Clinical Manifestations of Nipah Virus-Infected Patients Who Presented to the Emergency Department During an Outbreak in Kerala State in India, May 2018.

BACKGROUND: An outbreak of Nipah virus (NiV) disease occurred in the Kozhikode district of Kerala State in India in May 2018. Several cases were treated at the emergency medicine department (ED) of the Government Medical College, Kozhikode (GMCK). The clinical manifestations and outcome of these cases are described. METHODS: The study included 12 cases treated in the ED of GMCK. Detailed clinical examination, laboratory investigations, and molecular testing for etiological diagnosis were performed. RESULTS: The median age of the patients was 30 years and the male to female ratio was 1.4:1.0. All the cases except the index case contracted the infection from hospitals. The median incubation period was 10 days, and the case fatality ratio was 83.3%. Ten (83.3%) patients had encephalitis and 9 out of 11 patients whose chest X-rays were obtained had bilateral infiltrates. Three patients had bradycardia and intractable hypotension requiring inotropes. Encephalitis, acute respiratory distress syndrome, and myocarditis were the clinical prototypes, but there were large overlaps between these. Ribavirin therapy was given to a subset of the patients. Although there was a 20% reduction in NiV encephalitis cases treated with the drug, the difference was not statistically significant. The outbreak ended soon after the introduction of total isolation of patients and barrier nursing. CONCLUSION: The outbreak of NiV disease in Kozhikode in May 2018 presented as encephalitis, acute respiratory distress and myocarditis or combinations of these. The CFR was high. Ribavirin therapy was tried but no evidence for its benefit could be obtained.

Prevalence and spatial distribution of Ixodid tick populations in the forest fringes of Western Ghats reported with human cases of Kyasanur forest disease and monkey deaths in South India.

Kyasanur forest disease (KFD) is a major tick-borne viral haemorrhagic fever caused by KFD virus (KFDV) (Flaviviridae). The disease was reported to be confined to five districts of Karnataka state India until 2011. During 2012-2016, emergence of KFD has been reported in newer areas of Karnataka and adjoining states. Therefore, survey of tick vectors was carried out in these new areas of Karnataka and adjoining states reported with monkey deaths and human cases of KFD. In all selected sites, ticks from the forest floor were collected by lint clothes using flagging method. Tick samples were tested for KFDV nucleic acid by real-time RT-PCR. A total of 4772 ticks, comprising eight species of genus Haemaphysalis and one species each of genus Amblyomma, Ixodes and Rhipicephalus was collected. Haemaphysalis spinigera, the principal vector of KFDV was the predominant tick species (59.5%) collected followed by H. turturis (8.6%). The abundance of H. spinigera ranged from 9.2 to 33.9 per man-hour in the six districts surveyed. Of 214 (4418 tick samples) pools screened by real-time RT-PCR, two pools of H. spinigera were positive for KFDV. High abundance of Haemaphysalis vectors in the six districts indicated that the districts are receptive for KFD outbreaks. KFDV was detected in the tick vectors in the new foci of the KFD. Data on tick distribution will be useful in creating KFD risk map for strengthening the ongoing preventive measures such as vaccination and supply of insect repellents to the high risk groups and intensive health education.

Malsoor virus, a novel bat phlebovirus, is closely related to severe fever with thrombocytopenia syndrome virus and heartland virus.

During a survey in the year 2010, a novel phlebovirus was isolated from the Rousettus leschenaultii species of bats in western India. The virus was identified by electron microscopy from infected Vero E6 cells. Phylogenic analysis of the complete genome showed its close relation to severe fever with thrombocytopenia syndrome (SFTS) and Heartland viruses, which makes it imperative to further study its natural ecology and potential as a novel emerging zoonotic virus.

Emerging and re-emerging arboviral diseases in Southeast Asia.

Arthropod-borne viruses (arboviruses) have become significant public health problems, with the emergence and re-emergence of arboviral diseases nearly worldwide. The most populated Southeast Asia region is particularly vulnerable. The arboviral diseases such as dengue (DEN), Japanese encephalitis (JE), West Nile virus (WNV), chikungunya fever (CHIK), hemorrhagic fevers such as Crimean-Congo hemorrhagic (CCHF) fever, Kyasanur forest disease virus (KFDV), etc. are on the rise and have spread unprecedentedly, causing considerable burden of disease. The emergence/re-emergence of these diseases is associated with complex factors, such as viral recombination and mutation, leading to more virulent and adaptive strains, urbanization and human activities creating more permissive environment for vector-host interaction, and increased air travel and commerce. Climate is a major factor in determining the geographic and temporal distribution of arthropods, the characteristics of arthropod life cycles, the consequent dispersal patterns of associated arboviruses, the evolution of arboviruses; and the efficiency with which they are transmitted from arthropods to vertebrate hosts. The present and future arboviral threats must be mitigated by priority actions such as improving surveillance and outbreak response, establishing collaboration and communication intersectorally, and strengthening the prevention and control programmes along with improving biosafety aspects with regards to highly infectious nature of these arboviral diseases. Evidence from research needs to be generated and priority areas for research defined.

Isolation of a novel adenovirus from Rousettus leschenaultii bats from India.

Surveillance work was initiated to study the presence of highly infectious diseases like Ebola-Reston, Marburg, Nipah and other possible viruses that are known to be found in the bat species and responsible for causing diseases in humans. A novel adenovirus was isolated from a common species of fruit bat (Rousettus leschenaultii) captured in Maharashtra State, India. Partial sequence analysis of the DNA polymerase gene shows this isolate to be a newly recognized member of the genus Mastadenovirus (family Adenoviridae), approximately 20% divergent at the nucleotide level from Japanese BatAdV, its closest known relative.

Molecular characterization of Chittoor (Batai) virus isolates from India.

BACKGROUND & OBJECTIVES: Chittoor virus (CHITV) belongs to genus Orthobunyavirus, family Bunyaviridae. It has been isolated from various species of mosquitoes and pig from different parts of India. Five isolates of CHITV were characterized at the molecular level and compared with other Batai viruses (BATV) to find out any kind of reassortment in their genome. METHODS: Complete nucelocapsid (S), glycoprotein (M) and partial RNA polymerase (L) segments of CHITV were amplified and sequenced. These sequences were compared with those of Batai viruses, isolated from different geographical locations in Asia, Africa and Europe. RESULTS: Phylogenetic analysis revealed CHITV as a variant of BATV. High level of conservation was seen among the CHITV isolates studied. The CHITV sequences showed clustering in one lineage with the sequences from Japan and Malaysia, however, BATV sequences from Europe and Africa formed a separate phylogenetic lineage. INTERPRETATION & CONCLUSIONS: The study indicates the presence of a single genotype of CHITV circulating in India, despite the involvement of different hosts in the natural cycle by this virus. Analysis of the sequences of the S, M and L segments of genome indicated that the virus has not undergone any reassortment. This virus has not caused any epidemic involving humans, however, replication of the virus in different mosquito and vertebrate hosts species suggests that it is a cause of concern.

Managing dual use technology: it takes two to tango.

Like nuclear energy, most technologies could have dual use-for health and well being and disaster and terror. Some research publications have brought to the forefront the tragic consequences of the latter potential through their possible use. Monitoring life science research and development (R&D) to prevent possible misuse is a challenging task globally, more so in developing economies like India, which are emerging as major biotech hubs. As a signatory to the Biological and Toxin Weapons Convention, India has put in motion a process of evolving a series of measures to manage dual-use technology. The Indian Council of Medical Research (ICMR) has taken a lead in drafting model codes of conduct, ethics and practice for use by other S&T agencies to tailor them as per their requirements. Taking cue from the discussions held by the editors of the various medical and science journals in the developed world, the Indian Journal of Medical Research, the official publication of the ICMR, is working on policy and uniform practice of publication of dual-use research results. The Government of India too has promulgated legal provisions to minimize the risks of misuse of technology, like the Weapons of Mass Destruction Act. Clearly, no single agency would be able to manage the dual-use of technology effectively. Multiple agencies have to come together to work in tandem for effective implementation of various measure and also like Janus, ensure that they are neither too restrictive nor intrusive to discourage the development of science.

Isolation and characterization of densonucleosis virus from Aedes aegypti mosquitoes and its distribution in India.

OBJECTIVES: Mosquito densonucleosis viruses (DNVs) are known to persistently infect the insect cell line and mosquito population in nature, causing mortality in mosquitoes. Here we report the isolation and characterization of a DNV from Aedes aegypti and its distribution among different Ae. aegypti populations from India. METHODS: We screened Ae. aegypti mosquito populations from different states of India by PCR. Virus isolation and purification was performed using a cesium chloride gradient from a positive mosquito colony. Characterization of this isolate was carried out by electron microscopy, Western blot and sequencing. RESULTS: Electron microscopy showed the presence of parvovirus-like particles, and Western blot showed the presence of 2 viral proteins of 40 and 41 kDa. A total of 3,776 bases of genome were sequenced, which included a 3'UTR of 128 bases, a coding region of 3,507 bases and a 5'UTR of 141 bases. Three open reading frames (ORFs) were identified and characterized. The NIVDNV genome showed 95% similarity with Culex pipiens pallens DNV and 93% similarity with Ae. aegypti DNV. CONCLUSION: Phylogenetic analysis of all 3 ORFs showed that this new isolate falls in the lineage of Brevidensovirus along with other mosquito DNVs.

Complete genome sequencing of Kaisodi virus isolated from ticks in India belonging to Phlebovirus genus, family Phenuiviridae.

An unknown virus was repeatedly isolated from hard tick (Haemaphysalis spinigera) during a proactive arbovirus survey in ticks conducted in 1957, in India. The virus remained uncharacterized for a long time. The passages of this virus in different vertebrate and invertebrate cells along with human and monkey-derived cell culture showed no cytopathic effect. It was identified later to be a member of Kaisodi group among Phlebovirus genus in the family Phenuiviridae (Order: Bunyavirales) by serological methods. Due to its genomic diversity, sequencing of this virus was a challenge for a while. In this study, we were able to sequence the complete genome of this virus isolate using next-generation sequencing (NGS) platform. The unknown virus was identified to be Kaisodi virus (KASDV) using NGS analysis. De novo genome assembly derived three genomic segments for the KASDV which encode for RNA-dependent RNA polymerase, glycoprotein precursor, and nucleoprotein. Functional as well as conserved domains for Kaisodi serogroup viruses were predicted and compared to a known representative of the genus Phlebovirus. The phylogenetic tree revealed its closeness to Silverwater virus, of Kaisodi serogroup with nucleotide (69%, 62%, and 61%) and amino acid (52%, 51%, and 62%) identity for L, M, and S segment, respectively. The study demonstrates the presence of a conserved motif (72TRGNK76) around the RNA binding motif region in tick-borne phleboviruses. The intergenic region encompassing the S segment of Kaisodi serogroup was GC-rich whereas the other Phlebovirus had AT-rich genome. KASDV has the largest intergenic region and larger loops, suggesting stem-loops formed due to larger loops as a possible factor for instability and cause of transcription termination. This paper also describes the real-time RT-PCR and RT-PCR assays developed and used for the detection of KASDV RNA in ticks from Karnataka, Kerala and Maharashtra State, India. The KASDV positivity observed in the recently collected tick pools indicates that the KASDV, isolated from Karnataka state in 1957, is also circulating in the adjoining Kerala state. On the basis of the current study, it should be possible to develop diagnostic assays which would facilitate an in-depth field survey exploring the veterinary and medical significance of KASDV.

Xenodiagnosis: use of mosquitoes for the diagnosis of arboviral infections.

The arboviruses have a worldwide distribution and, mosquitoes and ticks contribute principally in their transmission. In the last two decades, arboviral diseases have been recognised due to their resurgence and spread in newer geographic areas. Surveys to determine the prevalence of arboviruses in any region largely depend on the isolation attempts from the arthropods along with the serosurveys. Xenodiagnosis means use of insects for the diagnosis of infectious diseases affecting human being. The present communication discusses the application of mosquitoes for propagation and assays of arboviruses, the technique of mosquito inoculation and importance of xenodiagnosis.

Occupational exposure of cashew nut workers to Kyasanur Forest disease in Goa, India.

A series of suspected cases of Kyasanur Forest disease (KFD) in subjects returning to Belgaum in Karnataka State from Goa, India, is reported herein. KFD was confirmed in 13 out of 76 cases, either by real time RT-PCR or IgM ELISA. No case fatality was recorded. KFD virus positivity was also recorded among humans and monkeys from Sattari taluk in Goa during the same period. The envelope gene sequence of positive human samples from Belgaum showed highest identity of 99.98% to 99.99% with sequences of KFD virus isolated from human cases and monkeys from Goa. KFD activity has been reported from Goa among humans and monkeys since 2015. However, it has not been reported from Belgaum to date. These findings suggest that the cases (migrant laborers) contracted infection during cashew nut harvesting from KFD-affected Keri village, Sattari taluk, Goa and became ill after or during migration from the affected area to their native residence.

Isolation of Ganjam virus from ticks collected off domestic animals around Pune, Maharashtra, India.

Studies on viruses of zoonotic importance in certain villages around Pune were undertaken between December 2000 and January 2002. A total of 1,138 adult ticks belonging to six different species were collected off domestic animals and processed for virus isolation. Six virus isolates were obtained. All six isolates were identified as Ganjam virus by Quick Complement Fixation test and reverse transcriptase-polymerase chain reaction using RNA nucleocapsid gene amplification. Five isolates were from the pools of adult Hemaphysalis intermedia ticks, and one isolate was from a pool of adult Rhipecephalus hemaphysaloides. This is the first report of isolation of Ganjam virus from Maharashtra state of India.

Insect cell culture in research: Indian scenario.

Insect cell cultures are widely used in viral diagnosis and biotechnology, for the production of recombinant proteins, viral pesticides and vaccines as well as in basic research in genetics, molecular biology, biochemistry, endocrinology and virology. Following KRP Singh's pioneering research in 1967, a large number of cell lines from diptera, hemiptera, and lepidopteran insects were established and characterized in India. With the availability of the modern tools in molecular biology and the advancements made in biotechnology, the indigenous cell lines may prove useful in creating a future without biohazardous chemical pesticides as well as producing life saving pharmaceuticals and vaccines for many diseases. This review summarizes information gathered regarding the insect cell lines established so far in India. It also covers the familiarization of the well characterized continuous cell lines and their potential applications. Special attention is given to virus susceptibility of the cell lines, the yield of virus with a comparative analysis with other conventional systems. The potential applications of dipteran and lepidopteran cell lines in agriculture and biotechnology are also briefly discussed for prospective studies.

Characterization of a newly established potato tuber moth (Phthorimaea operculella Zeller) cell line.

BACKGROUND & OBJECTIVE: Potato tuber moth (PTM), Phthorimaea operculella Zeller is a widely distributed, devastating pest of potatoes attacking the foliage and infest the tubers in both field and store causing serious economic damage. As application of PTM granulovirus (PTM-GV) has shown significant reduction in damage, attempts were made to develop a new cell line from this insect to grow PTM-GV for use as a biopesticide. METHODS: Approximately 100 mg of insect eggs were collected, surface sterilized and crushed gently in a boiling tube aseptically. The tissues were washed with physiological saline, suspended in growth medium and incubated stationary at 28 degrees C. Morphology of cells was studied after staining with Giemsa. Besides karyological and growth curve studies, PCR amplification was also done for rapid amplified polymorphic DNA pattern. RESULTS: A new cell line from the embryonic tissue of PTM was maintained in Mitsuhashi Maramorosch medium supplemented with 10 per cent foetal bovine serum. It is in the 78th passage level and designated as NIV-PTM-1095. Random amplified polymorphic DNA profile analysis indicated this as a new cell line from potato tuber moth and differed from the profiles of two other lepidopteran cell lines maintained in the laboratory. Three different cell types were observed at the 40th passage level and comprised of epithelial-like cells (77%), fibroblast-like cells (20%) and giant cells (3%). The chromosome number varied from 54-176. The cell line had a cell doubling time of approximately 42 h during the logarithmic phase of growth. The cell line did not support the multiplication of any of the baculoviruses used in the study. INTERPRETATION & CONCLUSION: Since the new cell line is found to replicate PTM-GV, it may be useful for the propagation of PTM-GV in large scale. Studies to scale up the production of the GV in the cell line and field trials may lead to its widespread use as an eco-friendly biopesticide.

Effect of temperature and insecticide stresses on Aedes aegypti larvae and their influence on the susceptibility of mosquitoes to dengue-2 virus.

Two major factors, higher temperatures and the application of insecticides, can drastically alter the genetic structure of a vector mosquito population. Due to these two stresses, the majority of the population gets wiped out, but the ones that withstand the stress and survive are likely to pass on survivability, and have an altered physiology. Our study shows that exposures to higher temperatures and DDT during the larval stage affects their susceptibility as adult mosquitoes to the DEN-2 virus. The overall transcription and translation status of heat shock protein (Hsp70) in virus high- and low-susceptible was the same as that in other batches. In the case of a DDT-resistant (R-7) strain two bands were obtained during RT-PCRs after heat shock. These two alleles were obtained only with HY-1 in which R-7 males were used for the crosses, suggesting that the second allele is probably male sex linked. The higher expression of Hsp70 may provide DDT-resistant strains a better chance of survival high temperature environments, particularly in homozygotes and hybrids. It was also interesting to note that these strains have a significantly lower susceptibility to the virus. Wide-spread DDT-resistance and a rise in temperature above the average temperature during summer may result in a population with a low susceptibility to the virus. Several families of heat shock proteins are known to be expressed in mosquitoes, and may have a cumulative role in determining susceptibility to the virus, which itself is governed by several genes.

Effect of temperature stress on immature stages and susceptibility of Aedes aegypti mosquitoes to chikungunya virus.

A high temperature stress of 44.5 degrees C for 10 minutes on the larval stages was found to affect the susceptibility of adult Aedes aegypti mosquitoes to chikungunya virus. At this temperature, the mortality of the mosquito larvae was found to be approximately 95%, whereas a temperature greater than 45 degrees C for 10 minutes was found to be lethal. A temperature tolerant (TT) strain was developed by exposing the larvae to a temperature of 44.5 degrees C for 10 minutes at every generation for five generations. This strain was established to determine whether increase in the susceptibility was due to any selection pressure of higher temperature or to the influence of other intrinsic factors such as expression of immunoresponsive (IR) genes. Other studies on these mosquito strains showed that when maintained at 28 +/- 1 degrees C, there was no difference in the larval duration and mortality in the immature stages, but the mean survival of female mosquitoes in the TT strain was 5-6 days longer. Conversely, when mosquitoes were maintained throughout at 37 degrees C the mean survival of the mosquitoes decreased drastically in both strains, but the mean survival of females in the TT strain was 5-6 days longer compared with the unstressed controls. This increases the probability of at least one more blood meal. Fecundity of the TT strain was found to be lower than that of the control mosquitoes. Data suggest that expression of certain IR genes was affected by the heat shock. Some of these genes were up-regulated and down-regulated, which may have affected the susceptibility of mosquitoes to the virus. Although there was some selection in the temperature-tolerant individuals in the TT strain, when stressed by heat they showed expression of IR genes in a pattern similar to that in the normal controls. It appears that an increase in temperature above the average temperature of an area might help increase the proportion of virus-susceptible mosquitoes in the population. Such an increase in temperature in an endemic area would not only enhance the selection of temperature-tolerant individuals in a population having more longevity, but would also affect both intrinsic and extrinsic factors by reducing the extrinsic incubation period and increasing susceptibility of mosquitoes to viruses due to affected expression of IR genes.

Persistence of dengue-3 virus through transovarial transmission passage in successive generations of Aedes aegypti mosquitoes.

Progeny of Aedes aegypti mosquitoes infected intrathoracically with dengue-3 virus was reared to subsequent generations. In each generation, blood-fed females were confined individually and the eggs obtained from the transovarially infected females were pooled. The seventh generation obtained from the infected parental mosquitoes showed that virus could persist in mosquitoes in successive generations through transovarial passage. The rate of vertical transmission initially increased in the few generations (F1-F2), but in subsequent generations it was found to be steady. Parental mosquitoes inoculated with virus showed higher mortality than the diluent-inoculated controls. There was an increase in the larval duration of transovarially infected batches at the seventh generation when compared with uninfected control mosquitoes. The fecundity and fertility of the transovarially infected batches of mosquitoes was also affected when compared with the controls. This is the first report demonstrating persistence of dengue virus in the successive generations of mosquitoes infected through vertical transmission. These observations, which have great epidemiologic importance, suggest that vector mosquitoes may play an important role in the maintenance of virus in nature, and that mosquitoes may act as reservoirs of these viruses.

Inheritance of oral susceptibility of Aedes aegypti to Chikungunya virus.

A colony of rosy eye mutants of Aedes aegypti was established. This strain was refractory to Chikungunya virus by oral route of infection when compared with the wild-type parent strain. The refractoriness of this strain seems to be due to a mesentronal barrier, since both the mosquito strains supported the multiplication of virus after intrathoracic inoculation. The rosy eye strain was also found to be refractory to Sagiyama virus (Alphaviridae: Getah virus subtype) when compared with wild-type parent strain, but no such difference in the oral susceptibility was found with dengue-2 (Flaviviridae) virus. The rosy eye mutant appears to be closely linked to the gene(s) for refractoriness to alpha viruses and may be useful in future studies in understanding the genetic basis of vector competence of Ae. aegypti to arboviruses.

Japanese encephalitis virus infection in mosquitoes reared from field-collected immatures and in wild-caught males.

Immature stages of mosquitoes collected in JE endemic areas of Karnataka, India between 1985 and 1987 were reared to adults and processed for the detection and isolation of Japanese encephalitis (JE) virus in an attempt to find naturally occurring vertical transmission of the virus. Males collected during 1985-1986 were also processed. A total of 15,785 adults reared from immatures and divided into 445 pools and 1,756 wild-collected males divided into 128 pools were processed using mosquito inoculation and immunofluorescence techniques. JE virus antigen was detected in 9 pools, 4 of which yielded JE virus. These were 2 pools of males and 1 pool of female Culex tritaeniorhynchus and 1 pool of male C. pseudovishnui, suggesting vertical transmission of JE virus in the mosquitoes.

Isolation of Japanese encephalitis virus from mosquitoes collected in Karnataka state, India from 1985 to 1987.

Detection and isolation of Japanese encephalitis (JE) virus using mosquito inoculation and immunofluorescence techniques were attempted from female mosquitoes collected in JE endemic areas of Kolar and Mandya districts of Karnataka state, India, from 1985 to 1987. 65,388 mosquitoes consisting of 19 species in 1541 pools were processed. Of these, 18 pools showed the presence of JE virus antigen. JE virus was isolated from 9 pools, 3 of Culex gelidus, 2 of C. tritaeniorhynchus, and one each of C. quinquefasciatus, C. fuscocephala, C. vishnui and Anopheles peditaeniatus. Isolation of JE virus from C. gelidus, C. fuscocephala, C. quinquefasciatus and An. peditaeniatus is reported for the first time in India.