Determination of a cut-off value for the serological diagnosis of scrub typhus by detecting anti-Orientia tsutsugamushi immunoglobulin M

Background & objectives: The diagnosis of scrub typhus (ST) is usually done using enzyme-linked immunosorbent assay (ELISA) due to its ease of performance and reading objectivity. The cut-off value for ELISA needs to be calculated for each geographical location as it depends on zonal endemicity of the disease. This study was, therefore, undertaken to calculate the pan-India cut-off for anti-Orientia tsutsugamushi (OT) immunoglobulin M (IgM) by ELISA. Methods: Samples from cases (cases of ST) and controls (voluntary, consenting, healthy adults) were collected by a network of 29 laboratories across India and tested for anti-OT IgM by immunofluorescence assay (IFA), the considered gold standard test. These samples were retested by ELISA for anti-OT IgM and their optical densities (ODs) were used for cut-off estimation by receiver operating characteristic (ROC) curve. Results: Anti-OT IgM ELISA ODs from 273 controls and 136 cases were used for the cut-off estimation. The ODs of the anti-OT IgM ELISA on healthy individuals and those of confirmed ST cases ranged from 0.1 to 0.75 and 0.5 to 4.718, respectively. ROC curve-based cut-off for ELISA was calculated as 0.554 at a sensitivity of 95.2 per cent and specificity of 95.1 per cent. A value of >1 was noted to have a specificity of 100 per cent in diagnosing ST. Interpretation & conclusions: The cut-off calculated for India was similar to the previous cut-off that was used until now.

Unusual clinical presentations of scrub typhus, a neglected tropical disease: A case series from north India

Background & objectives: Scrub typhus is a neglected tropical disease common in Asia and Africa. It usually presents with non-specific symptoms like fever, rashes, and lymphadenopathy. It has a varying range of clinical picture that often leads to misdiagnosis and initiation of non-specific treatment. This disease is thus associated with high morbidity and mortality. We aim to highlight the uncommon presentations of this common disease to create awareness regarding the unusual presentations of scrub typhus. Methods: This prospective study was performed over a period of two months enrolling eleven adult patients with serological evidence of anti-scrub typhus IgM antibodies. Results: All enrolled 11 cases [5 males (45.5%) and 6 females (54.5%)] were positive for anti-ST IgM antibodies and negative for other tested microbial agents. 7/11 (63.6%) patients were admitted with a clinical diagnosis of acute encephalitis syndrome (AES as per standard WHO definition), 3/11 (27.3%) patients presented with jaundice and 1/11 (9.1%) patients presented with rashes. Two out of 7 (28.6%) AES cases had developed peripheral gangrene of extremities. Interpretation & conclusion: Scrub typhus is a common tropical disease that can have various unusual clinical presentations like meningoencephalitis, vasculitis, acute kidney injury, jaundice, MODS. It closely mimics other infective etiologies making its diagnosis difficult. A high index of suspicion and clinical awareness is required in clinical practice to identify the different presentations of this disease so that early treatment can be initiated to reduce morbidity and mortality associated with this disease.

Seropositivity of Anti-SARS CoV2 IgG antibodies in health care workers of an Indian tertiary care hospital during COVID-19

Purpose: Health care workers [HCW] are at a higher risk of infection SARS CoV2 infection due to frequent and close contact to patients with COVID-19. Methods: Serum samples from 500 HCW's were tested for SARS CoV2 IgG antibodies in October 2020. A questionnaire was used to collect demographic and clinical data. All these HCWs were tested for COVID-19, in 2nd week of September 2020, as a hospital policy. Results: Anti SARS CoV2 antibodies were detected in 128/ 500 [25.6%] HCWs. A total of 195/ 500 [39%] enrolled cases had already tested positive for Covid-19 at least once in last six months by RT-PCR. Sixty eight percent of HCWs with previous COVID-19 positivity by RT- PCR tested positive for Anti SARS CoV2 antibodies, whereas only 2.76% of asymptomatic HCWs tested positive. Of 121 anti SARS-CoV-2 IgG positive persons, 70 [57.85%] had CT value < 25. Low CT value and asymptomatic cases had a strong reverse statistically significant association with SARS CoV2 IgG antibody positivity. Conclusions: We report that sero-conversion rate in HCWs is similar to that in general population suggesting that preventive practices used in hospitals are satisfactory. Cases with low viral counts in respiratory sample and asymptomatic cases have lower rate of seroconversion.

Drug resistance profile among multi-drug resistant tuberculosis patients at diagnosis and correlation with history of anti-tubercular treatment in a tertiary care center

Background: Drug Resistant Tuberculosis (DR-TB) is a major threat to the realization of the goal of a TB free world in the near future. It is important to study the reasons for the increasing number of such cases so that effective action can be taken to control this growing epidemic.Methods: Sputum from 36 patients diagnosed with acquired pulmonary Multidrug Resistant Tuberculosis (MDR-TB) were subjected to first- and second-line Drug Sensitivity Testing (DST) after liquid culture in mycobacterium growth Indicator Tube (MGIT). Primary MDR-TB cases were excluded. The relation of the drug sensitivity profile with the history of prior treatment taken was statistically analysed.Results: Majority of the patients had received appropriate treatment, and most had adhered to prescribed treatment. Among the 36 patients, 24(66.7%) were found to be Pre-Extensively Drug Resistant (Pre-XDR-TB) and 4(11.1%) were extensively drug resistant XDR-TB cases. Inappropriate prescription of fluoroquinolone (FQ) was found to be most common. Prior intake of any drug was not found to significantly affect subsequent resistance to that drug.Conclusions: Fluoroquinolone resistance is quite common in patients with DR-TB (66.7%). This study did not find the prior use of FQ or any other drug to significantly affect subsequent resistance to the drug. Primary drug resistance is thus a major concern. 11.1% patients were found to be XDR-TB cases. Hence DST for first- and second-line drugs should be done at the time of diagnosis to avoid failure of treatment with a predesigned regimen.

A study on pre-XDR & XDR tuberculosis & their prevalent genotypes in clinical isolates of Mycobacterium tuberculosis in north India.

Background & objectives: Pre-extensively drug resistant (pre-XDR) and extensively drug resistant tuberculosis (XDR-TB) have been areas of growing concern, and are posing threat to global efforts of TB control. The present study was planned to study the presence of pre-XDR and XDR Mycobacterium tuberculosis and their genotypes in clinical isolates obtained from previously treated cases of pulmonary TB. Methods: A total of 219 isolates obtained from previously treated cases of pulmonary TB were subjected to first-line (streptomycin, isoniazid, rifampicin and ethambutol) and second-line (ofloxacin, kanamycin, capreomycin and amikacin) drug susceptibility testing on solid Lowenstein-Jensen medium by proportion method. Genotyping was done for pre-XDR and XDR-TB isolates using 12 loci Mycobacterial Interspersed Repetitive Units-Variable Number Tandem Repeats (MIRU-VNTR). Results: Multi-drug resistance was observed in 39.7 per cent (87/219) isolates. Pre-XDR and XDR M. tuberculosis isolates amongst 87 multi-drug resistant (MDR) TB isolates were 43 (49.4%) and 10 (11.4%), respectively. Two most dominant genotypes among pre-XDR and XDR M. tuberculosis isolates were Beijing and Delhi/CAS types. Interpretation & conclusions: Resistance to second-line anti-tubercular drugs should be routinely assessed in areas endemic for TB. Similar genotype patterns were seen in pre-XDR and XDR-TB isolates. Beijing and Delhi/CAS were predominant genotypes.

Observation on dengue cases from a virus diagnostic laboratory of a tertiary care hospital in north India.

Background & objectives: The epidemiology of dengue fever (DF) is complex in the Indian subcontinent as all the four serotypes are circulating. This study reports observations on dengue cases from a virus diagnostic laboratory of a north Indian tertiary care hospital catering to areas in and around Lucknow, Uttar Pradesh. Methods: Serum samples were obtained from suspected cases of dengue referred to the virus diagnostic laboratory during 2011 to 2013, and detailed history was taken on a pre-structured datasheet. All samples were tested for anti-dengue virus (DV) IgM antibodies and DV-non structural protein 1 antigen (NS1Ag) by ELISA. NS1Ag positive samples were tested further by conventional RT-PCR for DV-RNA detection and serotyping. Results: Of the 4019 suspected patients of dengue, 886 (22%) showed laboratory evidence of dengue virus infection. Of these, 19, 17 and 27 per cent were positive in 2011, 2012 and 2013, respectively. Children and adults were similarly affected by dengue in all the three years. Males were more commonly affected than females. The predominant DV serotype detected was DV-2, DV-1 and DV-3 in 2011, 2012 and 2013, respectively. DV-4 serotype was not detected. About half the cases positive for DV infection, showed symptoms of dengue with warning signs/ severe dengue. A distinct seasonality with increase in number of dengue cases in the post monsoon period was seen. Interpretation & conclusions: Change in circulating serotype of dengue virus; a distinct adult dengue involvement; and a remarkable number of cases presenting with severe dengue manifestations are the main findings of this study.

Molecular characterization of the rotavirus enterotoxin NSP4 gene of strains causing diarrhoea in children aged 0-5 years in northern India.

Non structural protein 4 (NSP4) gene of Rotavirus encodes a multifunctional protein which has significant role in viral multiplication and pathogenesis of acute watery diarrhoea associated with rotaviral gastroenteritis. It is known as the first viral enterotoxin and mutations of the gene have been linked to altered pathogenesis. This study was planned to ascertain the genotypes and genetic variations of NSP4 gene in the rotavirus strains prevalent in this area. We collected consecutive diarrhoeal stools from equal no of children aged under five years hospitalized with diarrhoea in a period from January 2010 to June 2012 and tested them for rotavirus antigen by ELISA. NSP4 gene was amplified by RT-PCR and subsequently sequenced (Big-Dye terminator kit using 3130 ABI, Genetic analyzer) and genotyped by Rotavirus C software. Of the 260 samples, 58(22.3%) samples were positive by ELISA. We were able to amplify NSP4 gene by RTPCR from 45 strains of which 35 amplicons were selected for sequencing. Total 25(71.4%) strains belonged to genotype E1, 6 (17.1%) strains to genotype E2 and 4 (11.4%) matched with the genotype E6. Sequence analysis revealed changes in the nucleotides causing punctate mutations in the conserved regions, the Inter species variable domain (ISVD) and the enterotoxin region (amino acid 114-135). On evolutionary analysis of 33 strains amino acid at position 131 was found under positive selection.

In vitro validation of self designed “universal human Influenza A siRNA”.

The genomic variability of Influenza A virus (IAV) makes it difficult for the existing vaccines or anti-influenza drugs to control. The siRNA targeting viral gene induces RNAi mechanism in the host and silent the gene by cleaving mRNA. In this study, we developed an universal siRNA and validated its efficiency in vitro. The siRNA was designed rationally, targeting the most conserved region (delineated with the help of multiple sequence alignment) of M gene of IAV strains. Three level screening method was adopted, and the most efficient one was selected on the basis of its unique position in the conserved region. The siRNA efficacy was confirmed in vitro with the Madin Darby Canine Kidney (MDCK) cell line for IAV propagation using two clinical isolates i.e., Influenza A/H3N2 and Influenza A/pdmH1N1. Of the total 168 strains worldwide and 33 strains from India, 97 bp long (position 137-233) conserved region was identified. The longest ORF of matrix gene was targeted by the selected siRNA, which showed 73.6% inhibition in replication of Influenza A/pdmH1N1 and 62.1% inhibition in replication of Influenza A/H3N2 at 48 h post infection on MDCK cell line. This study provides a basis for the development of siRNA which can be used as universal anti-IAV therapeutic agent.

Rotavirus Nonstructural Protein 4 (NSP4)-Viral Enterotoxin with Multiple roles in Pathogenesis of Diarrhoea in Children.

Nonstructural protein 4 (NSP4) of Rotavirus has been designated as the first viral enterotoxin. Its role in viral replication is already well known. Intensive research over the past decade has shown the involvement of this protein in many cellular activities both in ‘expressed’ as well as ‘secreted’ form. It is responsible for increased intracellular calcium levels in the infected cell leading to a cascade of events which involve phospholipase C mediated secretion of Chloride ions. NSP4 also inhibits intestinal disaccharidases and sodium glucose symporter (SGLT1) so that complex sugars are retained resulting in malabsorption. It also alters actin in the villi resulting in their flattening and overall decreased absorptive area. NSP4 is associated with extracellular proteins and is hypothesized to have paracrine effects on neighbouring cells. Recent research has found it to be an activator of enteric nervous system too. All these factors contribute to the pathogenesis of diarrhoea which looks multifactorial and certainly very different from the bacterial toxin mediated diarrhoeas of E. coli and V. cholerae. We still don’t have the final word on this intriguing protein which is now a potential candidate for a vaccine against rotavirus. The aim of this review is to put forward the salient features of the research done to elucidate the functions of NSP4.

Aetiology of childhood viral gastroenteritis in Lucknow, north India.

Background & objectives: Due to limited availability of data on viral aetiology of acute gastroenteritis in north India, the present study was planned to detect rotavirus, norovirus, sapovirus and astrovirus in stool samples of both in hospitalized and non-hospitalized children less than five years of age presenting with acute gastroenteritis. Methods: A total of 278 stool samples from equal number of children were tested for rotavirus antigen using ELISA and for norovirus, sapovirus and astroviruses by reverse transcription (RT)-PCR. Results: Of the 169 samples from hospitalized patients, rotavirus, norovirus, sapovirus and astrovirus were detected in 19.5, 2.3, 3.5 and 2.9 per cent samples, respectively. Of the 109 samples collected from the non-hospitalized patients, frequency of rotavirus and sapovirus detection was 9.1 and 1.8 per cent, respectively while norovirus and astrovirus were not detected. Interpretation & conclusions: Rotavirus was the most frequent cause of viral gastroenteritis in both hospitalized and non-hospitalized children. Maximum positivity of the viruses was seen in children less than two years of age.

Management Information Systems (HMIS): A Method for Strengthening HMIS in Uttar Pradesh, India.

Objectives: Estimates from robust cross sectional surveys have brought into question the accuracy of HMIS of VAS in India, including potential errors as HMIS data is rolled up at various levels from health worker- to state-level, limiting the usefulness of these data for program feedback and improvement. In response, we sought to identify errors in monitoring data at different levels, suggest corrective action and establish coverage by a cross sectional survey triangulated with HMIS data. Methods: This exercise was conducted in 16 districts where 48 primary health centers (PHCs) were selected randomly. Data on Vitamin A coverage recorded at districts, PHCs, sub-health centers (SHCs) and health worker/volunteer level were cross-verified with coverage figures recorded at their respective constituent units. Discrepancies between coverage data recorded at health facilities and that aggregated from their constituent units were computed. A 30X7 cluster survey was also undertaken in each of these centers to establish population-based coverage. Results: Overall, there was a 7% discrepancy between figures reported by PHCs and that aggregated from their SHCs. In some PHCs the discrepancy was as large as 40%. The cross-sectional household survey identified 10% higher coverage than that reported by the state government (52% vs 42%). District specific findings were used to identify and facilitate systemic changes in reporting and data compilation. Conclusions: This is a cost-effective method and useful exercise for improving internal data quality and minimizing reporting error. The involvement of government functionaries in the process increased the ownership of study results and facilitated corrective actions.

In silico designing of siRNA targeting PB 1 gene of Influenza A virus and in vitro validation.

Genomic variability makes Influenza A virus (IAV) ‘the least susceptible’ to existing vaccines or anti-influenza drugs. siRNA targeting viral gene silents the gene by cleaving mRNA. Present study aimed to develop siRNA targeting polymerase basic 1 (PB1) gene and to validate its efficiency in vitro. siRNA was designed rationally, targeting the most conserved region of PB1 gene of IAV strains. Total 147 strains worldwide and 42 Indian strains, when aligned, showed seven sets of conserved regions (> 30 bp stretch and < 5% mismatches). To choose the most efficient siRNA, three levels screening method was developed. Finally one pair of siRNA was chosen due to its unique position in conserved region. siRNA efficacy was confirmed in vitro on Madin Darby Canine Kidney (MDCK) cell line propagating two clinical isolates i.e. Influenza A/H3N2 [A/India/LKO864/ 2011(H3N2)] and Influenza A/pandemicH1N1 [A/India/LKO2151/2012(H1N1)]. The longest ORF was targeted by the selected siRNA, which showed 57 % inhibition in replication of Influenza A/pdmH1N1 and 60.6 % inhibition in replication of Influenza A/H3N2 at 72 hpi and 48 hpi respectively on MDCK cell line. This study shows that siRNA targeting PB1 may be moderately effective in controlling IAV replication so can be used as anti-IAV therapeutic agent.

Comparison of third generation ELISA and conventional nested RT-PCR for detection of HCV among hemodialysis patients.

Hepatitis C virus is one of the main cause of chronic hepatitis in developing countries. The current study was done to evaluate the efficacy of the third generation ELISA compared to nested RT- PCR for establishing the diagnosis of hepatitis C virus (HCV) in patients on hemodialysis. This descriptive, cross-sectional study was carried out on 237 Hemodialysis patients in Lucknow, Uttar Pradesh. The retrospective demographic data of the subjects was collected and the patient’s serum samples were analyzed by ELISA & RT-PCR for HCV. In the present study, of total 21 HCV positive either by ELISA or PCR 12 (57.14%) were positive for both RT-nested PCR and ELISA. Total four (19.05%) patients were positive for HCV by RT-nested PCR and negative by ELISA while five (23.81%) patients were negative for RT-nested PCR and positive for ELISA. PCR method is accredited as a specific and reliable method suitable for screening of HCV and is recommended for establishing exact and final diagnosis of these patients. However third generation ELISA assays have many advantages in the diagnostic setting including ease of automation, ease of use, relative cost-effectiveness, and low variability.

Influenza virus genotypes circulating in and around Lucknow, Uttar Pradesh, India, during post pandemic period, August 2010 - September 2012.

Background & objectives: During the post influenza pandemic period, continuous surveillance of influenza virus and its subtypes is mandatory to help the policy makers to take effective and appropriate decisions. Therefore, this study was planned to determine the pattern of influenza virus activity in context to various meteorological and clinical parameters in and around Lucknow, Uttar Pradesh, India, during post pandemic period August 2010 - September 2012. Methods: Nasal swabs/throat swabs/nasopharyngeal aspirates of 2669 patients were collected. One-step real time PCR for detection of influenza virus was done according to the Centers for Disease Control and Prevention (CDC) protocol. Results: Influenza positivity was 15.8 per cent (423/2669) in symptomatic patients. Of the 423 total positives, 192 (7.2%) were influenza A and 231 (8.7%) were influenza B. Positivity for influenza virus was significantly (P=0.001, OR=2.9, CI=1.9-4.3) higher in patients with Influenza like illness (ILI) (17.4%, 396/2271) than those with severe acute respiratory illness (SARI) (6.8%, 27/398). Influenza A positive samples were subtyped as; pdmH1N1 (67.2%, 129/192) and seasonal H3N2 (32.8%, 63/192). It significantly correlated with monthly mean rainfall, humidity and dew point while atmospheric pressure was inversely related. No significant association was found with temperature and wind speed. Clinical variations were observed between different strains of Influenza virus. Interpretation & conclusions: The findings provide a clear picture of different clinical presentations of various strains of influenza A and B viruses and epidemiology of influenza infection from Lucknow (UP), India. The seasonality of influenza virus infection showed variation in relation to different environmental factors. Pandemic H1N1 caused more systemic infection than seasonal influenza A/H3N2 virus.

Glucose & sodium chloride induced biofilm production & ica operon in clinical isolates of staphylococci.

Background & objectives: All colonizing and invasive staphylococcal isolates may not produce biofilm but may turn biofilm producers in certain situations due to change in environmental factors. This study was done to test the hypothesis that non biofilm producing clinical staphylococci isolates turn biofilm producers in presence of sodium chloride (isotonic) and high concentration of glucose, irrespective of presence or absence of ica operon. Methods: Clinical isolates of 100 invasive, 50 colonizing and 50 commensal staphylococci were tested for biofilm production by microtiter plate method in different culture media (trypticase soy broth alone or supplemented with 0.9% NaCl/ 5 or 10% glucose). All isolates were tested for the presence of ica ADBC genes by PCR. Results: Biofilm production significantly increased in the presence of glucose and saline, most, when both glucose and saline were used together. All the ica positive staphylococcal isolates and some ica negative isolates turned biofilm producer in at least one of the tested culture conditions. Those remained biofilm negative in different culture conditions were all ica negative. Interpretation & conclusions: The present results showed that the use of glucose or NaCl or combination of both enhanced biofilm producing capacity of staphylococcal isolates irrespective of presence or absence of ica operon.

Initial drug resistance pattern among Pulmonary Tuberculosis patients.

Background: Drug resistant tuberculosis (DRTB) is an emerging problem that adversely affects treatment outcomes and public health in the developing world. Objective: To determine the initial drug resistance pattern among pulmonary tuberculosis patients registered under the Revised National Tuberculosis Control Programme. Study Design: A cross-sectional study design. Setting: Two urban Directly Observed Treatment Supervised (DOTS) centres in Lucknow District of Uttar Pradesh. Methods: The present study consisted of newly diagnosed sputum smear-positive for acid-fast bacilli (AFB) cases at the time of registration under the tuberculosis control programme. All sputum smear positive cases were subjected to culture and drug-susceptibility testing by 1% proportion method on Lowenstein-Jensen (LJ) medium. Results: A total of 185 newly diagnosed sputum smear positive for AFB in pulmonary tuberculosis patients were subjected to culture and drug sensitivity test. Among 185 isolates, 170 (91.4%) isolates were culture positive. Of these 170 isolates, 169 (99.4%) were M. tuberculosis and one (0.5%) was Mycobacterium other than tuberculosis (MOTT). Out of 99.4% M. tuberculosis positive isolates, 21.3% were resistant to at least one drug. Resistance pattern of 21.3% strains of M. tuberculosis showing resistance to single, double, triple, and quadruple drugs were 5.9%, 10.7%, 2.4% and 2.4% respectively. Multi-drug resistance (MDR) was observed in 4.7% isolates. Conclusion: The present study highlights the high rate of drug resistance pattern among the new sputum smear positive pulmonary tuberculosis patients and also high MDR tuberculosis. Routine surveillance of drug resistance profile of patients provides useful information for adopting new strategies of effective treatment within National Tuberculosis Control Programmes in order to combat the threat of MDR-TB in the general population.

Trend of dengue virus infection at Lucknow, north India (2008- 2010): A hospital based study.

Background & objectives: Dengue virus (DV) infection has emerged as a major health problem in north India. Here, we report the annual trend of dengue virus infection as seen in Lucknow, Uttar Pradesh, during 2008-2010. Methods: Blood samples from clinically suspected cases of dengue virus infection were collected and history was taken on structured clinical data sheet. All samples were tested for dengue IgM by antibody capture ELISA. Selected samples were tested by conventional RT-PCR for dengue virus RNA. Weather information was continuously recorded from website of world weather information service. Results: There was a gradual increase in number of dengue fever cases with increased occurrence in 2010. Cases referred in January - December 2008 were 398 (54.5% anti DV IgM positive), in January - December 2009 were 599 (51.9% anti DV IgM positive) and in January - December 2010 were 1602 (64.9% anti DV IgM positive). Serotypes circulating in years 2008, 2009 and 2010 were DV-2 & DV-3, DV -1, 2 & 3 and DV-1 and DV-2 respectively. There is no statistical significant correlation between weather data and increasing dengue positive cases. Interpretation & conclusions: Increased cases of dengue fever were seen in 2010, which was not correlated with any change in environmental factors. A change in circulating serotypes was noted.

Consensus Guidelines on Evaluation and Management of Suspected Acute Viral Encephalitis in Children in India.

Justification: Viral encephalitis is an important cause of mortality and morbidity in children. The etiological agents are varied, and physicians treating such children often feel limited by the lack of uniform guidelines on evaluation and management of these critically ill children in resource-constrained settings. Process: An ‘Expert Group Meeting on Viral Encephalitis in Children’ was held on 19th January, 2012 in Gurgaon, Haryana (under the aegis of PEDICON 2012, the National Conference of Indian Academy of Pediatrics). The invited experts included pediatricians and microbiologists with expertise in the relevant field. Various issues related to the subject were discussed and it was decided to bring out recommendations on the topic. The final recommendations were produced after circulating the draft document, and incorporating/discussing all changes, by e-mail. Objectives: To aid the pediatrician in the evaluation and management of children with suspected viral encephalitis and to assist the public health authorities in acute encephalitis surveillance. These guidelines do not cover viral encephalitis in the neonatal period and in immunocompromised children, Rabies encephalitis, and chronic viral encephalitis such as Subacute sclerosing panencephalitis (SSPE). Recommendations: Recommendation for evaluation and management of suspected viral encephalitis in children are presented. In any acute encephalitis outbreak, pediatricians should be aware of the common viral causes of encephalitis in their area, what information and samples they should collect, and the contact details of the District Surveillance Unit. Pending specific diagnosis and therapy (which may or may not be possible), prompt empirical therapy and meticulous supportive care are important to prevent ongoing brain damage, and improve outcome.

Dengue in India.

Dengue virus belongs to family Flaviviridae, having four serotypes that spread by the bite of infected Aedes mosquitoes. It causes a wide spectrum of illness from mild asymptomatic illness to severe fatal dengue haemorrhagic fever/dengue shock syndrome (DHF/DSS). Approximately 2.5 billion people live in dengue-risk regions with about 100 million new cases each year worldwide. The cumulative dengue diseases burden has attained an unprecedented proportion in recent times with sharp increase in the size of human population at risk. Dengue disease presents highly complex pathophysiological, economic and ecologic problems. In India, the first epidemic of clinical dengue-like illness was recorded in Madras (now Chennai) in 1780 and the first virologically proved epidemic of dengue fever (DF) occurred in Calcutta (now Kolkata) and Eastern Coast of India in 1963-1964. During the last 50 years a large number of physicians have treated and described dengue disease in India, but the scientific studies addressing various problems of dengue disease have been carried out at limited number of centres. Achievements of Indian scientists are considerable; however, a lot remain to be achieved for creating an impact. This paper briefly reviews the extent of work done by various groups of scientists in this country.