Babasaheb V. Tandale

Chikungunya outbreaks caused by African genotype, India.

Chikungunya fever is reported in India after 32 years. Immunoglobulin M antibodies and virus isolation confirmed the cause. Phylogenic analysis based on partial sequences of NS4 and E1 genes showed that all earlier isolates (1963–1973) were Asian genotype, whereas the current and Yawat (2000) isolates were African genotype.

Systemic involvements and fatalities during Chikungunya epidemic in India, 2006.

BACKGROUND In addition to classical manifestations of Chikungunya infection, severe infections requiring hospitalization were reported during outbreaks in India in 2006. OBJECTIVES To describe the systemic syndromes and risk groups of severe Chikungunya infections. STUDY DESIGN We prospectively investigated suspected Chikungunya cases hospitalized in Ahmedabad, Gujarat during September-October 2006, and retrospectively investigated laboratory-confirmed Chikungunya cases hospitalized with neurologic syndromes in Pune, Maharashtra. Hospital records were reviewed for demographic, comorbidity, clinical and laboratory information. Sera and/or cerebrospinal fluid were screened by one or more methods, including virus-specific IgM antibodies, viral RNA and virus isolation. RESULTS Among 90 laboratory-confirmed Chikungunya cases hospitalized in Ahmedabad, classical Chikungunya was noted in 25 cases and severe Chikungunya was noted in 65 cases, including non-neurologic (25) and neurologic (40) manifestations. Non-neurologic systemic syndromes in the 65 severe Chikungunya cases included renal (45), hepatic (23), respiratory (21), cardiac (10), and hematologic manifestations (8). Males (50) and those aged >or=60 years (50) were commonly affected with severe Chikungunya, and age >or=60 years represented a significant risk. Comorbidities were seen in 21 cases with multiple comorbidities in 7 cases. Among 18 deaths, 14 were males, 15 were aged >or=60 years and 5 had comorbidities. In Pune, 59 laboratory-confirmed Chikungunya cases with neurologic syndromes were investigated. Neurologic syndromes in 99 cases from Ahmedabad and Pune included encephalitis (57), encephalopathy (42), and myelopathy (14) or myeloneuropathy (12). CONCLUSIONS Chikungunya infection can cause systemic complications and probably deaths, especially in elderly adults.

Seroepidemiology of pandemic influenza A (H1N1) 2009 virus infections in Pune, India

BackgroundIn India, Pune was one of the badly affected cities during the influenza A (H1N1) 2009 pandemic. We undertook serosurveys among the risk groups and general population to determine the extent of pandemic influenza A (H1N1) 2009 virus infections.MethodsPre-pandemic sera from the archives, collected during January 2005 to March 2009, were assayed for the determination of baseline seropositivity. Serosurveys were undertaken among the risk groups such as hospital staff, general practitioners, school children and staff and general population between 15th August and 11th December 2009. In addition, the PCR-confirmed pandemic influenza A (H1N1) 2009 cases and their household contacts were also investigated. Haemagglutination-inhibition (HI) assays were performed using turkey red blood cells employing standard protocols. A titre of ≥1:40 was considered seropositive.ResultsOnly 2 (0.9%) of the 222 pre-pandemic sera were positive. The test-retest reliability of HI assay in 101 sera was 98% for pandemic H1N1, 93.1% for seasonal H1N1 and 94% for seasonal H3N2. The sera from 48 (73.8%) of 65 PCR-confirmed pandemic H1N1 cases in 2009 were positive. Seropositivity among general practitioners increased from 4.9% in August to 9.4% in November and 15.1% in December. Among hospital staff, seropositivity increased from 2.8% in August to 12% in November. Seropositivity among the schools increased from 2% in August to 10.7% in September. The seropositivity among students (25%) was higher than the school staff in September. In a general population survey in October 2009, seropositivity was higher in children (9.1%) than adults (4.3%). The 15-19 years age group showed the highest seropositivity of 20.3%. Seropositivity of seasonal H3N2 (55.3%) and H1N1 (26.4%) was higher than pandemic H1N1 (5.7%) (n = 2328). In households of 74 PCR-confirmed pandemic H1N1 cases, 25.6% contacts were seropositive. Almost 90% pandemic H1N1 infections were asymptomatic or mild. Considering a titre cut off of 1:10, seropositivity was 1.5-3 times as compared to 1:40.ConclusionsPandemic influenza A (H1N1) 2009 virus infection was widespread in all sections of community. However, infection was significantly higher in school children and general practitioners. Hospital staff had the lowest infections suggesting the efficacy of infection-control measures.

Avian influenza H9N2 seroprevalence among poultry workers in Pune, India, 2010.

Avian influenza (AI) H9N2 has been reported from poultry in India. A seroepidemiological study was undertaken among poultry workers to understand the prevalence of antibodies against AI H9N2 in Pune, Maharashtra, India. A total of 338 poultry workers were sampled. Serum samples were tested for presence of antibodies against AI H9N2 virus by hemagglutination inhibition (HI) and microneutralization (MN) assays. A total of 249 baseline sera from general population from Pune were tested for antibodies against AI H9N2 and were negative by HI assay using ≥40 cut-off antibody titre. Overall 21 subjects (21/338 = 6.2%) were positive for antibodies against AI H9N2 by either HI or MN assays using ≥40 cut-off antibody titre. A total of 4.7% and 3.8% poultry workers were positive for antibodies against AI H9N2 by HI and MN assay respectively using 40 as cut-off antibody titre. This is the first report of seroprevalence of antibodies against AI H9N2 among poultry workers in India.

Buffalopox outbreak in humans and animals in Western Maharashtra, India.

An outbreak of febrile illness with rash was reported in humans and buffaloes with pox lesions in some villages of Solapur and Kolhapur districts of Maharashtra state, India. Detailed clinico-epidemiological investigations were done with collection of blood, vesicular fluid and scab from humans and animals. A total of 166 suspected human cases from Kasegaon village in Solapur district and 185 cases were reported from 21 different villages from Kolhapur district. The attack rate in humans in Kasegaon village was 6.6% while in Kolhapur district the attack rate for buffaloes was 11.7%. Pox-like lesions were associated with fever, malaise, pain at site of lesion and axillary and inguinal lymphadenopathy in the humans. Infected buffaloes had lesions on teats, udders, external ears and eyelids. Laboratory investigations included detection of Buffalopox virus (BPXV) by electron microscopy (EM), virus isolation and polymerase chain reaction (PCR). Presence of BPXV was confirmed in 7 human cases and one buffalo in Kasegaon and 14 human cases from Kolhapur. The virus was isolated from 3 clinical specimens and Orthopoxvirus (OPXV) particles could be observed in EM. Thus, BPXV was identified as the etiological agent of the outbreak among both humans and buffaloes. Phylogenetic analysis based on the ATI and C18L gene revealed that a single strain of virus is circulating in India. Re-emergence of OPXV like BPXV is a real danger and contingency planning is needed to define prophylactic and therapeutic strategies to prevent or stop an epidemic. Considering the productivity losses caused by buffalopox infection and its zoonotic impact, the importance of control measures in reducing the economic and public health impact cannot be underestimated.

New focus of Kyasanur Forest disease virus activity in a tribal area in Kerala, India, 2014.

BackgroundKyasanur Forest disease (KFD) is a febrile illness characterized by hemorrhages, and is reported endemic in the Shimoga district in Karnataka state, India. It is caused by the KFD virus (KFDV) of the family Flaviviridae, and is transmitted to monkeys and humans by Haemaphysalis ticks.FindingsWe investigated a new focus of KFD among tribals in a reserve forest in Kerala state, India. A suspected case was defined as a person presenting with acute fever, headache, or myalgia. Human sera were collected and tested for KFDV RNA by real-time RT-PCR, RT-nPCR assay, and anti-KFDV IgM and IgG by ELISA. The index case was a tribal woman with febrile illness, severe myalgia, gum bleeding, and hematemesis. Anti-KFDV IgM antibody was detected in acute and convalescent sera of the index case along with IgG in the second serum. None of her family members reported fever. On verbal autopsy, two more fatal cases were identified as probable primary cases. Acute serum from a case in the second cluster was detected positive for KFDV RNA by real time RT-PCR (Ct = 32) and RT-nPCR. Sequences of E gene showed highest similarity of 98.0% with the KFDV W-377 isolate nucleotide and 100% identity with amino acid. Anti-KFDV IgM was detected in the serum of one family member of the index case, as well as in one out of 17 other tribals.ConclusionsWe confirmed a new focus of KFDV activity among tribals in a reserve forest in the Malappuram district of Kerala, India.

On the transmission pattern of Kyasanur Forest disease (KFD) in India

Kyasanur Forest disease (KFD), a tick-borne viral hemorrhagic fever, is endemic in five districts of Karnataka state, India. Recent reports of the spread of disease to neighboring districts of the Western Ghats, namely Chamarajanagar district in Karnataka, Nilgiri district in Tamil Nadu, Wayanad and Malappuram districts in Kerala, and Pali village in Goa are a cause for concern. Besides vaccination of the affected population, establishing an event-based surveillance system for monkey deaths in the national parks, wildlife sanctuaries and reserve forests of the Western Ghats would help detect the disease early and thereby help implement appropriate control measures.

Development and evaluation of a real-time one step Reverse-Transcriptase PCR for quantitation of Chandipura Virus

BackgroundChandipura virus (CHPV), a member of family Rhabdoviridae was attributed to an explosive outbreak of acute encephalitis in children in Andhra Pradesh, India in 2003 and a small outbreak among tribal children from Gujarat, Western India in 2004. The case-fatality rate ranged from 55–75%. Considering the rapid progression of the disease and high mortality, a highly sensitive method for quantifying CHPV RNA by real-time one step reverse transcriptase PCR (real-time one step RT-PCR) using TaqMan technology was developed for rapid diagnosis.MethodsPrimers and probe for P gene were designed and used to standardize real-time one step RT-PCR assay for CHPV RNA quantitation. Standard RNA was prepared by PCR amplification, TA cloning and run off transcription. The optimized real-time one step RT-PCR assay was compared with the diagnostic nested RT-PCR and different virus isolation systems [in vivo (mice) in ovo (eggs), in vitro (Vero E6, PS, RD and Sand fly cell line)] for the detection of CHPV. Sensitivity and specificity of real-time one step RT-PCR assay was evaluated with diagnostic nested RT-PCR, which is considered as a gold standard.ResultsReal-time one step RT-PCR was optimized using in vitro transcribed (IVT) RNA. Standard curve showed linear relationship for wide range of 102-1010 (r2 = 0.99) with maximum Coefficient of variation (CV = 5.91%) for IVT RNA. The newly developed real-time RT-PCR was at par with nested RT-PCR in sensitivity and superior to cell lines and other living systems (embryonated eggs and infant mice) used for the isolation of the virus. Detection limit of real-time one step RT-PCR and nested RT-PCR was found to be 1.2 × 100 PFU/ml. RD cells, sand fly cells, infant mice, and embryonated eggs showed almost equal sensitivity (1.2 × 102 PFU/ml). Vero and PS cell-lines (1.2 × 103 PFU/ml) were least sensitive to CHPV infection. Specificity of the assay was found to be 100% when RNA from other viruses or healthy individual was used.ConclusionOn account of the high sensitivity, reproducibility and specificity, the assay can be used for the rapid detection and quantitation of CHPV RNA from clinical samples during epidemics and from endemic areas. The assay may also find application in screening of antiviral compounds, understanding of pathogenesis as well as evaluation of vaccine.

Antibody persistence after Pandemic H1N1 2009 influenza vaccination among healthcare workers in Pune, India.

The healthcare workers having seroprotection at 3 weeks (n = 127) following Pandemic H1N1 2009 influenza vaccination were followed up for antibody persistence. Seroprotection at 12 mo (60.2%) was significantly lower as compared with 3 weeks (74.7%), 3 mo (77.8%) and 6 mo (75.4%). The vaccine provided seroprotection up to one year.

A large outbreak of Japanese encephalitis predominantly among adults in northern region of West Bengal, India

Unusual rise of acute encephalitis syndrome cases (AES) were reported in July 2014 in the northern region of West Bengal, India. Investigations were carried out to characterize the outbreak and to identify the associated virus etiology. This observational study is based on 398 line listed AES cases, mostly (70.8%, 282/398) adults, with case fatality ratio of 28.9% (115/398). Japanese encephalitis virus infection was detected in 134 (49.4%) among 271 AES cases tested and most of them (79.1%, 106/134) were adults. The study reports a large outbreak of genotype III Japanese encephalitis among adults in northern region of West Bengal, India. J. Med. Virol. 88:2004–2011, 2016.