Bhim Gopal Dhoubhadel

Serotype-specific effectiveness of 23-valent pneumococcal polysaccharide vaccine against pneumococcal pneumonia in adults aged 65 years or older: a multicentre, prospective, test-negative design study

BACKGROUND The serotype-specific effectiveness of 23-valent pneumococcal polysaccharide vaccine (PPV23) against pneumococcal pneumonia has not been established in people aged 65 years or older. We assessed the effectiveness of PPV23 in this population. METHODS For this multicentre, prospective study, we enrolled all individuals aged 65 years or older with community-onset pneumonia who visited four study hospitals in Japan between Sept 28, 2011, and Aug 23, 2014. Streptococcus pneumoniae was isolated from sputum and blood samples, and serotyped by the capsular Quellung method. Sputum samples were further tested by PCR assay to identify pneumococcal DNA, and positive samples were examined for 50 serotypes by a nanofluidic real-time PCR assay. Urine samples were tested by a urinary antigen test. Serotype-specific vaccine effectiveness was estimated using the test-negative design. FINDINGS 2621 eligible patients visited the study hospitals, of whom 585 did not have sputum samples available and were excluded from our analysis. 419 (21%) of 2036 patients were positive for pneumococcal infection (232 by sputum culture, 317 by sputum PCR, 197 by urinary antigen test, and 14 by blood culture). 522 (26%) patients were judged to be vaccinated in the analyses. Effectiveness of PPV23 was 27·4% (95% CI 3·2 to 45·6) against all pneumococcal pneumonia, 33·5% (5·6 to 53·1) against PPV23 serotypes, and 2·0% (-78·9 to 46·3) against non-PPV23 serotypes. Although no significant differences between subgroups were seen, higher protection was noted in people younger than 75 years, women, and individuals with lobar pneumonia or health-care-associated pneumonia. INTERPRETATION PPV23 showed low to moderate effectiveness against vaccine serotype pneumococcal pneumonia in people aged 65 years or older. To improve the current pneumococcal vaccination programme, the variability of PPV23 effectiveness in different groups of older people must be further investigated. FUNDING Pfizer and Nagasaki University.

A novel high-throughput method for molecular serotyping and serotype-specific quantification of Streptococcus pneumoniae using a nanofluidic real-time PCR system

Serotype-specific quantification data are essential for elucidating the complex epidemiology of Streptococcus pneumoniae and evaluating pneumococcal vaccine efficacy. Various PCR-based assays have been developed to circumvent the drawback of labour-intensive and time-consuming culture-based procedures for serotype determination and quantification of pneumococcus. Here, we applied a nanofluidic real-time PCR system to establish a novel assay. Twenty-nine primer pairs, 13 of which were newly designed, were selected for the assay to cover 50 serotypes including all currently available conjugate and polysaccharide vaccine serotypes. All primer pairs were evaluated for their sensitivity, specificity, efficiency, repeatability, accuracy and reproducibility on the Fluidigm Biomark HD System, a nanofluidic real-time PCR system, by drawing standard curves with a serial dilution of purified DNA. We applied the assay to 52 nasopharyngeal swab samples from patients with pneumonia confirmed by chest X-ray to validate its accuracy. Minimum detection levels of this novel assay using the nanofluidic real-time PCR system were comparable to the conventional PCR-based assays (between 30 and 300 copies per reaction). They were specific to their targets with good repeatability (sd of copy number of 0.1), accuracy (within ±0.1 fold difference in log10 copy number) and reproducibility (sd of copy number of 0.1). When artificially mixed DNA samples consisting of multiple serotypes in various ratios were tested, all the serotypes were detected proportionally, including a minor serotype of one in 1000 copies. In the nasopharyngeal samples, the PCR system detected all the culture-positive samples and 22 out of 23 serotypes identified by the conventional method were matched with PCR results. We conclude that this novel assay, which is able to differentially quantify 29 pneumococcus groups for 45 test samples in a single run, is applicable to the large-scale epidemiological study of pneumococcus. We believe that this assay will facilitate our understanding of the roles of serotype-specific bacterial loads and implications of multiple serotype detections in pneumococcal diseases.

Bacterial Load of Pneumococcal Serotypes Correlates with Their Prevalence and Multiple Serotypes Is Associated with Acute Respiratory Infections among Children Less Than 5 Years of Age

Background Among pneumococcal serotypes, some serotypes are more prevalent in the nasopharynx than others; determining factors for higher prevalence remain to be fully explored. As non-vaccine serotypes have emerged after the introduction of 7-valent conjugate vaccines, study of serotype specific epidemiology is in need. When two or more serotypes co-colonize, they evolve rapidly to defend hosts immune responses; however, a clear association of co-colonization with a clinical outcome is lacking. Methods Children less than 5 years old who were admitted to hospital due to acute respiratory infections (ARI) (n = 595) and healthy children (n = 350) were recruited. Carriage of pneumococcus was determined by culture and lytA PCR in the nasopharyngeal samples. Serotype/serogroup detection and its quantification were done by the nanofluidic real time PCR system. Spearmans correlation and logistic regression were used to examine a correlation of serotype/serogroup specific bacterial load with its prevalence and an association of co-colonization with ARI respectively. Results Serotype/serogroup specific bacterial load was correlated with its prevalence, both in ARI cases (Spearmans rho = 0.44, n = 186; P<0.0001) and healthy children (Spearmans rho = 0.41, n = 115; P<0.0001). The prevalence of multiple serotypes was more common in ARI cases than in healthy children (18.5% vs 7.1%; aOR 2.92, 95% CI: 1.27–6.71; P = 0.01). The dominant serotype in the co-colonization had a 2 log10 higher bacterial load than the subdominant serotype, both in ARI cases (P<0.001) and healthy children (P<0.05). Conclusions High bacterial load in the nasopharynx may help transmit pneumococci among hosts, and increase the chance of successful acquisition and colonization. Co-colonization of multiple serotypes of pneumococci is linked with ARI, which infers the interactions of multiple serotypes may increase their pathogenicity; however, they may compete for growth in number.

23-valent pneumococcal polysaccharide vaccine against pneumococcal pneumonia

www.thelancet.com/infection Vol 17 August 2017 803 2 Revised National Tuberculosis Control Programme. Guidelines for the use of bedaquiline in RNTCP through conditional access under programmatic management of drug resistant tuberculosis in India. RNTCP, Central TB Division, New Delhi, India. http://tbcindia.nic.in/index1.php?lang=1&level =2&sublinkid=4682&lid=3248. (accessed June 9, 2017). 3 Mbuagbaw L. Review of available evidence on the use of bedaquiline for the treatment of multidrug-resistant tuberculosis: data analysis report 2017. http://www.who.int/tb/ publications/2017/Appendix_GDGReport_ Bedaquiline.pdf (accessed June 9, 2017). 4 Udwadia ZF, Amale RA, Mullerpattan JB. Initial experience of bedaquiline use in a series of drug-resistant tuberculosis patients from India. Int J Tuberc Lung Dis 2014; 18: 1315–18. 5 Udwadia ZF, Ganatra S, Mullerpattan JB. Compassionate use of bedaquiline in highly drug-resistant tuberculosis patients in Mumbai, India. Eur Respir J 2017; 49: 1601699.

Predicting deaths in a resource-limited neonatal intensive care unit in Nepal.

Background This study aimed to determine whether the Neonatal Acute Physiology (SNAP) scoring system (SNAP II) and with perinatal extension (SNAP II PE) can be used to predict neonatal deaths in a resource-limited neonatal intensive care unit in Nepal. Methods A prospective observational study was conducted in a neonatal intensive care unit (NICU) of Kanti Childrens Hospital in Kathmandu, Nepal. Data required for the SNAP II and SNAP II PE scores were collected. The relationships between the SNAP II and SNAP II PE scores and neonatal mortality were analyzed. Results There were 135 neonates admitted during the 6 month study period, of whom 126 met the inclusion criteria. Of these 126 neonates, 29 (23.0%) died. Mortality was 83% (5/6) when SNAP II was >40, and 66.7% (6/9) when SNAP II PE was >50. A SNAP II score of ≥12 had a sensitivity of 75.9%, and specificity of 73.2% for predicting mortality, and a SNAP II PE score of ≥14 had a sensitivity of 82.8% and specificity of 67.0% for it. Conclusions SNAP II and SNAP II PE scoring of neonates can be used to predict prognosis of neonates in resource-limited NICUs in Nepal.

Detection of Cryptosporidium parvum and Cyclospora cayetanensis infections among people living in a slum area in Kathmandu valley, Nepal

ObjectiveThe aim of this study is to determine the prevalence of Cyclospora cayetanensis and Cryptosporidium parvum infections among people living a slum in Kathmandu valley, Nepal.ResultsTen different parasites were detected in the stool samples; the prevalence of any parasite was in 27.1% (71/262). The prevalence of C. cayetanensis and C. parvum were 14.1% (10/71) and 5.6% (4/71), respectively. This study showed high prevalence of intestinal parasitic infections along with the coccidian parasites in the slum area of Kathmandu Valley.

A 14-year-old girl presenting with tuberculous intestinal perforation while in a temporary shelter after the 2015 earthquake in Nepal

Abstract A 14-year-old Nepalese girl presented with fever, abdominal pain and vomiting. She was living with her family in a temporary settlement camp following the earthquake in Nepal in 2015. She had had abdominal pain for 2 months and fever for 1 month. Abdominal examination suggested acute peritonitis. At laparotomy, three ileal perforations were detected and histopathology demonstrated caseous granulomas. Her father had sputum-positive pulmonary tuberculosis. She was diagnosed with abdominal tuberculosis and responded well to anti-tuberculosis chemotherapy. Intestinal perforation is a rare complication of tuberculosis in children.

Accuracy of High-Throughput Nanofluidic PCR-Based Pneumococcal Serotyping and Quantification Assays Using Sputum Samples for Diagnosing Vaccine Serotype Pneumococcal Pneumonia: Analyses by Composite Diagnostic Standards and Bayesian Latent Class Models

ABSTRACT The lack of reliable diagnostic tests for detecting vaccine serotype pneumococcal pneumonia (VTPP) remains a challenging issue in pneumococcal vaccine studies. This study assessed the performances of high-throughput nanofluidic PCR-based pneumococcal serotyping and quantification assay methods using sputum samples (the nanofluidic sputum quantitative PCR [Sp-qPCR] assay) to diagnose 13-valent pneumococcal conjugate VTPP compared with the performance of the serotype-specific urinary antigen detection (UAD) assay using urine samples. Adult pneumonia patients from Japan were enrolled in this study between September 2012 and August 2014. Sputum samples were subjected to the nanofluidic Sp-qPCR assay, quantitatively cultured, and serotyped by the Quellung reaction (SpQt). Urine samples were tested by the UAD method. The diagnostic performances of these tests were assessed using composite reference standards and Bayesian latent class models (BLCMs). Among 244 total patients, 27 (11.1%) tested positive with the UAD assay, while 16 (6.6%) and 34 (13.9%) tested positive with the SpQt and nanofluidic Sp-qPCR assays, respectively, with a cutoff value of ≥104 DNA copies/ml, which showed the maximum value of the Youden index. Using BLCMs, the estimated prevalence for VTPP was 12.9%, and the nanofluidic Sp-qPCR assay demonstrated the best performance (sensitivity, 90.2%; specificity, 96.9%), followed by UAD (sensitivity, 75.6%; specificity, 97.9%) and SpQt (sensitivity, 45.8%; specificity, 99.5%). However, when a higher cutoff value of ≥107 DNA copies/ml was applied, the performance of UAD became comparable to that of Sp-qPCR. The vaccine serotype-specific pneumococcal DNA load in sputum among UAD-positive patients was 3 logs higher than that among UAD-negative patients (P = 0.036). The nanofluidic Sp-qPCR assay may be accurate and useful for detecting VTPP among adults.

Influenza Vaccine Effectiveness Against Influenza-Associated Pneumonia and Pneumococcal Pneumonia in Older Adults: A Prospective Test-Negative Design Study

Abstract Background Studies have shown that influenza vaccines are effective in preventing influenza-associated acute respiratory illnesses in older adults. However, the influenza vaccine effectiveness (IVE) against influenza-associated pneumonia in this age group has not been established. No study has formally investigated the IVE against pneumococcal pneumonia. Methods This study was conducted as part of a multicenter prospective investigation of adult pneumonia by the Adult Pneumonia Study Group-Japan (APSG-J). All community-onset pneumonia patients aged 65 years or older who visited a community-based hospital in Chiba, central Japan were enrolled to the study from December 2012 to January 2014. Sputum samples were tested for 13 viruses and 6 bacteria by multiplex PCR assays. Patients were diagnosed as influenza-associated pneumonia if sputum PCR assays were positive for influenza A or B. Patients were diagnosed as pneumococcal pneumonia if sputum culture yielded pneumococcus, sputum PCR assays were positive for both ply and lytA genes, or a urinary antigen test showed a positive result. Patients were considered vaccinated if they had received at least one dose of seasonal inactivated influenza vaccine in the 12 months before the hospital visit. A test-negative design was applied to estimate the IVE for influenza-associated pneumonia and pneumococcal pneumonia. IVEs were calculated as (1 – odds ratio) × 100%. Results A total of 1044 patients were enrolled to the study. Among them, 49 (4.7%) were influenza-associated pneumonia, and 168 (16.1%) were pneumococcal pneumonia. The adjusted IVE against influenza-associated pneumonia was 57.2% (95% CI, 17.9% to 76.8%). The adjusted IVE against pneumococcal pneumonia was 31.7% (0.6% to 53.1%); the estimate did not change before and after controlling for pneumococcal vaccination history. Conclusion Influenza vaccines effectively prevent influenza-associated pneumonia in older adults. Influenza vaccines are also associated with decreased risk of pneumococcal pneumonia in this age group, while some residual confounding may remain. Disclosures All authors: No reported disclosures.

Risk for Death among Children with Pneumonia, Afghanistan

In Afghanistan, childhood deaths from pneumonia are high. Among 639 children at 1 hospital, the case-fatality rate was 12.1%, and 46.8% of pneumococcal serotypes detected were covered by the 13-valent vaccine. Most deaths occurred within 2 days of hospitalization; newborns and malnourished children were at risk. Vaccination could reduce pneumonia and deaths.