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Biomedical subjects

S N Madhusudana

Publications and source records attributed to S N Madhusudana.

At least 19 recordsLinked to original sources
PubMed2006

Presence of rabies specific immune complexes in cerebro-spinal fluid can help in ante-mortem diagnosis of human paralytic rabies.

BACKGROUND: Human rabies presents in two clinical forms, viz. furious or encephalitic and paralytic. Clinical diagnosis of paralytic form is difficult and requires laboratory confirmation. Presently available diagnostic techniques are not very sensitive for ante-mortem confirmation of rabies. OBJECTIVE: In the present study, we investigated whether presence of rabies specific immune complexes in cerebro-spinal fluid (CSF) of paralytic rabies patients could help in ante-mortem diagnosis of rabies. STUDY DESIGN: A capture ELISA based on monoclonal antibodies to rabies nucleoprotein (N) and glycoprotein (G) was developed to detect immune complexes to rabies N and G proteins. We studied CSF samples collected ante-mortem from 30 suspected paralytic rabies patients in whom diagnosis was later confirmed by autopsy. We included 30 CSF samples from people undergoing spinal anesthesia as negative controls and 30 CSF samples from other viral encephalitis as disease controls. RESULTS: Twenty-three out of 30 CSF samples (76.6%) showed presence of immune complexes to both rabies N and G proteins. None of the negative controls and CSFs from other confirmed viral infections were positive. Thus, the results were 100% specific and the sensitivity of this test was 76.6%. CONCLUSIONS: Detection of immune complexes to rabies antigens may be used as one of the techniques for rapid ante-mortem diagnosis of human rabies.

Adult↗
PubMed2006

Assessing the burden of human rabies in India: results of a national multi-center epidemiological survey.

OBJECTIVE: Human rabies has been endemic in India since time immemorial, and the true incidence of the disease and nationwide epidemiological factors have never been studied. The main objectives of the present study were to estimate the annual incidence of human rabies in India based on a community survey and to describe its salient epidemiological features. METHODS: The Association for Prevention and Control of Rabies in India (APCRI) conducted a national multi-center survey with the help of 21 medical schools during the period February-August 2003. This community-based survey covered a representative population of 10.8 million in mainland India. Hospital-based data were also obtained from the 22 infectious diseases hospitals. A separate survey of the islands of Andaman, Nicobar, and Lakshadweep, reported to be free from rabies, was also undertaken. RESULTS: The annual incidence of human rabies was estimated to be 17,137 (95% CI 14,109-20,165). Based on expert group advice, an additional 20% was added to this to include paralytic/atypical forms of rabies, providing an estimate of 20,565 or about 2 per 100000 population. The majority of the victims were male, adult, from rural areas, and unvaccinated. The main animals responsible for bites were dogs (96.2%), most of which were stray. The most common bite sites were the extremities. The disease incubation period ranged from two weeks to six months. Hydrophobia was the predominant clinical feature. Many of the victims had resorted to indigenous forms of treatment following animal bite, and only about half of them had sought hospital attention. Approximately 10% of these patients had taken a partial course of either Semple or a cell culture vaccine. The islands of Andaman, Nicobar, and Lakshadweep were found to be free of rabies. CONCLUSION: Human rabies continues to be endemic in India except for the islands of Andaman, Nicobar, and Lakshadweep. Dogs continue to be the principal reservoir. The disease is taking its toll on adult men and children, the majority from rural areas, due to lack of awareness about proper post-exposure immunization. The keys to success in the further reduction of rabies in India lies in improved coverage with modern rabies vaccines, canine rabies control, and intensifying public education about the disease.

Adolescent↗
PubMed2006

Ante mortem diagnosis of human rabies using saliva samples: comparison of real time and conventional RT-PCR techniques.

BACKGROUND: Rabies is an enzootic and fatal disease and is still a major problem in developing countries. Ante mortem diagnosis in human cases is necessary for medical management of the patient and to ensure appropriate post-exposure treatment of contacts. Both conventional RT-PCR and Real time PCR (TaqMan) have been described for the detection of rabies virus RNA from saliva and tissue respectively, however to date, there have been no studies comparing conventional and real time PCR assays for detection of rabies virus nucleic acid using saliva samples for ante mortem diagnosis. OBJECTIVES: In this study, we evaluated the utility of conventional RT-PCR and SYBR Green I Real time PCR in the ante mortem diagnosis of rabies using saliva samples. STUDY DESIGN: Saliva samples collected from twenty-four patients presenting with typical clinical manifestations of rabies were tested in the two assays. RESULTS: Amongst the 24 samples tested, 21 samples (87.5%) were positive by either of the two molecular methods. Of these 21, rabies virus RNA was detected in 6/21 in the conventional RT-PCR assay while SYBR Green I Real time PCR could detect RNA in 18/21 samples. CONCLUSION: Real time PCR assay was more sensitive than conventional RT-PCR assay (sensitivity 75% versus 37%, p=0.0189). This study highlights the utility of molecular diagnostic tests in establishing ante mortem diagnosis of rabies using saliva samples within a few hours.

Adolescent↗
PubMed2005

Assessing the relationship between antigenicity and immunogenicity of human rabies vaccines. Results of a meta-analysis.

A meta-analysis was done to study the relationship between antigenecity and immunogenecity of human rabies vaccines. The data of ten cell culture human rabies vaccine studies conducted at a single centre during 1993-2004 were used in the study. The vaccines studied included Purified Chick Embryo Cell Vaccine (Kaketsuken, Japan and Rabipur, India), Purified Vero cell Rabies Vaccine (Verorab, France), Human Diploid Cell Vaccine (MIRV, France and Rabivax, Adsorbed and Lyophilized, India) and Rhesus Diploid Rabies Vaccine (adsorbed, USA). Interestingly, it was revealed that an higher antigenecity of rabies vaccines viz. potency of > or = 5 IU per single intramuscular dose did not result in significantly higher immunogenecity, as measured by rabies virus neutralizing antibody (RVNA) titers in the vaccinees, both on day 14 (t = 0.42, p > 0.66, GMR = 1.06, 95% CI of GMR = 0.82, 1.37) and day 90 (t = 0.80, p > 0.43, GMR = 1.15, 95% CI of GMR = 0.74, 1.14). However, as there are no reports of meta-analysis of cell culture human rabies vaccine trials, to confirm this observation the authors recommend further studies in this regard.

Adolescent↗
PubMed2004

Simulated post-exposure rabies vaccination with purified chick embryo cell vaccine using a modified Thai Red Cross regimen.

OBJECTIVES: Currently, two intradermal regimens for the administration of cell culture rabies vaccines are approved by the WHO for rabies post-exposure prophylaxis: the two site Thai Red Cross regimen (TRC) and the eight site regimen. For the TRC regimen the volume of vaccine recommended per dose is 0.1 ml of purified Vero cell rabies vaccine (PVRV) and 0.2 ml of purified chick embryo cell vaccine (PCEC). The objective of the present study was to evaluate comparatively the immune response to PCEC and PVRV vaccines administered by the TRC regimen using a uniform dose of 0.1 ml of vaccine. METHODS: Forty-two subjects received TRC regimen (2-2-2-0-1-1) with 0.1 ml of PCEC vaccine and 38 subjects received the same regimen with PVRV. The rabies neutralizing antibody response in these subjects on days 10, 28, 90 and 180 was determined by the standard mouse neutralization test (MNT). RESULTS: There was adequate antibody response with both the vaccines and 100% seroconversion was observed by day 10. Furthermore, the antibody titers obtained with PCEC did not differ significantly from those obtained with PVRV on all days tested (p > 0.05). CONCLUSIONS: It can be concluded from the results that an adequate antibody response can be obtained with PCEC vaccine when administered by the TRC regimen even after reducing the quantity of vaccine from 0.2 ml to 0.1 ml per intradermal dose. The feasibility of using this regimen in true post-exposure cases needs to be further evaluated.

Adult↗
PubMed2004

Development and evaluation of an enzyme immunoassay for rapid diagnosis of rabies in humans and animals.

The presently advocated tests for rapid diagnosis of rabies such as fluorescent antibody test (FAT) is expensive and requires expertise to carry out and interpret the results. In this study we have developed and evaluated a simple enzyme immuno-assay (EIA) to detect rabies antigen in the brain specimens of animals and humans. We have also evaluated the utility of this test in ante mortem diagnosis of human rabies. The brain homogenates of suspected rabid animals (n=250), humans (n=16) and clinical samples like saliva (n=16) and cerebrospinal fluid (CSF, n=16) applied on to ELISA plates coated with rabies antinucleoprotein antibody and the absorbed rabies nucleoprotein antigen was detected using biotinylated anti-nucleoprotein antibody followed by treatment with streptavidin peroxidase conjugate and colour development with OPD. Rabies infected and normal mouse brain homogenates were used as positive and negative controls respectively. The results of this test was evaluated with fluorescent antibody technique (for brain samples) and mice inoculation test (for saliva and CSF samples). A distinct dark brown color was seen in positive control and all positive samples and there was no color development in negative control and samples. The concordance between FAT and EIA was 98.4%. With brain samples, 83.3% with saliva and 91.6% with CSF samples. The specificity of the test was found to be 100%. It can be concluded that the EIA described here is a sensitive, specific and rapid test for post mortem diagnosis of rabies in animals and humans. The utility of this test for ante mortem diagnosis of rabies needs to be further evaluated.

Animals↗
PubMed2003

Development and evaluation of a latex agglutination test for rabies antibodies.

BACKGROUND: The presently recommended tests for estimation of rabies neutralising antibodies like Rapid Fluorescent Focus Inhibition test (RFFIT) and Mouse Neutralisation test (MNT) are laborious, time consuming and not cost-effective for routine use. Simple, rapid and economical tests need to be developed for routine use. OBJECTIVES: The main objective of the present study was to develop and evaluate a rapid Latex Agglutination Test (LAT) to detect rabies specific antibodies. METHODS: Latex beads were coated with purified rabies glycoprotein at a concentration of 1 mg/ml followed by coating with 0.3% bovine serum albumin (BSA). These sensitised beads were used to detect antiglycoprotein antibodies in sera of 152 people who had taken a course of post exposure rabies vaccination with different cell culture vaccines and whose antibody titers were pre determined by MNT. Sera from 52 normal healthy people without any detectable levels of rabies antibodies were included as controls. The test was carried out on glass slides by mixing 20 micro l of sensitised beads and 20 micro l serum. RESULTS: Preliminary evaluation with rabbit serum of known potency indicated that for clear agglutination of sensitised beads, a minimum of 2 IU/ml of rabies antibody should be present in the serum samples. Visible agglutination was noticed in positive sera with a titer > or =2 IU/ml within 3-5 min after mixing. Seven Sera whose MNT titers were less than 2 IU/ml did not show agglutinati or n. None of the negative control sera showed agglutination. Thus the specificity of the test was 100% and sensitivity was 95.4%. CONCLUSIONS: The LAT described here detects rabies specific antibodies > or =2 IU/ml and can be used to screen large number of sera from vaccinated people to know the protective status after vaccination. This simple and rapid test may be used routinely in antirabies treatment centres to monitor sero conversion in vaccinated people.

Agglutination Tests↗
PubMed2003

A passive haemagglutination test for rabies antibodies using rabies glycoprotein coupled erythrocytes.

The presently recommended tests for assaying rabies antibodies like mouse neutralization test (MINT) and rapid fluorescent focus inhibition test (RFFIT) are either time consuming or expensive and are generally performed in reference laboratories. There is a need to develop a specific and rapid method for detection of rabies antibodies that can be used to monitor sero-conversion after pre-or post-exposure vaccination. In this study, we have developed a passive haemagglutination (PHA) using purified rabies virus glycoprotein coupled to sheep erythrocytes using chromium chloride (0.04%) as a coupling agent. Two hundred and fifty five serum samples from people vaccinated with different rabies vaccines, 16 paired serum and CSF samples from autopsy confirmed cases of paralytic rabies, and serum samples from 65 normal healthy controls were tested and evaluated in comparison to standard MNT. Among the vaccinees, 250 samples were positive both by MNT and PHA but 5 samples were negative by PHA and positive by MNT. The titres obtained by PHA were lower compared to MNT, but there was significant correlation between the two (r=0.885). The specificity of the test was 99.7% and sensitivity was 100% as compared to MNT. Thus this PHA test promises to be a rapid and specific test for assaying rabies antibodies and may be useful in screening large number of serum samples for sero conversion after vaccination. It may also assist in rapid laboratory confirmation of paralytic rabies cases, based on detection of antibodies in CSF and serum.

Antigens, Viral↗
PubMed2002

Economical multi-site intradermal regimen with purified chick embryo cell vaccine (Rabipur) prevents rabies in people bitten by confirmed rabid animals.

OBJECTIVE: To determine the efficacy of a cost-effective multi-site intradermal regimen with purified chick embryo cell vaccine (PCECV, Rabipur) in preventing rabies in people bitten by confirmed rabid dogs. METHODS: Thirty-two people of different age groups who were severely bitten by confirmed rabid dogs were immunized with PCECV using the WHO recommended multi-site intradermal regimen of 0.1 mL of vaccine at eight sites on day 0, at four sites on day 7, and at one site each on days 28 and 90. In addition, passive immunization with human or equine rabies immunoglobulin was administered to 22 of these people before administering vaccine. They were followed for up to 3 years with periodic estimation of neutralizing antibody levels in their serum by mouse neutralization test (MNT). RESULTS: There was an excellent immune response with more than protective titers (>0.5 IU/mL) on all days tested up to the end of the 3-year observation period. More significantly, protective titers were seen in all subjects by day 7. Only minimal side effects were observed. All the patients were doing well at the end of the 3-year observation period, which is generally considered to be the maximum incubation period for rabies in humans. CONCLUSIONS: It can be concluded that this multi-site regimen with or without passive immunization has prevented the development of rabies encephalitis in these people bitten by confirmed rabid dogs. This should encourage more such studies, so that this cost-effective economical regimen with safe and potent cell culture vaccines can replace highly reactogenic neural tissue-derived Semple vaccine in developing countries such as India.

Adolescent↗
PubMed2001

Comparative evaluation of a simple indirect immunofluorescence test and mouse neutralization test for assaying rabies antibodies.

In this study, we have developed and evaluated a simple indirect immunofluorescence test (IIFT) to detect rabies antibodies in a two-step immunofluorescence assay. One hundred and eighty five serum samples from people who had taken different rabies vaccines and 8 pairs of serum and CSF samples from confirmed paralytic rabies cases were tested by IIFT and results evaluated in comparison to standard mouse neutralization test (MNT). Though the titres of rabies antibodies obtained with IIFT were 2-4 times lesser in comparison to MNT, a significant correlation was seen between the two tests (R = 0.883). The specificity of this IIFT was found to be 97.9% and the sensitivity was 97.2%. These results indicate that this simple and rapid IIFT can be used to screen large number of serum samples to monitor sero-conversion after pre or post exposure vaccination and may also assist in rapid ante-mortem diagnosis of atypical human rabies.

Animals↗
PubMed1999

Post-exposure prophylaxis with purified vero cell rabies vaccine during pregnancy--safety and immunogenicity.

This study was conducted with the main objective of determining the safety and immunogenicity of purified vero cell rabies vaccine (PVRV) during pregnancy. Twenty nine pregnant women exposed to rabies were vaccinated with PVRV as per the Essen regimen advocated by World Health Organization. None of the women experienced any adverse side effects to the vaccine. The intrauterine growth and development monitored by ultrasound examination was found to be normal and the outcome of pregnancy was satisfactory. There were no congenital anomalies in any of the infants born and they were healthy and had normal growth and development during the one year follow-up period. The rabies neutralizing antibody titers from day 14 to day 365 following vaccination in these women was adequate and well above the minimum protective level of 0.5 iu/ml of serum. Protective levels of antibodies were also present in serum of some of the babies tested, for up to 3 months of age. The mothers and infants followed for one year period were doing well at the end of the study period. Consequently, PVRV was found safe and immunogenically efficacious during pregnancy.

Adolescent↗
PubMed1992

Human rabies: epidemiological and laboratory studies in 80 cases.

Epidemiological and laboratory studies were conducted on 80 clinically diagnosed human rabies cases. Incidence of rabies was more in adult males (55%) and boys (37.5%) than adult females (5%) and girls (2.5%) and more in rural areas (76.2%) than urban areas (23.8%). Dogs constituted the main vector of transmission (92.5%). Incomplete course of antirabic vaccine had been received by 31% of cases and 2.5% of cases had complete course of antirabic vaccine. Among the laboratory tests conducted 3.8% of corneal smears and 2.5% of saliva smears were positive by fluorescent antibody technique. Rabies virus was isolated from 3.8% of saliva and 3% of cerebrospinal fluid samples. Rabies neutralising antibody titre ranged from 1:64 to 1:128 in the serum of patients who were fully vaccinated.

Adult↗