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Antemortem diagnosis and prevention of human rabies
Madhusudana Shampur,Sukumaran Suja
Annals of Indian Academy of Neurology , 2008,
Abstract: Human rabies still continues to be a significant health problem in India and other developing countries where dogs are the major vectors of transmission. Rabies in humans can present in two clinical forms, i.e., furious and paralytic. While diagnosis of furious rabies can be made based on the typical symptoms and signs, paralytic rabies poses a diagnostic dilemma to the neurologists who may encounter these cases in their practice. Although there are certain clinical features that distinguish this disease from other forms of Guillain-Barre syndromes, confirmation of diagnosis may require laboratory assistance. Conventional techniques such as antigen detection, antibody assays and virus isolation have limited success. The recently introduced molecular techniques show more promise in confirming the cases of paralytic rabies. There has not been much success in the treatment of confirmed rabies cases and recovery from rabies is extremely rare. Therefore, preventive measures of this dreaded disease after an exposure become extremely important. The present article reviews the current status of human rabies with regard to antemortem diagnosis, disease management and post-exposure prophylaxis.
Rabies Diagnosis for Developing Countries  [PDF]
Salome Dürr,Service Na?ssengar,Rolande Mindekem,Colette Diguimbye,Michael Niezgoda,Ivan Kuzmin,Charles E. Rupprecht,Jakob Zinsstag
PLOS Neglected Tropical Diseases , 2008, DOI: 10.1371/journal.pntd.0000206
Abstract: Background Canine rabies is a neglected disease causing 55,000 human deaths worldwide per year, and 99% of all cases are transmitted by dog bites. In N'Djaména, the capital of Chad, rabies is endemic with an incidence of 1.71/1,000 dogs (95% C.I. 1.45–1.98). The gold standard of rabies diagnosis is the direct immunofluorescent antibody (DFA) test, requiring a fluorescent microscope. The Centers for Disease Control and Prevention (CDC, Atlanta, United States of America) developed a histochemical test using low-cost light microscopy, the direct rapid immunohistochemical test (dRIT). Methodology/Principal Findings We evaluated the dRIT in the Chadian National Veterinary Laboratory in N'Djaména by testing 35 fresh samples parallel with both the DFA and dRIT. Additional retests (n = 68 in Chad, n = 74 at CDC) by DFA and dRIT of stored samples enhanced the power of the evaluation. All samples were from dogs, cats, and in one case from a bat. The dRIT performed very well compared to DFA. We found a 100% agreement of the dRIT and DFA in fresh samples (n = 35). Results of retesting at CDC and in Chad depended on the condition of samples. When the sample was in good condition (fresh brain tissue), we found simple Cohen's kappa coefficient related to the DFA diagnostic results in fresh tissue of 0.87 (95% C.I. 0.63–1) up to 1. For poor quality samples, the kappa values were between 0.13 (95% C.I. ?0.15–0.40) and 0.48 (95% C.I. 0.14–0.82). For samples stored in glycerol, dRIT results were more likely to agree with DFA testing in fresh samples than the DFA retesting. Conclusion/Significance The dRIT is as reliable a diagnostic method as the gold standard (DFA) for fresh samples. It has an advantage of requiring only light microscopy, which is 10 times less expensive than a fluorescence microscope. Reduced cost suggests high potential for making rabies diagnosis available in other cities and rural areas of Africa for large populations for which a capacity for diagnosis will contribute to rabies control.
Influence of canine brain decomposition on laboratory diagnosis of rabies
Albas, Avelino;Ferrari, Clara Izabel de Lucca;Silva, Luzia Helena Queiroz da;Bernardi, Fernanda;Ito, Fumio Honma;
Revista da Sociedade Brasileira de Medicina Tropical , 1999, DOI: 10.1590/S0037-86821999000100004
Abstract: canine brains infected with rabies virus were submitted to decomposition by being left at room temperature of 25 to 29oc for up to 168h. at 24h intervals, brain fragments were analyzed by immunofluorescence (if) and by the mouse intracerebral inoculation (mi) test to confirm the diagnosis of rabies and to measure the putrefaction effect on the accuracy of the diagnosis. forty eight h after the beginning of the experiment, the mi test showed signs of impairment with four negative results, while after 72h, 100% of the results were negative to the mi test and only one result was negative to the if test, indicating that the threshold period for accurate diagnosis is 24 to 48h before putrefaction. the authors recommend the shipment of suspected cases of rabies to the laboratory for confirmation, but the use of putrid materials for diagnosis is meaningless because of false-negative results.
Influence of canine brain decomposition on laboratory diagnosis of rabies
Albas Avelino,Ferrari Clara Izabel de Lucca,Silva Luzia Helena Queiroz da,Bernardi Fernanda
Revista da Sociedade Brasileira de Medicina Tropical , 1999,
Abstract: Canine brains infected with rabies virus were submitted to decomposition by being left at room temperature of 25 to 29oC for up to 168h. At 24h intervals, brain fragments were analyzed by immunofluorescence (IF) and by the mouse intracerebral inoculation (MI) test to confirm the diagnosis of rabies and to measure the putrefaction effect on the accuracy of the diagnosis. Forty eight h after the beginning of the experiment, the MI test showed signs of impairment with four negative results, while after 72h, 100% of the results were negative to the MI test and only one result was negative to the IF test, indicating that the threshold period for accurate diagnosis is 24 to 48h before putrefaction. The authors recommend the shipment of suspected cases of rabies to the laboratory for confirmation, but the use of putrid materials for diagnosis is meaningless because of false-negative results.
Development and evaluation of an In vitro isolation of street rabies virus in mouse neuroblastoma cells as compared to conventional tests used for diagnosis of rabies  [cached]
Chhabra M,Mittal V,Jaiswal R,Malik S
Indian Journal of Medical Microbiology , 2007,
Abstract: In vitro isolation of rabies virus using mouse neuroblastoma cells (MNA) was evaluated. The sensitivity and reliability of in vitro procedure was performed in comparison with mouse inoculation test (MIT), the in vivo method of virus isolation, direct fluorescent antibody test (FAT) and Sellers staining. Of the 33 animal brain samples tested, 24 (72.72%) were positive by MIT. Sensitivity of Sellers stain, FAT and rapid tissue culture infection test (RTCIT) was found to be 54.16, 100 and 91.6% respectively. Concordance of Sellers stain, FAT, RTCIT with MIT was found to be 66.6, 100 and 93.93% respectively. Two samples which were positive by FAT and MIT showed gross contamination in cell lines, which is one of the drawbacks of RTCIT. However, rabies virus could be isolated in MNA cells from two of the eight human cerebrospinal fluid (CSF) samples from clinico-epidemiologically suspected cases of rabies. Both MIT and FAT showed negative results in the two CSF samples. RTCIT appears to be a fast and reliable alternative to MIT and holds promise in antemortem diagnosis of rabies, which is otherwise, a challenging task for a reference laboratory.
Rabies molecular virology, diagnosis, prevention and treatment
Muhammad Yousaf, Muhammad Qasim, Sadia Zia, Muti ur Rehman Khan, Usman Ashfaq, Sanaullah Khan
Virology Journal , 2012, DOI: 10.1186/1743-422x-9-50
Abstract: The current article mainly covers the genome, virology, symptoms, epidemiology, diagnostic methods, and the high risk countries around the globe.Rabies is a zoonotic (transmitted from animals to human) viral infectious disease. This infection is transmitted to human by the animals already suffering from it. The animals which are mainly reported as causes of rabies are; dogs, raccoons, skunks, bats, and foxes. Rabies or "Hydrophobia" is a disease which makes the dogs sick. In many eastern and western countries dogs are vaccinated against it, but it is not controlled yet. Rabies is caused by a virus that, attacks on the nerves system and later excreted in saliva [1]. A person or animal can become a victim of rabies in many ways including [2],a. Bitesb. Non-bites exposurec. Human to Human TransmissionBites from rabid animal to human are very common but the other two factors are rare [2]. Rabies affects the brain and spinal cord (central nervous system) with initial symptoms like; flu, fever, headache, but the infection can progress quickly to hallucinations, paralysis, and eventually death [3].Rabies virus is the "type species" of the Lyssavirus genus of Rhabdoviridae family. The virus is enveloped and has a single stranded, negative sense RNA genome [4]. The RNA genome of the virus encodes five genes whose order is highly conserved. These genes codes for: nucleoprotein (N), phosphoprotein (P), matrix protein (M), glycoprotein (G), and a viral RNA polymerase (L). All rahbdoviruses have two major structural components; helical ribonucleoprotein core (RNP) and surrounding envelops. The two proteins, P and L are associated with RNP. The glycoprotein forms approximately 400 trimeric spikes, which are tightly arranged on the surface of the virus [5]. The virus nucleoprotein (N) plays critical role in replication and transcription. Both viral transcription and replication are reduced, if the nucleoprotein is not phosphorylated [6]. Rhabdoviruses cell surface receptors are no
Rabies diagnosis and serology in bats from the State of S?o Paulo, Brazil
Almeida, Marilene Fernandes de;Martorelli, Luzia Fátima Alves;Sodré, Miriam Martos;Kataoka, Ana Paula Arruda Geraldes;Rosa, Adriana Ruckert da;Oliveira, Maria Lucia de;Amatuzzi, Elizabeth;
Revista da Sociedade Brasileira de Medicina Tropical , 2011, DOI: 10.1590/S0037-86822011005000011
Abstract: introduction: bats are one of the most important reservoirs and vectors of the rabies virus in the world. methods: from 1988 to 2003, the zoonosis control center in s?o paulo city performed rabies diagnosis on 5,670 bats by direct immunofluorescent test and mouse inoculation test. blood samples were collected from 1,618 bats and the sera were analyzed using the rapid fluorescent focus inhibition test to confirm rabies antibodies. results: forty-four (0.8%) bats were positive for rabies. the prevalence of rabies antibodies was 5.9% using 0.5iu/ml as a cutoff. insectivorous bats (69.8%) and bats of the species molossus molossus (51.8%) constituted the majority of the sample; however, the highest prevalence of antibodies were observed in glossophaga soricina (14/133), histiotus velatus (16/60), desmodus rotundus (8/66), artibeus lituratus (5/54), nyctinomops macrotis (3/23), tadarida brasiliensis (3/48), carollia perspicillata (3/9), eumops auripendulus (2/30), nyctinomops laticaudatus (2/16), sturnira lilium (2/17) and eumops perotis (1/13). the prevalence of rabies antibodies was analyzed by species, food preference and sex. conclusions: the expressive levels of antibodies associated with the low virus positivity verified in these bats indicate that rabies virus circulates actively among them.
Nested RT-PCR for ante mortem diagnosis of rabies from body secretion/excretion of animals suspected for rabies  [cached]
M Dandale,C K Singh,V Ramneek,D Deka
Veterinary World , 2012, DOI: 10.5455/vetworld.2012.690-693
Abstract: Aim: The present study deals with molecular technique Nested RT-PCR for detection of rabies viral RNA from biological fluid samples (Saliva, Milk and Urine) collected from animal suspected for rabies and to compare the sensitivity of Nested RT-PCR applied for ante mortem diagnosis of rabies with conventional technique (immunofluorescence) applied on neural tissue. Materials and Methods: Nested RT-PCR was applied on 62 biological fluid specimens collected from rabies suspected animals. First round amplification with nested set of primers (RabN1 and RabN5) yielded 1477 bp product while amplification with second round primers (RabNfor and RabNrev) yielded 762 bp product. Sensitivity of the technique was compared in accordance with WHO recommended gold standard test viz. Immunofluorescence (FAT) applied on brain samples. Results: By Nested RT-PCR, viral RNA could be detected in 9/24 (37.50%) saliva samples, 2/17 (11.76%) milk samples and 6/21 (28.57%) urine samples. Confirmatory diagnosis by Immunofluorescence performed on brain sample revealed 18 true positive cases. Overall, Sensitivity of Nested RT-PCR technique employed on fluid samples was 69.23% when compared with immunofluorescence performed on brain samples. Conclusions: Early reliable ante mortem diagnosis of rabies can be obtained from biological fluid samples of animals suspected to be rabid when tested with Nested RT-PCR technique. [Vet World 2012; 5(11.000): 690-693]
Advances in Diagnosis of Respiratory Virus Infections  [PDF]
Michael Loeffelholz,Tasnee Chonmaitree
International Journal of Microbiology , 2010, DOI: 10.1155/2010/126049
Abstract: The diagnosis of respiratory virus infections has evolved substantially in recent years, with the emergence of new pathogens and the development of novel detection methods. While recent advances have improved the sensitivity and turn-around time of diagnostic tests for respiratory viruses, they have also raised important issues such as cost, and the clinical significance of detecting multiple viruses in a single specimen by molecular methods. This article reviews recent advances in specimen collection and detection methods for diagnosis of respiratory virus infections, and discusses the performance characteristics and limitations of these methods.
Antemortem diagnosis of human rabies in a veterinarian infected when handling a herbivore in Minas Gerais, Brazil
Brito, Mariana Gontijo de;Chamone, Talita Leal;Silva, Fernando José da;Wada, Marcelo Yohito;Miranda, Alexandre Braga de;Castilho, Juliana Galera;Carrieri, Maria Luiza;Kotait, Ivanete;Lemos, Francisco Leopoldo;
Revista do Instituto de Medicina Tropical de S?o Paulo , 2011, DOI: 10.1590/S0036-46652011000100007
Abstract: the ministry of health's national human rabies control program advocates pre-exposure prophylaxis (pep) for professionals involved with animals that are at risk of contracting rabies. we report an antemortem and postmortem diagnosis of rabies in a veterinarian who became infected when handling herbivores with rabies. the antemortem diagnosis was carried out with a saliva sample and a biopsy of hair follicles using molecular biology techniques, while the postmortem diagnosis used a brain sample and conventional techniques. the veterinarian had collected samples to diagnose rabies in suspect herbivores (bovines and caprines) that were subsequently confirmed to be positive in laboratory tests. after onset of classic rabies symptoms, saliva and hair follicles were collected and used for antemortem diagnostic tests and found to be positive by rt-pcr. genetic sequencing showed that the infection was caused by variant 3 (desmodus rotundus), a finding confirmed by tests on the brain sample. it is essential that professionals who are at risk of infection by the rabies virus undergo pre-exposure prophylaxis. this study also confirms that molecular biology techniques were used successfully for antemortem diagnosis and therefore not only allow therapeutic methods to be developed, but also enable the source of infection in human rabies cases to be identified accurately and quickly.
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