Interplay of missed opportunity for vaccination and poor response to the vaccine led to measles outbreak in a slum area of Eastern Mumbai, India.

In the third week of September 2022, an outbreak of measles was reported from a slum in Eastern Mumbai, India. We sought to investigate whether failure to vaccinate or vaccine failure was the cause. We constructed an epidemic curve, drew a spot map, and calculated the attack rate and case-fatality ratio. We calculated vaccine effectiveness (VE) for one and two doses of measles vaccine in an unmatched case-control study and did stratified analysis by sex, availability of vaccination card, and migrant status. We identified 358 cases and four deaths with a 11.3% attack rate and 1.1% case fatality, both being highest among 0-24-month-old boys. The epidemic curve suggested a propagated mode of spread. The VE for two doses was 64% (95% confidence interval (CI): 23-73%) among under-5-year-old children and 70% (95% CI: 28-88%) among 5-15-year-old children. Failure to vaccinate, consequent to the COVID-19 pandemic, and vaccine hesitancy might have led to the accumulation of susceptible children in the community. Additionally, the occurrence of case-patients among vaccinated suggests reduced VE, which needs further investigation into humoral and cell-mediated immunity as well as contributory factors including nutritional status. Outbreak response immunization to complete immunization of missed and dropout children was carried out to control the outbreak.

Normative data for paediatric lymphocyte subsets: A pilot study from western India.

Background & objectives: Accurate diagnosis of immunodeficiencies requires a critical comparison of values with age-matched controls. In India, the existing reference values for rare lymphocyte subsets are currently not available and we rely on the data originating from other countries for the interpretation of the results. Furthermore, there is limited information on normal variation for these rare-subset parameters in Indian children. So, this study aimed to establish normative values for clinically important lymphocyte subsets in Indian children at different age groups. Methods: 148 children aged ≥16 yr were enrolled in this study. The study population included 61 per cent males and 39 per cent females and was divided into the following groups: cord blood (n=18), 0-6 months (n=9), 6-12 months (n=13), 1-2 yr (n=19), 2-5 yr (n=27), 5-10 yr (n=25) and 10-16 yr (n=37). The absolute and relative percentage of lymphocytes, T, B, natural killer cell, along with activated, naïve and memory subsets, was determined by flow cytometry. Results: Median values and the 10th and 90th percentiles were obtained for 34 lymphocyte sub-populations. The T and B naïve compartments showed a decreasing trend, whereas memory cells showed an increase with age. The activated T cell subset shows an increasing pattern up to one year and then declines gradually. Double negative T cells are relatively stable. TCRgd+T cell percentage increases with age. Interpretation & conclusions: This single-centre pilot study provides preliminary data that justifies the need for future large-scale multi centric studies to generate a reference range for interpreting extended immunophenotyping profiles in the paediatric age group, making it possible for clinicians to assess the immunological status in inborn errors of immunity, infectious and autoimmune diseases.

A Clinical Conundrum with Diagnostic and Therapeutic Challenge: a Tale of Two Disorders in One Case.

Living organisms are exposed to exogenous and endogenous agents that affect genomic integrity by creating DNA double strand breaks (DSBs). These breaks are repaired by DNA repair proteins to maintain homeostasis. Defects in DNA repair pathways also affect lymphocyte development and maturation, as DSB sites are critical intermediates for rearrangements required for V(D)J recombination. Recent classifications for inborn errors of immunity (IEIs) have listed DNA repair defect genes in a separate group, which suggests the importance of these genes for adaptive and innate immunity. We report an interesting case of a young female (index P1) with mutations in two different genes, DCLRE1C and FANCA, involved in DNA repair pathways. She presented with clinical manifestations attributed to both defects. With the advent of NGS, more than one defect is increasingly identified in patients with IEIs. Familial segregation studies and appropriate functional assays help ascertain the pathogenicity of these mutations and provide appropriate management and genetic counseling.

Assessment of Enterovirus Excretion and Identification of VDPVs in Patients with Primary Immunodeficiency in India: Outcome of ICMR-WHO Collaborative Study Phase-I.

The emergence of vaccine-derived polioviruses (VDPVs) in patients with Primary Immunodeficiency (PID) is a threat to the polio-eradication program. In a first of its kind pilot study for successful screening and identification of VDPV excretion among patients with PID in India, enteroviruses were assessed in stool specimens of 154 PID patients across India in a period of two years. A total of 21.42% of patients were tested positive for enteroviruses, 2.59% tested positive for polioviruses (PV), whereas 18.83% of patients were positive for non-polio enteroviruses (NPEV). A male child of 3 years and 6 months of age diagnosed with Hyper IgM syndrome was detected positive for type1 VDPV (iVDPV1) with 1.6% nucleotide divergence from the parent Sabin strain. E21 (19.4%), E14 (9%), E11 (9%), E16 (7.5%), and CVA2 (7.5%) were the five most frequently observed NPEV types in PID patients. Patients with combined immunodeficiency were at a higher risk for enterovirus infection as compared to antibody deficiency. The high susceptibility of PID patients to enterovirus infection emphasizes the need for enhanced surveillance of these patients until the use of OPV is stopped. The expansion of PID surveillance and integration with a national program will facilitate early detection and follow-up of iVDPV excretion to mitigate the risk for iVDPV spread.

Poliovirus surveillance in patients with primary immunodeficiencies, India.

Individuals with primary immunodeficiencies who are infected with vaccine-derived polioviruses may continue to shed poliovirus for months and go undetected by surveillance programmes of acute flaccid paralysis. These patients therefore pose a risk of initiating poliovirus outbreaks that jeopardize efforts towards global polio eradication. To identify these individuals, we designed a study protocol for the establishment of a network for surveillance of immunodeficiency-related vaccine-derived poliovirus in India. In the first step we identified recognized centres in India that could diagnose and enrol patients with primary immunodeficiency disorder into the study. Stool sample collection from study sites, culture, isolation, characterization of enteroviruses and reporting to study sites was carried out at the National Institute of Virology Mumbai Unit, as per the WHO national polio surveillance project protocol. In the first phase of the study from January 2020 to December 2021, we implemented the protocol at seven study sites at different medical institutes to determine the proportion of poliovirus infections in primary immunodeficiency disorder patients of India. We later expanded the study by including an additional 14 medical institutes across the country in the second phase running from January 2022 to December 2023. We believe this study protocol will help other countries to initiate immunodeficiency-related vaccine-derived poliovirus surveillance to identify and follow up patients who are long-term excretors of vaccine-derived poliovirus. Integration of immunodeficiency-related poliovirus surveillance with acute flaccid paralysis surveillance of the existing poliovirus network will enhance continuous screening of patients with primary immunodeficiency disorder in the future.

Certains individus qui présentent des immunodéficiences primaires et sont infectés par des poliovirus dérivés d'une souche vaccinale pourraient continuer à excréter le poliovirus pendant des mois sans que ce dernier ne soit détecté par le biais d'une surveillance de la paralysie flasque aiguë. Ces patients risquent donc de déclencher des épidémies de poliovirus qui mettent en péril les efforts visant à éradiquer la poliomyélite dans le monde. En vue d'identifier ces individus, nous avons élaboré un protocole d'étude pour établir, en Inde, un réseau de surveillance du poliovirus d'origine vaccinale lié à une immunodéficience. Au cours de la première étape, nous avons repéré des centres reconnus dans le pays, capables de diagnostiquer des patients atteints d'un syndrome d'immunodéficience primaire et de les recruter dans le cadre de l'étude. Le prélèvement des échantillons de selles auprès des sites participant à l'étude, la culture, l'isolement, la caractérisation des entérovirus et la communication des résultats à ces sites ont été pris en charge par le National Institute of Virology Mumbai Unit, conformément au protocole du Projet national de surveillance de la poliomyélite de l'OMS. Nous avons consacré la première phase de l'étude, qui s'est déroulée entre janvier 2020 et décembre 2021, à la mise en œuvre du protocole au sein de différents établissements médicaux sur sept sites participants, afin de déterminer le nombre d'infections au poliovirus chez les patients souffrant d'un syndrome d'immunodéficience primaire en Inde. Nous avons ensuite, durant la deuxième phase comprise entre janvier 2022 et décembre 2023, élargi l'étude en incluant 14 établissements supplémentaires à travers le pays. Nous sommes convaincus que ce protocole d'étude aidera d'autres pays à instaurer une surveillance du poliovirus dérivé d'une souche vaccinale et lié à une immunodéficience, qui leur servira à identifier et suivre les patients responsables d'une excrétion prolongée du poliovirus d'origine vaccinale. L'intégration, au sein du réseau existant dédié au poliovirus, d'une surveillance de ce type couplée à une surveillance de la paralysie flasque aiguë améliorera le dépistage systématique des patients atteints d'un syndrome d'immunodéficience primaire à l'avenir.

Las personas con inmunodeficiencias primarias infectadas por los poliovirus de origen vacunal pueden seguir excretando poliovirus durante meses sin que la vigilancia de la parálisis flácida aguda los detecte. Por lo tanto, estos pacientes suponen un riesgo de iniciar brotes de poliovirus que pongan en peligro los esfuerzos hacia la erradicación mundial de la poliomielitis. Para identificar a estas personas, diseñamos un protocolo de estudio para el establecimiento de una red de vigilancia de poliovirus de origen vacunal relacionados con inmunodeficiencias en la India. En el primer paso identificamos centros reconocidos en la India que pudieran diagnosticar e inscribir en el estudio a pacientes con trastorno de inmunodeficiencia primaria. La recogida de muestras de heces de los centros de estudio, el cultivo, el aislamiento, la caracterización de los enterovirus y la notificación a los centros de estudio se llevaron a cabo en el Instituto Nacional de Virología, Unidad de Mumbai, según el protocolo del Proyecto Nacional de Vigilancia de la Poliomielitis de la OMS. En la primera fase del estudio, de enero de 2020 a diciembre de 2021, aplicamos el protocolo en siete centros de estudio de diferentes institutos médicos para determinar la proporción de infecciones por poliovirus en pacientes con trastorno de inmunodeficiencia primaria de la India. A continuación, ampliamos el estudio con la inclusión de otros 14 institutos médicos de todo el país en la segunda fase, de enero de 2022 a diciembre de 2023. Creemos que este protocolo de estudio ayudará a otros países a iniciar la vigilancia de poliovirus de origen vacunal relacionados con la inmunodeficiencia para identificar y hacer un seguimiento de los pacientes que son excretores a largo plazo de poliovirus de origen vacunal. La integración de la vigilancia del poliovirus asociado a la inmunodeficiencia con la vigilancia de la parálisis flácida aguda de la red de poliovirus existente mejorará el cribado continuo de pacientes con trastorno por inmunodeficiencia primaria en el futuro.

Perturbations of immune landscape in COVID-19 associated mucormycosis.

BACKGROUND: A rise in secondary fungal infections during the COVID-19 pandemic necessitates a deeper understanding of the associated immunological perturbations. OBJECTIVES: To evaluate the clinical and immunological characteristics observed in patients with COVID-19 associated mucormycosis (CAM) infection. PATIENTS/ METHODS: Cases of mucormycosis with or post-COVID-19 infection were compared with cases of acute COVID-19 and convalescent COVID-19. Lymphocyte subsets, cytokines and other laboratory markers were compared between the groups. RESULTS: The frequency of proposed risk factors for CAM was diabetes mellitus (77%), recent history of steroid use (69%) and hypoxia during COVID-19 infection (52%). Iron metabolism was dysregulated in CAM patients with low TIBC and total iron. Further, CAM was accompanied with lymphopenia with drastic reduction in B cell counts; however, plasmablasts were not altered. Further, CAM patients had low immunoglobulin levels and antibodies specific to mucor peptide did not increase in CAM suggesting dysfunction in B-cell response. There was increase in activated effector cytotoxic CD8 T cells and NK cells in CAM compared with COVID-19 infection and healthy controls. Among T helper cells, Tregs were reduced and Th-1 frequency was increased in CAM compared with COVID-19 infection. A distinct cytokine signature was evident in CAM with increase in IL-1ß, IFN-γ, IL-6, IL-22, IL-17A, IL-10, IL-2, IL-8, IL-7, IL-21 and GM-CSF. CONCLUSION: This is the first study on immunophenotyping in CAM suggesting the need for long-term monitoring of B-cell function after SARS-CoV-2 in patients with dysregulated glycaemic control and the possible benefit of therapeutic supplementation with intravenous immunoglobulins in CAM.

Gastrointestinal involvement of common variable immunodeficiency: A diagnostic challenge to the physician.

A 35-year-old male presented with fatigue for 1 month and was found to have megaloblastic anaemia. Further evaluation showed low globulin levels and pan hypogammaglobulinemia. Past history was significant for chronic small bowel diarrhoea and bilateral genu valgum deformity from childhood. Hence, a malabsorption syndrome with a probable antibody deficiency was suspected. An upper gastrointestinal (GI) endoscopy was done, which revealed chronic atrophic gastritis with Helicobacter pylori infection, dysplasia and subtotal villous atrophy with a paucity of plasma cells, which was suggestive of common variable immunodeficiency (CVID)-related enteropathy. CVID can present with predominantly autoimmune GI manifestations without any history of recurrent infections. The risk of gastric dysplasia and malignancy is high in CVID and needs close monitoring.

Serosurvey for Health-Care Workers Provides Supportive Evidence for the Effectiveness of Hydroxychloroquine Prophylaxis against SARS-CoV-2 Infection.

BACKGROUND: The Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) pandemic has resulted in occupational exposure among Healthcare Workers (HCWs) and a high risk of nosocomial transmission. Asymptomatic infection and transmission of infection before the development of symptoms are well-recognized factors contributing to the spread of infection. We conducted a cross-sectional observational study to understand the seroprevalence of SARS-CoV-2 infection among HCWs and to verify the appropriateness of infection control measures, particularly Hydroxychloroquine (HCQ) prophylaxis. METHODS: A cross-sectional sero-surveillance study was conducted among 500 HCWs in Dombivli and surrounding Mumbai Metropolitan area (Maharashtra, India) between 21st July and 3rd August 2020. The vulnerability of the study participants to SARS-CoV-2 infection was ascertained through a history of (i) involvement in direct care, (ii) exposure to aerosol-generating procedures, (iii) co-morbidities, (iv) Personal Protective Equipment (PPE) use, and (v) HCQ prophylaxis. SARS-CoV-2 IgG antibodies were tested using COVID KAVACH anti-SARS-CoV-2 IgG antibody detection enzyme-linked immunosorbent assay (ELISA) from Zydus Cadila. A systematic analysis of the correlation between the development of antibodies and factors affecting vulnerability to infection was performed. RESULTS: The overall SARS-CoV-2 seroprevalence in the study population was 11%. Providing direct care to COVID-19 patients (Adjusted OR 16.4, 95% CI 3.3-126.9, p = 0.002) for long hours and irregular use of PPE (Adjusted OR 3.78, 95% CI 1.1-11.9, p = 0.02) were associated with an increased incidence of seropositivity. Prophylaxis with HCQ may have a role in reducing the vulnerability to infection as depicted by univariate and multivariate analysis (Adjusted OR 0.55, 95% CI 0.3-0.9, p = 0.047). It was also noted that those not on HCQ prophylaxis were threefold more prone to infection and developed severe disease as compared to those on HCQ prophylaxis. CONCLUSION: Prophylaxis with HCQ may have a role in mitigating the incidence and severity of SARS-CoV-2 infection. Although vaccination is the most robust strategy to safeguard against COVID-19, it will be months before vaccination percolates to the masses. In the face of the second wave of COVID-19, the use of HCQ prophylaxis in combination with use of face-masks regularly may be considered as a cost-effective measure for population dense areas like urban slums where social distancing is not possible.

Clinical and Molecular Findings in Mendelian Susceptibility to Mycobacterial Diseases: Experience From India.

Mendelian Susceptibility to Mycobacterial diseases (MSMD) are a group of innate immune defects with more than 17 genes and 32 clinical phenotypes identified. Defects in the IFN-γ mediated immunity lead to an increased susceptibility to intracellular pathogens like mycobacteria including attenuated Mycobacterium bovis-Bacillus Calmette-Guérin (BCG) vaccine strains and non-tuberculous environmental mycobacteria (NTM), Salmonella, fungi, parasites like Leishmania and some viruses, in otherwise healthy individuals. Mutations in the IL12RB1 gene are the commonest genetic defects identified. This retrospective study reports the clinical, immunological, and molecular characteristics of a cohort of 55 MSMD patients from 10 centers across India. Mycobacterial infection was confirmed by GeneXpert, Histopathology, and acid fast bacilli staining. Immunological workup included lymphocyte subset analysis, Nitro blue tetrazolium (NBT) test, immunoglobulin levels, and flow-cytometric evaluation of the IFN-γ mediated immunity. Genetic analysis was done by next generation sequencing (NGS). Disseminated BCG-osis was the commonest presenting manifestation (82%) with a median age of presentation of 6 months due to the practice of BCG vaccination at birth. This was followed by infection with Salmonella and non-typhi Salmonella (13%), Cytomegalovirus (CMV) (11%), Candida (7%), NTM (4%), and Histoplasma (2%). Thirty-six percent of patients in cohort were infected by more than one organism. This study is the largest cohort of MSMD patients reported from India to the best of our knowledge and we highlight the importance of work up for IL-12/IL-23/ISG15/IFN-γ circuit in all patients with BCG-osis and suspected MSMD irrespective of age.

The Spectrum of Clinical, Immunological, and Molecular Findings in Familial Hemophagocytic Lymphohistiocytosis: Experience From India.

Hemophagocytic lymphohistiocytosis (HLH) is a syndrome of immune dysregulation characterized by hyperactivation of the immune system, excessive cytokine secretion and severe systemic inflammation. HLH is classified as familial (FHL) when associated with mutations in PRF1, UNC13D, STX11, and STXBP2 genes. There is limited information available about the clinical and mutational spectrum of FHL patients in Indian population. This study is a retrospective analysis of 101 molecularly characterized FHL patients over the last 10 years from 20 different referral centers in India. FHL2 and FHL3 together accounted for 84% of cases of FHL in our cohort. Patients belonging to different FHL subtypes were indistinguishable based on clinical and biochemical parameters. However, flow cytometry-based assays viz. perforin expression and degranulation assay were found to be specific and sensitive in diagnosis and classification of FHL patients. Molecular characterization of respective genes revealed 76 different disease-causing mutations including 39 (51%) novel mutations in PRF1, UNC13D, STX11, and STXBP2 genes. Overall, survival was poor (28%) irrespective of the age of onset or the type of mutation in our cohort. Altogether, this article sheds light on the current scenario of FHL in India. Our data reveal a wide genetic heterogeneity of FHL in the Indian population and confirms the poor prognosis of FHL. This study also emphasizes that though mutational analysis is important for diagnostic confirmation of FHL, flow cytometry based assays help significantly in rapid diagnosis and functional validation of novel variants identified.

Spectrum of Inborn errors of immunity in a cohort of 90 patients presenting with complications to BCG vaccination in India.

World Health Organisation recommends the practice of BCG vaccination at birth in countries which have a high incidence of tuberculosis and/or high leprosy burden. The BCG vaccination is considered safe for a competent immune system. However, in children with weakened immune systems cause of which can be primary or secondary, the vaccine may lead to side effects which can be localized or disseminated. In this study, we report a spectrum of inborn errors of immunity (IEI) commonly referred to as primary immunodeficiency disorders (PIDs) diagnosed in a large cohort of patients presenting with complications to BCG vaccination from India. Retrospective data analysis of patients referred to ICMR- National Institute of Immunohematology (ICMR-NIIH) for IEI workup between 2007 and 2019 was done. IEI was identified in n = 52/90 (57.7%) patients presenting with BCG complications. Of these, n = 13(14.4%) patients were diagnosed with severe combined immune deficiency, n = 15(16.7%) with chronic granulomatous disease, n = 19(21.1%) with Inborn errors of IFN-γ immunity, n = 4(4.4%) with Combined immunodeficiency and n = 1(1.1%) with Leucocyte Adhesion Deficiency type1. Majority of cases with BCGosis (88%) had an underlying IEI. This study strongly highlights the need for evaluation of patients with BCG complications for underlying IEI. While disseminated BCGosis strongly predicts underlying IEI, even localized persistent adenitis may be a warning sign of underlying IEI. It is also strongly recommended to record a family history of previous sibling death prior to administration of this live vaccine and deferring live vaccine till the diagnosis of IEI is ruled out in cases with a positive family history.

Prenatal Diagnosis for Primary Immunodeficiency Disorders-An Overview of the Indian Scenario.

Prenatal Diagnosis (PND) forms an important part of primary preventive management for families having a child affected with primary immunodeficiency. Although individually sparse, collectively this group of genetic disorders represents a significant burden of disease. This paper discusses the prenatal services available for affected families at various centers across the country and the challenges and ethical considerations associated with genetic counseling. Mutation detection in the index case and analysis of chorionic villous sampling or amniocentesis remain the preferred procedures for PND and phenotypic analysis of cordocentesis sample is reserved for families with well-characterized index case seeking PND in the latter part of the second trimester of pregnancy. A total of 112 families were provided PND services in the last decade and the presence of an affected fetus was confirmed in 32 families. Post-test genetic counseling enabled the affected families to make an informed decision about the current pregnancy.

Clinical and Genetic Spectrum of a Large Cohort of Patients With Leukocyte Adhesion Deficiency Type 1 and 3: A Multicentric Study From India.

Leukocyte adhesion deficiency (LAD) syndrome is a group of inborn errors of immunity characterized by a defect in the cascade of the activation and adhesion leading to the failure of leukocyte to migrate to the site of tissue injury. Three different types of LAD have been described. The most common subtype is LAD type 1 (LAD1) caused due to defects in the ITGß2 gene. LAD type 2 (LAD2) is caused by mutations in the SLC35C1 gene leading to a generalized loss of expression of fucosylated glycans on the cell surface and LAD type 3 (LAD3) is caused by mutations in the FERMT3 gene resulting in platelet function defects along with immunodeficiency. There is a paucity of data available from India on LAD syndromes. The present study is a retrospective analysis of patients with LAD collated from 28 different centers across India. For LAD1, the diagnosis was based on clinical features and flow cytometric expression of CD18 on peripheral blood leukocytes and molecular confirmation by Sanger sequencing. For patients with LAD3 diagnosis was largely based on clinical manifestations and identification of the pathogenic mutation in the FERMT3 gene by next-generation Sequencing. Of the total 132 cases diagnosed with LAD, 127 were LAD1 and 5 were LAD3. The majority of our patients (83%) had CD18 expression less than 2% on neutrophils (LAD1°) and presented within the first three months of life with omphalitis, skin and soft tissue infections, delayed umbilical cord detachment, otitis media, and sepsis. The patients with CD18 expression of more than 30% (LAD1+) presented later in life with skin ulcers being the commonest manifestation. Bleeding manifestations were common in patients with LAD3. Persistent neutrophilic leukocytosis was the characteristic finding in all patients. 35 novel mutations were detected in the ITGß2 gene, and 4 novel mutations were detected in the FERMT3 gene. The study thus presents one of the largest cohorts of patients from India with LAD, focusing on clinical features, immunological characteristics, and molecular spectrum.