Human infection with B virus following a needlestick injury

Analysis of antiviral drug properties of thymidine kinase of herpes B virus using recombinant herpes simplex virus 1

IMPORTANCE

Zoonotic infection of humans with herpes B virus (BV) causes severe neurological diseases. Acyclovir (ACV) and ganciclovir (GCV), most frequently used as anti-herpes drugs, are recommended for prophylaxis and therapy in human BV infection. In this study, we examined the property of BV thymidine kinase (TK) against anti-herpes drugs using a recombinant herpes simplex virus type 1 (HSV-1) carrying BV TK gene. We found that HSV-1 carrying BV TK was similarly sensitive to GCV as HSV-1 carrying varicella zoster virus TK. In addition, we demonstrated that BV TK was not mutated in the GCV- and ACV-resistant HSV-1 carrying BV TK, suggesting that ACV- or GCV-resistant BV might be rare during treatment with these antiviral drugs. These data can provide a new insight into the properties of BV TK in terms of the development of drug resistance.

Towards a comprehensive view of the herpes B virus

Herpes B virus is a biosafety level 4 pathogen and widespread in its natural host species, macaques. Although most infected monkeys show asymptomatic or mild symptoms, human infections with this virus can cause serious neurological symptoms or fatal encephalomyelitis with a high mortality rate. Herpes B virus can be latent in the sensory ganglia of monkeys and humans, often leading to missed diagnoses. Furthermore, the herpes B virus has extensive antigen crossover with HSV, SA8, and HVP-2, causing false-positive results frequently. Timely diagnosis, along with methods with sensitivity and specificity, are urgent for research on the herpes B virus. The lack of a clear understanding of the host invasion and life cycle of the herpes B virus has led to slow progress in the development of effective vaccines and drugs. This review discusses the research progress and problems of the epidemiology of herpes B virus, detection methods and therapy, hoping to inspire further investigation into important factors associated with transmission of herpes B virus in macaques and humans, and arouse the development of effective vaccines or drugs, to promote the establishment of specific pathogen-free (SPF) monkeys and protect humans to effectively avoid herpes B virus infection.

A survey investigating the current practice of French health professionals regarding infection risk after monkey bites

International tourism is steadily increasing, with 15% of travellers reporting health problems when they come back. Animal bites represent 2% of consulting causes, of which 20% are due to monkey bites. The Monkey B virus (Macacine alphaherpesvirus 1) is an alphaherpesvirus (Herpesviridae, genus Simplexvirus) enzootic in macaques (Genus Macaca). Zoonotic infections with the Monkey B virus following exposure to macaques are exceptionally rare, but can cause fatal encephalomyelitis in humans. An observational survey was undertaken in 2018 to assess the practice of French health professionals regarding infection risk after monkey bites. French health professionals practicing in vaccination and rabies centres were specifically targeted for this study. Standardized questionnaires were sent by email to a sample of French health professionals. They were asked to participate on a voluntary and anonymous basis. The questionnaires requested epidemiological details and included multiple-choice questions about the infection management of monkey bites. The response rate was 33.5%. The frequency of monkey bites in 2017 was variable with a minority of centres managing more than 6 per year (12%), 46% managing 1-5 monkey bites and 42% none. Most of the monkey bites were described as occurring in South Asia at tourist sites, on naked upper limbs, shortly after the travellers arrived at their destination. Tetanus status verification, rabies post-exposure prophylaxis and antibiotic therapy were said to be prescribed in most cases. Knowledge about the Monkey B virus was reported as scarce for 38% of the participants. The number of monkey bites managed per year per centre varied greatly but practices regarding infectious risk after monkey bites were generally homogeneous. The risk of Monkey B virus transmission did not readily come to mind in the differential diagnosis of infection risk for many French health professionals.

Effective Prophylactic Therapy for Exposure to Monkey B Virus (Macacine alphaherpesvirus 1)

Zoonotic monkey B virus (Macacine alphaherpesvirus 1; BV) infections are extremely serious and usually fatal. Drugs currently used for treatment were developed for the treatment of herpes simplex virus but are less effective against BV. Effective suppression of viral replication in the skin could prevent the virus from invading the nervous system. To test this hypothesis, the efficacy of topical administration of several drugs against lethal BV infection was evaluated in female BALB/c mice that were infected by scarification. Drugs were then applied to the site of inoculation. As 3% preparations, most drugs were only minimally effective or ineffective. In contrast, ganciclovir and cidofovir were very effective. The ED₅₀ for cidofovir was 0.007%, compared with 1.1% for ganciclovir. At 0.5%, cidofovir protected against both death and neurologic signs, whereas 5% ganciclovir only protected against death but not neurologic involvement. All genotypes of BV were equally susceptible to cidofovir and ganciclovir. For maximal effectiveness, treatment with both cidofovir and ganciclovir had to be initiated within 8 h of infection. Cidofovir was completely protective when administered only on the day of infection, whereas a minimum of 5 d of treatment was required for maximal ganciclovir efficacy. These studies showed that topical cidofovir treatment started soon after BV exposure was very effective in preventing BV from invading the nervous system, whereas ganciclovir treatment was only partially effective. In addition, cidofovir was protective against a ganciclovir-resistant BV mutant, whereas ganciclovir was not. These studies showed that topical cidofovir treatment started soon after BV exposure is more effective than ganciclovir in preventing BV from invading the CNS.

Questioning the Extreme Neurovirulence of Monkey B Virus (Macacine alphaherpesvirus 1)

Monkey B virus (Macacine alphaherpesvirus 1; BV) occurs naturally in macaques of the genus Macaca, which includes rhesus and long-tailed (cynomolgus) monkeys that are widely used in biomedical research. BV is closely related to the human herpes simplex viruses (HSV), and BV infections in its natural macaque host are quite similar to HSV infections in humans. Zoonotic BV is extremely rare, having been diagnosed in only a handful of North American facilities with the last documented case occurring in 1998. However, BV is notorious for its neurovirulence since zoonotic infections are serious, usually involving the central nervous system, and are frequently fatal. Little is known about factors underlying the extreme neurovirulence of BV in humans. Here we review what is actually known about the molecular biology of BV and viral factors affecting its neurovirulence. Based on what is known about related herpesviruses, areas for future research that may elucidate mechanisms underlying the neurovirulence of this intriguing virus are also reviewed.

Understanding Primate Herpesviruses

Viruses related to the herpes simplex viruses of humans are present in all nonhuman primate (NHP) species tested and cross species transmission has been documented. The herpesvirus present in macaques, Herpes B virus (BV) rarely causes disease in its natural macaque host. However, when transmitted to a nonnative host, BV has occasionally caused severe and even fatal disease if not treated immediately. Here we present a comprehensive review of the taxonomy, molecular biology, physiology, epidemiology, diagnosis and treatment of BV. We also summarizes what is known about related herpesviruses of other NHP species and the zoonotic potential of these viruses.

The epidemiology of blood-contaminated needlestick injuries among veterinarians in Portugal

Needlestick injuries (NIs) are considered a substantial occupational health and safety hazard in contemporary health care practice. Unlike human medicine where much effort has been devoted to reduce the incidence of these events, the same aggressive approach has not been used in veterinary medicine. This study investigated the occurrence of blood-contaminated NIs in Portuguese veterinarians. Participants of a veterinary meeting were asked to complete a questionnaire-based survey. Univariate and multivariate logistic regression analyses were performed to produce predicted probabilities for NI episodes in veterinarians. From the total of 373 enrolled veterinarians, 293 (78.5%) reported having had at least one NI during their professional life. Veterinarians working with dogs were more likely to have experienced a NI (adjusted odds ratio [aOR]: 145.74, P < .001). The high level of NIs observed in these professionals shows that NIs are a potential occupational health problem in Portuguese veterinarians, with the possibility for transmission of haematogenous zoonosis.

Survey of occupational hazards in Minnesota veterinary practices in 2012

OBJECTIVE

To identify the scope of occupational hazards encountered by veterinary personnel and compare hazard exposures between veterinarians and technicians working in small and large animal practices.

DESIGN

Cross-sectional survey.

POPULATION

Licensed veterinarians and veterinary staff in Minnesota.

PROCEDURES

A survey of Minnesota veterinary personnel was conducted between February 1 and December 1, 2012. Adult veterinary personnel working in clinical practice for > 12 months were eligible to participate. Information was collected on various workplace hazards as well as on workplace safety culture.

RESULTS

831 eligible people responded, representing approximately 10% of Minnesota veterinary personnel. A greater proportion of veterinarians (93%; 368/394) reported having received preexposure rabies vaccinations than did veterinary technicians (54%; 198/365). During their career, 226 (27%) respondents had acquired at least 1 zoonotic infection and 636 (77%) had been injured by a needle or other sharps. Recapping of needles was reported by 87% of respondents; the most common reason reported by veterinarians (41%; 142/345) and veterinary technicians (71%; 238/333) was being trained to do so at school or work. Recent feelings of depression were reported by 204 (25%) respondents. A greater proportion of technicians (42%; 155/365) than veterinarians (21%; 81/394) indicated working in an environment in which employees experienced some form of workplace abuse.

CONCLUSIONS AND CLINICAL RELEVANCE

Veterinary personnel in Minnesota were exposed to several work-related hazards. Practice staff should assess workplace hazards, implement controls, and incorporate instruction on occupational health into employee training.

Factors Promoting Consistent Adherence to Safe Needle Precautions Among Hospital Workers

Objective:

To examine organizational factors and occupational characteristics associated with adherence to occupational safety guidelines recommending never recapping needles.

Design:

Mail surveys were conducted with healthcare workers (HCWs) and infection control professionals (ICPs).

Setting:

The surveys were conducted at all non-federal general hospitals in Iowa, except one tertiary-care hospital. Survey data were linked to annual survey data of the American Hospital Association (AHA).

Participants:

HCWs were sampled from statewide rosters of physicians, nurses, and laboratory workers in Iowa. Eligible HCWs worked in a setting and position in which they were likely to routinely handle needles. ICPs at all hospitals in the state were surveyed.

Results:

Ninety-nine ICPs responded (79% response rate). AHA data were available for all variables from 84 (85%) of the hospitals. Analyses were based on 1,454 HCWs who identified one of these hospitals as their primary hospital (70% response rate). Analyses were conducted using multiple logistic regression. Positive predictors of consistent adherence included infection control personnel hours per full-time–equivalent employee (odds ratio [OR], 1.03), frequency of standard precautions education (OR, 1.11), facilities providing personal protective equipment (OR, 1.82), facilities using needleless intravenous systems (OR, 1.42), and management support for safety (OR, 1.05). Negative predictors were use of “blood and body fluid precautions” isolation category (OR, 0.74) and increased job demands (OR, 0.90).

Conclusion:

Healthcare organizations can improve staff safety by investing wisely in educational programs regarding approaches to minimize these risks, providing protective equipment, and eliminating the use of blood and body fluid precautions as an isolation policy.

Xenozoonoses

Immunological and technical advances have led to tremendous increases in the number of people potentially able to benefit from allotransplantation. Ironically, it is the success of the field that has led to a renewed interest in xenotransplantation during the past several decades. To a large part, this has occurred because of the great scarcity of human organ and tissue donors. However, it has expanded to include the use of cells from animals into humans such as porcine islet cells for diabetes or extracorporeal perfusion of human blood through animal organs or cells. Similar to allotransplantation, issues regarding transmission of infections from the graft to the human recipient were brought up for consideration with these procedures in the 1990s (Michaels and Simmons, 1994; Chapman et al., 1995; Hammel et al., 1998; Fishman et al., 1998). A risk for infection exists with the use of any biologic agent regardless of whether it is from a human or an animal source. Accordingly, transmission of infections from human organs, tissues, or cells is a well-recognized cause of disease after allotransplantation (Ison and Grossi, 2013; Green and Michaels, 2012). As the human graft shortage continues, newer cellular therapies are explored. Thus, attention continues to be given to the potential use of xenogeneic organs, tissues, or cells for human maladies through xenotransplantation. The potential for novel zoonotic infections to emerge because of xenotransplantation (xenozoonoses or xenosis) led to a debate on whether the field should be permitted to progress. This chapter reviews the issues of xenotransplantation related to infections from animals to humans. Lessons learned from infections with prior nonhuman primate xenotransplantation and human allotransplantation are used to help inform about risks with newer xenogeneic procedures. In addition, information on known zoonoses is reviewed to better develop constructs to decrease the hazard of infection with these novel procedures.

A prospective look at the burden of sharps injuries and splashes among trauma health care workers in developing countries: true picture or tip of iceberg

OBJECTIVES

Health care workers (HCWs) face constant risk of exposure to cuts and splashes as occupational hazard. Hence, a prospective observational study was conducted to observe the exposure of HCWs to various sharp injuries and splashes during health care and to work up a baseline injury rate among HCWs for future comparison in trauma care set ups.

METHODS

A 2 year and 5 month study was conducted among the voluntarily reported exposed HCWs of the APEX trauma centre. Such reported cases were actively followed for 6 months after testing for viral markers and counselled. The outcomes of such exposed HCWs and rate of seroconversion was noted. To form a future reference point, the injury rate in trauma care HCWs based on certain defined parameters along with the rate of under reporting were also analysed in this study.

RESULTS

In our study, doctors were found to have the highest exposure (129, 36.2%), followed by nurses (52, 14.6%) and hospital waste disposal staff (27, 7.6%). Of the source patients, a high number of them were HBV positive (11, 3.1%), followed by HIV positive patients (8, 2.2%). No seroconversion was seen in any of the exposed HCWs. Injuries by sharps (303, 85.1%) outnumber those due to splashes (53, 14.9%) which were much higher in those working in pressing situations. Underreporting was common, being maximally prevalent in hospital waste disposal staff (182, 51.1%).

CONCLUSIONS

High rates of exposure to sharp injuries and splashes among HCWs call for proper safety protocols. Proper methods to prevent it, encouraging voluntary reporting and an active surveillance team are the need of the hour.

Herpes B virus, macacine herpesvirus 1, breaks simplex virus tradition via major histocompatibility complex class I expression in cells from human and macaque hosts

B virus of the family Herpesviridae is endemic to rhesus macaques but results in 80% fatality in untreated humans who are zoonotically infected. Downregulation of major histocompatibility complex (MHC) class I in order to evade CD8(+) T-cell activation is characteristic of most herpesviruses. Here we examined the cell surface presence and total protein expression of MHC class I molecules in B virus-infected human foreskin fibroblast cells and macaque kidney epithelial cells in culture, which are representative of foreign and natural host initial target cells of B virus. Our results show <20% downregulation of surface MHC class I molecules in either type of host cells infected with B virus, which is statistically insignificantly different from that observed in uninfected cells. We also examined the surface expression of MHC class Ib molecules, HLA-E and HLA-G, involved in NK cell inhibition. Our results showed significant upregulation of HLA-E and HLA-G in host cells infected with B virus relative to the amounts observed in other herpesvirus-infected cells. These results suggest that B virus-infected cell surfaces maintain normal levels of MHC class Ia molecules, a finding unique among simplex viruses. This is a unique divergence in immune evasion for B virus, which, unlike human simplex viruses, does not inhibit the transport of peptides for loading onto MHC class Ia molecules because B virus ICP47 lacks a transporter-associated protein binding domain. The fact that MHC class Ib molecules were significantly upregulated has additional implications for host-pathogen interactions.

Factors affecting occupational exposure to needlestick and sharps injuries among dentists in Taiwan: a nationwide survey

Background

Although the risks of needlestick and sharps injuries (NSIs) for dentists are well recognized, most papers published only described the frequency of occupational exposure to NSIs. Less has been reported assessing factors contributing to exposure to NSIs. The purpose of this study was to update the epidemiology of NSIs among dentists in Taiwan and identify factors affecting NSIs in order to find preventive strategies.

Methodology/Principal Findings

A nationwide survey was conducted in dentists at 60 hospitals and 340 clinics in Taiwan. The survey included questions about factors supposedly affecting exposure to NSIs, such as dentist and facility characteristics, knowledge and attitudes about infectious diseases, and practices related to infection control. Univariate and multivariate logistic regression analyses were conducted to determine the association between risk factors and exposure to NSIs. In total, 434 (74.8%) of 580 dentists returned the survey questionnaires, and 100 (23.0%) reported that they had experienced more than one NSI per week. Our data showed that the risk of occupational NSIs is similarly heightened by an older age (odds ratio [OR], 3.18; 95% confidence interval [CI], 1.62–6.25), more years in practice (OR, 2.57; 95% CI, 1.41–4.69), working in clinics (OR, 1.73; 95% CI, 1.08–2.77), exhibiting less compliance with infection-control procedures (OR, 1.82; 95% CI, 1.04–3.18), having insufficient knowledge of blood-borne pathogens (OR, 1.67; 95% CI, 1.04–2.67), and being more worried about being infected by blood-borne pathogens (OR, 1.82; 95% CI, 1.05–3.13).

Conclusions/Significance

High rates of NSIs and low compliance with infection-control procedures highly contribute to the chance of acquiring a blood-borne pathogen infection and threaten occupational safety. This study reveals the possible affecting factors and helps in designing prevention strategies for occupational exposure to NSIs.

Primates and primatologists: social contexts for interspecies pathogen transmission

Humans and nonhuman primates (NHP) interact in a variety of contexts. The frequency, duration, and intensity of interspecies interaction influence the likelihood that contact results in cross-species transmission of infectious agents. In this study, we present results of a cross-sectional survey of attendees at a national conference of primatologists, characterizing their occupational exposures to NHP. Of 116 individuals who participated in the study, 68.1% reported having worked with NHP in a field setting, 68.1% in a laboratory setting, and 24.1% at a zoo or animal sanctuary. Most subjects (N=98, 84.5%) reported having worked with multiple NHP taxa, including 46 (39.7%) who had worked with more than five distinct taxa. Sixty-nine subjects (59.5%) recalled having been scratched by a NHP and 48 (41.1%) had been bitten; 32 subjects reporting being bitten more than once. Eleven subjects (9.5%) reported having been injured by a needle containing NHP tissue or body fluids. We conclude that primatologists are at high risk for exposure to NHP-borne infectious agents. Furthermore, primatologists' varied occupational activities often bring them into contact with multiple NHP species in diverse contexts and geographic areas, over extended periods of time, making them a unique population with respect to zoonotic and anthropozoonotic disease risk.

Recommendation for post-exposure prophylaxis after potential exposure to herpes b virus in Germany

Although the risk of a herpes B virus (Cercopithecine herpes virus 1) infection is low, the clinical course of the infectious disease is generally unfavourable. A high safety standard can be achieved if people with professional contact to primates apply proper organisational, technical and personal safety precautions. The risk can be considerably reduced if animal keepers, laboratory assistants and scientists receive adequate information about the pathology of herpes B virus and are well trained in the necessary procedures and the precautions. For this reason, comprehensive and regular training, information and instruction must be provided to all primate workers and to laboratory workers who come into contact with potentially infectious material. After potential contamination, the risk for the affected worker must be assessed immediately and post-exposure chemoprophylaxis performed if necessary. This necessitates internal risk assessment. An interdisciplinary group of experts has developed an action plan for Germany.

Inhibition of B virus (Macacine herpesvirus 1) by conventional and experimental antiviral compounds

B virus infection of humans results in high morbidity and mortality in as many as 80% of identified cases. The main objective of this study was to conduct a comparative analysis of conventional and experimental antiviral drug susceptibilities of B virus isolates from multiple macaque species and zoonotically infected humans. We used a plaque reduction assay to establish the effective inhibitory doses of acyclovir, ganciclovir, and vidarabine, as well as those of a group of experimental nucleoside analogs with known anti-herpes simplex virus activity. Four of the experimental drugs tested were 10- to 100-fold more potent inhibitors of B virus replication than conventional antiviral agents. Drug efficacies were similar for multiple B virus isolates tested, with variations within 2-fold of the median effective concentration (EC(50)) for each drug, and each EC(50) was considerably lower than those for B virus thymidine kinase (TK) mutants. We observed no differences in the viral TK amino acid sequence between B virus isolates from rhesus monkeys and those from human zoonoses. Differences in the TK protein sequence between cynomolgus and pigtail macaque B virus isolates did not affect drug sensitivity except in the case of one compound. Taken together, these data suggest that future B virus zoonoses will respond consistently to conventional antiviral treatment. Further, the considerably higher potency of FEAU (2'-fluoro-5-ethyl-Ara-U) than of conventional antiviral drugs argues for its compassionate use in advanced human B virus infections.

Exposure rate of needlestick and sharps injuries among Australian veterinarians

BACKGROUND

Needlestick and sharps injuries (NSI) represent an important occupational health issue in veterinary practice. Little is known about the distribution and correlates of NSI among Australian veterinarians.

METHODS

A questionnaire-based NSI survey was mailed to 1094 veterinarians registered with the Veterinary Surgeons Board of Queensland during 2006.

RESULTS

A total of 664 surveys were returned from 1038 eligible participants (response rate 64.0%) with 56.8% being male, around one-third in the >50 years age group and about half aged 3150 years. Just over two-fifths were working in small animal practice only. Around three quarters (75.3%) reported suffering at least one NSI in the previous 12 months, while 58.9% reported suffering from at least one contaminated NSI during the previous 12 months, which crudely extrapolates to an exposure rate of 75.3 and 58.9 NSI per 100 person-years respectively. Risk factors for contaminated NSI were female gender, working in small or mixed animal practice, being less experienced, seeing more patients per week and working longer hours per week. The most common causative devices were syringes (63.7%), suture needles (50.6%) and scalpel blades (34.8%).

CONCLUSION

The exposure rate of NSI is high for Queensland veterinarians and clearly remains a major occupational health problem. Current guidelines and strategies to reduce NSI in veterinary practice should be promoted, but appear to be adapted from human health care. Studies to understand why veterinarians have such high NSI rates are required to not only identify risk factors for NSI, but also to determine attitudes and beliefs about NSI. From these studies specific strategies for veterinarians can be designed and trialed to develop evidence-based guidelines and policies that are effective in decreasing the exposure rate of NSI in veterinary practice.

Herpesviruses--a zoonotic threat?

Herpesviruses are highly host specific and share a long synchronous evolution with their hosts. Only in rare cases, species barriers fall and allow animal to human or human to animal transmission. Among the zoonotic herpesviruses, Cercopithecine herpesvirus 1 is the most significant and can be transmitted from macaques to human. Conversely, Human herpesvirus 1 is capable of causing severe disease in primates. Besides those two examples, there are several herpesviruses with a certainly limited or only suspected ability to cross species barriers. Those include Saimiriine herpesvirus 2, Phocid herpesvirus 2, Equid herpesvirus 1, Epstein-Barr Virus, Marek's disease virus, and Pseudorabies virus. Concerning xenotransplantations, porcine gammaherpesviruses must be considered as a zoonotic threat.

Infection risks following accidental exposure to blood or body fluids in health care workers: a review of pathogens transmitted in published cases

Hospital staff and all other human or veterinary health care workers, including laboratory, research, emergency service, or cleaning personnel are exposed to the risk of occupational infection following accidental exposure to blood or body fluids (BBF) contaminated with a virus, a bacteria, a parasite, or a yeast. The human immunodeficiency virus (HIV) or those of hepatitis B (HBV) or C (HCV) account for most of this risk in France and worldwide. Many other pathogens, however, have been responsible for occupational infections in health care workers following exposure to BBF, some with unfavorable prognosis. In developed countries, a growing number of workers are referred to clinicians responsible for the evaluation of occupational infection risks following accidental exposure. Although their principal task remains the evaluation of the risks of HIV, HBV, or HCV transmission and the possible usefulness of postexposure prophylaxis, these experts are also responsible for evaluating risks of occupational infection with other emergent or more rare pathogens and their possible timely prevention. The determinants of the risks of infection and the characteristics of described cases are discussed in this article.

DNA polymerase gene locus of Cercopithecine herpesvirus 1 is a suitable target for specific and rapid identification of viral infection by PCR technology

The family Herpesviridae comprises at least 100 herpesviruses. Numerous human and animal pathogenic herpesviruses have been identified so far, including Cercopithecine herpesvirus 1 (CeHV-1). This virus is a member of the subfamily Alphaherpesvirinae and is the most hazardous herpesvirus to man. CeHV-1 is also known as B-virus or monkey B virus and as Herpesvirus simiae. In order to gain more genetic information, the viral DNA polymerase (DPOL) gene was identified using polymerase chain reaction (PCR) and DNA nucleotide sequence analysis. The deduced amino acid sequence contains the motifs and signatures that are typical for the B-family of DPOLs. The DPOL gene of CeHV-1 was found to be a suitable target for the specific and rapid identification of the Cercopithecine herpesvirus 1 infection by PCR technology. Comparative analysis of the DNA sequences of the DPOL gene loci of CeHV-1, Human herpesvirus 1 and 2 (HHV-1 and HHV-2), and other herpesviruses was carried out for determination of unique genomic regions of the individual DPOL genes. A primer set of 12 primers was used for screening the DNA of CeHV-1, HHV-1, and HHV-2 by detailed PCR. It was found that six out of twelve primer combinations are able to detect specifically the CeHV-1 genome without cross reactivity with the genome of HHV-1 and/or HHV-2. The specificity of the individual amplified DNA fragments was confirmed by DNA nucleotide sequence analysis. The results of these studies indicate that the six primer combinations of the specific CeHV-1 DPOL primer set is the method of choice for a rapid, precise and specific identification of a CeHV-1 infection by PCR. Due to the fact that this specific CeHV-1 DPOL primer set does not amplify any DNAs of HHV-1 or HHV-2 genome this technology is stressing and can be successfully used unlimited and more credible in all laboratories with PCR technical facility routinely for detection of a CeHV-1 infection in vivo or in vitro.

Recommendations for prevention of and therapy for exposure to B virus (cercopithecine herpesvirus 1)

B virus (Cercopithecine herpesvirus 1) is a zoonotic agent that can cause fatal encephalomyelitis in humans. The virus naturally infects macaque monkeys, resulting in disease that is similar to herpes simplex virus infection in humans. Although B virus infection generally is asymptomatic or mild in macaques, it can be fatal in humans. Previously reported cases of B virus disease in humans usually have been attributed to animal bites, scratches, or percutaneous inoculation with infected materials; however, the first fatal case of B virus infection due to mucosal splash exposure was reported in 1998. This case prompted the Centers for Disease Control and Prevention (Atlanta, Georgia) to convene a working group in 1999 to reconsider the prior recommendations for prevention and treatment of B virus exposure. The present report updates previous recommendations for the prevention, evaluation, and treatment of B virus infection in humans and considers the role of newer antiviral agents in postexposure prophylaxis.

Survey of veterinary conference attendees for evidence of zoonotic infection by feline retroviruses

OBJECTIVE

To examine exposure risks, possibility of zoonosis, and potential disease associations for feline retroviruses among a group of occupationally exposed individuals.

DESIGN

Unlinked voluntary cross-sectional epidemiologic survey.

SAMPLE POPULATION

204 veterinarians, laboratory scientists, and other occupationally exposed individuals who attended a veterinary conference on feline geriatric medicine.

PROCEDURE

Blood was collected from participants who also completed a 13-question survey requesting demographic, occupational, exposure, and health information. Blood specimens were fractionated into plasma and mononuclear cell components. Plasma was tested for antibodies against feline immunodeficiency virus (FIV) and feline foamy virus (FeFV), as well as p27 antigen of FeLV. Mononuclear cell lysates were tested for FeLV provirus.

RESULTS

Subjects reported extensive duration of work with cats (mean, 17.3 years) and multiple high-risk exposures (eg, cat bites, scratches, and injuries with sharp instruments) per year. However, neither serologic nor molecular evidence of zoonosis with any of the 3 feline retroviruses was detected.

CONCLUSIONS AND CLINICAL RELEVANCE

Veterinarians encounter occupational exposures to animal material that place them at high risk for zoonoses. For feline retroviruses, the risk of zoonosis among healthy adult humans appears to be extremely small. However, potential for retroviral zoonosis, especially for viruses such as FeLV and FeFV that can replicate in human cells, cannot be eliminated, and universal precautions to reduce potential exposures should be used when handling sick cats.

Herpes B virus infection

Herpes B virus (B virus) infection is common in macaques. Primary infection of B virus in primates is similar to herpes simplex virus 1 infection in human beings, but B virus generally produces only mild localized lesions in its natural host. In human beings, however, B virus can cause severe infection that may lead to death from encephalitis. Contact with monkey saliva, tissues, or tissue fluids is the most commonly reported route of transmission of B virus; a single case of person-to-person transmission has been reported. Airborne transmission is postulated to have occurred as a result of clinical circumstances in two reported cases, but there is no strong evidence to support the hypothesis of aerosol infection. Because B virus infection in human beings is often fatal, awareness of the risk of B virus infection should be emphasized. Although B virus infection in human beings is rare, it is an occupational health risk in exposed health care workers and laboratory personnel. This review of the literature of B virus infection includes case reports and a discussion of the nature of the B virus, characteristics of B virus infection in primates and human beings, the treatment of human infection, and the implications for dental health care providers. This report also serves as an introduction of the disease to the dental literature.

B-virus from pet macaque monkeys: an emerging threat in the United States?

Of primary concern when evaluating macaque bites are bacterial and B-virus infections. B-virus infection is highly prevalent (80% to 90%) in adult macaques and may cause a potentially fatal meningoencephalitis in humans. We examined seven nonoccupational exposure incidents involving 24 persons and eight macaques. Six macaques were tested for herpes B; four (67%) were seropositive. A common observation was that children were more than three times as likely to be bitten than adults. The virus must be assumed to be a potential health hazard in macaque bite wounds; this risk makes macaques unsuitable as pets.

Risk of occupational exposure to potentially infectious nonhuman primate materials and to simian immunodeficiency virus

Five hundred fifty persons who worked with nonhuman primates (NHP) or with NHP material in 13 North American research institutions were surveyed for potential occupational exposures and tested for antibodies to simian immunodeficiency virus (SIV). Needlesticks and mucocutaneous exposures were reported more frequently among persons who handled SIV-negative or SIV-status-unknown (SIV-N/U) animals (36% and 35%) or who worked with SIV-N/U material in the laboratory (18% and 17%) than among persons who handled SIV-positive NHP (SIV-P) (9% and 4%) or worked with SIV-P material (6% and 8%). The risk for needlesticks when working with both SIV-N/U and SIV-P animals and the risk for mucocutaneous exposures from SIV-N/U animals increased with the number of years working with NHP. Persons who performed invasive tasks (e.g., obtaining blood samples, performing surgery/autopsies) were more likely than others to sustain needlesticks (adjusted OR = 3.55, 95%CI = 1.40-9.02). Two (0.4%) of 550 persons had antibodies to SIV. One appears to be infected with SIV, as previously reported. These data suggest that persons who work with NHP or with NHP material are at risk for occupational exposure to potentially infectious materials including SIV. Prevention strategies are needed to reduce the risk for needlesticks and mucocutaneous exposures around all NHP, and safety guidelines should emphasize prevention options for invasive tasks performed with animals.

Fatal disseminated cercopithecine herpesvirus 1 (herpes B infection in cynomolgus monkeys (Macaca fascicularis)

Two adult female cynomolgus monkeys (Macaca fascicularis) that had been housed together for 4 months died within 2 weeks of each other after brief illnesses. Monkey No. 1 presented with collapse, watery stool, and hypothermia and died overnight. Monkey No. 2 presented with dyspnea, nasal discharge, leukopenia, and hypoproteinemia and was euthanized after 2 days. Both animals had peritoneal effusions, massive necrosis of pharyngeal, esophageal, and gastric mucosa, and multifocal hepatic and pancreatic necrosis. Monkey No. 2 also had lingual ulcers and locally extensive necrosis of spleen, adrenal glands, and lymph nodes. Large numbers of eosinophilic intranuclear inclusion bodies were present in epithelial and syncytial cells adjoining the necrotic foci in Monkey No. 2 but were absent in Monkey No. 1. Monkey No. 1 seroconverted to cercopithecine herpesvirus 1 (CHV-1, commonly known as herpes B) in the month before death. CHV-1 was isolated from a sample of stomach from Monkey No. 2, and electron microscopy of liver from this animal demonstrated herpesvirus particles within hepatocytes. Both animals were seropositive for simian type D retrovirus, and the virus was cultured from the liver of Monkey No. 2. A diagnosis of disseminated CHV-1 infection was made, possibly occurring secondary to immunosuppression due to infection with simian type D retrovirus. Although a high percentage of cynomolgus monkeys are apparently infected with CHV-1, disseminated disease is rare. Because infection with CHV-1 in humans is associated with a high fatality rate, familiarity with the lesions of disseminated infection with this virus is important.

Viral infections in the immunocompetent patient

Human herpesviruses and human papillomaviruses are ubiquitous and may cause an array of oral disease. Herpesviruses are unique because recurrent localized disease occurs after the primary infection. Human papillomaviruses are known for their ability to produce benign epithelial proliferations and increasingly are implicated in the development of oral cancer. This article reviews the pathogenesis of common oral lesions induced by these viruses.

Sensitivity of NCI-H292 human lung mucoepidermoid cells for respiratory and other human viruses

NCI-H292 mucoepidermoid carcinoma cells from human lungs were shown in an earlier report to be a fully adequate substitute for primary rhesus monkey kidney (MK) cells for the isolation and propagation of the human paramyxoviruses. Although sensitivity for ortho- and paramyxoviruses was the principal reason for using MK cells, the cells were also sensitive to many other viruses, which constituted another important value of MK cells. That MK cells supported the initial isolation and growth of so many respiratory viruses made it a mandatory cell type for any clinical laboratory. We therefore felt it was imperative to evaluate the virus spectrum of NCI-H292 cells, which are being used as a substitute for MK cells in many laboratories. In the present report, we show that NCI-H292 cells are sensitive for vaccinia virus, herpes simplex virus, adenoviruses, BK polyomavirus, reoviruses, measles virus, respiratory syncytial virus, some strains of influenza virus type A, most enteroviruses, and rhinoviruses, in addition to the parainfluenza and mumps viruses originally reported. Furthermore, these viruses replicate in NCI-H292 cells to the same virus and antigen titers and at the same speed of replication as they do in their usually preferred cells. The NCI-H292 cells are therefore an excellent substitute for MK cells in terms of laboratory safety, ease of availability, paramyxovirus isolation, and broad virus spectrum but cannot substitute for MK cells for the isolation of influenza viruses.

Polymerase chain reaction for detection of herpesvirus simiae (B virus) in clinical specimens

A polymerase chain reaction (PCR) was designed which is specific to Macaca fascicularis (cynomolgus monkey) isolates of B virus. The PCR primers produced the expected 188 basepair product from the Cyno 2 strain and seven other cynomolgus monkey isolates of B virus. Oligomer hybridization with a 31-mer oligonucleotide was used to confirm the origin of this product. The PCR failed to amplify DNA of Epstein-Barr virus, cytomegalovirus, varicella-zoster virus, and other alphaherpesviruses (herpes simplex virus types 1 and 2, four SA 8 isolates and three rhesus isolates of B virus). PCR testing of swabs obtained from four orally-infected cynomolgus monkeys confirmed the presence of B virus DNA in samples previously shown to be positive by culture. In addition, PCR detected B virus in several swabs from infected monkeys that were culture negative. Total DNA extracts from the trigeminal and sacral ganglia of these animals were tested by nested PCR and B virus DNA was detected in the trigeminal ganglia of 3 of the 4 orally-infected cynomolgus monkeys. Nested PCR did not detect B virus DNA in total DNA extracts obtained from the brains of the four monkeys.