Clinical management and humoral immune responses to rabies post-exposure prophylaxis among three patients who received solid organs from a donor with rabies.

BACKGROUND: The rabies virus causes a fatal encephalitis and can be transmitted through organ transplantation. In 2013, a man developed rabies 18 months after receiving a kidney from a donor with rabies, who was not known to have been infected when the organs were procured. Three additional persons who received organs from the same donor (liver, kidney, heart), all of whom were not vaccinated for rabies before transplantation, received rabies post-exposure prophylaxis (PEP) with rabies immune globulin and 5 doses of rabies vaccine as soon as the diagnosis of rabies was made in the donor (18 months after their transplant surgeries). We describe their clinical management. METHODS: As the 3 recipients were all on immunosuppressive medications, post-vaccination serologic testing was performed using the rapid fluorescent focus inhibition test to measure rabies virus neutralizing antibodies (RVNAs). An acceptable antibody response to administration of rabies vaccine was defined as detection of RVNAs at a concentration ≥0.1 IU/mL from a serum specimen collected ≥7 days after the fifth vaccine dose. RESULTS: All 3 recipients demonstrated an acceptable antibody response despite their immunosuppressed states. More than 36 months have passed since their transplant surgeries, and all 3 recipients have no evidence of rabies. CONCLUSIONS: The survival of 3 previously unvaccinated recipients of solid organs from a donor with rabies is unexpected. Although the precise factors that led to their survival remain unclear, our data suggest that PEP can possibly enhance transplant safety in settings in which donors are retrospectively diagnosed with rabies.

Bat rabies surveillance in the former Soviet Union.

More than 3,000 bats were examined for lyssaviruses in the territory of the Former Soviet Union (FSU) over the past 41 years (1964-2004). European bat lyssavirus type 1 (EBLV-1) was registered in the Ukraine and the European part of Russia. Lyssaviruses Aravan (ARAV, Kyrgyzstan, 1991), Khujand (KHUV, Tajikistan, 2001), Irkut (IRKV, Irkutsk region, 2002) and West Caucasian Bat virus (WCBV, Krasnodar region, 2002) were proposed as new lyssavirus genotypes. All reports on rabies virus (RABV; serotype/genotype 1) isolation from bats to date are questionable and must be corroborated. Two human rabies cases of bat origin were registered in the town of Voroshilovgrad, the Ukraine (1977) and the town of Belgorod, Russia (1985). The second case was confirmed as EBLV-1, whereas the first case was not identified. At least five lyssaviruses, different from RABV and from each other, were recognized in the territory of the FSU, and their potential significance for veterinary and public health should not be underestimated.

Rapid clearance of SAG-2 rabies virus from dogs after oral vaccination.

This study investigated the safety, efficacy, and clearance of SAG-2, an attentuated rabies virus, after oral vaccination in dogs. Nineteen dogs consumed baits containing lyophilized vaccine, but residual SAG-2 virus was recovered in only one of 57 oral swabs, collected one hour post-vaccination. Seven vaccinates were euthanized between 24 and 96 h after consuming a bait. Rabies virus RNA was detected in tonsils from all seven dogs by nested RT-PCR, with primers to the viral glycoprotein. Genomic, sense-transcripts, and m-RNAs were detected in five of seven tonsil samples using primers to the rabies virus nucleoprotein gene, as well as in four of seven samples from the buccal mucosa and one of seven from the tongue. Rabies virus antigen was detected in all tonsils by an immunohistochemistry test, confirming the RT-PCR results. In addition, virus was isolated from one tonsil sample collected at 96 h, providing supportive evidence of viral replication. Ten of 12 (83%) of the vaccinated dogs demonstrated an anamnestic response, with viral neutralizing antibody titers (> or =0.5 IU/ml), after rabies virus challenge. These ten dogs survived, whereas all control dogs succumbed to rabies. Attenuated rabies viruses, such as SAG-2, replicate in local tissues of the oral cavity and can be cleared relatively quickly, without viral excretion, leading to protective immunity against the disease.

Molecular characterization of rabies virus isolates from Mexico: implications for transmission dynamics and human risk.

Twenty-eight samples from humans and domestic and wild animals collected in Mexico between 1990 and 1995 were characterized by using anti-nucleoprotein monoclonal antibodies and limited sequence analysis of the nucleoprotein gene. The variants of rabies viruses identified in these samples were compared with other isolates from Mexico and the rest of the Americas to establish epidemiologic links between cases and outbreaks and to increase the understanding of rabies epidemiology in the Western Hemisphere. Antigenic and genetic diversity was found in all samples from dogs and dog-related cases, suggesting a long-term endemic situation with multiple, independent cycles of virus transmission. Two isolates from bobcats were antigenically and genetically homologous to the rabies variant circulating in the Arizona gray fox population, indicating a wider distribution of this variant than previously reported. Rabies isolates from skunks were unrelated to any variant analyzed in this study and represent a previously unrecognized cycle of rabies transmission in skunks in Baja California Sur. Two antigenic and genetic variants co-circulating in southern and eastern Mexico were found in viruses obtained from cases epidemiologically related to vampire bats. These results serve as a baseline for the better understanding of the molecular epidemiology of rabies in Mexico.

Laboratory investigation of human deaths from vampire bat rabies in Peru.

In the spring of 1996, multiple cases of an acute febrile illness resulting in several deaths in remote locations in Peru were reported to the Centers for Disease Control and Prevention (CDC). The clinical syndromes for these cases included dysphagia and encephalitis. Because bat bites were a common occurrence in the affected areas, the initial clinical diagnosis was rabies. However, rabies was discounted primarily because of reported patient recovery. Samples of brain tissue from two of the fatal cases were received at CDC for laboratory confirmation of the rabies diagnosis. An extensive array of tests on the formalin-fixed tissues confirmed the presence of both rabies viral antigen and nucleic acid. The virus was shown to be most closely related to a vampire bat rabies isolate. These results indicate the importance of maintaining rabies in the differential diagnosis of acute febrile encephalitis, particularly in areas where exposure to vampire bats may occur.

Typing of rabies virus isolates by DNA enzyme immunoassay.

BACKGROUND: Alternatives to antigenic typing are needed for epidemiologic surveys of the rabies virus associated with translocated coyotes and foxes, especially in areas where a closely related rabies virus is transmitted by striped skunks. OBJECTIVES: We developed and evaluated two enzyme based typing methods for rabies virus. The products of a reverse transcription-polymerase chain reaction (RT/PCR) of the nucleoprotein gene were hybridized to type specific probes and detected by enzyme assay after immobilization on microtiter plates. STUDY DESIGN: We tested RT/PCR products of 27 rabies isolates by two different DNA enzyme immunoassays (DEIA) and evaluated the quality of the results from the corresponding nucleotide sequence of the samples. RESULTS: Using a set of two probes, one of the DEIAs correctly identified 26/27 samples as variants of rabies virus associated with either skunks, foxes, or coyotes. The identity of one fox rabies sample was unresolved by this assay. The second DEIA correctly identified 24/27 samples as variants of rabies virus associated with either skunks, foxes, or coyotes. This assay did not resolve the identity of two fox rabies samples, and misidentified one fox rabies sample as a skunk rabies sample. CONCLUSIONS: DEIA can be used for epidemiologic studies of variants of rabies virus associated with skunks, foxes, and coyotes. Both DEIA methods were effective when typing probes recognized changes at a minimum of two nucleotide positions between variants, but only one assay method was sufficiently stringent to detect a single base pair mismatch. The inherent mutability of RNA viruses must be considered when designing and evaluating typing methods.

A comparison of two serological methods for detecting the immune response after rabies vaccination in dogs and cats being exported to rabies-free areas.

Levels of rabies virus neutralizing antibody in sera from dogs and cats were titrated to endpoint by the Rapid Fluorescent Focus Inhibition Test (RFFIT) and retested by the RFFIT and the Fluorescent Antibody Virus Neutralization test (FAVN). The two tests were compared for their ability to detect the 0.5 international units/ml (I.U.) of antibody required by the World Health Organization and the Office International des Epizooties as the minimum response for proof of rabies immunization. No difference was observed in sensitivity or specificity for either method in tests of 168 sera from unvaccinated animals or 70 sera from vaccinated animals with high levels of neutralizing antibody (an initial RFFIT titre of > or = 1.0 I.U.). Test to test variation occurred for results obtained by both RFFIT and FAVN for 95 sera from vaccinated animals with low to moderate levels of neutralizing antibody (RFFIT titre < 1.0 I.U.). No significant differences were detected for the 95 sera in the frequency for one methodology more often than the other to have a positive response (> or = 0.5 I.U.), nor were significant differences detected for the symmetry (P = 0.43) or the marginal homogeneity (P = 0.39) of results obtained by the two methods. Both methods can adequately identity unvaccinated animals, but false positive and false negative results are possible for either method when a single test is used to measure the antibody response of low-responding vaccinated animals. Nucleotide sequence analysis identified several amino acid differences in stocks of the challenge rabies virus from different laboratories. The small differences in neutralizing antibody titre that may result from mutations in the challenge virus are not important for evaluating immunity induced by vaccines which are themselves prepared from a variety of different rabies virus strains, but differences in the challenge virus, rather than differences in methodology, may account for at least some of the discrepant results reported in inter-laboratory surveys. Comparative studies of serological methods for measuring rabies antibodies should use well-characterized unpassaged virus stocks obtained from a single reference laboratory.

Rabies in wild and domestic carnivores of Africa: epidemiological and historical associations determined by limited sequence analysis.

Virus isolates from three important reservoirs for rabies in Africa (domestic dogs, jackals and yellow mongooses) were compared by their reaction with a panel of monoclonal antibodies directed to the nucleocapsid protein and by the nucleotide sequence of a 200 base pair segment of the nucleocapsid gene. Although antigenically dissimilar, the variants commonly transmitted in dogs and jackals were very closely related by genetic analysis. Phylogenetic analysis and historical accounts support a common lineage for these variants in both past and present reservoirs for rabies in Europe. Two additional variants, distinct from the dog or jackal variant, were found in yellow mongoose samples and nucleotide sequence from these animals showed more divergence than any other group of samples. These variants and a third variant for which no host species could be identified, were shown to form two additional genetic groups only distantly related to each other. These three variants and a previously identified variant in Nigeria may be indigenous to African carnivores.

Epidemiologic and historical relationships among 87 rabies virus isolates as determined by limited sequence analysis.

Nucleotide sequence analysis of a 200-bp region of the nucleoprotein (N) gene of rabies virus differentiated unique genetic groups of rabies virus from samples collected in areas where dog rabies is enzootic in Asia, Africa, Europe, and the Americas. Patterns of nucleotide sequence identified for an outbreak area were conserved in samples collected over three decades. Epidemiologic relationships among isolates were determined by patterns of conserved nucleotide sequence, and the degree of sequence divergence between samples from separate outbreak areas were measured. This approach suggested that a historical reconstruction of events leading to the introduction of rabies into an area would be possible. In this broader view of rabies epidemiology, the cultural legacy of European exploration and colonization may have also included zoonotic disease.

Legionella in cooling towers.

Legionellosis (Legionnaires' disease and Pontiac fever) outbreaks have been associated with aerosols ejected from contaminated cooling towers--wet-type heat rejection units (WTHRUs) used to dissipate unwanted heat into the atmosphere. The Vermont Department of Health undertook a program to inventory, inspect, and sample all WTHRUs in Vermont from April 1981 to April 1982. All WTHRUs were sampled for Legionella pneumophila and data were obtained for location, design, construction, and operating characteristics. Of the 184 WTHRUs operating, statistical analyses were performed on those 130 which were sampled for L. pneumophila only once during the study period. Of these, 11 (8.5%) were positive for L. pneumophila. Sources of makeup water and period of operation had significant association with the recovery of L. pneumophila. Five out of 92 towers (5.4%) utilizing surface water sources for cooling were positive for L. pneumophila, in contrast to 6 positive towers of the 38 units (15.8%) which obtained makeup water from ground water sources (p = .054 by chi-square test). Nearly 15% of the 54 units which operated throughout the year were positive, compared to less than 4% of the 76 towers operating seasonally (p = .03 by chi-square test). The mean pH of the cooling water in units where L. pneumophila was recovered (8.3) was significantly higher than the mean pH of 7.9 in units testing negative (p less than .05 by t-test). In addition, the mean log-transformed turbidity of positive towers, 0.03 nephelometric units (ntu), was significantly lower than the mean of log turbidity of negative towers, 0.69 ntu (p less than .02 by t-test).

Pontiac fever associated with a whirlpool spa.

In March 1981, an outbreak of 34 cases of Pontiac fever occurred among 74 members of a social club who visited an inn in south-central Vermont. Environmental and epidemiologic investigations were done to identify the causes of the illness. The outbreak of Pontiac fever was most likely caused by L. pneumophila, serogroup 6, which was identified in a whirlpool spa at the inn. This is the first reported instance of an outbreak of Pontiac fever associated with a whirlpool spa.

Serotyping and serology studies of campylobacteriosis associated with consumption of raw milk.

A community outbreak of 15 cases of gastroenteritis was traced to consumption of unpasteurized milk produced at one commercial dairy. Using two different testing schemes, we found that a Campylobacter jejuni isolate from an ill patient and an isolate from a sick cow were the same serotype. Bacteriological studies suggested that a single epidemic strain of Campylobacter jejuni caused this outbreak.

Legionnaires' disease: the epidemiology of two outbreaks in Burlington, Vermont, 1980.

Eighty-five cases of Legionnaires' disease were diagnosed in two major outbreaks at a large regional medical center in Burlington, Vermont, in the summer of 1980. Cases in both outbreaks were positive for Legionella pneumophila, serogroup 1 by culture, serology, or direct fluorescent antibody tests. All cases had spent time in the city of Burlington in the 10 days before the onset of symptoms. Cases in both outbreaks were both hospital- and community-acquired. A case-control study identified no common in-hospital exposure, including shower use, that was associated with illness. Cases without previous exposure to the hospital were more likely to occur in persons with residences in neighborhoods just downwind of cooling tower A, but not throughout the municipal water system. Epidemiologic and environmental studies supported the association of this cooling tower, located 150 m from the hospital, with both outbreaks. Maintenance employees who worked with tower A had higher Legionella titers than those who worked with a comparison tower located 1.6 km away. Aerosolization of L. pneumophila by tower A and airborne spread to the hospital and community are postulated. The distance of airborne transmission of L. pneumophila in these consecutive outbreaks is greater than previously reported.