Wolbachia-carrying Aedes mosquitoes for preventing dengue infection.

BACKGROUND: Dengue is a global health problem of high significance, with 3.9 billion people at risk of infection. The geographic expansion of dengue virus (DENV) infection has resulted in increased frequency and severity of the disease, and the number of deaths has increased in recent years. Wolbachia,an intracellular bacterial endosymbiont, has been under investigation for several years as a novel dengue-control strategy. Some dengue vectors (Aedes mosquitoes) can be transinfected with specific strains of Wolbachia, which decreases their fitness (ability to survive and mate) and their ability to reproduce, inhibiting the replication of dengue. Both laboratory and field studies have demonstrated the potential effect of Wolbachia deployments on reducing dengue transmission, and modelling studies have suggested that this may be a self-sustaining strategy for dengue prevention, although long-term effects are yet to be elucidated. OBJECTIVES: To assess the efficacy of Wolbachia-carrying Aedes speciesdeployments (specifically wMel-, wMelPop-, and wAlbB- strains of Wolbachia) for preventing dengue virus infection. SEARCH METHODS: We searched CENTRAL, MEDLINE, Embase, four other databases, and two trial registries up to 24 January 2024. SELECTION CRITERIA: Randomized controlled trials (RCTs), including cluster-randomized controlled trials (cRCTs), conducted in dengue endemic or epidemic-prone settings were eligible. We sought studies that investigated the impact of Wolbachia-carrying Aedes deployments on epidemiological or entomological dengue-related outcomes, utilizing either the population replacement or population suppression strategy. DATA COLLECTION AND ANALYSIS: Two review authors independently selected eligible studies, extracted data, and assessed the risk of bias using the Cochrane RoB 2 tool. We used odds ratios (OR) with the corresponding 95% confidence intervals (CI) as the effect measure for dichotomous outcomes. For count/rate outcomes, we planned to use the rate ratio with 95% CI as the effect measure. We used adjusted measures of effect for cRCTs. We assessed the certainty of evidence using GRADE. MAIN RESULTS: One completed cRCT met our inclusion criteria, and we identified two further ongoing cRCTs. The included trial was conducted in an urban setting in Yogyakarta, Indonesia. It utilized a nested test-negative study design, whereby all participants aged three to 45 years who presented at healthcare centres with a fever were enrolled in the study provided they had resided in the study area for the previous 10 nights. The trial showed that wMel-Wolbachia infected Ae aegypti deployments probably reduce the odds of contracting virologically confirmed dengue by 77% (OR 0.23, 95% CI 0.15 to 0.35; 1 trial, 6306 participants; moderate-certainty evidence). The cluster-level prevalence of wMel Wolbachia-carrying mosquitoes remained high over two years in the intervention arm of the trial, reported as 95.8% (interquartile range 91.5 to 97.8) across 27 months in clusters receiving wMel-Wolbachia Ae aegypti deployments, but there were no reliable comparative data for this outcome. Other primary outcomes were the incidence of virologically confirmed dengue, the prevalence of dengue ribonucleic acid in the mosquito population, and mosquito density, but there were no data for these outcomes. Additionally, there were no data on adverse events. AUTHORS' CONCLUSIONS: The included trial demonstrates the potential significant impact of wMel-Wolbachia-carrying Ae aegypti mosquitoes on preventing dengue infection in an endemic setting, and supports evidence reported in non-randomized and uncontrolled studies. Further trials across a greater diversity of settings are required to confirm whether these findings apply to other locations and country settings, and greater reporting of acceptability and cost are important.

Acute Encephalitis Syndrome in Children and Adolescents: A Five-Year Descriptive Study From South India.

OBJECTIVE: Acute encephalitis syndrome (AES) in children results in significant neurocognitive deficits or mortality. It is pertinent to study the AES patterns periodically to identify the changes in the etiological trends and outcomes. Our objective was to find the etiological agents of AES, mode of diagnosis, treatment given, and outcomes. METHODS: We reviewed the electronic records of children aged 1 month to 15 years who were admitted with AES in our centre from January 2015 to December 2019. We analyzed the the clinical, laboratory, and radiological profile of these children and adolescents in relation to their outcome. Poor outcome was defined as death, discharge against medical advice with neurological deficits, or Glasgow Outcome Score Extended (GOS-E) d≤ 5 at the time of discharge. RESULTS: Among 250 patients admitted with AES during the study period, a definitive etiological diagnosis was established in 56.4% of children (30.4% viral, 22% bacterial). Scrub typhus (11.2%) and dengue (9%) were the two most common underlying illnesses. Serology helped in clinching the diagnosis in 30% of children. A surge in AES cases in the post-monsoon season was observed in our cohort. Third-generation cephalosporin drugs (85.7%) and acyclovir (77.7%) were the most commonly used empiric antimicrobial drugs. About one-third of children (n = 80) had a poor outcome. GCS ≤ 8 at presentation and requirement for invasive ventilation were found to be significant predictors of poor outcome. CONCLUSIONS: A definitive diagnosis was obtained in about half of the children with AES. Viral (30.4%) and rickettsial infections (22%) were the common etiologies identified. Poor outcome was observed in 32 % of patients.

Distinct patterns of postoperative fever in paediatric neurosurgery patients.

PURPOSE: Postoperative fever is a common problem following neurosurgery but data on the causes among paediatric patients is sparse. In this report, we determined the incidence, causes, and outcomes of postoperative fever in paediatric neurosurgical patients (< 18 years), and contrasted the findings with an adult cohort published recently from our unit. METHODS: We recruited 61 patients who underwent 73 surgeries for non-traumatic neurosurgical indications over 12 months. A standard protocol was followed for the evaluation and management of postoperative fever. We prospectively collected data pertaining to operative details, daily maximal temperature, clinical features, and use of surgical drains, urinary catheters, and other adjuncts. Elevated body temperature of > 99.9 °F or 37.7 °C for > 48 h or associated with clinical deterioration or localising features was considered as "fever"; elevated temperature not meeting these criteria was classified as transient elevation in temperature (TET). RESULTS: Twenty-six patients (35.6%) had postoperative fever, more frequent than in adult patients. TET occurred in 12 patients (16.4%). The most common causes of fever were aseptic meningitis (34.6%), followed by urinary tract infections (15.4%), pyogenic meningitis, COVID-19, and wound infections. Postoperative fever was associated with significantly longer duration of hospital admission and was the commonest cause of readmission. CONCLUSION: In contrast to adults, early temperature elevations in paediatric patients may portend infectious and serious non-infectious causes of fever, including delayed presentation with aseptic meningitis, a novel association among paediatric patients. Investigation guided by clinical assessment and conservative antibiotic policy in keeping with the institutional microbiological profile provides the most appropriate strategy in managing paediatric postoperative fever.

Aspergillosis Causing Orbital Subperiosteal Abscess in an Immunocompetent Child: A Rare Presentation.

Orbital abscesses are primarily seen in children as complication of ethmoid bacterial sinusitis. We report a case of invasive aspergillosis causing orbital abscess in an immunocompetent child which resolved with surgery followed by antifungal therapy. This case highlights need for histopathological, and microbiological examination, including fungal culture in such cases.

An observer-blinded, cluster randomised trial of a typhoid conjugate vaccine in an urban South Indian cohort.

BACKGROUND: Typhoid fever causes nearly 110,000 deaths among 9.24 million cases globally and disproportionately affects developing countries. As a control measure in such regions, typhoid conjugate vaccines (TCVs) are recommended by the World Health Organization (WHO). We present here the protocol of a cluster randomised vaccine trial to assess the impact of introducing TyphiBEV® vaccine to those between 1 and 30 years of age in a high-burden setting. METHODS: The primary objective is to determine the relative and absolute rate reduction of symptomatic, blood-culture-confirmed S. Typhi infection among participants vaccinated with TyphiBEV® in vaccine clusters compared with the unvaccinated participants in non-vaccine clusters. The study population is residents of 30 wards of Vellore (a South Indian city) with participants between the ages of 1 and 30 years who provide informed consent. The wards will be divided into 60 contiguous clusters and 30 will be randomly selected for its participants to receive TyphiBEV® at the start of the study. No placebo/control is planned for the non-intervention clusters, which will receive the vaccine at the end of the trial. Participants will not be blinded to their intervention. Episodes of typhoid fever among participants will be captured via stimulated, passive fever surveillance in the area for 2 years after vaccination, which will include the most utilised healthcare facilities. Observers blinded to the participants' intervention statuses will record illness details. Relative and absolute rate reductions will be calculated at the end of this surveillance and used to estimate vaccine effectiveness. DISCUSSION: The results from our trial will allow countries to make better-informed decisions regarding the TCV that they will roll-out and may improve the global supplies and affordability of the vaccines. TRIAL REGISTRATION: Clinical Trials Registry of India (CTRI) CTRI/2022/03/041314. Prospectively registered on 23 March 2022 ( https://ctri.nic.in/Clinicaltrials/pmaindet2.php?trialid=62548&EncHid=&userName=vellore%20typhoid ). CTRI collects the full WHO Trial Registration Data Set.

Characterization of immune responses to two and three doses of the adenoviral vectored vaccine ChAdOx1 nCov-19 and the whole virion inactivated vaccine BBV152 in a mix-and-match study in India.

Infections with SARS-CoV-2 variants and declining immunity after primary vaccination, encouraged the use of booster doses. Some countries changed their immunization programmes to boost with vaccines different from the ones in their original schedule, based on results from immunogenicity and effectiveness studies. This study reports immunological analysis of samples collected in a phase 4 randomized trial, where participants who had previously received two primary doses of ChAdOx1 nCov-19 (ChAd) or inactivated BBV152 vaccine were randomized to receive either ChAd or BBV152 booster and further categorized as: Group 1 (two primary doses of ChAd - ChAd booster), Group 2 (two primary doses of ChAd - BBV152 booster), Group 3 (two primary doses of BBV152 - ChAd booster), and Group 4 (two primary doses of BBV152 - BBV152 booster). SARS-CoV-2 specific cellular and humoral responses at day 0 (pre-boost samples 12-36 weeks after the second primary dose), and at day 28 post booster, were measured in a subset of participants (ChAd recipients, n = 37 and BBV152 recipients, n = 36). Additionally, on day180 post-booster humoral responses were assessed for the entire cohort (N = 378). Primary vaccination with 2 doses of BBV152 generated higher memory-B cells (median% 0.41 vs 0.35) and cytokine producing CD8-Tcells (median% 0.09 vs 0.04) while lower anti-spike IgG levels (medianAU/ml: 12,433 vs 27,074) as compared to ChAd. Irrespective of the primary vaccine received, ChAd boosted individuals generated higher memory-B cell frequencies and anti-spike IgG levels as compared to BBV152 booster. The percentage ACE-2 inhibition against Omicron and its sub-variants was higher in Group 3 (median > 60 %) as compared to other groups (median < 25 %). At day180 post booster the hierarchy of the antibody amounts was Group 1 âˆ¼ Group 2 âˆ¼ Group 3 > Group 4. Sustained humoral and robust cellular immune response to SARS-CoV-2 can be obtained with ChAd booster irrespective of the primary vaccination regimen. The trial is registered with ISRTCN (CTRI/2021/08/035648).

Clinical Spectrum and Microbial Etiology of Bone and Joint Infections in Children: A Retrospective Analysis from South India.

Acute infections of bone and joints are medical emergencies. Early diagnosis and treatment are essential for limb salvage and prevention of deformities. Data from developing countries are essential to develop region-specific treatment guidelines including choice of empiric antibiotics. We reviewed electronic medical records of children (≤ 12 years old) admitted to the pediatrics or orthopedics department of a tertiary care hospital in South India from 2013 to 2017 with a diagnosis of septic arthritis and/or osteomyelitis. Clinical, microbiological, and follow-up data were collected and analyzed. The median (interquartile range, IQR) age of the children (N = 207) was 48 (7.5-105) months. Acute infections were more common in infants, whereas chronic cases were common in children > 5 years of age. Staphylococcus aureus (71%) was the most common organism identified. Gram-negative organisms were more frequently isolated in infants compared with older children. Blood and/or wound culture positivity was 78% (N = 161) overall and 78% (N = 31) in chronic cases. The median (IQR) duration of antibiotics was 7 (5-8) weeks. Sequelae and readmissions occurred in 47% (N = 81) of the 172 patients followed for a year. Culture positivity rates especially of wound were high even after receiving antibiotics.

Immunogenicity and safety of homologous and heterologous booster vaccination of ChAdOx1 nCoV-19 (COVISHIELD™) and BBV152 (COVAXIN®): a non-inferiority phase 4, participant and observer-blinded, randomised study.

Background: Primary SARS-CoV-2 vaccination has been shown to wane with time and provide lower protection from disease with new viral variants, prompting the WHO to recommend the administration of booster doses. We determined the safety and immunogenicity of homologous or heterologous boosters with ChAdOx1 nCoV-19 (COVISHIELD™) or BBV152 (COVAXIN®), the two vaccines used widely for primary immunization in India, in participants who had already received two primary doses of these vaccines. Methods: Participants primed with two doses each of COVISHIELD™ or COVAXIN® 12-36 weeks previously, were randomised to receive either COVISHIELD™ or COVAXIN® booster in a 1:1 ratio. The primary outcome was day 28 post-booster anti-spike IgG seropositivity and secondary outcomes were anti-spike IgG levels and assessment of safety and reactogenicity. The results of 90 days intention-to-treat analysis are presented. This trial is registered with ISRCTN (CTRI/2021/08/035648). Findings: In the COVISHIELD™ primed group with 200 participants, the seropositivity 28 days post booster in the heterologous COVAXIN® arm was 99% and non-inferior to the homologous COVISHIELD™ arm, which was also 99% (difference 0%; 95% CI: -2.8% to 2.7%). The geometric mean concentration (GMC) of anti-spike antibodies following heterologous COVAXIN® boost on day 28 was 36,190.78 AU/mL (95% CI: 30,526.64-42,905.88) while the GMC following homologous COVISHIELD™ boost was 97,445.09 AU/mL (82,626.97-114,920.7). In the COVAXIN® primed group with 204 participants, the seropositivity 28 days post booster in the heterologous COVISHIELD™ arm was 100% and non inferior to the homologous COVAXIN® arm which was 96% (difference 4%, 95% CI: 0.2%-7.8%). The GMC following heterologous COVISHIELD™ boost was 241,681.6 AU/mL (95% CI: 201,380.2-290,048.3) compared to homologous COVAXIN® boost, which was 48,473.94 AU/mL (95% CI: 38,529.56-60,984.95). The day 28 geometric mean ratio (GMR) of the anti-spike IgG between the heterologous and homologous boosted arms was 0.42 (95% CI: 0.34-0.52) in the COVISHIELD™ primed group and 5.11 (95% CI: 3.83-6.81) in the COVAXIN® primed group. There were no related serious adverse events reported in any group. Interpretation: Homologous and heterologous boosting with COVISHIELD™ or COVAXIN® in COVISHIELD™ or COVAXIN® primed individuals are immunogenic and safe. A heterologous boost with COVISHIELD™ after COVAXIN® prime offers the best immune response among the four combinations evaluated. Funding: Azim Premji Foundation and Bill and Melinda Gates Foundation.

Epidemiology and outcomes of pneumococcal sepsis in children with nephrotic syndrome in a developing country.

BACKGROUND: Pneumococcal infections are common in children with nephrotic syndrome. Knowledge of the commonly available serotypes and antibiotic susceptibility will help in prevention and appropriate management of pneumococcal sepsis, especially in resource-limited countries. METHODS: Demographic, clinical, and laboratory data on children with nephrotic syndrome and pneumococcal infections were extracted from the electronic medical records. RESULTS: Sixty-three isolates of pneumococci obtained from 60 children with nephrotic syndrome, over a period of 14 years, were included in the study. This represented 18% of all pneumococcal infections occurring in children during the same period. Commonly available vaccines covered up to 58% of all the serotypes causing infection. Severe disease, with shock, intensive care admission and/or meningitis, was observed in 38% children and mortality was observed in 10%. Resistance to commonly used antibiotics was not observed, except for erythromycin. CONCLUSIONS: Pneumococcal sepsis was observed to be common in children with nephrotic syndrome and results in significant morbidity and mortality. Commonly used antibiotics were observed to be effective in management of the infections.

Clinical, Microbiological Profile and Treatment Outcomes of Infants with BCG Adenitis: A Retrospective Study.

BACKGROUND: Bacille Calmette-Guérin (BCG) adenitis is an uncommon complication following BCG vaccination. In rare cases, infants can develop other complications. Controversy exists regarding the diagnosis and management of these cases. Not much information is available in literature regarding their microbiological and immunological characteristics. METHODS: Electronic medical records of children presenting to the Pediatric Infectious Diseases clinic in a tertiary care hospital from January 2011-December 2020 with a diagnosis of BCG adenitis were retrospectively reviewed. Their clinical, microbiological, treatment and follow-up data were noted and analyzed. FINDINGS: During the study period, 40 infants presented with a probable diagnosis of BCG adenitis with or without disseminated BCG. Median age at symptom onset was 4(2.5-5.9) months. Nine infants had disseminated disease at presentation. Fifteen infants were suspected to have underlying immune deficiency of whom 12 had proven defects in immune function. On multivariable logistic regression analysis, presence of disseminated disease was the only factor predictive of underlying immunodeficiency. Isoniazid monoresistance was seen in seven cases (32%) of the 22 samples sent for TB cultures. CONCLUSIONS: Though BCG adenitis runs a benign course, it could rarely be the first manifestation of an underlying immune defect. There is sizable isoniazid monoresistance, hence sending tissue samples for microbiologic evaluation is necessary to guide anti-tubercular therapy.

Scrub Typhus: A Spatial and Temporal Analysis from South India.

Scrub typhus is a zoonotic rickettsial disease caused by the bacterium Orientia tsutsugamushi. The non-specificity of presentation, low index of suspicion and the poor availability of diagnostic tests often lead to delayed diagnosis and significant morbidity and mortality. Temperature, humidity, rainfall and Normalized Difference Vegetation Index (NDVI) on the spatio-temporal clustering of scrub typhus cases in children in three contiguous administrative districts in South India over 5 years were studied. A total of 419 children were diagnosed with scrub typhus during the study period. A surge of children with scrub typhus was noted when the NVDI ranged between 0.6 and 0.8 µm. Temperature, humidity and rainfall had a major role in the incidence of scrub typhus.

Epidemiological investigation of the COVID-19 outbreak in Vellore district in South India using Geographic Information Surveillance (GIS).

OBJECTIVES: Geographical Information Surveillance (GIS) is an advanced digital technology tool that maps location-based data and helps in epidemiological modeling. We applied GIS to analyze patterns of spread and hotspots of COVID-19 cases in the Vellore district in South India. METHODS: Laboratory-confirmed COVID-19 cases from the Vellore district and neighboring taluks from March 2020 to June 2021 were geocoded and spatial maps were generated. Time trends exploring urban-rural burden with an age-sex distribution of cases and other variables were correlated with outcomes. RESULTS: A total of 45,401 cases of COVID-19 were detected, with 20,730 cases during the first wave and 24,671 cases during the second wave. The overall incidence rates of COVID-19 were 462.8 and 588.6 per 100,000 population during the first and second waves, respectively. The spread pattern revealed epicenters in densely populated urban areas with radial spread sparing rural areas in the first wave. The case fatality rate was 1.89% and 1.6% during the first and second waves, which increased with advancing age. CONCLUSIONS: Modern surveillance systems like GIS can accurately predict the trends and spread patterns during future pandemics. In addition, real-time mapping can help design risk mitigation strategies, thereby preventing the spread to rural areas.

Single Dose of Ivermectin is not Useful in Patients with Hematological Disorders and COVID-19 Illness: A Phase II B Open Labelled Randomized Controlled Trial.

Repurposed drugs may reduce morbidity and mortality in patients with hematological disorders who develop COVID-19 illness. 112 patients with predominantly hematological illnesses were randomized to receive standard of care, ivermectin 12 mg [Iv 12] or 24 mg [Iv24] for asymptomatic, mild, or moderate COVID 19 illness. Serial respiratory samples for rRT-PCR samples were sent on Day 3, 5 and 7. rRT-PCR negativity and ≥ 2 log10 reduction in viral loads on day 3, 5 and 7 were similar between the 3 treatment groups across all disease categories. Symptom progression occurred in 26 patients [21.6%] with no difference across 3 treatment groups. Twenty-two patients [18.3%] have expired while 98 [81.7%] survived. Survival rates were similar across treatment groups [controls-80.5%, Iv12-77.5%, Iv24-87.2% respectively]. Overall, poorer survival was seen with moderate illness compared to others [51.6% vs 92.1%; p = 0.000] and was the only significant risk factor identified on multivariate analysis. In this Phase II randomised trial, single dose of 12 or 24 mg of ivermectin did not reduce viral loads, prevent symptom progression, or reduce mortality in patients with predominantly haematological illnesses who develop mild to moderate COVID 19 illness.