Evaluating the effect of measles and rubella mass vaccination campaigns on seroprevalence in India: a before-and-after cross-sectional household serosurvey in four districts, 2018-2020.

BACKGROUND: India did phased measles-rubella supplementary immunisation activities (MR-SIAs; ie, mass-immunisation campaigns) targeting children aged 9 months to less than 15 years. We estimated measles-rubella seroprevalence before and after the MR-SIAs to quantify the effect on population immunity and identify remaining immunity gaps. METHODS: Between March 9, 2018 and March 19, 2020 we did community-based, cross-sectional serosurveys in four districts in India before and after MR-SIAs. 30 villages or wards were selected within each district, and one census enumeration block from each was selected as the survey cluster. Households were enumerated and 13 children in the younger age group (9 months to <5 years) and 13 children in the older ager group (5 to <15 years) were randomly selected by use of computer-generated random numbers. Serum samples were tested for IgG antibodies to measles and rubella viruses by enzyme immunoassay. FINDINGS: Specimens were collected from 2570 children before the MR-SIA and from 2619 children afterwards. The weighted MR-SIA coverage ranged from 73·7% to 90·5% in younger children and from 73·6% to 93·6% in older children. Before the MR-SIA, district-level measles seroprevalence was between 80·7% and 88·5% among younger children in all districts, and between 63·4% and 84·5% among older children. After the MR-SIA, measles seroprevalence among younger children increased to more than 90% (range 91·5 to 96·0) in all districts except Kanpur Nagar, in which it remained unchanged 80·4%. Among older children, measles seroprevalence increased to more than 90·0% (range 93·7% to 96·5%) in all districts except Hoshiarpur (88·7%). A significant increase in rubella seroprevalence was observed in all districts in both age groups, with the largest effect in Dibrugarh, where rubella seroprevalence increased from 10·6% to 96·5% among younger children. INTERPRETATION: Measles-rubella seroprevalence increased substantially after the MR-SIAs but the serosurvey also identified remaining gaps in population immunity. FUNDING: The Bill & Melinda Gates Foundation and Indian Council of Medical Research.

Two novel genomic DNA sequences as common diagnostic targets to detect Cryptosporidium hominis and Cryptosporidium parvum: Development of quantitative polymerase chain reaction assays, and clinical evaluation.

Introduction: Cryptosporidium is an intestinal parasite responsible for gastroenteritis. Conventional diagnosis of Cryptosporidium is made by microscopy. The most frequent molecular detection method for this parasite is polymerase chain reaction (PCR). The objective of the present study was to identify the novel DNA targets and development of PCR-based assays for the specific detection of two major human infecting species Cryptosporidium parvum and Cryptosporidium hominis. Methodology: Sensitive and specific SYBR green quantitative PCR (qPCR) and TaqMan qPCR assays were developed and validated at both diagnostic and analytical level using the new identified targets TU502HP-1 and TU502HP-2. Results: Assay validation results showed that the newly developed real-time PCR assays are 100% specific with a reliable limit of detection. Overall repeatability and reproducibility of these assays showed good quality results over intra- and inter-laboratory analysis. Conclusion: Novel target-based qPCR assays can be rapid an efficient tool for simultaneous detection of a C. parvum and C. hominis. These genes could also be utilized for the development of innovative DNA-based Point-of-Care test development.

Major enteropathogens in humans, domestic animals, and environmental soil samples from the same locality: prevalence and transmission considerations in coastal Odisha, India.

OBJECTIVES: Regions with limited sanitation facilities have higher rates of infections with various enteric pathogens. It is therefore important to identify different hosts and their relative contribution to pathogen shedding into the environment, and to assess the subsequent health risks to humans. METHODS: In this study, human faecal (n=310), animal faecal (n=150), and environmental (soil) samples (n=40) were collected from the same locality and screened for selected enteric pathogens by immunochromatography and/or polymerase chain reaction. RESULTS: At least 1 microbial agent was detected in 49.0%, 44.7%, and 40.0% of the samples from human, animals, and soil, respectively. Among humans, rotavirus was predominantly detected (17.4%) followed by enteropathogenic Escherichia coli (EPEC) (15.4%), Shigella (13.8), and Shiga toxin-producing E. coli (STEC) (9.7%). Among animals, STEC was detected most frequently (28.0%), and EPEC was the major enteric pathogen detected in soil (30.0%). The detection rate of rotavirus was higher among younger children (≤2 years) than among older children. Single infections were more commonly detected than multiple infections in humans (p<0.01), unlike the observations in animal and soil samples. For diarrhoeagenic E. coli and Shigella, most of the human and animal isolates showed close relatedness, suggesting possible cross-infection between humans and domesticated animals in the area studied. CONCLUSIONS: The present study provides an improved understanding of the distribution of major enteric pathogens coexisting in humans and animals in the region, thereby suggesting a high potential for possible transmission among livestock and communities residing in the studied locality.

Burden and Molecular Epidemiology of Rotavirus Causing Diarrhea among Under-Five Children: A Hospital-based Study from Eastern India.

BACKGROUND: Rotavirus (RVA) causes severe gastroenteritis in under-five children, and there are many diverse strains of the virus that are localized to different parts of the world. OBJECTIVES: To study the burden and molecular epidemiology of RVA causing gastroenteritis among children from Eastern India. MATERIALS AND METHODS: This hospital-based cross-sectional study included children under-five with gastroenteritis. Demographic and clinical parameters were recorded in a predesigned pro forma. Stool samples collected from these children were initially screened for RVA VP6 antigen by enzyme immunoassay (EIA). Each EIA-positive sample was then subjected to RNA extraction, followed by reverse transcription, and heminested multiplex polymerase chain reaction for genotyping of RVA strains. RESULTS: Of 320 included children, RVA was detected in 30.62% (98/320) cases by EIA. The highest incidence for RVA-positive cases (34.61%) was observed among children in the age group of 24-36 months, followed by 0-12 months (33.04%). Of the 97 completely typed samples, single genotype was detected in 85 (87.62%) samples with either G (VP7) or P (VP4) types. However, mixed genotypes were detected in 12 (11.21%) samples. G3P[8] (44.09%) was the most common genotype, followed by G1P[8] (32.65%), G2[P4] (5.10%), G1[P6] (3.06%), and G9[P4] (1.02%). CONCLUSIONS: The present study found RVA positivity in 30.62% of children with gastroenteritis, with the highest burden among 24-36 months old. The predominant genotypes were G1, G3, and P[8]. Further large-scale/multicentric studies should be conducted to document the diversity of circulating RVA genotypes in this region for giving inputs for vaccination strategy.

Detection and molecular typing of campylobacter isolates from human and animal faeces in coastal belt of Odisha, India.

Introduction: Campylobacter-mediated diarrhoea is one of the major causes of gastroenteritis globally. A majority of the Campylobacter spp. that cause disease in humans have been isolated from animals. Faecal contamination of food and water is the identified frequent cause of human campylobacteriosis. Methodology: In the present study, faecal samples from patients with symptoms of acute diarrhoea (n = 310) and domestic animals including cows (n = 60), sheep (n = 45) and goats (n = 45) were collected from the same localities in the peri-urban Bhubaneswar city. Genomic DNA isolation followed by polymerase chain reaction and sequencing was employed to analyse Campylobacter spp.-positive samples. Results: Of the 460 faecal samples, 16.77% of human samples and 25.33% of animal samples were found to be positive for Campylobacter spp. Among animals, the isolation rate was highest in sheep followed by cows and goats with 9.33%, 8.66% and 7.33%, respectively. The highest number of Campylobacter-positive cases was diagnosed in infants of 2-5 years age. Concurrent infection of other pathogens in addition to Campylobacter spp. was frequently detected in the samples. Conclusion: The present study showed the incidence of Campylobacter infections in human and different animal species in and around Bhubaneswar, Odisha. The analysis suggested that domestic animals can be the potential sources for human campylobacteriosis in the region.

Revisiting the global problem of cryptosporidiosis and recommendations.

Cryptosporidiosis is a gastrointestinal illness caused by the protozoan parasite Cryptosporidium species, which is a leading cause of diarrhea in a variety of vertebrate hosts. The primary mode of transmission is through oral routes; infections spread with the ingestion of oocysts by susceptible animals or humans. In humans, Cryptosporidium infections are commonly found in children and immunocompromised individuals. The small intestine is the most common primary site of infection in humans while extraintestinal cryptosporidiosis occurs in immunocompromised individuals affecting the biliary tract, lungs, or pancreas. Both innate and adaptive immune responses play a critical role in parasite clearance as evident from studies with experimental infection in mice. However, the cellular immune responses induced during human infections are poorly understood. In this article, we review the currently available information with regard to epidemiology, diagnosis, therapeutic interventions, and strategies being used to control cryptosporidiosis infection. Since cryptosporidiosis may spread through zoonotic mode, we emphasis on more epidemiological surveillance-based studies in developing countries with poor sanitation and hygiene. These epidemiological surveys must incorporate fecal source tracking measures to identify animal and human populations contributing significantly to the fecal burden in the community, as mitigation measures differ by host type.

Multiple etiologies of infectious diarrhea and concurrent infections in a pediatric outpatient-based screening study in Odisha, India.

BACKGROUND: There are multiple etiologies responsible for infectious gastroenteritis causing acute diarrhea which are often under diagnosed. Also acute diarrhea is one of the major causes of morbidity and mortality among children less than 5 years of age. METHODS: In our study, fecal samples (n = 130) were collected from children (<5 years) presenting with symptoms of acute diarrhea. Samples were screened for viral, bacterial, and parasitic etiologies. Rotavirus and Adenovirus were screened by immunochromatographic tests. Diarrheagenic Escherichia coli (EPEC, EHEC, STEC, EAEC, O157, O111), Shigella spp., Salmonella spp., Vibrio cholera, Cryptosporidium spp., and Giardia spp. were detected by gene-specific polymerase chain reaction. RESULTS: Escherichia coli was detected to be the major etiological agent (30.07%) followed by Rotavirus (26.15%), Shigella (23.84%), Adenovirus (4.61%), Cryptosporidium (3.07%), and Giardia (0.77%). Concurrent infections with two or more pathogens were observed in 44 of 130 (33.84%) cases with a predominant incidence particularly in <2-year-old children (65.90%) compared to children of 2-5 years age group (34.09%). An overall result showed significantly higher detection rates among children with diarrhea in both combinations of two as well as three infections concurrently (p = 0.004915 and 0.03917, respectively). CONCLUSION: Suspecting possible multiple infectious etiologies and diagnosis of the right causative agent(s) can aid in a better pharmacological management of acute childhood diarrhea. It is hypothesized that in cases with concurrent infections the etiological agents might be complementing each other's strategies of pathogenesis resulting in severe diarrhea that could be studied better in experimental infections.

In silico identification and validation of a novel hypothetical protein in Cryptosporidium hominis and virtual screening of inhibitors as therapeutics.

Computational approaches to predict structure/function and other biological characteristics of proteins are becoming more common in comparison to the traditional methods in drug discovery. Cryptosporidiosis is a major zoonotic diarrheal disease particularly in children, which is caused primarily by Cryptosporidium hominis and Cryptosporidium parvum. Currently, there are no vaccines for cryptosporidiosis and recommended drugs are ineffective. With the availability of complete genome sequence of C. hominis, new targets have been recognized for the development of effective and better drugs and/or vaccines. We identified a unique hypothetical protein (TU502HP) in the C. hominis genome from the CryptoDB database. A three-dimensional model of the protein was generated using the Iterative Threading ASSEmbly Refinement server through an iterative threading method. Functional annotation and phylogenetic study of TU502HP protein revealed similarity with human transportin 3. The model is further subjected to a virtual screening study form the ZINC database compound library using the Dock Blaster server. A docking study through AutoDock software reported N-(3-chlorobenzyl)ethane-1,2-diamine as the best inhibitor in terms of docking score and binding energy. The reliability of the binding mode of the inhibitor is confirmed by a complex molecular dynamics simulation study using GROMACS software for 10 ns in the water environment. Furthermore, antigenic determinants of the protein were determined with the help of DNASTAR software. Our findings report a great potential in order to provide insights in the development of new drug(s) or vaccine(s) for treatment and prophylaxis of cryptosporidiosis among humans and animals.