Pragya D. Yadav

Recent Ancestry of Kyasanur Forest Disease Virus

Clinicians in Asia should consider this disease when diagnosing acute febrile illnesses.

Thottapalayam virus is genetically distant to the rodent-borne hantaviruses, consistent with its isolation from the Asian house shrew (Suncus murinus)

Thottapalayam (TPM) virus belongs to the genus Hantavirus, family Bunyaviridae. The genomes of hantaviruses consist of three negative-stranded RNA segments (S, M and L) encoding the virus nucleocapsid (N), glycoprotein (Gn, Gc), and polymerase (L) proteins, respectively. The genus Hantavirus contains predominantly rodent-borne viruses, with the prominent exception of TPM virus which was isolated in India in 1964 from an insectivore, Suncus murinus, commonly referred to as the Asian house shrew or brown musk shrew. Analysis of the available TPM virus S (1530 nt) RNA genome segment sequence and the newly derived M (3621 nt) and L (6581 nt) segment sequences demonstrate that the entire TPM virus genome is very unique. Remarkably high sequence differences are seen at the nucleotide (up to S – 47%, M – 49%, L – 38%) and protein (up to N – 54%, Gn/Gc – 57% and L – 39%) levels relative to the rodent-borne hantaviruses, consistent with TPM virus having a unique host association.

Detection of Nipah Virus RNA in Fruit Bat (Pteropus giganteus) from India

The study deals with the survey of different bat populations (Pteropus giganteus, Cynopterus sphinx, and Megaderma lyra) in India for highly pathogenic Nipah virus (NiV), Reston Ebola virus, and Marburg virus. Bats (n = 140) from two states in India (Maharashtra and West Bengal) were tested for IgG (serum samples) against these viruses and for virus RNAs. Only NiV RNA was detected in a liver homogenate of P. giganteus captured in Myanaguri, West Bengal. Partial sequence analysis of nucleocapsid, glycoprotein, fusion, and phosphoprotein genes showed similarity with the NiV sequences from earlier outbreaks in India. A serum sample of this bat was also positive by enzyme-linked immunosorbent assay for NiV-specific IgG. This is the first report on confirmation of Nipah viral RNA in Pteropus bat from India and suggests the possible role of this species in transmission of NiV in India.

Kyasanur Forest disease, India, 2011-2012.

To determine the cause of the recent upsurge in Kyasanur Forest disease, we investigated the outbreak that occurred during December 2011–March 2012 in India. Male patients >14 years of age were most commonly affected. Although vaccination is the key strategy for preventing disease, vaccine for boosters was unavailable during 2011, which might be a reason for the increased cases.

Spread of Kyasanur Forest Disease, Bandipur Tiger Reserve, India, 2012–2013

To the Editor: Kyasanur Forest disease virus (KFDV; family Flaviviridae, genus Flavivirus) was first recognized in 1956 in Shimoga District, Karnataka State, India (1). The natural cycle of KFDV involves 2 monkey species—black-faced langurs (Semnopithecus entellus) and red-faced bonnet monkeys (Macaca radiata)—and various tick species (genus Haemaphysalis). Monkeys become infected with KFDV through the bite of infected ticks; the virus is then transmitted to other ticks feeding on infected monkeys. KFDV infection causes severe febrile illness in some monkeys. When infected monkeys die, ticks drop from the body, thereby generating hot spots of infectious ticks that further spread the virus. In the enzootic state, KFDV circulates through small mammals (e.g., rodents, shrews, ground birds) and ticks (2). n nHumans can also be infected with KFDV. In humans, the disease causes high fever, frontal headache, and severe myalgia, followed by bleeding from the nasal cavity, throat, gingivae, and, in some cases, gastrointestinal tract (3). In the natural KFDV cycle, humans are dead-end hosts. n nKFD is unique to 5 districts (Shimoga, Chikkamagalore, Uttara Kannada, Dakshina Kannada, and Udupi) in the Malnad region of Karnataka State, India, where each year during January–May, 100–500 persons are affected by the disease (2,4). During December 2011–March 2012, a total of 215 suspected KFD case-patients were identified in 80 villages in Shimoga District; laboratory testing confirmed that 61 (28%) were infected with KFDV (5). n nIn November 2012, the deaths of 12 monkeys in Bandipur National Park, Chamarajanagara District, Karnataka State, were reported. At the same time, 6 humans from Mole Hole village and Madhur colony in the Bandipur Tiger Reserve who handled and incinerated the sick monkeys were reported to have clinical signs and symptoms typical of KFD (Technical Appendix Figure 1). The monkey handlers (20–55 years of age) were admitted to the local hospital in Gundlupet Taluk. Monkey autopsy specimens, serum samples from suspected human case-patients, and tick pools were collected by staff from the Virus Diagnostic Laboratory in Shimoga. The samples were sent to the National Institute of Virology in Pune for determination of the etiologic agent. Additional samples from humans with suspected KFDV infection, monkeys, and tick pools were received from Chamarajanagar District and adjoining border areas of Tamil Nadu State and Kerala State (Table). n n n nTable n nReal-time reverse transcription PCR and nested reverse transcription PCR results for specimens screened for Kyasanur Forest disease virus, India, November 2012–May 2013* n n n nMonkey brain and liver and tick pools were sonicated in 600 μL of Minimum Essential Media (GIBCO/BRL, Life Technologies, Grand Island, NY, USA), and 400 μL of media was added to the homogenate. TriPure Isolation Reagentxa0(Roche Diagnostics, Indianapolis, IN, USA) was used to perform RNA extraction as described (6). n nSamples were tested for KFDV by nested reverse transcription PCR (RT-PCR) and real-time RT-PCR as described (6); 12 of 21 human samples and 4 monkey samples were positive (Table). Two of 14 tick pools screened for KFDV by real-time RT-PCR were positive; however, 1 was weakly positive (Table). The PCR-amplified products were purified by using the QIAquick Gel Extraction Kit (QIAGEN, Hilden, Germany) and then sequenced. KFDV sequences from the samples showed 95.8%−98.1% similarity with prototype strain KFDV P9605. This finding supports the earlier conclusion that a high level of conservation exists for KFDV sequences (7). The phylogenetic tree formed 2 clades: the first included mainly KFDV sequences from 1957–2006, the second included KFDV sequences (human and monkey) from Chamarajanagara District (Technical Appendix Figure 2). n nKFDV has not been detected previously in Chamarajanagara District, the location of Bandipur National Park. Affected areas in the district share a border with Mysore District (Karnataka State), Kerala State, and Tamil Nadu State. In addition,we subsequently found monkey samples from Nilgiri, Tamil Nadu, to be positive for KFDV. n nThe human case-patients from Chamarajanagara District were mainly forest workers involved in the incineration of the dead monkeys. Infection among these workers indicates that they did not follow appropriate biosafety procedures while handling the infected animals. n nOur findings confirm that KFD has occurred outside the districts in Karnataka State where KFDV is known to be endemic. A hemagglutination inhibition antibody survey conducted during December 1988–January 1989 (8) indicated the possible existence of this disease in other regions of India. The presence of KFD becomes noticeable when enzootic infections occur and sentinel animals, like monkeys, start dying (9). Detection of KFDV in Chamarajanagara District, Tamil Nadu State (Nilgiri), and Kerala State indicates the presence of the virus in many evergreen and semi-evergreen forest areas of India. Infections in these areas may have been missed previously because of the lack of an organized surveillance system. n nDuring the first week of December 2012, immediately after the KFD outbreak was confirmed, the Karnataka public health department vaccinated 322 persons, including villagers, forest officials, health workers, and members of local tribes in the Maddur Forest Range of Bandipur Tiger Reserve. Hot-spot areas caused by monkey deaths were dusted with malathion insecticide to kill ticks. In addition, to prevent additional human infections, epidemiologists recommended establishment of a health education campaign and the use of protective clothing and tick repellents, especially by persons frequently visiting forested areas. n nTechnical Appendix: nReal-time reverse transcription PCR and reverse transcription PCR results for specimens tested for Kyasanur Forest disease virus (KFDV), new KFD outbreak areas in Karnataka State, India, during 2012–2013, and phylogenetic analysis of KFDV sequences. n nClick here to view.(309K, pdf)

Genomic analysis reveals Nairobi sheep disease virus to be highly diverse and present in both Africa, and in India in the form of the Ganjam virus variant.

Nairobi sheep disease (NSD) virus, the prototype tick-borne virus of the genus Nairovirus, family Bunyaviridae is associated with acute hemorrhagic gastroenteritis in sheep and goats in East and Central Africa. The closely related Ganjam virus found in India is associated with febrile illness in humans and disease in livestock. The complete S, M and L segment sequences of Ganjam and NSD virus and partial sequence analysis of Ganjam viral RNA genome S, M and L segments encoding regions (396 bp, 701 bp and 425 bp) of the viral nucleocapsid (N), glycoprotein precursor (GPC) and L polymerase (L) proteins, respectively, was carried out for multiple Ganjam virus isolates obtained from 1954 to 2002 and from various regions of India. M segments of NSD and Ganjam virus encode a large ORF for the glycoprotein precursor (GPC), (1627 and 1624 amino acids in length, respectively) and their L segments encode a very large L polymerase (3991 amino acids). The complete S, M and L segments of NSD and Ganjam viruses were more closely related to one another than to other characterized nairoviruses, and no evidence of reassortment was found. However, the NSD and Ganjam virus complete M segment differed by 22.90% and 14.70%, for nucleotide and amino acid respectively, and the complete L segment nucleotide and protein differing by 9.90% and 2.70%, respectively among themselves. Ganjam and NSD virus, complete S segment differed by 9.40-10.40% and 3.2-4.10 for nucleotide and proteins while among Ganjam viruses 0.0-6.20% and 0.0-1.4%, variation was found for nucleotide and amino acids. Ganjam virus isolates differed by up to 17% and 11% at the nucleotide level for the partial S and L gene fragments, respectively, with less variation observed at the deduced amino acid level (10.5 and 2%, S and L, respectively). However, the virus partial M gene fragment (which encodes the hypervariable mucin-like domain) of these viruses differed by as much as 56% at the nucleotide level. Phylogenetic analysis of partial sequence differences suggests considerable mixing and movement of Ganjam virus strains within India, with no clear relationship between genetic lineages and virus geographic origin or year of isolation. Surprisingly, NSD virus does not represent a distinct lineage, but appears as a variant with other Ganjam virus among NSD virus group.

Cross-sectional Serosurvey of Crimean-Congo Hemorrhagic Fever Virus IgG in Livestock, India, 2013–2014

We conducted a cross-sectional serosurvey of Crimean-Congo hemorrhagic fever (CCHF) among livestock in 22 states and 1 union territory of India. A total of 5,636 samples from bovines, sheep, and goats were screened for CCHF virus IgG. IgG was detected in 354 samples, indicating that this virus is widespread in this country.

Equine Encephalosis Virus in India, 2008

A virus isolated from a sick horse from India in 2008 was confirmed by next-generation sequencing analysis to be equine encephalosis virus (EEV). EEV in India is concerning because several species of Culicoides midge, which play a major role in EEV natural maintenance and transmission, are present in this country.

First laboratory confirmation on the existence of Zika virus disease in India

• After WHO declaration of Zika threat, a surveillance program was conducted under the initiative of Department of Health research/ Indian council of Medical Research, Ministry of Health, India using Virology Research and Diagnostic Laboratories (VRDL) network.

Crimean-Congo Hemorrhagic Fever in Migrant Worker Returning from Oman to India, 2016

In January 2016, a migrant worker who returned home to India after becoming ill in Oman was confirmed to have Crimean-Congo hemorrhagic fever (CCHF). Physicians should include CCHF in the differential diagnosis for patients with hemorrhagic signs and a history of recent travel to any area where CCHF is endemic or prevalent.