Mycobacterium chimaera: A novel pathogen with potential risk to cardiac surgical patients.

Mycobacterium chimaera was first described in 2004, coming to prominence in 2011 with reports from across the globe of invasive infections following cardiac surgery. This outbreak was linked to a specific type of heater cooler machine used for cardiac surgery by whole-genome sequencing. We briefly outline what is currently known about this pathogen, highlighting the importance of clinical vigilance and the diagnostic options for the clinician.

Patterns of antibiotic use in the community and challenges of antibiotic surveillance in a lower-middle-income country setting: a repeated cross-sectional study in Vellore, South India.

OBJECTIVES: There is considerable evidence linking antibiotic usage to bacterial resistance. Intervention strategies are needed to contain antibiotic use and thereby resistance. To plan appropriate strategies, it is imperative to undertake surveillance in the community to monitor antibiotic encounters and drivers of specific antibiotic misuse. Such surveillance is rarely in place in lower-middle-income countries (LMICs). This study describes antibiotic patterns and challenges faced while developing such surveillance systems in an LMIC. PATIENTS AND METHODS: Surveillance of antibiotic encounters (prescriptions and dispensations) was carried out using a repeated cross-sectional design for 2 years in Vellore, south India. Every month, patients attending 30 health facilities (small hospitals, general practitioner clinics and pharmacy shops) were observed until 30 antibiotic encounters were attained in each. Antibiotic use was expressed as the percentage of encounters containing specific antibiotics and defined daily doses (DDDs)/100 patients. Bulk antibiotic sales data were also collected. RESULTS: Over 2 years, a total of 52,788 patients were observed and 21,600 antibiotic encounters (40.9%) were accrued. Fluoroquinolones and penicillins were widely used. Rural hospitals used co-trimoxazole more often and urban private hospitals used cephalosporins more often; 41.1% of antibiotic prescriptions were for respiratory infections. The main challenges in surveillance included issues regarding sampling, data collection, denominator calculation and sustainability. CONCLUSIONS: Patterns of antibiotic use varied across health facilities, suggesting that interventions should involve all types of health facilities. Although challenges were encountered, our study shows that it is possible to develop surveillance systems in LMICs and the data generated may be used to plan feasible interventions, assess impact and thereby contain resistance.

Differential diagnosis of scrub typhus meningitis from bacterial meningitis using clinical and laboratory features.

BACKGROUND: Central nervous system (CNS) involvement in the form of meningitis or meningoencephalitis is common in scrub typhus. As specific laboratory methods remain inadequate or inaccessible in developing countries, prompt diagnosis is often difficult. AIM: To identify the clinical and laboratory parameters that may help in differentiating scrub typhus meningitis from bacterial meningitis. SETTING AND DESIGN: This is a cross-sectional analysis of adult patients admitted with scrub typhus and bacterial meningitis to a tertiary care teaching institute in South India. MATERIALS AND METHODS: A comparison of clinical and laboratory features of 25 patients admitted with meningitis to a university teaching hospital during a 15-month period was made. These patients had meningitis diagnosed based on abnormal cerebrospinal fluid (CSF) analysis with either positive IgM scrub typhus ELISA serology (n =16) or with CSF culture isolating bacteria known to cause bacterial meningitis (n =9). The clinical and laboratory features of the patients with scrub typhus meningitis and bacterial meningitis were compared. RESULTS: The mean age was similar in the scrub typhus and bacterial meningitis groups (44.0 ± 18.5 years vs. 46.3 ± 23.0 years). Features at admission predictive of a diagnosis of scrub typhus meningitis were duration of fever at presentation >5 days (8.4 ± 3.5 days vs. 3.3 ± 4.2 days, P < 0.001), CSF white cell count of a lesser magnitude (83.2 ± 83.0 cells/cumm vs. 690.2 + 753.8 cells/cumm, P < 0.001), CSF lymphocyte proportion >50% (83.9 ± 12.5% vs. 24.8 ± 17.5% P < 0.001), and alanine aminotransferase (ALT) elevation more than 60 IU (112.5 ± 80.6 IU vs. 35 ± 21.4 IU, P =0.02). CONCLUSION: This study suggests that clinical features, including the duration of fever and laboratory parameters such as CSF pleocytosis, CSF lymphocyte proportion >50%, and ALT values are helpful in differentiating scrub typhus from bacterial meningitis.

Surveillance of antimicrobial resistance in resource-constrained settings - experience from five pilot projects.

OBJECTIVE: The rapid increase in antimicrobial resistance (AMR) among bacteria is a major public health concern. The WHO Global Strategy for Containment of Antimicrobial Resistance proposed that model systems be developed for AMR surveillance and for monitoring antimicrobial use. METHODS: Pilot projects were established in three sites in India and two in South Africa to collect monthly AMR data on target bacteria for at least 12 months. Escherichia coli was used as the target bacterium in four sites (three in India, one in South Africa). One South African site used Streptococcus pneumoniae and Haemophilus influenzae. Each site sought to obtain at least 960 isolates per year. Resistance was determined by disc diffusion or minimum inhibitory concentration (MIC) methods. RESULTS: Data were collected for 12 and 16 months respectively in the South African sites and for 14 months in one Indian site and 24 months in the other two. All sites found difficulty collecting the required number of isolates, with three sites failing to do so. Escherichia coli isolates were more easily obtained and two sites developed methods to increase their yield. Disc diffusion testing provided more timely and reliable AMR data than did MIC determinations. Although methodological issues limit the comparability of data, high AMR rates were observed at all five sites. CONCLUSION: All five pilot sites provided data on AMR, but also raised several issues related to logistics of long-term surveillance in settings under resource constraints. For surveillance of AMR in such settings, E. coli is probably the best indicator bacterium.

Antimicrobial resistance surveillance among commensal Escherichia coli in rural and urban areas in Southern India.

OBJECTIVE: To assess antimicrobial resistance (AMR) in Tamil Nadu, India. METHODS: Data on AMR of commensal and uropathogenic Escherichia coli were collected from one urban (Christian Medical College Hospital, Vellore) and one rural (CMCH Rural Unit for Health and Social Affairs) centre in Tamil Nadu at monthly intervals for 1 year. RESULTS: Forty-two per cent of commensal E. coli was resistant to one or more of the tested antimicrobials. 8.4% were resistant to three drugs commonly used for the treatment of urinary tract infections, namely ampicillin, co-trimoxazole and nalidixic acid. 1.5% of isolates were resistant to nitrofurantoin. There was no significant difference between resistance rates in commensal E. coli collected in rural and urban areas. Resistance was more common in infecting than commensal strains. DISCUSSION: Resistance to most antimicrobials is high both in urban and rural areas. Higher resistance to antimicrobials used widely for the treatment suggests that drug use contributes to it. Hence unnecessary use of antimicrobials must be avoided. Surveillance among commensal E. coli can be used to monitor changes in AMR over time.

Serological evidence for wide distribution of spotted fevers & typhus fever in Tamil Nadu.

BACKGROUND & OBJECTIVE: Although the re-emergence of spotted fevers and typhus was documented from southern India a few years ago, there was a paucity of community based data. Therefore a collaborative study was carried out in several districts of Tamil Nadu to understand the distribution of these infections. METHODS: Blood (3 ml) was collected from patients presenting to primary health centres (PHCs) with fever >10 days duration in 15 districts of Tamil Nadu during January 2004 to December 2005. Patients negative for malaria, were tested by Weil-Felix test. Clinical data were collected from patients visiting two hospitals. RESULTS: A total 306 samples were tested in 2004 and 115 (37.5%) had titres of >or=80 with OX K antigen, suggesting a diagnosis of scrub typhus. During 2005, 964 patients were tested and 89 (9.2%) were positive for scrub typhus. An additional 44 (4.6%) were positive for other rickettsial illnesses. In both years majority of scrub typhus occurred in individuals above 14 yr of age. Cases increased from August until the earlier part of next year. INTERPRETATION & CONCLUSION: This community based study from south India involving several districts in Tamil Nadu, showed that scrub typhus and rickettsial illnesses were widely distributed in the State. Measures to increase awareness and also to diagnose and treat this infection in the affected areas are essential.

Evaluation of tests for serological diagnosis of scrub typhus.

Two specific serological tests, a Dot enzyme immunoassay (EIA) and an immunoglobulin (Ig)M enzyme-linked immunosorbent assay (ELISA) using the 56 kDa antigen and the Weil-Felix test were evaluated for diagnosis of scrub typhus. Sensitivity of 100, 86.5 and 43.5% were observed with Dot EIA, IgM ELISA and Weil-Felix test, respectively. False-positive reactions were observed in patients with falciparum malaria, pulmonary tuberculosis, S. viridans septicemia and typhoid fever using Dot EIA and IgM ELISA. Therefore, although Dot EIA and IgM ELISA are useful in the serodiagnosis of scrub typhus, efforts should be made to rule out other febrile illnesses.

Some virulence characteristics of uropathogenic Escherichia coli in different patient groups.

BACKGROUND & OBJECTIVE: Uropathogenic Escherichia coli have virulence properties, that are absent in non pathogenic E. coli. The distribution of these markers can vary according to patient populations. Hence, a study was undertaken to describe the presence of virulence factors like Pfimbriae, type 1 fimbriae and haemolysin in E.coli causing urinary infections in three groups of patients. Antibiogram was also recorded to determine differences, if any, between the groups. METHODS: E. coli isolated from three groups of subjects, in counts of >10(5) CFU/ml and in pure growth were tested for mannose resistant haemagglutination (MRHA) to indicate P fimbriae and mannose sensitive haemagglutination (MSHA) to indicate type 1 fimbriae. Haemolysin production and antimicrobial susceptibility patterns were also recorded. RESULTS: Significantly more isolates from antenatal and postnatal women possessed P fimbriae compared to groups with urologic abnormalities (P=0.05). Haemolysin production was also significantly higher (P<0.001) in this group. Greater proportions of isolates from pregnant women were susceptible to commonly used antimicrobials. However, resistance to third generation cephalosporins was present even in these isolates from community infections. INTERPRETATION & CONCLUSION: In patients with urological abnormality, E. coli with lower virulence can cause infections. Isolates from these patients exhibited greater drug resistance. In pregnant women and in community acquired infections, simple antimicrobial drugs like nitrofurantoin might still be useful. However, urgent and stringent policies for antimicrobial use and infection control in hospitals are required in India.

Integrons and multidrug resistance among Escherichia coli causing community-acquired urinary tract infection in southern India.

Antimicrobial resistance genes are often clustered in integrons, genetic elements capable of recombination. There is a paucity of data on the prevalence and role of integrons from community-acquired infections in developing countries where resistance to co-trimoxazole is high. We determined the prevalence of integrons among Escherichia coli causing community-acquired urinary tract infection (UTI). Consecutive isolates of E. coli obtained from UTI of pregnant women at the Christian Medical College Hospital, Vellore, India, during 2002 were included. All isolates were tested for susceptibility to 16 antimicrobials using the disc diffusion method and for integrons of classes 1 and 2 by PCR. Of the 58 isolates tested, 28 (48.3%) were resistant to co-trimoxazole and trimethoprim. All these isolates carried integrons. Three additional isolates were sulfonamide resistant but integron negative. Class 1 integrons were present in 21 (36.2%) isolates. Resistance to ampicillin (p=0.000), nalidixic acid (p=0.001), chloramphenicol (p=0.02), tetracycline (p=0.004) and gentamicin (p=0.02) was significantly more common in isolates with integrons. DNA sequencing of two isolates with integrons showed the presence of aadA, dfr1 and dfr7 genes. This study demonstrated that integrons are widely prevalent in India and that they might play a role in multidrug resistance in E. coli from community-acquired UTI.

Evaluation of topical povidone-iodine in chronic suppurative otitis media.

OBJECTIVES: To evaluate if povidone-iodine (PVP-I) can be used topically in the treatment of chronic suppurative otitis media-tubotympanic disease and to compare it with ciprofloxacin hydrochloride ear drops. DESIGN: Prospective double-blind randomized study. SETTING: Academic tertiary medical center. PATIENTS: Forty patients with chronic suppurative otitis media were randomized into 2 groups. INTERVENTION: One group (19 patients) received 5% PVP-I ear drops, while the other group (21 patients) received 0.3% ciprofloxacin ear drops. Both were administered topically, 3 drops 3 times daily for 10 days. These patients were followed up at weekly intervals for up to 4 weeks after commencing therapy. RESULTS: Clinical improvement at the end of study was 88% in the PVP-I group and 90% in the ciprofloxacin group. The most commonly isolated organism was Pseudomonas aeruginosa. In vitro resistance to ciprofloxacin was seen in 17% of organisms, while no resistance was seen for PVP-I. CONCLUSIONS: To our knowledge, this is the first study to evaluate the efficacy of PVP-I as a topical agent in the treatment of chronic suppurative otitis media. The results show that clinically, topical PVP-I is as effective as topical ciprofloxacin, with a superior advantage of having no in vitro drug resistance. Also, there is an added benefit of reduced cost of therapy.

Typhidot test to detect IgG & IgM antibodies in typhoid fever.

BACKGROUND & OBJECTIVES: As typhoid fever is endemic in India, there is a continuing search for a simple test which can be carried out in small laboratories for an early and rapid diagnosis. We have evaluated the Typhidot test for this purpose. METHODS: The Typhidot test was carried out on coded sera according to the manufacturer's instructions. The test was performed on 30 Widal positive sera, 30 sera from blood culture positive patients, 60 Widal negative sera and 30 samples from patients whose blood culture grew Gram negative bacilli (GNB) other than Salmonella Typhi. RESULTS: Typhidot test was positive for both IgG and IgM in 39 samples, IgM alone in 24 and IgG alone in 2. Of the 30 culture positive samples, 27 were positive by Typhidot. The Typhidot test gave a sensitivity of 100 per cent and specificity of 80 per cent when bacteraemic patients were analysed. INTERPRETATION & CONCLUSION: The Typhidot is easy to perform, and requires no special equipment or training of staff for interpretation of results. It will be a useful complementary test to blood culture and the Widal test in the diagnosis of typhoid fever.

Indirect immunofluorescent antibody test for the rapid diagnosis of melioidosis.

Culture is the only reliable method available at present for the diagnosis of melioidosis. Though serological tests have been described, their value in routine diagnosis is controversial. All indirect immunofluorescent assay (IFA) was therefore evaluated to determine its use in the diagnosis of melioidosis. Whole cell antigen prepared from a laboratory isolate of Burkholderia pseudomallei was used to assay IgG and IgM antibodies. Fourteen of the 22 (63.6%) culture proven cases had IgM antibodies while only 10 (45.5%) had IgG antibodies. Negative predictive value of IgM assay was 92 per cent. Positive predictive value was 100 per cent if both IgM and IgG were considered together. The present study done on a limited number of samples suggests that IFA may be useful in routine diagnosis of melioidosis.

Scrub typhus.

Scrub typhus is being increasingly reported in adults in India. It should be considered a strong possibility in all undifferentiated fevers. Two children with this infection are being reported highlighting the wide variation in clinical presentation. Specific tests should be preferred over Weil Felix test wherever possible especially in areas reporting a high incidence of the infection.

Is C-reactive protein level useful in differentiating infected from uninfected neonates among those at risk of infection?

OBJECTIVE: To document effects of intrapartum risk factors for early onset sepsis (EOS) on CRP levels in neonates and to assess the suitability of this test in diagnosing EOS. DESIGN: Cohort study. SETTING: Labour and post natal wards in a tertiary level teaching hospital in India. SUBJECTS: 250 neonates at risk of developing infection. METHODS: CRP levels in cord blood and neonatal blood at 24 hrs were estimated using commercial kits. Babies were observed for signs of sepsis for at least 48 hours. RESULTS: Seven (2.8 Percent) neonates had elevated CRP levels in the cord blood. At 24 hours, 102 (40.8 Percent) babies had elevated levels. Elevated cord CRP levels was significantly associated with rupture of membranes for 24 hours (p =0.04), labour more than 12 hours (p = 0.002), and maternal fever (p = 0.01). At 24 hours, elevated CRP levels were associated with primiparity (p= 0.006), more than three vaginal examinations after membrane rupture (p=0.02), meconium staining of amniotic fluid (p =0.02) and amnioinfusion (p =0.02). Ten (4 Percent) babies developed EOS. The negative predictive value for elevated CRP levels at 24 h was 99 Percent. CONCLUSION: Several intrapartum risk factors for EOS can cause elevation in CRP levels. However, this test may be useful in excluding infection.

Evaluation of serological tests for the diagnosis of tuberculosis.

To evaluate the use of antibody detection kits in the diagnosis of pulmonary tuberculosis in an endemic area, serum samples from cases (sputum smear positive for AFB) and controls (healthy young adults) were collected and tested using five different kits. Sensitivity, specificity and predictive values were calculated using smear positivity as gold standard. Sensitivity of tests varied from 46% to 68% and the specificity from 68% to 100%. None of the kits evaluated can be used as a single screening test for tuberculosis. However kits with good specificity may be used in conjunction with conventional methods for diagnosis.

Antibiotic use and resistance: perceptions and ethical challenges among doctors, pharmacists and the public in Vellore, South India.

Inappropriate antibiotic use and resistance are major public health challenges. Interventional strategies require ascertaining the perceptions of major stakeholders and documenting the challenges to changing practice. Towards this aim, a qualitative study was conducted in Vellore, South India, using focus group discussions among doctors, pharmacists and public. There were eight groups with six to eight participants each. The themes explored were: understanding of infections, antibiotics and resistance; practices and pressure driving antibiotic use; and strategies for appropriate use. Data were transcribed, analysed, verified and a summary prepared with salient features and quotations. It was found that the public had minimal awareness of resistance, antibiotics and infections. They wanted symptomatic relief. Doctors reported prescribing antibiotics for perceived patient expectations and quick recovery. Business concerns contributed to antibiotics sales among pharmacists. Pharmaceutical industry incentives and healthcare provider competition were the main ethical challenges. Suggested interventional strategies by the participants included creating public awareness, better healthcare provider communication, improved diagnostic support, strict implementation of guidelines, continuing education, and strengthening of regulations. Perceived patient benefit, unrestricted autonomy and business-cum-industry pressures are promoting inappropriate use of antibiotics. Strategies improving responsible use will help preserve their effectiveness, and provide distributive justice and benefit for future generations.

Pagers and stethoscopes as vehicles of potential nosocomial pathogens in a tertiary care hospital in a developing country.

It has long been recognized that stethoscopes and other inanimate objects carry virulent micro-organisms that can cause nosocomial infections in susceptible patients. Among the frequently used items in hospitals are pagers and stethoscopes. The manner in which these items are used has the potential to cause colonization of bacteria and transfer of these bacteria to another person. This prospective study was performed in order to assess the colonization rates among randomly selected pagers and stethoscopes. We found that 15 (25%) pagers and 11 (27.5%) stethoscopes were contaminated. Enterococci (10%) were the most common isolates found followed by Staphylococci (8%) and Enterobacteriaceae (7%). There was no significant difference in the rates of colonization between shared and personal pagers (P = 0.16). Stethoscopes were more likely to be contaminated with Enterococci compared to pagers (P = 0.013, 95% confidence interval 1.3-52.9). Our findings confirm the need for protocols to prevent transmission of infection through inanimate objects.