus type 2 was assayed in parallel. The mean times required for a ten-fold decline in HIV concentration were calculated to be 1.8 days in tap water, 2.9 days in sewage, 1.6 days in sea water and 1.3 days in tissue culture fluid controls. A 10-fold decline of poliovirus 2 occurred after 23–30 days in sewage, sea water and tissue culture fluid but in tap water there was no significant decline over 30 days. Herpes simplex was the most sensitive virus requiring only 1.4 days to decline by a factor of ten in sewage. Controls in tissue culture fluid showed no significant change within 7 days. These tests suggest that although HIV was more robust than herpes simplex virus when associated with the organic matter found in sewage, it was more sensitive than poliovirus, an enterovirus widely used as an indicator of the efficiency of water treatment processes. This susceptibility makes it extremely unlikely that HIV poses any threat to disinfected water supplies.

Survival of herpes simplex virus during cryosurgery with liquid nitrogen.

Because many viruses can survive extremely cold temperatures for extended periods of time, transmission of viral diseases from person to person using improper cryosurgical techniques might conceivably occur. To investigate the survivability of herpes simplex virus during cryotherapy, virus was first inoculated onto cotton-tipped applicators from either tissue cultures or from active lesions on patients, and then frozen for variable times in liquid nitrogen (-196 degrees C). After thawing, the applicators were cultured for the virus. The virus survived 12 hours of freezing (the maximum time of freezing in the study), which suggests that herpes simplex could be transmitted between cryosurgical patients if care is not taken to use separate cotton-tipped applicators and liquid nitrogen containers for each case.

Survival of herpes simplex virus and other selected microorganisms on patient charts: potential source of infection

This study indicated that when inoculated onto dental charts, both viruses and bacteria were capable of survival allowing the potential for transmission of infection within the dental office. The conscientious dental practitioner can take steps to reduce this possible mode of infection by removing contaminated surgical gloves or washing hands before handling the chart. An additional method of reducing this potential would be to wipe the chart with an antiseptic solution. Although this study has shown that there is a potential for the spread of infection with the organisms tested, the actual extent of dental chart contamination and resultant illnesses contracted are the basis for further study. Additional studies are needed to follow the pattern of chart distribution from person to person within the dental office, determine the types and quantities of pathogens present in the mouth that would contaminate the charts, and sample the charts under actual clinical conditions to determine the types and viability of the organisms present.

Survival of herpes simplex virus in water specimens collected from hot tubs in spa facilities and on plastic surfaces: Nerurkar LS, West F, May M, et al JAMA 250:3081–3803 Dec 9, 1983

Survival of herpes simplex virus in water specimens collected from hot tubs in spa facilities and on plastic surfaces: Nerurkar LS, West F, May M, et al JAMA 250:3081–3803 Dec 9, 1983

Transmission of Herpes Simplex

To the Editor.— We have several objections to the article entitled Survival of Herpes Simplex Virus in Water Specimens Collected From Hot Tubs in Spa Facilities and on Plastic Surfaces, by Nerurkar et al. 1 The most important objections center around the authors' repeated statements that it is important to consider possible nonvenereal modes of transmission of herpes simplex virus [HSV] infections, that those sources [tap water and plastic surfaces] must be considered as important possible routes for nonvenereal spread of HSV, and, finally, that further epidemiologic studies will be needed to clarify the recognized of fomites in the spread of HSV. Neither the studies cited 2-3 nor the study reported 1 support an increasingly recognized role for fomites in the spread of genital herpes. The theoretical possibility of nonsexual transmission of genital herpes may seem reasonable to laboratory investigators, the press, the general public, or to physicians not

Herpes simplex Virus Adsorption to and Survival within Placental Lymphoid Populations

Neonatal herpes simplex virus (HSV) infections are frequently characterized by widespread dissemination and high morbidity and mortality. To assess the potential role of the lymphocyte in permitting or promoting dissemination of HSV, we studied lymphoid populations of placental and adult blood with respect to HSV survival. Adsorption of HSV to the lymphocyte surface did not differ between placental and adult cells. Placental blood permitted greater survival of HSV than adult lymphocytes. T-cell-enriched lymphocytes appeared to be slightly more permissive than T-cell-depleted lymphocytes, but these differences were not statistically significant and apparently less than adult-placental blood differences. These findings lend support to the hypothesis that intracellular changes common to various neonatal lymphoid populations may permit or promote dissemination of HSV in the neonate.

Survival of Herpes Simplex Virus in Water Specimens Collected From Hot Tubs in Spa Facilities and on Plastic Surfaces

Several health spas were closed temporarily because of possible nonvenereal spread of herpes simplex virus (HSV) in spa water at these facilities. We collected water specimens from two health spas and studied them for (1) the presence of HSV; (2) bromine (Br2), chlorine (Cl2), and pH levels; and (3) the ability of HSV to survive in water. No HSV could be isolated from the spa water specimens. Spa water had high levels of Cl2 and Br2, tap water specimens had low levels of Cl2, and distilled water had no detectable Cl2 or Br2. The addition of spa water to laboratory stock virus immediately inactivated the virus. The HSV survived four hours in the tap water and 24 hours in distilled water. The survival of HSV appeared to be related to the free halogen content of water. To approximate the conditions of survival of HSV on plastic-coated benches and seats in spa facilities, HSV was placed on plastic surfaces in a humid atmosphere at 37 to 40 degrees C. The virus was found to survive up to 4.5 hours under these conditions. The survival of HSV from human lesions may be different due to the presence of tissue secretions and proteins. Furthermore, transmission may require other factors, such as rubbing of skin or penetration through abrasions. However, survival of significant amounts of virus for 4.5 hours on plastic surfaces suggests that fomites such as these may be nonvenereal routes of HSV transmission.

Survival of herpes simplex virus in water specimens collected from hot tubs in spa facilities and on plastic surfaces

Survival of herpes simplex virus in water specimens collected from hot tubs in spa facilities and on plastic surfaces

Shedding and Survival of Herpes Simplex Virus from ‘Fever Blisters’

Shedding of herpesvirus by adults with herpes labialis and survival of the virus in the environment were examined. In nine adults with virus-positive herpes labialis, herpesvirus was detected in the anterior oral pool of seven (78%) and on the hands of six (67%). Herpesviruses isolated from patients with oral lesions were found to survive for as long as two hours on skin, three hours on cloth, and four hours on plastic. These findings support earlier recommendations for the protection of neonates from adults with "fever blisters." In addition, environmental surfaces may be a source of transmission of herpesvirus to the neonate.

Optimal Cooling and Warming Rates in the Preservation of Herpes Simplex Virus (Type 2)

Fast rates of cooling and warming were optimal for survival of herpes simplex virus, type 2. Under these conditions cryoprotectants were not necessary for virus preservation.

Comparative studies of host-cell reactivation, colony forming ability and excision repair after UV irradiation of xeroderma pigmentosum, normal human and some other mammalian cells

Host-cell reactivation, that is, the degree of survival of Herpes simplex virus after UV irradiation, was high in African green monkey BSC-1 cells, intermediate in normal human fibroblasts and human FL cells, and low in both xeroderma pigmentosum (XP) cells and mouse L cells. However, colony-forming ability after UV was high for FL, normal human fibroblasts and L cells, slightly low for BSC-1 cells and extremely low for XP cells. During the 24-h post-UV incubation period, up to about 50% of the thymine-containing dimers in the acid-insoluble DNA fraction disappeared at an almost equal rate for BSC-1, FL and normal human cells but remained unaltered for the XP cells. Alkaline sucrose gradient centrifugation of DNA after UV irradiation revealed only a slight difference between FL and BSC-1 cells in the kinetics of formation of single-strand breaks and their apparent repair. From these and the previously known characters of L cells possessing reduced excision-repair ability, if any, we may conclude that, if the survival of UV-irradiated Herpes simplex virus on a test line of human or other mammalian cells is as low as that on excisionless XP cells, then it is very probable that the test cell line is defective in excision repair. This reasoning leads to the presumptive conclusion that mouse L cells have an enhanced post-replication repair other than excision repair to deal with UV damage responsible for inactivation of colony-forming ability.