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BackgroundCystic echinococcosis (CE) caused by the Echinococcus granulosus, is a major public health problem worldwide, including India. The different genotypes of E. granulosus responsible for human hydatidosis have been reported from endemic areas throughout the world. However, the genetic characterization of E. granulosus infecting the human population in India is lacking. The aim of study was to ascertain the genotype(s) of the parasite responsible for human hydatidosis in North India.Methodology/Principal FindingsTo study the transmission patterns of E. granulosus, genotypic analysis was performed on hydatid cysts obtained from 32 cystic echinococcosis (CE) patients residing in 7 different states of North India. Mitochondrial cytochrome c oxidase subunit1 (cox1) sequencing was done for molecular identification of the isolates. Most of the CE patients (30/32) were found to be infected with hydatid cyst of either G3 (53.1%) or G1 (40.62%) genotype and one each of G5 (cattle strain) and G6 (camel strain) genotype.Conclusions/SignificanceThese findings demonstrate the zoonotic potential of G1 (sheep strain) and G3 (buffalo strain) genotypes of E. granulosus as these emerged as predominant genotypes infecting the humans in India. In addition to this, the present study reports the first human CE case infected with G5 genotype (cattle strain) in an Asian country and presence of G6 genotype (camel strain) in India. The results may have important implications in the planning of control strategies for human hydatidosis.

The number of Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) cases is increasing in India. This study looks upon the geographic distribution of the virus clades and variants circulating in different parts of India between January and August 2020. The NPS/OPS from representative positive cases from different states and union territories in India were collected every month through the VRDLs in the country and analyzed using next-generation sequencing. Epidemiological analysis of the 689 SARS-CoV-2 clinical samples revealed GH and GR to be the predominant clades circulating in different states in India. The northern part of India largely reported the ‘GH’ clade, whereas the southern part reported the ‘GR’, with a few exceptions. These sequences also revealed the presence of single independent mutations—E484Q and N440K—from Maharashtra (first observed in March 2020) and Southern Indian States (first observed in May 2020), respectively. Furthermore, this study indicates that the SARS-CoV-2 variant (VOC, VUI, variant of high consequence and double mutant) was not observed during the early phase of virus transmission (January–August). This increased number of variations observed within a short timeframe across the globe suggests virus evolution, which can be a step towards enhanced host adaptation.

The genetic diversity and population genetics of the Echinococcus granulosus sensu stricto complex were investigated based on sequencing of mitochondrial DNA (mtDNA). Total 81 isolates of hydatid cyst collected from ungulate animals from different geographical areas of North India were identified by sequencing of cytochrome c oxidase subunit1 (coxi) gene. Three genotypes belonging to E. granulosus sensu stricto complex were identified (G1, G2 and G3 genotypes). Further the nucleotide sequences (retrieved from GenBank) for the coxi gene from seven populations of E. granulosus sensu stricto complex covering 6 continents, were compared with sequences of isolates analysed in this study. Molecular diversity indices represent overall high mitochondrial DNA diversity for these populations, but low nucleotide diversity between haplotypes. The neutrality tests were used to analyze signatures of historical demographic events. The Tajima’s D test and Fu’s FS test showed negative value, indicating deviations from neutrality and both suggested recent population expansion for the populations. Pairwise fixation index was significant for pairwise comparison of different populations (except between South America and East Asia, Middle East and Europe, South America and Europe, Africa and Australia), indicating genetic differentiation among populations. Based on the findings of the present study and those from earlier studies, we hypothesize that demographic expansion occurred in E. granulosus after the introduction of founder haplotype particular by anthropogenic movements.

BackgroundEchinococcosis is a human and animal health problem in many endemic areas worldwide. There are numerous reports and hospital-based studies from Kashmir, North India, yet there has been no epidemiological study conducted in Kashmir, the apparently endemic area for human hydatidosis. This study was designed to determine the seroprevalence of hydatid infection in Kashmir Valley and to find out association of risk factors for acquisition of this infection.MethodologyFourteen hundred and twenty-nine samples were collected from different districts in the Kashmir region (North India) using systematic random sampling. The 130 control samples included were from apparently healthy blood donors (100), patients with other parasitic infections (20), surgically confirmed hydatidosis patients (5), and apparently healthy subjects excluded for hydatidosis and intestinal parasitic infections (5). Hydatid-specific IgG antibody was detected by enzyme-linked immunosorbent assay, and seropositive samples were analysed further by Western blotting.ResultsOut of 1,429 samples, 72 (5.03%) were IgG positive by ELISA. The percentage occurrence of the highly immunoreactive antigenic fractions in IgG ELISA positive samples was 57 kDa (72.2%) followed by 70 kDa (66.7%) and 39kDa (58.3%) by immunoblotting. Samples with other parasitic infections were reactive with the cluster of 54-59 kDa antigenic fractions. Age <15 years, male gender, contact with dog, and rural residence were the most significant factors associated with the seropositivity.ConclusionThe study revealed that 72 (5.03%) out of 1,429 subjects asymptomatic for hydatidosis were seropositve to E.granulosus antigen by ELISA. Western blot analysis of 72 ELISA seropositive samples showed that 66.7% and 58.3% of samples were immunoreactive with 70 and 39kDa specific antigenic fractions, respectively. The seropositivity was significantly higher (5.79%) in the younger age group (<15 years) as compared to the 16-55 years (4.07%) and > 55 years (3.05%) age groups, suggesting ongoing transmission of this infection in the younger age group. The number of seropositive males was significantly higher as compared to females. The risk factors identified were rural residence and contact with dogs. The study suggests the presence of asymptomatic infection in subjects in Kashmir, North India, and efforts need to be made for implementation of effective prevention measures to reduce the infection burden, which may otherwise lead to symptomatology and complications in the infected subjects.

During March to June 2021 India has experienced a deadly second wave of COVID19 with an increased number of post vaccination breakthrough infections reported across the country. To understand the possible reason of these breakthroughs we collected 677 clinical samples (throat swab/ nasal swabs) of individuals who had received two doses (n=592) and one dose (n=85) of vaccines (Covishield and Covaxin,) and tested positive for COVID19, from 17 states/Union Territories of country. These cases were telephonically interviewed and clinical data was analyzed. A total of 511 SARS-CoV-2 genomes were recovered with genome coverage of higher than 98% from both the cases. Analysis of both the cases determined that 86.69% (n=443) of them belonged to the Delta variant along with Alpha, Kappa, Delta AY.1 and Delta AY.2. The Delta variant clustered into 4 distinct sub-lineages. Sub-lineage I had mutations: ORF1ab, A1306S, P2046L, P2287S, V2930L, T3255I, T3446A, G5063S, P5401L, A6319V and N G215C; Sub lineage II : ORF1ab P309, A3209V, V3718A, G5063S, P5401L and ORF7a L116F; Sub lineage III : ORF1ab A3209V, V3718A, T3750I, G5063S, P5401L and Spike A222V; Sub-lineage IV ORF1ab P309L, D2980N, F3138S and spike K77T. This study indicated that majority of the clinical cases in the breakthrough were infected with the Delta variant and only 9.8% cases required hospitalization while fatality was observed in only 0.4% cases. This clearly suggests that the vaccination does provide reduction in hospital admission and mortality.

Cytokine-mediated regulation of chronic intestinal helminth infections is well documented. The present study reports the serum cytokine responses in 38 ascariasis (stool samples positive for Ascaris lumbricoides ova) and toxocariasis (seropositive) patients, 8 ascariasis-positive and toxocariasis-seronegative patients, 22 endemic, normal, healthy subjects residing in areas hyperendemic for ascariasis and 16 normal healthy subjects residing in a low-endemic area in India. The results indicated T-helper type-2-type cytokine responses in ascariasis and toxocariasis (seropositive) and ascariasis-positive and toxocariasis-seronegative patients. The important observation was that both patients and healthy individuals in ascariasis-hyperendemic areas had significantly higher interleukin-5 (IL-5) responses than non-endemic control subjects. The altered immune responses of patients in areas hyperendemic of ascariasis may have further implications. Earlier reports suggest that the geohelminth parasites in endemic areas may modulate the immune response to oral vaccines. A critical role for IL-5 in the immune response against challenge infection consistent with the association of type-2 cytokines with vaccine-mediated protection has been reported. Furthermore, co-infection by pathogens that elicit opposing immune responses, particularly helminths vs HIV and tuberculosis, could influence the infection dynamics, progression and immunoprophylaxis of the diseases they cause. Further studies are warranted to ascertain these findings.