The spotted fever group (SFG) of
Rickettsia
are zoonotic disease-causing pathogens, commonly transmitted by hard ticks to a wide range of hosts, including humans.
Rickettsia conorii
is the common SFG ...recognised in India, whereas most of the infections due to other group species go undifferentiated at the species level. Hence, this study was conducted to screen host-seeking ticks in the Western Ghats region, India, for the DNA of SFG
Rickettsia.
The ticks were collected from Kerala, Goa, and Maharashtra states of India during a survey conducted between November 2017 and January 2018. In total, 288 tick pools were screened for
Rickettsia
spp. DNA using pan-
Rickettsia
real-time PCR, and conventional PCR targeting the
glt
A,
Omp
A and 17-kDa protein-coding genes. Nucleotide sequences were subjected to phylogenetic analysis using the NCBI BLAST tool to identify submitted sequences with higher homology. Neighbour-joining trees were constructed using the reference sequences of the GenBank database. Overall,
Rickettsia
spp. DNA was detected in 27.2% (62/228 pools) of host-seeking ticks across the Western Ghats region, with an estimated minimum infection rate of 0.057. Upon phylogenetic analysis, it was identified that the detected sequences were highly similar (> 99% sequence homology) to
R. africae
,
Candidatus
R. laoensis and an un-categorised
Rickettsia
species, and they were widely carried by
Haemaphysalis
ticks. The current study is the first report of
R. africae
and
Candidatus
R. laoensis in ticks in India. Although the pathogenicity of these species is not well documented, they may pose a potential threat to both animal and the human population in this geographical region.
Hand, foot, and mouth disease (HFMD) is a common childhood infection caused by human enteroviruses and is clinically characterised by fever with vesicular rash on the hands, feet, and mouth. While ...enterovirus A71 (EV-A71) and coxsackievirus A16 (CVA16) were the major etiological agents of HFMD in India earlier, the data on recently circulating enteroviruses associated with HFMD are sparse. Here, we describe the molecular epidemiology of enteroviruses associated with HFMD in South India from 2015 to 2017. We used archived enterovirus real-time reverse transcription (RT) PCR-positive vesicle swab and/or throat swab specimens from clinically suspected HFMD cases collected from four secondary-care hospitals in South India between July 2015 and December 2017. PCR amplification and sequencing were done based on the 5’VP1, 3’VP1, VP2, or 5´NCR regions to identify enterovirus types. Genetic diversity among enteroviruses was inferred by phylogenetic analysis. Of the 107 enterovirus RNA real-time RT-PCR-positive HFMD cases, 69 (64%) were typed as CVA6, 16 (15%) were CVA16, and one (1%) was CVA10, whereas in 21 (20%) cases, the virus was not typeable by any of the methods used in the study. The majority of HFMD cases (89, 83%) were in children less than five years old, while 11 (10.3%) were in adults. 5’VP1 yielded the maximum number of enteroviruses genotyped, and phylogenetic analysis showed that the CVA6 strains belonged to subclade D3, while the subclades of CVA16 and CVA10 were B1c and D, respectively. The predominant etiological agent of HFMD in South India during 2015-2017 was CVA6, followed by CVA16 and CVA10.
Nipah virus (NiV) is 1 of 10 potential causes of imminent public health emergencies of international concern. We investigated the NiV outbreak that occurred in May 2018 in Kerala, India. Here we ...describe the longitudinal characteristics of cell-mediated and humoral immune responses to NiV infection during the acute and convalescent phases in 2 human survivors.
Serial blood samples were obtained from the only 2 survivors of the NiV outbreak in Kerala. We used flow cytometry to determine the absolute T-lymphocyte and B-lymphocyte counts and the phenotypes of both T and B cells. We also detected and quantitated the humoral immune response to NiV by virus-specific immunoglobulin M (IgM) and immunoglobulin G (IgG) enzyme-linked immunosorbent assay.
Absolute numbers of T lymphocytes remained within normal limits throughout the period of illness studied in both survivors. However, a marked elevation of activated CD8 T cells was observed in both cases. More than 30% of total CD8 T cells expressed Ki67, indicating active proliferation. Proliferating (Ki-67+) CD8 T cells expressed high levels of granzyme B and PD-1, consistent with the profile of acute effector cells. Total B-lymphocyte, activated B-cell, and plasmablast counts were also elevated in NiV survivors. These individuals developed detectable NiV-specific IgM and IgG antibodies within a week of disease onset. Clearance of NiV RNA from blood preceded the appearance of virus-specific IgG and coincided with the peak of activated CD8 T cells.
We describe for the first time longitudinal kinetic data on the activation status of human B- and T-cell populations during acute NiV infection. While marked CD8 T-cell activation was observed with effector characteristics, activated CD4 T cells were less prominent.
Kyasanur Forest Disease (KFD) is a viral haemorrhagic fever, transmitted to humans and other hosts by a tick vector of genus
Haemaphysalis
. It affects 400–500 people annually in the Western Ghats ...region of India through spring to summer season. To understand the species composition, distribution, and abundance of
Haemaphysalis
ticks in endemic taluks (sub-districts) of India, a surveillance for ticks was conducted between October 2017 and January 2018. In total 105 sites were selected based on grid sampling from five taluks representing five KFD endemic states in south India. A sum of 8373 ticks were collected by using standard flagging method. The study showed a wide distribution of host seeking tick species among the selected taluks, wherein
Haemaphysalis spinigera
was predominant in 3/5 taluks,
Haemaphysalis bispinosa
in 1/5 taluks, and both the species in 1/5 taluks. Further, the
H. spinigera
abundance was categorised and compared with the incidence of human cases during the same season. The grids with very high and high
H. spinigera
abundance had 70% of the 205 human cases reported. This method of tick surveillance could be efficiently used as a standard model for KFD transmission risk assessment and prediction of impending outbreaks.
Chikungunya disease (CHIKD) is a threat to global health, as it impairs the quality of life of an infected individual ranging from months to years. A systematic evaluation of the serological, ...virological, and immunological aspects of the circulating viruses and their impact on the host response is imperative for better understanding of the evolving disease dynamics.
Serum samples were collected from 196 acute CHIKD patients from ten tertiary care hospitals across India during 2016–2021. Out of 196 patients, paired convalescent samples were collected from 51 patients (one-month post-onset of symptoms). The serum samples were profiled for cytokines and neutralisation capacity. Further, chikungunya virus (CHIKV) was isolated from the acute sera and the replication kinetics of the clinical isolates was evaluated.
Serological analysis indicated that neutralisation could be correlated to seroconversion in the convalescent phase but not found significant in acute phase. In the acute phase samples, there was a correlation between elevated serum levels of IFN-γ, IP-10, MCP-1 and MIG and disease severity. During convalescent phase, pro-inflammatory markers such as IL-6, IL-1β, IL-9 and IP-10 were found to be elevated with a corresponding decline in the secretion of anti-inflammatory cytokines such as IL-4 and IL-10, which correlated with persistent arthralgia. Analysis of replication of the clinical isolates revealed that 68.4% of viruses were fast-growing in the Vero cells (cytopathic effect CPE observed within 24 h post-infection), and their corresponding acute serum samples showed an elevated secretion of IFN-α, IL-1RA, IL-17F, IL-9, MCP-1 and MIP-1α.
This study provides an important overview of neutralisation capabilities and cytokine responses along with virus pathogenesis associated with CHIKV infections in India.
Biotechnology Industry Research Assistance Council (BIRAC).
The COVID-19 pandemic and public health response to the pandemic has caused huge setbacks in the management of other infectious diseases. In the present study, we aimed to (i) assess the trends in ...numbers of samples from patients with influenza-like illness and severe acute respiratory syndrome tested for influenza and the number and proportion of cases detected from 2015-2021 and (ii) examine if there were changes during the COVID-19 period (2020-2021) compared to the pre-COVID-19 period (2015-2019) in three states of India. The median (IQR) number of samples tested per month during the pre-COVID-19 period was 653 (395-1245), compared to 27 (11-98) during the COVID-19 period (p value < 0.001). The median (IQR) number of influenza cases detected per month during the pre-COVID-19 period was 190 (113-372), compared to 29 (27-30) during the COVID-19 period (p value < 0.001). Interrupted time series analysis (adjusting for seasonality and testing charges) confirmed a significant reduction in the total number of samples tested and influenza cases detected during the COVID-19 period. However, there was no change in the influenza positivity rate between pre-COVID-19 (29%) and COVID-19 (30%) period. These findings suggest that COVID-19-related disruptions, poor health-seeking behavior, and overburdened health systems might have led to a reduction in reported influenza cases rather than a true reduction in disease transmission.
The three major issues that Digital India needs to consider include the responsibility of the big companies, evolving a policy framework in terms of digital electronics and platforms by the ...government and a focus on local manufacture The three major issues that Digital India needs to consider include the responsibility of the big companies, evolving a policy framework in terms of digital electronics and platforms by the government and a focus on local manufacture.
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