Effect of Non-Rotavirus Enteric Infections on Vaccine Efficacy in a ROTASIIL Clinical Trial

This study examined the relative proportion of enteric pathogens associated with severe gastroenteritis (GE) among children younger than 2 years in a phase III efficacy trial of the ROTASIIL® vaccine in India, evaluated the impact of co-infections on vaccine efficacy (VE), and characterized the association between specific pathogens and the clinical profile of severe GE. Stored stool samples collected from cases of severe GE in the phase III trial were tested by quantitative polymerase chain reaction using TaqMan™ Array Cards. Etiology was attributed by calculating the adjusted attributable fraction (AF) for each pathogen. A test-negative design was used to estimate VE. The pathogens with the highest AFs for severe diarrhea were rotavirus (23.5%), adenovirus 40/41 (17.0%), Shigella spp./enteroinvasive Escherichia coli, norovirus GII, enterotoxigenic E. coli, and Cryptosporidium spp. A considerable proportion of the disease in these children could not be explained by the pathogens tested. Severe GE cases associated with rotavirus and Shigella spp. were more likely to have a longer duration of vomiting and diarrhea, respectively. Cases attributed to Cryptosporidium spp. were more severe and required hospitalization. In the intention-to-treat population, VE was estimated to be 43.9% before and 46.5% after adjustment for co-infections; in the per-protocol population, VE was 46.7% before and 49.1% after adjustments. Rotavirus continued to be the leading cause of severe GE in this age group. The adjusted VE estimates obtained did not support co-infections as a major cause of lower vaccine performance in low- and middle-income countries.

Sensitivity and specificity of phrenic nerve electrophysiology to predict mechanical ventilation in the Guillain-Barré syndrome

INTRODUCTION/AIMS

In Guillain-Barré syndrome (GBS), the sensitivity and specificity of phrenic compound muscle action potential (CMAP) measurements to predict endotracheal mechanical ventilation are unknown. Hence, we sought to estimate sensitivity and specificity.

METHODS

We performed a 10-year retrospective analysis of adult GBS patients from our single-center laboratory database (2009 to 2019). The phrenic nerve amplitudes and latencies before ventilation were recorded along with other clinical and demographic features. Receiver operating curve (ROC) analysis with area under the curve (AUC) was used to determine the sensitivity and specificity with 95% confidence interval (CI) for phrenic amplitudes and latencies in predicting the need for mechanical ventilation.

RESULTS

Two hundred five phrenic nerves were analyzed in 105 patients. The mean age was 46.1 ± 16.2 years, with 60% of them being male. Fourteen patients (13.3%) required mechanical ventilation. The average phrenic amplitudes were lower in the ventilated group (P = .003), but average latencies did not differ (P = .133). ROC analysis confirmed that phrenic amplitudes could predict respiratory failure (AUC = 0.76; 95% CI, 0.61 to 0.91; P < .002), but phrenic latencies could not (AUC = 0.60; 95% CI, 0.46 to 0.73; P = .256). The best threshold for amplitude was ≥0.6 mV, with sensitivity, specificity, and positive and negative predictive values of 85.7%, 58.2%, 24.0%, and 96.4%, respectively.

DISCUSSION

Our study suggests that phrenic CMAP amplitudes can predict the need for mechanical ventilation in GBS. In contrast, phrenic CMAP latencies are not reliable. The high negative predictive value of phrenic CMAP amplitudes ≥0.6 mV can preclude mechanical ventilation, making these a useful adjunct to clinical decision-making.

Rural South Indian spirometry values show wide variation compared to existing prediction equations

Background and Objective

India, a highly heterogeneous country, has no common reference standards for predicting spirometry values, with very few recent studies from south India. This study aimed to create reference equations for rural south Indian adults, based on a population-based survey in Vellore, south India and compare it with other equations from India.

Methods

The data from 583 non-smoking, asymptomatic participants (30 years and older) from a spirometry-based survey for airflow obstruction (rural Vellore, 2018), were used to develop equations for FEV1, FEV1/FVC, and FVC. The dataset was divided for development (70%) and validation (30%), by gender. Differences between observed and predicted values were assessed using the new equations and comparisons made with other equations from India.

Results

Predictions with Vellore rural equations were closest to the previous south Indian equations from urban Bangalore. However, the Bangalore equations led to overestimation of FVC values in males, and of both FEV1 and FVC values in females. Using the rural Vellore equations also led to a higher percent of males being classified as having airflow obstruction, compared to the Bangalore equations which underestimated airflow obstruction in this rural population. Comparison with previously derived Indian equations from other parts of the country showed pronounced variations.

Conclusions

Our study reiterates the need for representative rural and urban studies of adults from various parts of India, to obtain region specific reference equations, given the wide variations in spirometry values in "normal" individuals, due to social heterogeneities of the Indian population and resulting complexities in defining normal.

Persistent bacteremia predicts poor outcomes among neutropenic patients with carbapenem-resistant gram-negative bloodstream infections receiving appropriate therapy

PURPOSE

Identifying persistent bacteremia early in patients with neutropenia may improve outcome. This study evaluated the role of follow-up blood cultures (FUBC) positivity in predicting outcomes among patients with neutropenia and carbapenem-resistant gram-negative bloodstream infections (CRGNBSI).

METHODS

This retrospective cohort study conducted between December 2017 and April 2022 included patients more than 15 years old with neutropenia and CRGNBSI, who survived for ≥ 48 h, receiving appropriate antibiotic therapy and had FUBCs. Patients with polymicrobial bacteremia within 30 days were excluded. The primary outcome was 30 day mortality. Persistent bacteremia, septic shock, recovery from neutropenia, prolonged or profound neutropenia, requirement of intensive care and dialysis, and initiation of appropriate empirical therapy were also studied.

RESULTS

In our study cohort of 155 patients, the 30 day mortality rate was 47.7%. Persistent bacteremia was common in our patient cohort (43.8%). Carbapenem resistant isolates identified in the study were K.pneumoniae (80%), E.coli (12.26%), P.aeruginosa (5.16%), A.baumanii (1.94%) and E.cloacae (0.65%). The median time for sending a FUBC was 2 days (IQR, 1-3 days). Patients with persistent bacteremia had higher mortality than those without (56.76% versus 32.1%; p < 0.001). Appropriate initial empirical therapy was given to 70.9%. Recovery from neutropenia occurred in 57.4% while 25.8% had prolonged or profound neutropenia. Sixty-nine percent (107/155) had septic shock and needed intensive care; 12.2% of patients required dialysis. Non-recovery from neutropenia (aHR, 4.28; 95% CI 2.53-7.23), presence of septic shock (aHR, 4.42; 95%CI 1.47-13.28), requirement of intensive care (aHR,3.12;95%CI 1.23-7.93), and persistent bacteremia (aHR,1.74; 95%CI 1.05-2.89) significantly predicted poor outcomes in multivariable analysis.

CONCLUSION

FUBC showing persistent bacteremia predicted poor outcomes among neutropenic patients with carbapenem-resistant gram-negative bloodstream infections (CRGNBSI) and should be routinely reported.

Toll-Like Receptors and Mannose Binding Lectin Gene Polymorphisms Associated with Cryptosporidial Diarrhea in Children in Southern India

In low-resource settings, Cryptosporidium spp. is a common cause of diarrheal disease in children under the age of 3 years. In addition to diarrhea, these children also experience subclinical episodes that have been shown to affect growth and cognitive function. In this study, we screened polymorphisms in the promoter and exon1 regions of the mannose binding lectin 2 (MBL2) gene, as well as single nucleotide polymorphisms (SNPs) described in toll-like receptors (TLR) TLR1, TLR2, TLR4, and TLR9 and TIR domain-containing adaptor protein (TIRAP) genes among children with cryptosporidial diarrhea (cases) and children who only experienced asymptomatic (subclinical) cryptosporidiosis (controls). Among the polymorphisms screened, the variant allele B at codon 54 (rs1800450) of the MBL2 gene was associated with susceptibility to cryptosporidial diarrhea (odds ratio [OR] = 2.2, 95% confidence interval [CI] 1.1–4.5). When plasma MBL levels were compared, 72% of cases were found to be deficient compared with 32% among controls (OR = 5.09). Among TLR polymorphisms screened, multivariate analysis showed that heterozygous genotypes of TLR4 896A/G (rs4986790, OR = 0.33, 95% CI: 0.11–0.98) and TIRAP 539 C/T (rs8177374, OR = 0.19, 95% CI: 0.06–0.64) SNPs were associated with protection from cryptosporidial diarrhea. Although not statistically significant, these findings suggest that polymorphisms of MBL2 and TLR genes influence susceptibility to symptomatic cryptosporidial diarrhea even in settings with high exposure levels. Further studies to validate these findings in a larger cohort and to understand the role of these polymorphisms in mediating innate and adaptive immune responses to cryptosporidial infection are necessary.

Time to debridement in open high-grade lower limb fractures and its effect on union and infections: A prospective study in a tropical setting

PURPOSE

To prospectively evaluate whether time to debridement has any correlation with union, infection, and quality of life in high-grade lower limb fractures in a tropical setting.

METHODS

A prospective cohort study was conducted at a tertiary care center in South India. Two hundred fifty-four adult skeletally mature patients with 301 grade 3 fractures involving the femur, tibia, or fibula were recruited. The cohort was empirically divided into two groups (early and late) based on the time to debridement (less than or more than 12 h from injury).

OUTCOME

The primary outcome was nonunion. Secondary outcomes were deep infection rates and patients' quality of life. Short form-36 (SF-36) and short musculoskeletal functional assessment (SMFA) questionnaires were also used. Patients were followed up for 9 months.

RESULTS

The follow-up rate was 93%. The late group had a significantly higher risk of nonunion (odds ratio(OR): 6.5, 95% confidence interval (CI): 2.82-14.95) and infections (OR: 6.05, 95% CI: 2.85-12.82). There was a 4% increase in the infection risk for each hour of delay for the initial 50 h (p < 0.0001). SF-36 and SMFA scores were superior in the early group (p < 0.0001).

CONCLUSION

The study contradicts findings reported in the literature from the West. Our study was in agreement with our hypothesis and proved that debridement within 12 h resulted in significantly lower rates of nonunion and infections and an overall improved quality of life in high-grade open lower limb fractures in a developing country.

LEVEL OF EVIDENCE

Level II.

TRIAL REGISTRATION

German Clinical Trials Register DRKS00015186.

Association of interleukin-28B rs12979860 and rs8099917 polymorphisms with sustained viral response in hepatitis C virus genotype 1 and 3 infected patients from the Indian subcontinent

BACKGROUND

Polymorphisms of the IL28B gene (rs12979860 and rs8099917) have been shown to impact treatment responses in hepatitis C virus (HCV) infected patients. The association of these polymorphisms with sustained viral response (SVR) has been studied in HCV genotype 3 infected patients in India, but not in genotype 1.

OBJECTIVES

This study aimed to determine the association of IL28B gene polymorphisms and other host and viral factors with treatment response in patients with HCV genotype 1 and 3 infection.

MATERIALS AND METHODS

DNA from 42 HCV-infected patients on antiviral therapy was analysed for the IL28B polymorphisms using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Bidirectional sequencing was performed on a subset of samples for verification of PCR-RFLP results. Information on age, weight, height, diabetic status, pre-treatment viral load and alanine aminotransferase (ALT) levels was obtained from clinical records. The IL28B genotypes and the other factors were analysed for their association with SVR.

RESULTS

The frequency distribution of rs12979860 CC/CT/TT genotypes was found to be 66.7%, 26.2% and 7.1%, respectively. For rs8099917 genotype, the TT/GT/GG distribution was 73.8%, 21.4% and 4.8%, respectively. SVR was seen in 61.9% of cases (55.6% in genotype 1 and 62.5% in genotype 3). CC genotype at rs12979860 and TT genotype at rs8099917 were significantly higher in responders (P = 0.013 and 0.042, respectively). Lower baseline ALT and rapid viral response were also found to be associated with SVR. On logistic regression analysis, CC genotype at rs12979860 emerged as the most powerful predictor of treatment response.

CONCLUSION

IL28B polymorphisms are strong predictors of SVR in patients from the Indian subcontinent infected with HCV genotype 3 and genotype 1.