Rajni Gaind

Current perspectives of enteric fever: a hospital-based study from India

Abstract The last two decades have seen a change in the pattern of enteric fever with the emergence of multidrug-resistant strains (MDRS), particularly strains resistant to nalidixic acid. Aim: The aim of the study was to undertake a retrospective analysis of blood culture-confirmed cases of enteric fever diagnosed at Safdarjang Hospital, New Delhi, India from January 2001 to December 2003. Methods: The epidemiological details, clinical features, treatment outcome and antimicrobial resistance patterns were studied. Results: Of 377 blood culture-positive cases, 80.6% were Salmonella typhi and 19.4% Salmonella paratyphi A; 21.7% were children aged under 5 years and 6.1% were under 2 years. A significant decline in MDRS was observed, from 21.9% in 2001 to 12.4% in 2003 (p=0.04). There was a significant increase in nalidixic acid-resistant Salmonella (NARS) from 56.9% in 2001 to 88.9% in 2003 (p=0.0001). Complete resistance to ciprofloxacin (MIC>4 μg/ml) was detected in only two isolates, both Salmonella paratyphi A. Minimal inhibitory concentrations (MICs) of ciprofloxacin for NARS were increased (0.125–0.5 μg/ml) but were within National Committee for Clinical Laboratory Standards susceptibility ranges. NARS had a significantly longer fever defervescence time (7.7 vs 4.7 days, p<0.001) and hospital stay (12.1 vs 8.2 days, p<0.001), and higher rates of complications (55.5% vs 24.0%, p=0.014) and mortality than nalidixic acid-sensitive Salmonella (NASS). The rate of isolation of MDRS was higher in NARS than NASS (18.8% vs 7.3%, p=0.013). Conclusion: The high rate of occurrence of enteric fever in children <5 years and also of infections caused by Salmonella paratyphi A in India calls for critical re-assessment of vaccination strategy. Nalidixic acid resistance and rising MICs of fluoroquinolones in Salmonella spp pose a new global threat requiring debate on the optimum treatment of enteric fever.

Genetic characterization of Chikungunya virus from New Delhi reveal emergence of a new molecular signature in Indian isolates

BackgroundChikungunya (CHIK) is currently endemic in South and Central India and exist as co-infections with dengue in Northern India. In 2010, New Delhi witnessed an outbreak of CHIK in the months October-December. This was the first incidence of a dominant CHIK outbreak in Delhi and prompted us to characterize the Delhi virus strains. We have also investigated the evolution of CHIK spread in India.FindingsClinical samples were subjected to RT-PCR to detect CHIK viral RNA. The PCR amplified products were sequenced and the resulting sequences were genetically analyzed. Phylogenetic analysis based on partial sequences of the structural proteins E1 and E2 revealed that the viruses in the latest outbreak exhibited ECSA lineage. Two novel mutations, E1 K211E and E2 V264A were observed in all Delhi isolates. In addition, CHIKV sequences from eight states in India were analyzed along with Delhi sequences to map the genetic diversity of CHIKV within the country. Estimates of average evolutionary divergence within states showed varying divergence among the sequences both within the states and between the states. We identified distinct molecular signatures of the different genotypes of CHIKV revealing emergence of a new signature in the New Delhi clade. Statistical analyses and construction of evolutionary path of the virus within the country revealed gradual spread of one specific strain all over the country.ConclusionThis study has identified unique mutations in the E1 and E2 genes and has revealed the presence of ancestral CHIKV population with maximum diversity circulating in Maharashtra. The study has further revealed the trend of CHIK spread in India since its first report in 1963 and its subsequent reappearance in 2005.

Extended-spectrum β lactamase-producing gram-negative bacteria: clinical profile and outcome in a neonatal intensive care unit

Abstract Background & aims: Multidrug-resistant extended-spectrum β lactamase-producing bacteria (ESBL) have emerged as a common problem globally. However, data regarding clinical profile and outcome in neonates infected with ESBL-producing gram-negative bacteria are sparse. Methods: A retrospective study was undertaken of all neonates admitted between April 2002 and May 2003 to the neonatal intensive care unit, Safdarjang Hospital, New Delhi who had blood cultures positive for gram-negative bacteria. The clinical profile and outcome in each patient was obtained from the case notes. The mortality and morbidity of the ESBL (cases) and non-ESBL groups were compared. Data were analysed using the χ2 and Students t-tests. Results: There were 75 cases of gram-negative septicaemia, 46 newborns (61.3%) were infected with ESBL-producing strains and 63 case records were available. ESBL production was associated with prematurity (24/38 vs 9/25, p=0.03), prolonged rupture of membranes (14/38 vs 2/25, p=0.01) and previous antibiotic administration to the infant (15/38 vs 1/25, p=0.002). Fifty per cent of infants with early-onset sepsis and 82.1% with late-onset sepsis were infected with ESBL strains. Newborns with ESBL sepsis were more likely to manifest persistent thermal instability (13/38 vs 3/25, p=0.04) and pre-feed gastric aspirates (18/38 vs 3/25, p=0.004). More than 90% of ESBL isolates were susceptible to carbapenems, cefperazone–sulbactam and piperacillin–tazobactam. The mean length of nursery stay (15.8 vs 10.7, p=0.02) and mortality (23.6 vs 4.0%, p=0.07) were higher in the ESBL group and onset of feeds was delayed (7.6 vs 3.9 days, p=0.007) in this group. Conclusions: Isolation of ESBL in cases of early-onset sepsis indicates that ESBL producers might have percolated into the community. Early suspicion of ESBL-producing isolates in cases of neonatal sepsis can facilitate prompt institution of appropriate empirical therapy and lead to an improved outcome.

Community acquisition of β-lactamase producing Enterobacteriaceae in neonatal gut

BackgroundCommensal flora constitutes a reservoir of antibiotic resistance. The increasing variety of β-lactamases and the emergence of Carbapenem resistant Enterobacteriaceae (CRE) in community, raise concerns regarding efficacy of β-lactams. It is important to know the exact load of antibiotic resistance in the absence of any antibiotic selection pressure including via food and water.In the present study gut colonization in neonates with no direct antibiotic pressure was used as a model to evaluate β-lactam resistance in the community.ResultsIn this prospective study, 75 healthy, vaginally delivered, antibiotic naive, breast fed neonates were studied for gut colonization by Extended spectrum β-lactamases (ESBL), AmpC β-lactamases hyperproducing Enterobacteriaceae and CRE on day 0, 21 and 60. Total 267 Enterobacteriaceae were isolated and E.coli was the predominant flora. ESBL, AmpC and coproduction was seen in 20.6%, 19.9% and 11.2% isolates respectively. ESBL carriage increased threefold from day 1 to 60 showing predominance of CTX-M group 15 (82.5%), ampC genes were heterogeneous. Colonization with CRE was rare, only one baby harboured Enterobacter sp positive for kpc-2. The reservoirs for these genes are likely to be mother and the environment.ConclusionsData strongly suggests that in absence of any antibiotic pressure there is tremendous load of antibiotic resistance to β-lactam drugs. Wide spread presence of ESBL and AmpC can drive rapid emergence and dissemination of CRE. This is the first report from India which depicts the smaller picture of true antibiotic pressure present in the Indian community.

Evaluation of a modified double-disc synergy test for detection of extended spectrum β-lactamases in AMPC β-lactamase-producing proteus mirabilis

The detection of extended-spectrum β-lactamases (ESBLs) in gram-negative bacteria that produce AmpC β-lactamases is problematic. In the present study, the performance of modified double-disc synergy test (MDDST) that employs a combination of cefepime and piperacillin-tazobactam for the detection of Proteus mirabilis producing extended spectrum and AmpC β-lactamases was evaluated and compared with double-disc synergy test (DDST) and NCCLS phenotypic disc confirmatory test (NCCLS-PDCT). A total of 90 clinical isolates of P. mirabilis , which met the CLSI (Clinical and Laboratory Standards Institute) screening criteria that these had broth microdilution (BMD) MIC of ≥2 mg/mL for at least one extended spectrum cephalosporin [ceftazidime (CAZ), cefotaxime (CTX) and cefpodoxime], were selected for the study. MDDST detected ESBLs in 40/90 of the isolates, whereas DDST detected ESBLs in only 25 isolates. NCCLS-PDCT could detect ESBLs in 39 isolates using CAZ and CAZ + clavulanic acid (CLA) combination, whereas CTX and CTX + CLA combination could detect only 37 isolates as ESBL positive. As many as 34/40 ESBL positive isolates were confirmed to be AmpC β-lactamase positive by the modified three-dimensional test (MTDT). MDDST and NCCLS-PDCT could detect ESBLs in all the 34 AmpC positive isolates, whereas DDST could detect ESBLs in only 19 isolates. The study demonstrated that MDDST is superior to DDST and as sensitive as NCCLS-PDCT. However, MDDST seems to have enhanced potential for the detection of ESBLs in AmpC β-lactamase-producing P. mirabilis .

Phenotypic characterization and colistin susceptibilities of carbapenem- resistant of Pseudomonas aeruginosa and Acinetobacter spp.

INTRODUCTION Pseudomonas aeruginosa and Acinetobcter spp. are important nosocomial pathogens and carbapenem resistance is an emerging threat. Therapeutic options for infections with these isolates include colistin. This study was conducted to determine the prevalence of carbapenem resistance in P. aeruginosa and Acinetobacter spp. bloodstream isolates, phenotypically characterize the resistance mechanisms and evaluate the in vitro activity of colistin. METHODOLOGY Consecutive 145 (95 P.aeruginosa and 50 Acinetobacter spp.) non-repeat isolates were included. Antibiotic susceptibility testing was performed per CLSI guidelines. MIC for carbapenems and colistin was performed using Etest. Isolates showing reduced susceptibility or resistance to the carbapenems were tested for metallo-β-lactamase (MBL) production using imipenem-EDTA combined disk and MBL Etest. RESULTS Carbapenem resistance was observed in 40% P. aeruginosa and 66.0% Acinetobacter spp. Carbapenem-resistant (CA-R) isolates were significantly (p <0.05) more frequently resistant to the other antibiotics than carbapenem-susceptible isolates. Approximately half of the CA-R strains were multidrug-resistant, and 3.1-5.5% were resistant to all antibiotics tested. MBL was found in 76.3% and 69.7% of the P. aeruginosa and Acinetobacter spp., respectively. Colistin resistance was observed in three (6.0%) Acinetobacter isolates and eight (8.4%) P. aeruginosa. MIC50 for carbapenems were two to four times higher for MBL-positive compared to MBL-negative isolates, but no difference was seen in MIC for colistin. CONCLUSION Carbapenem resistance was observed to be mediated by MBL in a considerable number of isolates. Colistin is an alternative for infections caused by CA-R isolates; however, MIC testing should be performed whenever clinical use of colistin is considered.

Clinically and Microbiologically Derived Azithromycin Susceptibility Breakpoints for Salmonella enterica Serovars Typhi and Paratyphi A

ABSTRACT Azithromycin is an effective treatment for uncomplicated infections with Salmonella enterica serovar Typhi and serovar Paratyphi A (enteric fever), but there are no clinically validated MIC and disk zone size interpretative guidelines. We studied individual patient data from three randomized controlled trials (RCTs) of antimicrobial treatment in enteric fever in Vietnam, with azithromycin used in one treatment arm, to determine the relationship between azithromycin treatment response and the azithromycin MIC of the infecting isolate. We additionally compared the azithromycin MIC and the disk susceptibility zone sizes of 1,640 S. Typhi and S. Paratyphi A clinical isolates collected from seven Asian countries. In the RCTs, 214 patients who were treated with azithromycin at a dose of 10 to 20 mg/ml for 5 to 7 days were analyzed. Treatment was successful in 195 of 214 (91%) patients, with no significant difference in response (cure rate, fever clearance time) with MICs ranging from 4 to 16 μg/ml. The proportion of Asian enteric fever isolates with an MIC of ≤16 μg/ml was 1,452/1,460 (99.5%; 95% confidence interval [CI], 98.9 to 99.7) for S. Typhi and 207/240 (86.3%; 95% CI, 81.2 to 90.3) (P < 0.001) for S. Paratyphi A. A zone size of ≥13 mm to a 5-μg azithromycin disk identified S. Typhi isolates with an MIC of ≤16 μg/ml with a sensitivity of 99.7%. An azithromycin MIC of ≤16 μg/ml or disk inhibition zone size of ≥13 mm enabled the detection of susceptible S. Typhi isolates that respond to azithromycin treatment. Further work is needed to define the response to treatment in S. Typhi isolates with an azithromycin MIC of >16 μg/ml and to determine MIC and disk breakpoints for S. Paratyphi A.

Oropharyngeal candidiasis and Candida colonization in HIV positive patients in northern India.

INTRODUCTION Oropharyngeal candidiasis (OPC) is the most common opportunistic fungal infection reported in human immunodeficiency virus (HIV) positive patients worldwide. This prospective study was undertaken to investigate OPC and Candida colonization (CC) and their correlation with CD4+ cell counts and antiretroviral therapy (ART) in HIV-positive patients. METHODOLOGY In total, 190 HIV-positive patients were enrolled for study in three groups as follows: Group A, 90 patients without ART; Group B, 100 patients undergoing treatment with ART; and Group C, 75 HIV-negative control patients. All HIV patients underwent clinical examination and were subjected to CD4+ cell counts. Swabs were collected from the oral cavity of all individuals and plated on Sabourauds dextrose agar. Identification of Candida species was performed by conventional methods. RESULTS Candida species were isolated in 84/190 (44.2%) and 20/75 (26.6%) of the HIV-positive subjects and controls respectively (p<0.01). OPC was noted in 21/190 (11%) of the HIV-positive patients. Candida albicans was the most frequently isolated species. Patients with CD4+ cell counts ≤ 200 cells/mm3 were significantly (p<0.001) more frequently colonized (37/63; 58.7%) and infected (18/21; 85.7 %) with Candida species. Candida species was seen in patients with CC and OPC with CD4+cell counts between 201 and 500 (21/63; 33.4% vs 3/21; 14.3%) and > 500 cell/mm3 (5/63; 7.9% versus 0/21 0%) respectively. CONCLUSION OPC and Candida colonization occur more frequently in HIV-positive patients with CD4+ cell counts ≤ 200 cell/mm3. ART significantly reduces OPC. C. albicans is the most frequently isolated species in both OPC and colonization, suggesting endogenous infection.

Role of probiotics VSL#3 in prevention of suspected sepsis in low birthweight infants in India: a randomised controlled trial.

Objectives To assess the effect of the probiotic VSL#3 in prevention of neonatal sepsis in low birthweight (LBW) infants. Design Randomised, double-blind, placebo-controlled trial. Setting Community setting in rural India. Participants LBW infants aged 3–7 days. Interventions Infants were randomised to receive probiotic (VSL#3, 10 billion colony-forming units (cfu)) or placebo for 30 days, and were followed up for 2 months. Main outcome measure Possible serious bacterial infection (PSBI) as per the Integrated Management of Neonatal Childhood Illnesses algorithm, as diagnosed by fieldworkers/physicians. Results 668 infants were randomised to VSL#3 and 672 to placebo. By intention-to-treat analysis, the risk of PSBI among infants in the overall population of LBW infants was not statistically significant (RR 0.79 (95% CI 0.56 to 1.03)). Probiotics reduced median days of hospitalisation (6 days vs 3 days in probiotics) (p=0.018) but not the risk of hospitalisation (RR 0.66 (95% CI 0.42 to 1.04). The onset of PSBI in 10% of infants occurred on the 40th day in the probiotics arm versus the 25th day in the control arm (p=0.063). Conclusions Daily supplementation of LBW infants with probiotics VSL#3 (10 billion cfu) for 30 days led to a non-significant 21% reduction in risk of neonatal sepsis. A larger study with sufficient power and a more specific primary end point is warranted to confirm the preventive effect of VSL#3 on neonatal sepsis in LBW infants. Trial registration number The study is registered at the Clinical Trial Registry of India (CTRI/2008/091/000049).

Chikungunya outbreak in Delhi, India, 2016: report on coinfection status and comorbid conditions in patients

Chikungunya fever is a major public health issue in India affecting billions. After 2010, the infection was in a decline until in 2016, when a massive outbreak affected the country. In this report, we present serologic and molecular investigations of 600 patient samples for chikungunya and dengue viruses along with clinical and comorbidity features. We recruited 600 patients during this outbreak and evaluated them for chikungunya and dengue virus antibodies and virus RNA through IgM, NS1 antigen and quantitative real-time PCR (qPCR). We further evaluated Zika virus RNA by qPCR. Additionally, we documented all clinical and comorbid features that were observed during the outbreak in the hospital. We report a total incidence rate of 58% of chikungunya during the outbreak in our hospital. Within the recruited patients, 70% of the patients were positive for chikungunya virus IgM whereas 24.17% were positive by qPCR. None of the samples was positive for Zika virus RNA. Additionally, coinfection of dengue and chikungunya was seen in 25.33% of patients. Analysis of clinical features revealed that 97% of patients had restricted movements of the joints with other features like swelling, itching and rashes of varying severity observed. Twelve patients presented with comorbid conditions, and two fatalities occurred among these comorbid patients. The high incidence of coinfection in the current outbreak warrants implementation of routine testing of both chikungunya and dengue virus in suspected patients for better patient management. The post–acute phase complications reported in the hospitals require in-depth studies to understand the actual impact of the current outbreak.