Rabies update for travel medicine advisors

Sequencing and sequence analysis of partial nucleoprotein (N) gene and phylogenetic analysis of rabies virus field isolates from Gujarat state, India

The present study was undertaken with an aim of characterization of rabies virus (genus Lyssavirus of the family Rhabdoviridae under the order Mononegavirales) by sequencing of partial nucleoprotein (N) gene of rabies virus and phylogenetic analysis to know the genotype and lineage of rabies virus present in Gujarat state of India. A total of 32 samples (18 brain samples and 14 saliva samples) were aseptically collected from live and dead animals (viz. dog, buffalo, cow, goat, donkey and hyena) for rabies virus detection. Out of 32 samples, 24 samples were found positive by Reverse Transcriptase Polymerase Chain Reactions and from these 24 positive samples, 20 samples were selected for sequencing having good concentration of gene product. ClustalW alignment of nucleotide sequences and amino acid sequences of field rabies isolates revealed 95.20-100 and 97.95-100% similarity among themselves, respectively. Multiple sequence alignment of field rabies isolates and reference vaccine strains [Pasteur strain and Challenge Virus Strain (CVS)] indicated single nucleotide mutations at total 91 positions and amino acid mutations at total 17 different positions. Phylogenetic analysis of N gene sequences using our 20 field rabies isolates and 21 other reported isolates in Genbank resulted in 3 phylogenetic clusters. All the field rabies isolates showed same genetic lineage among themselves and with other earlier reported Indian rabies isolates placing them in Arctic like lineage of Genotype 1 Rabies virus. However, they were at genetic distance with reference Pasteur and CVS strains, which grouped in different phylogenetic cluster.

Immunogenicity and feasibility of intradermal vaccination against rabies in Quebec

OBJECTIVES

Preexposure vaccination against rabies is recommended for some travellers and individuals exposed to the virus through their work. At a cost of at least $150 per intramuscular (IM) dose, few follow this recommendation. In Canada, provided certain conditions are met, the National Advisory Committee on Immunization (NACI) and the Comité d'immunisation du Québec allow a more economical alternative, intradermal vaccine administration (ID) which uses 1/10 the IM dose. The purpose of this study is to assess the feasibility and immunogenicity of intradermal preexposure vaccination.

METHODS

Students and employees at the Faculty of Veterinary Medicine received three doses of ImovaxRage™ (Sanofi Pasteur) inactivated, human diploid cell rabies vaccine at days 0, 7 and 21 or 28. An IM or ID booster dose was administered after two years when indicated.

OUTCOMES

Among the 159 participants who received three doses, 139 underwent serological testing in the year following vaccination and all achieved protective antibody levels. The antibody level was higher when measured within five weeks of the third dose. When the serological control was performed two years later, 65% of participants had a <0.5 IU/ml titre. Of the 22/30 participants who chose an ID booster, 100% responded and the average antibody titres were multiplied by 11, indicating a strong anamnestic response.

DISCUSSION

ID rabies vaccination is immunogenic, economic and could be considered for the booster dose. Protective antibodies decline rapidly after primary immunization by ID, so it would seem prudent to perform a serological control one year later on individuals at high risk of occult occupational exposure. An alternative would be to give these individuals a routine ID booster dose one year after primary vaccination, which would simplify initial treatment and reduce related costs (follow-up, blood sampling, serological tests, etc.). The persistence of protective antibodies after this booster dose should be assessed to determine the need for subsequent serological tests and the ideal interval between tests.

Characterizing rabies epidemiology in remote Inuit communities in Québec, Canada: a "One Health" approach

Rabies is endemic throughout arctic areas including the region of Nunavik, situated north of the 55th parallel of Québec, Canada, and raises public health concerns. The aim of this paper is to provide a descriptive overview of the temporal and regional distributions of three important components of arctic rabies in Nunavik from 1999 to 2012, following a "One Health" approach: animal rabies tests and confirmed cases, dog vaccination, and human consultations for potential rabies exposures. Forty-four cases of rabies, involving mainly arctic and red foxes, were confirmed in animals during this period. The mean number of dogs vaccinated per 1,000 inhabitants was highly variable and lower in the Hudson region than the Ungava region. 112 consultations for potential rabies exposure were analyzed, of which 24 were exposure to a laboratory confirmed rabid animal. Children less than 10 years of age were the age group most commonly exposed. The median time between potential exposure and administration of the first post-exposure prophylaxis dose was four days. This study confirms that the risk of human exposure to rabid animals in Nunavik is present and underlines the need to follow a "One Health" approach to prevent rabies in humans in similar contexts worldwide.

Strategic model of national rabies control in Korea

Rabies is an important zoonosis in the public and veterinary healthy arenas. This article provides information on the situation of current rabies outbreak, analyzes the current national rabies control system, reviews the weaknesses of the national rabies control strategy, and identifies an appropriate solution to manage the current situation. Current rabies outbreak was shown to be present from rural areas to urban regions. Moreover, the situation worldwide demonstrates that each nation struggles to prevent or control rabies. Proper application and execution of the rabies control program require the overcoming of existing weaknesses. Bait vaccines and other complex programs are suggested to prevent rabies transmission or infection. Acceleration of the rabies control strategy also requires supplementation of current policy and of public information. In addition, these prevention strategies should be executed over a mid- to long-term period to control rabies.

Evolutionary history and phylogeography of rabies viruses associated with outbreaks in Trinidad

Bat rabies is an emerging disease of public health significance in the Americas. The Caribbean island of Trinidad experiences periodic outbreaks within the livestock population. We performed molecular characterisation of Trinidad rabies virus (RABV) and used a Bayesian phylogeographic approach to investigate the extent to which outbreaks are a result of in situ evolution versus importation of virus from the nearby South American mainland. Trinidadian RABV sequences were confirmed as bat variant and clustered with Desmodus rotundus (vampire bat) related sequences. They fell into two largely temporally defined lineages designated Trinidad I and II. The Trinidad I lineage which included sequences from 1997-2000 (all but two of which were from the northeast of the island) was most closely related to RABV from Ecuador (2005, 2007), French Guiana (1990) and Venezuela (1993, 1994). Trinidad II comprised sequences from the southwest of the island, which clustered into two groups: Trinidad IIa, which included one sequence each from 2000 and 2007, and Trinidad IIb including all 2010 sequences. The Trinidad II sequences were most closely related to sequences from Brazil (1999, 2004) and Uruguay (2007, 2008). Phylogeographic analyses support three separate RABV introductions from the mainland from which each of the three Trinidadian lineages arose. The estimated dates for the introductions and subsequent lineage expansions suggest periods of in situ evolution within Trinidad following each introduction. These data also indicate co-circulation of Trinidad lineage I and IIa during 2000. In light of these findings and the likely vampire bat origin of Trinidadian RABV, further studies should be conducted to investigate the relationship between RABV spatiotemporal dynamics and vampire bat population ecology, in particular any movement between the mainland and Trinidad.

The global availability of rabies immune globulin and rabies vaccine in clinics providing direct care to travelers

BACKGROUND

Rabies, which is globally endemic, poses a risk to international travelers. To improve recommendations for travelers, we assessed the global availability of rabies vaccine (RV) and rabies immune globulin (RIG).

METHODS

We conducted a 20-question online survey, in English, Spanish, and French, distributed via e-mail to travel medicine providers and other clinicians worldwide from February 1 to March 30, 2011. Results were compiled according to the region.

RESULTS

Among total respondents, only 190 indicated that they provided traveler postexposure care. Most responses came from North America (38%), Western Europe (19%), Australia and South and West Pacific Islands (11%), East and Southeast Asia (8%), and Southern Africa (6%). Approximately one third of 187 respondents stated that patients presented with wounds from an animal exposure that were seldom or never adequately cleansed. RIG was often or always accessible for 100% (n = 5) of respondents in the Middle East and North Africa; 94% (n = 17) in Australia and South and West Pacific Islands; 20% (n = 1) in Tropical South America; and 56% (n = 5) in Eastern Europe and Northern Asia. Ninety-one percent (n = 158) of all respondents reported that RV was often or always accessible. For all regions, 35% (n = 58) and 26% (n = 43) of respondents felt that the cost was too high for RIG and RV, respectively.

CONCLUSION

The availability of RV and RIG varied by geographic region. All travelers should be informed that RIG and RV might not be readily available at their destination and that travel health and medical evacuation insurance should be considered prior to departure. Travelers should be educated to avoid animal exposures; to clean all animal bites, licks, and scratches thoroughly with soap and water; and to seek medical care immediately, even if overseas.

Risk of potentially rabid animal exposure among foreign travelers in Southeast Asia

Background

Each year millions of travelers visit Southeast Asia where rabies is still prevalent. This study aimed to assess the risk of rabies exposure, i.e., by being bitten or licked by an animal, among travelers in Southeast Asia. The secondary objective was to assess their attitudes and practices related to rabies.

Methodology/Principal Findings

Foreign travelers departing to the destination outside Southeast Asia were invited to fill out the study questionnaire in the departure hall of Bangkok International Airport. They were asked about their demographic profile, travel characteristics, pre-travel health preparations, their possible exposure and their practices related to rabies during this trip. From June 2010 to February 2011, 7,681 completed questionnaires were collected. Sixty-two percent of the travelers were male, and the median age was 32 years. 34.0% of the participants were from Western/Central Europe, while 32.1% were from East Asia. Up to 59.3% had sought health information before this trip. Travel clinics were the source of information for 23.6% of travelers. Overall, only 11.6% of the participants had completed their rabies pre-exposure prophylaxis, and 15.3% had received only 1–2 shots, while 73.1% had not been vaccinated at all. In this study, the risk of being bitten was 1.11 per 100 travelers per month and the risk of being licked was 3.12 per 100 travelers per month. Among those who were bitten, only 37.1% went to the hospital to get post exposure treatment. Travelers with East Asian nationalities and longer duration of stay were significantly related to higher risk of animal exposure. Reason for travel was not related to the risk of animal exposure.

Conclusions

Travelers were at risk of being exposed to potentially rabid animals while traveling in Southeast Asia. Many were inadequately informed and unprepared for this life-threatening risk. Rabies prevention advice should be included in every pre-travel visit.

Rabies is a fatal disease most commonly transmitted through a bite or a lick of a rabid animal on the broken skin. Most deaths from rabies are reported in Asia and Africa where animal rabies is poorly controlled. Not only local people, but travelers in these areas are inevitably at risk also. In this study we surveyed foreign travelers just before they departed Southeast Asia at Bangkok International Airport. We aimed to determine the risk of possible rabies exposure and their attitudes and practices related to rabies. The risk of being bitten among 7,681 participants studied was 1.11 per 100 travelers per month and the risk of being licked was 3.12 per 100 travelers per month. Among those who were bitten, only 37.1% went to the hospital to get rabies post exposure treatment. Travelers with East Asian nationalities and who stay longer were more likely to be exposed to animals. The risk of animal exposure was not related with the reason for travel. These findings confirm that travelers in Southeast Asia were at real risk of possible exposure to rabies. However, most of them were inadequately informed and unprepared for this life-threatening disease. Rabies prevention advice should be given to all travelers in rabies endemic area.

Animal bites and rabies exposure in Australian travellers

OBJECTIVES

To examine the circumstances of animal exposure in a case series of Australian travellers who required rabies postexposure prophylaxis, and to assess the appropriateness of current guidelines for rabies pre-exposure vaccination.

DESIGN, PARTICIPANTS AND SETTING

Prospective case series of 65 returned travellers who presented to four Australian travel medicine clinics between 1 April 2009 and 31 July 2010 for rabies post-exposure prophylaxis.

MAIN OUTCOME MEASURES

Demographic characteristics associated with risk of injury; countries where injuries occurred; circumstances of the injuries; and travellers' experiences of obtaining postexposure prophylaxis overseas.

RESULTS

Animal bites and scratches occurred most commonly among travellers aged 20-29 years. Most injuries occurred in Bali, Indonesia (30 [46%]) and Thailand (21 [32%]), and the most common animals responsible for the injuries to the 65 travellers were monkeys (29 travellers [45%]) and dogs (27 [42%]). Thirty-nine of the travellers (60%) initiated contact with the animal. Forty travellers (62%) were able to commence rabies vaccination overseas, but only nine (14%) were able to obtain rabies immunoglobulin overseas.

CONCLUSIONS

Most travellers had difficulty obtaining rabies postexposure prophylaxis overseas, resulting in significant delays in appropriate treatment. We recommend that current National Health and Medical Research Council guidelines for at-risk persons be broadened, and that the risk of rabies and the option of pre-exposure vaccination be discussed with all travellers to rabies-endemic areas.

Immunogenicity of Simulated PCECV Postexposure Booster Doses 1, 3, and 5 Years after 2-Dose and 3-Dose Primary Rabies Vaccination in Schoolchildren

Objectives. To assess the immunogenicity of intradermal (ID) booster doses of Purified Chick Embryo Cell rabies vaccine (PCECV, Rabipur) administered to Thai schoolchildren one, three and five years after a primary ID pre-exposure (PrEP) vaccination series. Methods. In this follow-up study of a randomized, open-label, phase II clinical trial, two simulated post-exposure booster doses of PCECV were administered on days 0 and 3 intradermally to 703 healthy schoolchildren, one, three or five years after primary vaccination with either two or three ID doses of 0.1 mL PCECV. Blood was drawn immediately before and 7, 14 and 365 days after the first booster dose to determine rabies virus neutralizing antibody (RVNA) concentrations. Results. An anamnestic response of approximately 30-fold increase in RVNA concentrations was demonstrated within 14 days after booster. All children (100%) developed adequate RVNA concentrations above 0.5 IU/mL. No vaccine related serious adverse events were seen in any of the vaccinees. Conclusion. ID rabies PrEP with PCECV is safe and immunogenic in schoolchildren and the anamnestic response to a two booster dose vaccination series was found to be adequate one, three, and five years after a two- or three-dose primary PrEP vaccination series.

Characterization of a human antibody fragment Fab and its calcium phosphate nanoparticles that inhibit rabies virus infection with vaccine

Recombinant antibody phage display technology has been used to mimic many aspects of the processes that govern the generation and selection of high-affinity natural human antibodies in the human immune system, especially for infectious disease prophylaxis. An anti-rabies virus immunized phage-display Fab library was constructed from peripheral blood lymphocytes from vaccinated volunteers. The immunized antibody library, with a diversity of 6.7×10(8), was used to select and produce antibodies that bound to rabies virus glycoprotein. After five rounds of immobilized fixed rabies virion panning, four unique DNA sequences were found in the higher binding clones, and only one, Fab094, showed neutralization activity. Fab094 components were analyzed by ELISA, immunoprecipitation and immunofluorescent staining. ELISA and immunofluorescence showed that Fab094 bound specifically to rabies virions. Immunoprecipitation and mass spectrometry showed that Fab094 reacted with rabies virus glycoprotein. To improve the penetration power of Fab094 antibodies, we developed Fab094 calcium phosphate nanoparticles (Fab094-CPNPs) and tested their efficacy. The rapid fluorescent focus inhibition test indicated that the neutralizing antibody titers of Fab094 and Fab094-CPNPs were reached at 200.17 IU/Kg and 246.12 IU/Kg, respectively. These findings were confirmed in vivo in a Kunming mouse challenge model. Our results demonstrate that human Fab094 and Fab094-CPNPs are efficacious candidate drugs to replace rabies immunoglobulin in post-exposure prophylaxis (PEP).

Equivalence between pre-exposure schemes for human rabies and evaluation of the need for serological monitoring

OBJECTIVE

To evaluate the humoral immune response to the pre-exposure schedule of human rabies vaccination through intradermal and intramuscular routes, as well as the need for serological monitoring.

METHODS

A randomized and controlled intervention study was carried out in São Paulo, Southeastern Brazil, from 2004-2005. There were 149 volunteers, of which 127 completed the vaccination schedule (65 intradermal and 62 intramuscular) and underwent humoral immune response evaluation at ten, 90 and 180 days post-vaccination. Two outcomes were considered for comparing the two routes of administration: the geometric average of neutralizing antibody titers and the proportion of individuals with satisfactory titers (> 0.5 IU/mL) at each evaluation point. The association of the humoral immune response with anthropometric and demographic data was analyzed through a normal distribution test and a chi-square test with a Yates correction. After completion of the vaccination schedule, the proportion of seropositive results was compared by the Kruskall Wallis test, and the average titers were compared by variance analysis.

RESULTS

the average antibody titers were higher in patients who were vaccinated intramuscularly. The percentage of volunteers with satisfactory titers (> 0.5% IU/mL) decreased over time in both groups. However, in the group vaccinated intradermally the rate of satisfactory titers on day 180 ranged from 20% to 25%, while the intramuscular route varied from 63% to 65%. An association between the humoral immune response and the demographic and anthropometric variables was not observed.

CONCLUSIONS

Serology after the third dose can be considered unnecessary in unexposed patients, since 97% and 100% of volunteers respectively vaccinated by the intradermal and intramuscular route presented satisfactory antibody levels (> 0.5% IU/mL).

Transplantation and tropical infectious diseases

The number of transplant recipients with tropical infectious diseases is growing due to increasing international travel and the rising number of transplants taking place in the tropics and subtropics. With increases in population migration, the prevalence of individuals infected with geographically restricted organisms also rises. There are three potential categories of tropical infections in transplant patients: (1) donor-related infections transmitted by the graft or through transfusion of blood products; (2) reactivation or recrudescence of latent infections in the donor recipient; and (3) de novo acquisition of infection in the post-transplant period through the traditional route of infection. We present an overall discussion of the association of parasitic (protozoa and helminths) and non-parasitic (viral, bacterial, and fungal) tropical infectious diseases and solid-organ and hematopoietic transplantation. We also suggest potential screening guidelines for some of these tropical infections.

An evaluation of two commercially available ELISAs and one in-house reference laboratory ELISA for the determination of human anti-rabies virus antibodies

The envelope glycoprotein G of rabies virus in vaccines induces the production of neutralizing antibodies important in the protection against the disease. The measurement of anti-envelope glycoprotein antibodies is a good predictor of the degree of humoral immunity in people during anti-rabies treatment or after vaccination. Several assays exist for the serological determination of antibody protection against rabies virus infection. Antibody neutralization by the rapid fluorescent focus inhibition test (RFFIT) or the fluorescent antibody virus neutralization (FAVN) test is currently the gold standard. Performance of the highly complex RFFIT and FAVN tests, however, requires specialized reference laboratories with expertise with this assay. Although not widely used, ELISA test kits are available and may be an additional option for testing that is more accessible. The aim of the present study was to evaluate available ELISA assays for the determination of anti-rabies antibodies. We compared the Bio-Rad Platelia Rabies II ELISA, DRG Rabies Virus IgG Ab ELISA and Focus Diagnostics Rabies Antibody Detection by ELISA to RFFIT. Bland–Altman plots comparing the Bio-Rad Platelia assay and the Focus Diagnostics assay to RFFIT showed a low degree of variability between the ELISA assays and RFFIT results except in samples with high RFFIT values. The agreement, sensitivity and specificity of Bio-Rad Platelia Rabies II ELISA when compared to RFFIT were 95.1 %, 94.1 % and 95.8 %, respectively. The DRG Rabies assay compared to RFFIT had an agreement of 77.7 %, a sensitivity of 86.7 % and a specificity of 69.4 %. The agreement, sensitivity and specificity of Focus Diagnostics Rabies Detection by ELISA when compared to RFFIT were 82.2 %, 91.7 % and 73.0 %, respectively. Overall, the Bio-Rad Platelia assay showed higher accuracy and specificity than either the DRG or Focus assays. All of these ELISAs, however, measure all antibody types and do not discriminate the neutralizing antibodies as measured by functional assays (RFFIT and FAVN) and cannot be relied upon to predict the neutralizing activity of the sera. The results of this study offer insight into the availability of alternative, less-complex methods to monitor rabies antibody titres in at-risk individuals following vaccination.

Immunogenicity and booster efficacy of pre-exposure rabies vaccination

A multivariate analysis was used to identify factors influencing the immunogenicity of rabies vaccine and to assess the efficacy of booster injections in a cohort of 407 people monitored prospectively for 10 years after primary vaccination. Rabies vaccine (HDCV or PVRV) was injected by intramuscular route either on days 0 and 28 or on days 0, 7 and 28. All the participants received a booster injection on day 365. At the end of follow-up (year 10), 163 subjects had titers >0.5IU/ml (group A) and 59 subjects had titers <0.5IU/ml (group B: poor responders). The number of injections had a significant influence (P<0.001) on the magnitude of the serological response to rabies vaccine, but the type of vaccine and the potency of the batches did not (P=0.07 and P=0.06, respectively). The difference between GMTs on day 365 and day 379 was significantly lower in group B than in group A (13 and 50.70IU/ml, respectively; P<0.001). In conclusion, our study confirms that the rabies pre-exposure vaccination protocol of three intramuscular injections significantly decreases the proportion of poor responders at 10 years. Moreover, our findings indicate that a routine booster injection at 1 year could significantly increase the levels and duration of antibody titers.

Rabies: epidemiology, pathogenesis, and prophylaxis

Rabies is a viral zoonosis that causes approximately 50,000 to 100,000 deaths per year worldwide. Most deaths occur in developing countries. Dogs are the major vector, especially in developing countries. The virus is usually transmitted to humans by infected saliva through the bite of a rabid animal; the incubation period averages 30 to 90 d. Hyperexcitability, autonomic dysfunction, hydrophobia, and aerophobia are characteristic of encephalitic rabies, which accounts for 80% of cases. The paralytic form is characterized by flaccid paralysis in the bitten limb, which ascends symmetrically or asymmetrically. Once symptoms develop, the disease is invariably fatal. Animal rabies can be controlled by proper induction of herd immunity, humane removal of stray animals, promotion of responsible pet ownership through education, and enactment of leash laws. Preexposure vaccination with modern cell culture vaccine is recommended for people at high risk of exposure to rabies and for travelers who spend longer than 1 mo in countries where rabies is a constant threat, or who travel in a country where immediate access to appropriate care is limited. Postexposure prophylaxis consists of prompt and thorough wound cleansing and immunization with modern cell culture vaccine, together with administration of rabies immune globulin to those individuals who have not previously received preexposure prophylaxis.

Immunisation of the travelling child

As a direct consequence of the current increase in international mobility, a significant increase in family travel is occurring. Protection against vaccine preventable diseases in the travelling child plays a key role both from an individual and a public health perspective: pre-travel immunisation protects travelling children and, at the same time, prevents the importation of pathogens that can spread throughout the community. Children immunisation presents unique challenges in travel medicine practice: some vaccines cannot be given below a definite age for several reasons and altering the standard schedule of routine vaccines is sometimes needed to ensure early protection. Furthermore, the risk for some travel-related diseases is higher among children. The aim of this review is to analyse the main epidemiological and clinical aspects relevant to immunisation of travelling children and to provide travel medicine practitioners with a practical approach to this issue.

Pre-exposure rabies vaccination using purified chick embryo cell rabies vaccine intradermally is immunogenic and safe

OBJECTIVE

To demonstrate the safety and immunogenicity of intradermal rabies pre-exposure prophylaxis with purified chick embryo cell vaccine (PCECV) in schoolchildren age 5 to 8 years in Thailand.

STUDY DESIGN

In a randomized, open-label, phase II clinical trial, 2 or 3 intradermal doses of 0.1 mL PCECV (Rabipur) were administered to 703 schoolchildren on days 0 and 28 or on days 0, 7, and 28. In 206 children, 2 simulated post-exposure booster doses were given 1 year after the primary vaccination series. Rabies virus- neutralizing antibody (RVNA) titers were determined by the rapid fluorescent focus inhibition test.

RESULTS

In school-age children in Thailand, a pre-exposure immunization regimen of 3 intradermal doses of PCECV produced adequate immune responses. After primary vaccination, all subjects developed RVNA titers > or =0.5 IU/mL and demonstrated a rapid increase in RVNA titer after 2 simulated post-exposure booster immunizations 1 year after the primary vaccination series. No serious adverse drug reactions occurred.

CONCLUSIONS

Rabies pre-exposure immunization with PCECV is safe and immunogenic, and its implementation could save the lives of many children in rabies-endemic areas.

Rabies antibody seroprotection rates among travelers in Nepal: "rabies seroprotection in travelers"

BACKGROUND

Rabies preexposure immunization is recommended for international travelers who are at risk for exposure to rabid animals, especially in areas where postexposure treatment may be limited. Rabies antibody seroprotection rates among international travelers has not been previously investigated.

OBJECTIVE

To assess preexisting rabies seroprotection among travelers presenting to a health clinic in Nepal.

METHODS

A prospective convenience sample of international travelers evaluated at a health center in Kathmandu, Nepal during a 2-month period. Subjects were eligible for inclusion if they had received rabies preexposure vaccination within the previous 5 years. Demographic information and vaccination records of rabies preexposure prophylaxis were obtained. Consenting subjects provided serum for rabies antibody measurement measured using the rapid fluorescent focus inhibition test. A dilution greater than or equal to 1:5 (0.5 IU/mL) was considered positive. Data were analyzed using chi-squares and two-sample t-tests with unequal variances.

RESULTS

A total of 43 patients consented to enroll. Complete data were available for 38 patients. Subjects had received human diploid cell vaccine (HDCV) or purified Vero cell rabies vaccine (PVRV) vaccine, either via the intradermal or intramuscular route. All patients had adequate antibody titers except one, who had a titer below 0.5 IU/mL. There was no statistically significant relationship between antibody titer and type of vaccine, route of administration, time since vaccination, number of vaccinations, or patient age.

CONCLUSIONS

Among 38 travelers to Nepal who had received documented preexposure rabies HDCV or PVRV vaccination series, 37 demonstrated adequate titers of > or =0.5 IU/mL and would be considered boostable if exposed to rabies virus. One traveler had a titer of <0.5 IU/mL. Type of vaccine, method of administration, number of vaccinations, and time since vaccination did not influence rabies antibody titer. Rabies vaccination with HDCV and PVRV vaccine was effective in stimulating adequate seroprotection in this sample of travelers.

Awareness of rabies risks and knowledge about preventive measures among experienced German travel health advisors

BACKGROUND

Every year, millions of people travel to countries where rabies is enzootic. However, the quality of rabies-specific information provided by travel health advisors and the extent of their knowledge about pre- and postexposure prophylaxis have not been examined on a large-scale basis up to now.

METHODS

5,780 German physicians and pharmacists, who identified themselves as active travel health advisors, were chosen from a database. The selected providers were asked to complete an Internet-based questionnaire. The form requested both demographic information and the assessment of different concrete scenarios, each of which featured individuals seeking pre-travel advice on rabies or appropriate postexposure treatment after returning from abroad.

RESULTS

Overall, 496 physicians and pharmacists completed the questionnaire. Almost all respondents indicated that they would mention the risk of rabies and appropriate preventive measures to long-term travelers and tourists planning to visit rural areas. However, only 35% to 60% of the advisors would provide this information to individuals on business trips, package tours, or travelers in urban centers as well. The assessment of the scenarios yielded 51% to 98% of adequate advice. Potentially harmful decisions included, for instance, the failure to recommend further prophylactic measures after exposure of already vaccinated people or the fact that the necessary postexposure prophylaxis was inappropriately withheld in cases where treatment had been initially delayed.

CONCLUSIONS

Although the participants of this study were well aware of the travel-associated rabies risks and provided adequate information about this health hazard to most of their clients, evident flaws exist regarding the correct assessment of specific situations in pre- and postexposure rabies prophylaxis. Our findings therefore provide important cues on topics that should be more intensely covered during future postgraduate training in travel medicine and also underline the need for more practically orientated, readily available information on specific prophylactic treatment against rabies.

Renal involvement in human rabies: clinical manifestations and autopsy findings of nine cases from northeast of Brazil

A retrospective study was conducted in nine patients with rabies admitted to a hospital of Fortaleza, Brazil. Autopsy was performed in all cases. The ages ranged from three to 81 years and six were males. They all were bitten by dogs. The time between the accident and the hospital admission ranged from 20 to 120 days (mean 45 +/- 34 days). The time until death ranged from one to nine days (mean 3.3 +/- 5.5 days). The signs and symptoms presented were fever, hydrophobia, aerophobia, agitation, disorientation, dyspnea, sialorrhea, vomiting, oliguria, sore throat, pain and hypoesthesia in the site of the bite, headache, syncope, cough, hematemesis, mydriasis, hematuria, constipation, cervical pain and priapism. In three out of six patients, there was evidence of acute renal failure, defined as serum creatinine > or = 1.4 mg/dL. The post-mortem findings in the kidneys were mild to moderate glomerular congestion and mild to intense peritubular capillary congestion. Acute tubular necrosis was seen in only two cases. This study shows some evidence of renal involvement in rabies. Histopathologic findings are nonspecific, so hemodynamic instability, caused by autonomic dysfunction, hydrophobia and dehydration must be responsible for acute renal failure in rabies.

Family travel: An overview

Paediatric travel medicine involves the education of parents about the numerous health and safety issues related to traveling with infants and young children--whether overseas or a weekend at a local lake. It includes providing children with vaccines and medications, giving telephone advice to parents while they are traveling, and treating children should they come home ill. Practitioners must be knowledgeable about such varied topics like avoiding diarrhoea, infant safety seats for air travel, altitude sickness, sun exposure, waterfront safety, insect protection, dealing with hot and cold environments, and at what age it is safe to begin scuba diving, to name just a very few. Practitioners must also know when adult recommendations can--and cannot--be adapted for children; that vaccine doses, needle size, and injection site may vary with the size of the child; and the answers to hundreds of everyday questions such as how to administer an essential but bitter tasting medication to an uncooperative child--and what to do when the child refuses to take the medication or vomits it.

Illness in returned travelers and immigrants/refugees: the 6-year experience of two Australian infectious diseases units

BACKGROUND

Data comparing returned travelers and immigrants/refugees managed in a hospital setting is lacking.

METHODS

We prospectively collected data on 1,106 patients with an illness likely acquired overseas who presented to two hospital-based Australian infectious diseases units over a 6-year period.

RESULTS

Eighty-three percent of patients were travelers and 17% immigrants/refugees. In travelers, malaria (19%), gastroenteritis/diarrhea (15%), and upper respiratory tract infection (URTI) (7%) were the most common diagnoses. When compared with immigrants/refugees, travelers were significantly more likely to be diagnosed with gastroenteritis/diarrhea [odds ratio (OR) 8], malaria (OR 7), pneumonia (OR 6), URTI (OR 3), skin infection, dengue fever, typhoid/paratyphoid fever, influenza, and rickettsial disease. They were significantly less likely to be diagnosed with leprosy (OR 0.03), chronic hepatitis (OR 0.04), tuberculosis (OR 0.05), schistosomiasis (OR 0.3), and helminthic infection (OR 0.3). In addition, travelers were more likely to present within 1 month of entry into Australia (OR 96), and have fever (OR 8), skin (OR 6), gastrointestinal (OR 5), or neurological symptoms (OR 5) but were less likely to be asymptomatic (OR 0.1) or have anaemia (OR 0.4) or eosinophilia (OR 0.3). Diseases in travelers were more likely to have been acquired via a vector (OR 13) or food and water (OR 4), and less likely to have been acquired via the respiratory (OR 0.2) or skin (OR 0.6) routes. We also found that travel destination and classification of traveler can significantly influence the likelihood of a specific diagnosis in travelers. Six percent of travelers developed a potentially vaccine-preventable disease, with failure to vaccinate occurring in 31% of these cases in the pretravel medical consultation.

CONCLUSIONS

There are important differences in the spectrum of illness, clinical features, and mode of disease transmission between returned travelers and immigrants/refugees presenting to hospital-based Australian infectious diseases units with an illness acquired overseas.

Rabies: a review of UK management

Rabies is endemic worldwide, and causes approximately 30 000 deaths per year. In the past 20 years, 12 deaths have occurred in the UK, although all but one case were contracted overseas. We have reviewed the current literature regarding the management of possible rabies exposure in the setting of a UK emergency department. The article offers an overview of rabies, including pathology, risk assessment, and current treatment, including both pre-exposure and post-exposure prophylaxis. We have also included a form online, which allows the correct information to be obtained and recorded prior to seeking advice from the local virology services.

Pharmacotherapy, vaccines and malaria advice for HIV-infected travellers

Since the introduction of effective antiretroviral therapy (ART), HIV-infected individuals are travelling more frequently and international travel has become much safer. Specific concerns include the safety of ART during travel, drug adherence and interaction considerations, and effects of immunosuppression. This review describes potentially important infections, vaccine effectiveness, safety and special approaches for their use, and HIV-related issues regarding predeparture counselling. With advanced immunosuppression (CD4+ T-cell count < 200/microl or < 14%), the immunogenicity of several vaccines is reduced, complications could occur after live attenuated vaccines and certain infections acquired during travel may be more frequent or severe. Challenges include the best options for malaria chemoprophylaxis, standby treatment and medical follow-up of the increasing number of HIV-infected long-term travellers.

Adenoviruses as vaccine vectors

Adenoviruses have transitioned from tools for gene replacement therapy to bona fide vaccine delivery vehicles. They are attractive vaccine vectors as they induce both innate and adaptive immune responses in mammalian hosts. Currently, adenovirus vectors are being tested as subunit vaccine systems for numerous infectious agents ranging from malaria to HIV-1. Additionally, they are being explored as vaccines against a multitude of tumor-associated antigens. In this review we describe the molecular biology of adenoviruses as well as ways the adenovirus vectors can be manipulated to enhance their efficacy as vaccine carriers. We describe methods of evaluating immune responses to transgene products expressed by adenoviral vectors and discuss data on adenoviral vaccines to a selected number of pathogens. Last, we comment on the limitations of using human adenoviral vectors and provide alternatives to circumvent these problems. This field is growing at an exciting and rapid pace, thus we have limited our scope to the use of adenoviral vectors as vaccines against viral pathogens.

Vaccine-preventable diseases in long-term expatriates

The term "expatriates" refers to professionals and their families who live abroad for several months or years. Owing to potential prolonged exposure, and living conditions that may be closer to those of the local population, they are at higher risk of acquiring infectious diseases that are endemic in their new place of residence. They often have reduced access to medical services, putting them at higher risk of complications and more severe outcomes. Vaccination is probably one of the most effective means of preventing expatriates from acquiring endemic or epidemic diseases. Incapacitation or sickness in the field may cause serious disruption to project activities and impose an extra workload on the local team. It may also result in repatriation, with further extra direct and indirect costs for the organization. Predeparture advice and preparation, to promote risk reduction behavior, coupled with adequate support in the field are key ingredients to ensure effective and successful activities of collaborators. Institutions and organizations sending expatriates to developing countries have a clear responsibility, and it is in their own interests to promote the health of their employees working abroad.

Reducing the cost of post-exposure rabies prophylaxis: efficacy of 0.1ml PCEC rabies vaccine administered intradermally using the Thai Red Cross post-exposure regimen in patients severely exposed to laboratory-confirmed rabid animals

Purified chick embryo cell rabies vaccine (PCECV) administered as 0.1 ml intradermally according to the Thai Red Cross (TRC) regimen could reduce the cost of PEP by up to 84% when compared to the traditional five-dose Essen regimen. To confirm the efficacy of 0.1 ml of PCECV using the TRC regimen, a clinical trial was conducted in 113 patients presenting with category III exposures from confirmed rabid animals at two bite referral centres in the Philippines. Patients were monitored monthly for 1 year after exposure. PCECV was well tolerated, no vaccine-related serious adverse events occurred and all patients were alive 1 year after their initial exposure.