The incidence and aetiology of hospitalised community-acquired pneumonia among Vietnamese adults: a prospective surveillance in Central Vietnam

Antimicrobial Resistance Patterns of Common Gram-Negative Microorganisms Isolated from Patients with Lower Respiratory Tract Infections in a Teaching Hospital in Vietnam

This cross-sectional study investigated the antimicrobial resistance (AMR) patterns of gram-negative pathogens isolated from 4,789 hospitalized patients with lower respiratory tract infections (LRTIs). Of the collected specimens, 1,325 (27.7%) tested positive for gram-negative bacteria. Acinetobacter baumannii (38.6%), Pseudomonas aeruginosa (33.5%), Klebsiella pneumoniae (18.7%), Escherichia coli (5.6%), and Klebsiella aerogenes (3.5%) were the most prevalent isolates. AMR analysis revealed high resistance rates (79.9%-100%) of A. baumannii isolates to multiple classes of antibiotics except amikacin, trimethoprim/sulfamethoxazole, and colistin. P. aeruginosa displayed low resistance to colistin (< 10%) but high resistance to other antibiotics. K. pneumoniae displayed high resistance rates of 90.0%-100.0% to most penicillins, whereas resistance rates were notably lower for colistin (7.1%) and amikacin (16.7%). K. aerogenes exhibited high resistance to various antibiotics and sensitivity to amikacin (95.1%), ampicillin (100.0%), and colistin (100.0%). E. coli isolates exhibited resistance to ampicillin (96.9%) and maximum sensitivity to several antibiotics. Our study identified significant AMR trends and highlighted the prevalence of multidrug-resistant strains (93.6% for K. aerogenes and 69.1%-92.4% for other isolates). These findings emphasize the urgent need for appropriate antibiotic management practices to combat AMR in gram-negative pathogens associated with LRTIs.

Epidemiology of pneumonia in hospitalized adults ≥18 years old in four districts of Ulaanbaatar, Mongolia, 2015-2019

BACKGROUND

Community-acquired pneumonia is a leading cause of morbidity and mortality among children and adults worldwide. Adult pneumonia surveillance remains limited in many low- and middle-income settings, resulting in the disease burden being largely unknown.

METHODS

A retrospective cohort study was conducted by reviewing medical charts for respiratory admissions at four district hospitals in Ulaanbaatar during January 2015-February 2019. Characteristics of community-acquired pneumonia cases were summarized by disease severity and age. To explore factors associated with severe pneumonia, we ran univariable and age-adjusted logistic regression models. Incidence rates were calculated using population denominators.

RESULTS

In total, 4290 respiratory admissions met the case definition for clinical pneumonia, including 430 admissions of severe pneumonia. The highest proportion of severe pneumonia admissions occurred in adults >65 years (37.4%). After adjusting for age, there were increased odds of severe pneumonia in males (adjusted odds ratio [aOR]: 1.63; 95% confidence interval [CI]: 1.33-2.00) and those with ≥1 underlying medical condition (aOR: 1.46; 95% CI: 1.14-1.87). The incidence of hospitalized pneumonia in adults ≥18 years increased from 13.49 (95% CI: 12.58-14.44) in 2015 to 17.65 (95% CI: 16.63-18.71) in 2018 per 10,000 population. The incidence of severe pneumonia was highest in adults >65 years, ranging from 9.29 (95% CI: 6.17-13.43) in 2015 to 12.69 (95% CI: 9.22-17.04) in 2018 per 10,000 population.

INTERPRETATIONS

Vaccination and other strategies to reduce the risk of pneumonia, particularly among older adults and those with underlying medical conditions, should be prioritized.

FUNDING

Pfizer clinical research collaboration agreement (contract number: WI236621).

Short-Term Readmission Following Community-Acquired Pneumonia: A Cross-Sectional Study

Background:Community-acquired pneumonia continues to be a major cause of morbidity and mortality. Hospital readmissions following community-acquired pneumonia are linked to significant cost of care and medical burdens. This study aimed to determine the incidence and reasons for readmission as well as to assess factors associated with short-term hospital readmission among community-acquired pneumonia patients. Methods:A retrospective, cross-sectional study was conducted on 582 medical records of community-acquired pneumonia inpatients from December 2018 to December 2019 at an 800-bed tertiary hospital in Ho Chi Minh City, Vietnam. We collected data on patient characteristics, pneumonia severity at hospital admission, microbiology and antibiotic resistance, appropriateness of empiric antibiotic therapies, and the readmissions information. Multivariable logistic regression analyses were performed to identify factors associated with 30-day hospital readmission. Results: Of the 582 hospitalized community-acquired pneumonia patients, 11.9% were readmitted to the hospital within 30 days. About half of the cases (43.5%) were due to pneumonia. Multidrug-resistant bacteria accounted for 43.2% of the pathogen isolates. A high Charlson comorbidity index (aOR, 1.40; CI 95%, 1.08-1.82) and multidrug-resistant infection (aOR, 2.63; CI 95%, 1.05-6.56) were associated with higher odds of all-cause readmission. Conclusions:Hospital readmissions within 30 days occurred frequently among community-acquired pneumonia inpatients, and the most common reason for readmission recorded was pneumonia-related. Monitoring closely patients with multimorbidity or multidrug-resistant infections may improve treatment outcomes.

Lung penetration and pneumococcal target binding of antibiotics in lower respiratory tract infection

OBJECTIVES

To achieve the therapeutic effects, antibiotics must penetrate rapidly into infection sites and bind to targets. This study reviewed updated knowledge on the ability of antibiotics to penetrate into the lung, their physicochemical properties influencing the pulmonary penetration and their ability to bind to targets on pneumococci.

METHODS

A search strategy was developed using PubMED, Web of Science, and ChEMBL. Data on serum protein binding, drug concentration, target binding ability, drug transporters, lung penetration, physicochemical properties of antibiotics in low respiratory tract infection (LRTI) were collected.

RESULTS

It was seen that infection site-to-serum concentration ratios of most antibiotics are >1 at different time points except for ceftriaxone, clindamycin and vancomycin. Most agents have proper physicochemical properties that facilitate antibiotic penetration. In antimicrobial-resistant Streptococcus pneumoniae, the binding affinity of antibiotics to targets mostly decreases compared to that in susceptible strains. The data on binding affinity of linezolid, clindamycin and vancomycin were insufficient. The higher drug concentration at the infection sites compared to that in the blood can be associated with inflammation conditions. Little evidence showed the effect of drug transporters on the clinical efficacy of antibiotics against LRTI.

CONCLUSIONS

Data on antibiotic penetration into the lung in LRTI patients and binding affinity of antibiotics for pneumococcal targets are still limited. Further studies are required to clarify the associations of the lung penetration and target binding ability of antibitotics with therapeutic efficacy to help propose the right antibiotics for LRTI.

Pham S, P.M. Vo T, X. Duong C, A. Perwitasari D, H.K. Truong N, T.H. Quach D, N.P. Nguyen T, T.T. Duong V, M. Nguyen P, H. Nguyen T, Taxis K, Nguyen T. Pneumonia: Drug-Related Problems and Hospital Readmissions

Pneumonia is one of the most common infectious diseases and the fourth leading cause of death globally. According to US statistics in 2019, pneumonia is the most common cause of sepsis and septic shock. In the US, inpatient pneumonia hospitalizations account for the top 10 highest medical costs, totaling $9.5 billion for 960,000 hospital stays. The emergence of antibiotic resistance in the treatment of infectious diseases, including the treatment of pneumonia, is a globally alarming problem. Antibiotic resistance increases the risk of death and re-hospitalization, prolongs hospital stays, and increases treatment costs, and is one of the greatest threats in modern medicine. Drug-related problems (DRPs) in pneumonia - such as suboptimal antibiotic indications, prolonged treatment duration, and drug interactions - increase the rate of antibiotic resistance and adverse effects, thereby leading to an increased burden in treatment. In a context in which novel and effective antibiotics are scarce, mitigating DRPs in order to reduce antibiotic resistance is currently a prime concern. A variety of interventions proven useful in reducing DRPs are antibiotic stewardship programs, the use of biomarkers, computerized physician order entries and clinical decision support systems, and community-acquired pneumonia scores.

Pneumonia—Overview

Pneumonia is very common and continues to exact a high burden on health. The Global Burden of Disease Study 2015 found lower respiratory infections (LRIs) were the leading infectious cause of death and the fifth leading cause of death overall. Pneumococcal pneumonia caused 55% of LRI deaths in all ages (1.5 million deaths).

Novel pathogens, particularly viruses, continue to emerge as causes of pneumonia. The rise of drug-resistance among common respiratory pathogens is a further challenge. Pneumonia is commonly classified according to patient location at the time of infection, leading to the categories of community-acquired, hospital-acquired and ventilator-acquired pneumonia.

Capacity and use of diagnostics and treatment for patients with severe acute respiratory infections in the pre-COVID-19 era in district and provincial hospitals in Viet Nam

Objective

To describe the burden of severe acute respiratory infection (SARI) and the infrastructure and current practices of SARI management in hospitals in Viet Nam.

Methods

We conducted a short observational study at critical care units (CCUs) in 32 district hospitals and 16 provincial hospitals in five provinces in Viet Nam from March to July 2019. We collected data on hospital equipment and medicines used in SARI management. At the patient level, data were collected for 14 consecutive days on all patients presenting to CCUs, including information on demographics, intervention and treatment within 24 hours of CCU admission and 7-day outcome.

Results

There were significant differences between district and provincial hospitals in the availability of microbial culture, rapid influenza diagnostic tests, inflammatory markers and mechanical ventilation. Among 1722 eligible patients admitted to CCUs, there were 395 (22.9%) patients with SARI. The median age of SARI patients was 74 (interquartile range: 58–84) years; 49.1% were male. Although systemic antibiotics were available in all hospitals and were empirically given to 93.4% of patients, oseltamivir was available in 25% of hospitals, and only 0.5% of patients received empiric oseltamivir within 24 hours of admission. The 7-day mortality was 6.6% (26/395). Independent factors associated with 7-day mortality were septic shock and requiring respiratory support within 24 hours of admission.

Discussion

SARI is a major burden on CCUs in Viet Nam. Barriers to delivering quality care include the limited availability of diagnostics and medication and non-protocolized management of SARI in CCUs.

Clinical characteristics and outcomes of community-acquired pneumonia in western Saudi Arabia: A four-year retrospective analysis of medical records

BACKGROUND

Community-acquired pneumonia (CAP) is a significant cause of morbidity and mortality, especially for the elderly and people who suffer from chronic conditions. This study was conducted to assess the clinical and microbiological characteristics and disease outcomes associated with the occurrence of CAP.

METHODS

This retrospective chart review was conducted at King Abdulaziz Medical City, Jeddah, Saudi Arabia. Cases with documented clinical diagnosis of CAP during the period from 2016 to 2019 were included. Data were collected on demographic, clinical, and microbiological characteristics, used antimicrobials and patients' outcomes, including length of hospital stay, intensive care unit admission, and mortality. Multivariate regression analysis was performed to identify risk factors for increased length of hospital stay.

RESULTS

A total of two hundred and eighteen CAP episodes were identified. Patients had a median age of 64.5 years, and 54.1% were males. Microbiological diagnosis was established in 33 patients (15.1%). Admission to ICU and diagnosis of a neurological disease were significantly associated with longer hospital stay (>7 days). An average of 2.7 antimicrobials were used per patient, and the most common antibiotics used were Piperacillin/Tazobactam (46.3%), Doxycycline (44%), then Ceftriaxone (42.7%). Four patients (1.8%) died during hospital stay.

CONCLUSIONS

This retrospective analysis of CAP cases identified a lack of microbiological diagnosis and increased burden associated with disease severity and the need for hospitalization. The ability to identify CAP at an earlier stage will be a cornerstone to mitigate its impact on the healthcare system and ICU units.

Improving antibiotic prescribing for community-acquired pneumonia in a provincial hospital in Northern Vietnam

Objectives

To test the effectiveness of a quality improvement programme to promote adherence to national quality standards (QS) for patients hospitalized with community-acquired pneumonia (CAP), exploring the factors that hindered improvements in clinical practice.

Methods

An improvement bundle aligned to the QS was deployed using plan-do-study-act methodology in a 600 bed hospital in northern Vietnam from July 2018 to April 2019. Proposed care improvements included CURB65 score guided hospitalization, timely diagnosis and inpatient antibiotic treatment review to limit the spectrum and duration of IV antibiotic use. Interviews with medical staff were conducted to better understand the barriers for QS implementation.

Results

The study found that improvements were made in CURB65 score documentation and radiology results available within 4 h (P < 0.05). There were no significant changes in the other elements of the QS studied. We documented institutional barriers relating to the health reimbursement mechanism and staff cultural barriers relating to acceptance and belief as significant impediments to implementation of the standards.

Conclusions

Interventions led to some process changes, but these were not utilized by clinicians to improve patient management. Institutional and behavioural barriers documented may inhibit wider national uptake of the QS. National system changes with longer term support and investment to address local behavioural barriers are likely to be crucial for future improvements in the management of CAP, and potentially other hospitalized conditions, in Vietnam.

Incidence, risk factors, and viral etiology of community-acquired acute lower respiratory tract infection among older adults in rural north India

BACKGROUND

There are limited data on incidence, risk factors and etiology of acute lower respiratory tract infection (LRTI) among older adults in low- and middle-income countries.

METHODS

We established a cohort of community dwelling older adults ≥60 years and conducted weekly follow-up for acute respiratory infections (ARI) during 2015-2017. Nurses assessed ARI cases for LRTI, collecting combined nasal/throat swabs from all LRTI cases and an equal number of age- and sex-matched asymptomatic neighbourhood controls. Swabs were tested for influenza viruses, respiratory syncytial virus (RSV), human metapneumovirus (hMPV), and parainfluenza viruses (PIV) using polymerase chain reaction. LRTI and virus-specific LRTI incidence was calculated per 1000 person-years. We estimated adjusted incidence rate ratios (IRR) for risk factors using Poisson regression and calculated etiologic fractions (EF) using adjusted odds ratios for detection of viral pathogens in LRTI cases vs controls.

RESULTS

We followed 1403 older adults for 2441 person-years. LRTI and LRTI-associated hospitalization incidences were 248.3 (95% confidence interval (CI) = 229.3-268.8) and 12.7 (95% CI = 8.9-18.1) per 1000 person-years. Persons with pre-existing chronic bronchitis as compared to those without (incidence rate ratio (IRR) = 4.7, 95% CI = 3.9-5.6); aged 65-74 years (IRR = 1.6, 95% CI = 1.3-2.0) and ≥75 years (IRR = 1.8, 95% CI = 1.4-2.4) as compared to 60-64 years; and persons in poorest wealth quintile (IRR = 1.4, 95% CI = 1.1-1.8); as compared to those in wealthiest quintile were at higher risk for LRTI. Virus was detected in 10.1% of LRTI cases, most commonly influenza (3.8%) and RSV (3.0%). EF for RSV and influenza virus was 83.9% and 83.6%, respectively.

CONCLUSION

In this rural cohort of older adults, the incidence of LRTI was substantial. Chronic bronchitis was an important risk factor; influenza virus and RSV were major viral pathogens.

Pneumonia in older adults

PURPOSE OF REVIEW

The purpose of this review is to address the relevant issues surrounding older adults with community-acquired pneumonia (CAP) today.

RECENT FINDINGS

Approximately 1 million people >65 years have CAP in the US per year, which is more than previously reported (or realized). Older adults are vulnerable to the increasing prevalence of viral CAP, as the SARS-CoV-2 pandemic emphasizes, but pneumococcus is still the most common pathogen to cause CAP. Racial disparities continue to need to be addressed in order to improve early and late outcomes of older adults with CAP.

SUMMARY

The epidemiology of CAP, specifically for older adults is changing. More recent pathogen incidence studies have included culture, as well as newer microbiological methods to determine etiology. Current disparities among disadvantaged populations, including African-Americans, result in more comorbidities which predisposes to more severe CAP. However, outcomes in the hospital between races tend to be similar, and outcomes between age groups tends to be worse for older compared to younger adults. Finally, the cost of CAP is significant compared to diabetes mellitus, myocardial infarction and stroke.

Community-Acquired Bacterial Pneumonia-Changing Epidemiology, Resistance Patterns, and Newer Antibiotics: Spotlight on Delafloxacin

Community-acquired pneumonia (CAP) is a major cause of morbidity and mortality both in the USA and globally. As the burden of CAP continues to increase due to several factors, the advances in its diagnosis, prevention, and treatment have taken on even greater interest and importance. The majority of CAP patients are treated empirically, and selection of appropriate antibiotic treatment is increasingly difficult because the epidemiology of CAP is changing, in part due to antimicrobial resistance, and the causative CAP pathogens differ between countries and regions. There is also an increasing prevalence of chronic co-morbid diseases among CAP patients. Treatment of CAP has become challenging because of these factors along with the varying safety profiles and efficacy of well-established antibiotics, as well as limited new therapeutic options. Recently, however, new antibiotics have been approved, which will expand the treatment options for CAP, particularly in those patients with underlying complications. Recently approved delafloxacin, an anionic fluoroquinolone, has a unique structure and distinct chemical characteristics; it demonstrated non-inferiority to moxifloxacin in a phase III clinical trial, but was shown to be superior to moxifloxacin at early clinical response in CAP patients who also have chronic obstructive pulmonary disease (COPD) or asthma as a co-morbidity, and in CAP patients who may have severe illness. Delafloxacin could offer an additional therapy against resistant isolates and among these difficult-to-treat patients. This review summarizes the development, latest research, and safety profile of the new antibiotic delafloxacin, and its potential future role in the treatment of CAP.

Virus detections among patients with severe acute respiratory illness, Northern Vietnam

Severe acute respiratory illness (SARI) is a major cause of death and morbidity in low- and middle-income countries, however, the etiologic agents are often undetermined due to the lack of molecular diagnostics in hospitals and clinics. To examine evidence for select viral infections among patients with SARI in northern Vietnam, we studied 348 nasopharyngeal samples from military and civilian patients admitted to 4 hospitals in the greater Hanoi area from 2017–2019. Initial screening for human respiratory viral pathogens was performed in Hanoi, Vietnam at the National Institute of Hygiene and Epidemiology (NIHE) or the Military Institute of Preventative Medicine (MIPM), and an aliquot was shipped to Duke-NUS Medical School in Singapore for validation. Patient demographics were recorded and used to epidemiologically describe the infections. Among military and civilian cases of SARI, 184 (52.9%) tested positive for one or more respiratory viruses. Influenza A virus was the most prevalent virus detected (64.7%), followed by influenza B virus (29.3%), enterovirus (3.8%), adenovirus (1.1%), and coronavirus (1.1%). Risk factor analyses demonstrated an increased risk of influenza A virus detection among military hospital patients (adjusted OR, 2.0; 95% CI, 1.2–3.2), and an increased risk of influenza B virus detection among patients enrolled in year 2017 (adjusted OR, 7.9; 95% CI, 2.7–22.9). As influenza A and B viruses were commonly associated with SARI and are treatable, SARI patients entering these hospitals would benefit if the hospitals were able to adapt onsite molecular diagnostics.

Severe community-acquired pneumonia in general medical wards: outcomes and impact of initial antibiotic selection

Background

Most international guidelines recommend empirical therapy for community-acquired pneumonia (CAP) to be based on site of care. Some patients with severe CAP are managed in general wards because of limited intensive care unit (ICU) bed or because of unrecognition of the pneumonia severity. Appropriate initial antibiotic treatment for severe CAP outside ICU has not yet been established. This study aimed to determine the prevalence and the impact of initial antibiotic selection on the outcomes of patients with severe CAP who were admitted and managing in general wards.

Methods

This prospective observational study included consecutive patients hospitalized for presumed CAP in general wards over a 1-year period. Severe CAP was identified using the 2007 Infectious Diseases Society of America (IDSA)/American Thoracic Society (ATS) criteria. Initial antibiotic treatment in the first 24 h were collected. The primary outcome was the rate of unfavorable outcome (composite outcome of treatment failure and in-hospital death). The secondary outcome was the number of hospital-free days assessed 30 days after enrollment into the study.

Results

There were 94 patients hospitalized with CAP of which 50 (53.2%) patients were compatible with severe CAP. An etiologic diagnosis was found in 43 (45.8%) patients. The most common pathogens identified in patients with severe CAP were Staphylococcus aureus (28.6%) and Klebsiella pneumoniae (28.6%), followed by Pseudomonas aeruginosa (17.9%). Patients with severe CAP had significantly more positive blood culture than patients with non-severe CAP (24% VS 4.5%; p = .008). Initial antibiotic treatment were discordant with the IDSA/ATS guidelines in 42% of all patients hospitalized with CAP, and 52% of patients with severe CAP. Multivariate analysis revealed that age (OR 1.1, 95% CI 1.01–1.1) and initial antibiotic treatment discordant to guidelines for severe CAP in ICU (OR 4.6, 95% CI 1.3–17.1) were independent risk factors of the unfavorable outcome of patients with severe CAP. Patients with unfavorable outcome had lower number of hospital-free days than patients with favorable outcome (5.2 ± 8 days VS 18 ± 7.1 days; p < .001).

Conclusions

Patients with severe CAP outside ICU should be recognized for appropriate initial antibiotic selection to improve outcomes.

Etiology and epidemiology of community-acquired pneumonia in adults requiring hospital admission: A prospective study in rural Central Philippines

BACKGROUND

Community-acquired pneumonia (CAP) is a common cause of morbidity and mortality among adults worldwide. However, the distribution of the etiology of CAP varies from one country to another, with limited data from rural areas.

METHODS

A prospective hospital-based study on adult CAP was conducted in Leyte, Central Philippines from May 2010 to May 2012. Blood, sputum, and nasopharyngeal samples obtained from patients were used to identify pathogens using standard microbiological culture methods and PCR.

RESULTS

Of the 535 patients enrolled, 38% were younger than 50 years old. More than half of the patients had an underlying disease, including pulmonary tuberculosis (22%). The detection rate was higher for bacteria (40%) than viruses (13%). Haemophilus influenzae (12%) was the most commonly detected bacterium and influenza virus (5%) was the most commonly detected virus. The proportion of CAP patients with Mycobacterium tuberculosis infection was higher in the younger age group than in the older age group. Among CAP patients, 14% died during hospitalization, and drowsiness on admission and SpO₂ <90% were independent risk factors for mortality.

CONCLUSIONS

Bacterial infections contribute substantially to the number of hospitalizations among CAP patients in rural Philippines. This study also highlights the importance of treatment of tuberculosis in reducing the burden of adult CAP in the country.

Primary care influenza-like illness surveillance in Ho Chi Minh City, Vietnam 2013-2015

Background

Year‐round transmission of influenza has been detected in Vietnam through both national surveillance and other epidemiological studies. Understanding the demographic and clinical features of influenza‐like illness (ILI) presenting to primary care in urban Vietnam is vital to understand these transmission dynamics.

Methods

An observational study of patients with ILI in Ho Chi Minh City, Vietnam, was conducted between August 2013 and November 2015 in a mix of public and private primary care settings. Molecular testing for influenza A and influenza B and 12 other respiratory viruses was performed.

Results

A total of 1152 ILI patients were recruited. 322 and 136 subjects tested positive for influenza A and influenza B, respectively. 193 subjects tested positive for another respiratory virus; most commonly rhinovirus and parainfluenza virus 3. Influenza was detected in 81% of the 116 study weeks. Three peaks of influenza activity were detected; an H3N2 peak April‐June 2014, an influenza B peak July‐December 2014, and a mixed H3N2 and H1N1 peak March‐September 2015. Subjects recruited from private clinics were more likely to have higher income and to have reported previous influenza vaccination. Antibiotic use was common (50.3%) despite limited evidence of bacterial infection.

Conclusion

Influenza in southern Vietnam has complex transmission dynamics including periods of intense influenza activity of alternating types and subtypes. Broadening surveillance from hospital to the community in tropical settings is feasible and a valuable for improving our understanding of the global spread and evolution of the virus.

Literature review of the epidemiology of influenza B disease in 15 countries in the Asia-Pacific region

Influenza control strategies focus on the use of trivalent influenza vaccines containing two influenza A virus subtypes and one of the two circulating influenza type B lineages (Yamagata or Victoria). Mismatches between the vaccine B lineage and the circulating lineage have been regularly documented in many countries, including those in the Asia‐Pacific region. We conducted a literature review with the aim of understanding the relative circulation of influenza B viruses in Asia‐Pacific countries. PubMed and Western Pacific Region Index Medicus were searched for relevant articles on influenza type B published since 1990 in English language for 15 Asia‐Pacific countries. Gray literature was also accessed. From 4834 articles identified, 121 full‐text articles were analyzed. Influenza was reported as an important cause of morbidity in the Asia‐Pacific region, affecting all age groups. In all 15 countries, influenza B was identified and associated with between 0% and 92% of laboratory‐confirmed influenza cases in any one season/year. Influenza type B appeared to cause more illness in children aged between 1 and 10 years than in other age groups. Epidemiological data for the two circulating influenza type B lineages remain limited in several countries in the Asia‐Pacific, although the co‐circulation of both lineages was seen in countries where strain surveillance data were available. Mismatches between circulating B lineages and vaccine strains were observed in all countries with available data. The data suggest that a shift from trivalent to quadrivalent seasonal influenza vaccines could provide additional benefits by providing broader protection.

Comparison of viral infection in healthcare-associated pneumonia (HCAP) and community-acquired pneumonia (CAP)

Background

Although viruses are known to be the second most common etiological factor in community-acquired pneumonia (CAP), the respiratory viral profile of the patients with healthcare-associated pneumonia (HCAP) has not yet been elucidated. We investigated the prevalence and the clinical impact of respiratory virus infection in adult patients with HCAP.

Methods

Patients admitted with HCAP or CAP, between January and December 2016, to a tertiary referral hospital in Korea, were prospectively enrolled, and virus identification was performed using reverse-transcription polymerase chain reaction (RT-PCR).

Results

Among 452 enrolled patients (224 with HCAP, 228 with CAP), samples for respiratory viruses were collected from sputum or endotracheal aspirate in 430 (95.1%) patients and from nasopharyngeal specimens in 22 (4.9%) patients. Eighty-seven (19.2%) patients had a viral infection, and the proportion of those with viral infection was significantly lower in the HCAP than in the CAP group (13.8% vs 24.6%, p = 0.004). In both the HCAP and CAP groups, influenza A was the most common respiratory virus, followed by entero-rhinovirus. The seasonal distributions of respiratory viruses were also similar in both groups. In the HCAP group, the viral infection resulted in a similar length of hospital stay and in-hospital mortality as viral–bacterial coinfection and bacterial infection, and the CAP group showed similar results.

Conclusions

The prevalence of viral infection in patients with HCAP was lower than that in patients with CAP, and resulted in a similar prognosis as viral–bacterial coinfection or bacterial infection.

Incidence, Etiology, and Outcomes of Community-Acquired Pneumonia: A Population-Based Study

Background

The microbial etiology of community-acquired pneumonia (CAP) is often unclear in clinical practice, and previous studies have produced variable results. Population-based studies examining etiology and incidence are lacking. This study examined the incidence and etiology of CAP requiring hospitalization in a population-based cohort as well as risk factors and outcomes for specific etiologies.

Methods

Consecutive admissions due to CAP in Reykjavik, Iceland were studied. Etiologic testing was performed with cultures, urine-antigen detection, and polymerase chain reaction analysis of airway samples. Outcomes were length of stay, intensive care unit admission, assisted ventilation, and mortality.

Results

The inclusion rate was 95%. The incidence of CAP requiring hospitalization was 20.6 cases per 10000 adults/year. A potential pathogen was detected in 52% (164 of 310) of admissions and in 74% (43 of 58) with complete sample sets. Streptococcuspneumoniae was the most common pathogen (61 of 310, 20%; incidence: 4.1/10000). Viruses were identified in 15% (47 of 310; incidence: 3.1/10000), Mycoplasmapneumoniae were identified in 12% (36 of 310; incidence: 2.4/10000), and multiple pathogens were identified in 10% (30 of 310; incidence: 2.0/10000). Recent antimicrobial therapy was associated with increased detection of M pneumoniae (P < .001), whereas a lack of recent antimicrobial therapy was associated with increased detection of S pneumoniae (P = .02). Symptoms and outcomes were similar irrespective of microbial etiology.

Conclusions

Pneumococci, M pneumoniae, and viruses are the most common pathogens associated with CAP requiring hospital admission, and they all have a similar incidence that increases with age. Symptoms do not correlate with specific agents, and outcomes are similar irrespective of pathogens identified.

Pneumonia in the developing world: Characteristic features and approach to management

Community-acquired pneumonia (CAP) is a common cause of morbidity and mortality in adults worldwide, but its epidemiology varies markedly by region. Whilst in high-income countries, the predominant burden of CAP is in the elderly and those with chronic cardiovascular and pulmonary co-morbidity, CAP patients in low-income settings are often of working age and, in sub-Saharan Africa, frequently HIV-positive. Although region-specific aetiological data are limited, they are sufficient to highlight major trends: in high-burden settings, tuberculosis (TB) is a common cause of acute CAP; Gram-negative pathogens such as Klebsiella pneumoniae are regionally important; and HIV-associated opportunistic infections are common but difficult to diagnose. These differences in epidemiology and aetiological profile suggest that modified approaches to diagnosis, severity assessment and empirical antimicrobial therapy of CAP are necessary, but tailored individualized management approaches are constrained by limitations in the availability of radiological and laboratory diagnostic services, as well as medical expertise. The widespread introduction of the Xpert MTB/RIF platform represents a major advance for TB diagnosis, but innovations in rapid diagnostics for other opportunistic pathogens are urgently needed. Severity assessment tools (e.g. CURB65) that are used to guide early management decisions in CAP have not been widely validated in low-income settings and locally adapted tools are required. The optimal approach to initial antimicrobial therapy choices such as the need to provide early empirical cover for atypical bacteria and TB remain poorly defined. Improvements in supportive care such as correcting hypoxaemia and intravenous fluid management represent opportunities for substantial reductions in mortality.

Viral infection in community-acquired pneumonia: a systematic review and meta-analysis

The advent of PCR has improved the identification of viruses in patients with community-acquired pneumonia (CAP). Several studies have used PCR to establish the importance of viruses in the aetiology of CAP.We performed a systematic review and meta-analysis of the studies that reported the proportion of viral infection detected via PCR in patients with CAP. We excluded studies with paediatric populations. The primary outcome was the proportion of patients with viral infection. The secondary outcome was short-term mortality.Our review included 31 studies. Most obtained PCR via nasopharyngeal or oropharyngeal swab. The pooled proportion of patients with viral infection was 24.5% (95% CI 21.5-27.5%). In studies that obtained lower respiratory samples in >50% of patients, the proportion was 44.2% (95% CI 35.1-53.3%). The odds of death were higher in patients with dual bacterial and viral infection (OR 2.1, 95% CI 1.32-3.31).Viral infection is present in a high proportion of patients with CAP. The true proportion of viral infection is probably underestimated because of negative test results from nasopharyngeal or oropharyngeal swab PCR. There is increased mortality in patients with dual bacterial and viral infection.

Community-Acquired Pneumonia in the Asia-Pacific Region

Community-acquired pneumonia (CAP) is an important cause of mortality and morbidity worldwide. Aging population, dense urbanization, and poor access to health care make the Asia-Pacific region vulnerable to CAP. The high incidence of CAP poses a significant health and economic burden in this region. Common etiologic agents in other global regions including Streptococcus pneumoniae, Mycoplasma pneumoniae, Haemophilus influenzae, Chlamydophila pneumoniae, Staphylococcus aureus, and respiratory viruses are also the most prevalent pathogens in the Asia-Pacific region. But the higher incidence of Klebsiella pneumoniae and the presence of Burkholderia pseudomallei are unique to the region. The high prevalence of antimicrobial resistance in S. pneumoniae and M. pneumoniae has been raising the need for more prudent use of antibiotics. Emergence and spread of community-acquired methicillin-resistant S. aureus deserve attention, while the risk has not reached significant level yet in cases of CAP. Given a clinical and socioeconomic importance of CAP, further effort to better understand the epidemiology and impact of CAP is warranted in the Asia-Pacific region.

Results from the Survey of Antibiotic Resistance (SOAR) 2009-11 in Vietnam

OBJECTIVES

To investigate the susceptibility of respiratory tract infection pathogens collected between 2009 and 2011 from the SOAR study in Vietnam.

METHODS

MICs were determined using Etest(®) and susceptibility was assessed using CLSI, EUCAST and pharmacokinetic/pharmacodynamic (PK/PD) breakpoints.

RESULTS

Two hundred and eighty-nine Streptococcus pneumoniae and 195 Haemophilus influenzae were collected from 11 centres. Overall, 4.8% of S. pneumoniae were penicillin susceptible (CLSI oral and EUCAST breakpoints). Using CLSI intravenous breakpoints, 86.9% were penicillin susceptible. Susceptibility to high-dose amoxicillin/clavulanic acid (or amoxicillin) using PK/PD breakpoints, cefuroxime (using CLSI or PK/PD breakpoints), cefaclor (CLSI breakpoint) and azithromycin (CLSI breakpoint) was 96.9%, 18.7%, 8% and 4.2%, respectively. Ofloxacin susceptibility was 93.4% by CLSI but 0% by EUCAST. All S. pneumoniae were fully vancomycin susceptible. S. pneumoniae from children were significantly less susceptible to most antimicrobials than those from the elderly. For ofloxacin, however, the reverse was true.Among H. influenzae isolates, 40.5% produced β-lactamase and 13.8% were β-lactamase negative but ampicillin resistant (BLNAR) by CLSI. H. influenzae were highly susceptible (97.4%) in vitro to amoxicillin/clavulanic acid and also to ceftriaxone by CLSI and PK/PD breakpoints but not EUCAST breakpoints. However, BLNAR isolates should be considered clinically resistant, with susceptibility reduced to 84.1%. With EUCAST breakpoints, amoxicillin/clavulanic acid susceptibility was lower, at 63.1%. Azithromycin susceptibility was 79.5% (CLSI).

CONCLUSIONS

Resistance to antibacterials in Vietnam was high, with amoxicillin/clavulanic acid being the most active agent. Ceftriaxone was highly active against H. influenzae while ofloxacin appeared highly active against S. pneumoniae using CLSI but not by EUCAST breakpoints. Ongoing surveillance through SOAR will further assist in understanding susceptibility trends over time.

Assessing the burden of pneumonia using administrative data from Malaysia, Indonesia, and the Philippines

OBJECTIVES

To describe the incidence, mortality, cost, and length of stay (LOS) of hospitalized community-acquired pneumonia (CAP) and hospital-acquired pneumonia (HAP) in three Southeast Asian countries: Malaysia, Indonesia, and the Philippines.

METHODS

Using Casemix system data from contributing hospitals, patients with International Classification of Diseases 10(th) revision (ICD-10) codes identifying pneumonia were categorized into CAP or HAP using a logical algorithm. The incidence among hospitalized patients, case fatality rates (CFR), mean LOS, and cost of admission were calculated. The population incidence was calculated based on Malaysian data.

RESULTS

For every 100000 discharges, CAP and HAP incidences were 14245 and 5615 cases, respectively, in the Philippines, 4205 and 2187, respectively, in Malaysia, and 988 and 538, respectively, in Indonesia. The impact was greatest in the young and the elderly. The CFR varied from 1.4% to 4.2% for CAP and from 9.1% and 25.5% for HAP. The mean LOS was 6.1-8.6 days for CAP and 6.9-10.2 days for HAP. The cost of hospitalization was between USD 254 and USD 1208 for CAP and between USD 275 and USD 1482 for HAP.

CONCLUSIONS

The burden of CAP and HAP is high. Results varied between the three countries, likely due to differences in socio-economic conditions, health system differences, and ICD-coding practices.

Pathogen profiles and molecular epidemiology of respiratory viruses in Japanese inpatients with community-acquired pneumonia

Background

The etiological profile of viruses among adult patients with community-acquired pneumonia (CAP) has not been characterized yet. The aim of this study was twofold: first, investigate the pathogen profiles and the molecular epidemiology of respiratory viruses among Japanese CAP patients; and second, explore the clinical significance of viral infections.

Methods

A cross-sectional observational study was conducted at Kyorin University Hospital. To identify respiratory pathogens, hospitalized CAP patients were enrolled, and reverse transcriptase–polymerase chain reaction technology was applied alongside conventional microbiological methods. Phylogenetic and pairwise distance analyses of 10 viruses were performed. CAP patients were divided into four etiological groups (virus alone, bacteria alone, co-detection of virus and bacteria, and not detected) and the clinical findings were compared.

Results

Seventy-six patients were enrolled. Bacteria alone were detected in 39.5% (n=30) of CAP patients. Virus alone or co-detection were found in 10.5% (n=8) and 11.8% (n=9) of cases, respectively. Streptococcus pneumoniae and human metapneumovirus were the most frequently detected bacterium and virus, respectively. Phylogenetic analyses of human metapneumovirus, human rhinovirus, and human respiratory syncytial virus showed that different subgroups and genotypes might be associated with CAP. Respiratory failure was more common when a virus was detected (both virus alone and co-detection groups; n=17, 100%, p<0.05) than when a bacteria alone was detected (n=17, 56.7%).

Conclusion

Prevalence of respiratory virus infection in CAP inpatients was 22.3%. The detected viruses display high genetic divergence and correlate with increased respiratory failure.

Healthcare-seeking behaviors for acute respiratory illness in two communities of Java, Indonesia: a cross-sectional survey

Understanding healthcare-seeking patterns for respiratory illness can help improve estimations of disease burden and inform public health interventions to control acute respiratory disease in Indonesia. The objectives of this study were to describe healthcare-seeking behaviors for respiratory illnesses in one rural and one urban community in Western Java, and to explore the factors that affect care seeking. From February 8, 2012 to March 1, 2012, a survey was conducted in 2520 households in the East Jakarta and Bogor districts to identify reported recent respiratory illnesses, as well as all hospitalizations from the previous 12-month period. We found that 4% (10% of those less than 5 years) of people had respiratory disease resulting in a visit to a healthcare provider in the past 2 weeks; these episodes were most commonly treated at government (33%) or private (44%) clinics. Forty-five people (0.4% of those surveyed) had respiratory hospitalizations in the past year, and just over half of these (24/45, 53%) occurred at a public hospital. Public health programs targeting respiratory disease in this region should account for care at private hospitals and clinics, as well as illnesses that are treated at home, in order to capture the true burden of illness in these communities.

Respiratory viruses and torque teno virus in adults with acute respiratory infections

Objective

To define the molecular epidemiology of respiratory viral infections in adult patients.

Methods

Nasal and throat swabs were collected from all adult patients with influenza-like illness (ILI), acute respiratory infection (ARI), or severe ARI (SARI) admitted to a tertiary hospital in Surakarta, Indonesia, between March 2010 and April 2011 and analyzed for 19 respiratory viruses and for torque teno virus (TTV) and human gyrovirus (HGyV).

Results

Respiratory viruses were detected in 61.3% of the subjects, most of whom had ARI (90.8%, OR = 11.39), were hospitalized (96.9%, OR = 22.31), had asthma exacerbation (90.9%, OR = 8.67), and/or had pneumonia (80%, OR = 4.0). Human rhinovirus (HRV) A43 predominated. Influenza A H3N2, human metapneumovirus (HMPV) subtypes A1 and A2, the influenza B virus, human adenovirus B, and human coronavirus OC43 were also detected. All respiratory viruses were detected in the transition month between the rainy and dry seasons. No mixed respiratory virus infection was found. Coinfections of the influenza A H3N2 virus with TTV, HMPV with TTV, HRV with TTV, and human parainfluenza virus-3 with TTV were found in 4.7, 2.8, 19.8, and 0.9% of the samples, respectively.

Conclusions

This study highlights the need to perform routine detection of respiratory viruses in adults hospitalized with ARI, asthma exacerbation, and/or pneumonia.

Incidence of respiratory viral infections detected by PCR and real-time PCR in adult patients with community-acquired pneumonia: a meta-analysis

Background

With the development of more rapid and sensitive detection methods based on PCR techniques, the contributions of respiratory viral infections to community-acquired pneumonia (CAP) in adult patients are being more and more recognized. Yet, up to now, there has been a lack of synthetic data that clearly demonstrates the incidence of respiratory viral infections in adult patients with CAP.

Objectives

We intended to demonstrate the incidence of respiratory viral infections detected by PCR and real-time PCR in adult patients with CAP.

Methods

We searched PubMed and Embase for studies providing the incidence of respiratory viral infections in adult patients with CAP. We investigated potential sources of heterogeneity by a univariant metaregression analysis and calculated the combined incidence of viral infections, viral infections mixed with other pathogens and individual respiratory virus species.

Results

We eventually identified 23 eligible reports with a total number of 6,404 patients. Incidences ranged from 8.6 to 56.2% for overall respiratory viral infections. We noted significant heterogeneity in incidence estimates for the incidence of viral infections (Cochran's χ² = 269.9, p < 0.0001, I² = 91.8%). The combined incidence of viral infections was 22.4% (95% CI = 19.0-25.7). Incidences of viral coinfections with other pathogens ranged from 3 to 28%. A high level of heterogeneity was identified as well during the estimates for incidences of coinfections (χ² = 200.9, p < 0.0001, I² = 91.5%). The combined incidence of viral coinfections with other pathogens was 12.4% (95% CI = 9.7-15.0). Our heterogeneity analyses suggested that a lower respiratory tract sample was associated with higher overall viral incidence. Moreover, the influenza virus, rhinovirus and coronavirus were the 3 most frequently detected viral pathogens in adult patients with CAP according to our study.

Conclusions

Respiratory viruses are probably crucial pathogens of adult patients with CAP, with the influenza virus being the most frequent viral pathogen identified. More than half of the viral infections are characterized as mixed infections with other pathogens.

Community-acquired pneumonia

PURPOSE OF REVIEW

This review examines the epidemiology, diagnosis, prognosis, treatment and prevention of community-acquired pneumonia (CAP) in adults.

RECENT FINDINGS

CAP is a significant cause of morbidity and mortality. Streptococcus pneumoniae is the most common CAP pathogen; however, microbial cause varies by geographic location and host factors. Identification of a microbial cause in CAP remains challenging - 30-65% of cases do not have a pathogen isolated. The use of molecular techniques in addition to culture, serology and urinary antigen testing has improved diagnostic yield. Scoring systems are useful for CAP prognostication and site of care decisions. Studies evaluating novel biomarkers including pro-B-type natriuretic peptide and procalcitonin suggest potential adjunctive roles in CAP prognosis. Guideline-based treatment for CAP has changed little in recent years. Effective and timely antimicrobial therapy is crucial in optimizing outcomes and should be based on local antimicrobial susceptibility patterns. Macrolides may have additional anti-inflammatory properties and a mortality benefit in severe CAP. Preventive strategies include immunization and modification of specific patient risk factors.

SUMMARY

CAP is common and causes considerable morbidity and mortality. A comprehensive approach including advanced diagnostic testing, effective and timely antimicrobial therapy and prevention is required to optimize CAP outcomes.

Epidemiology, etiology, x-ray features, importance of co-infections and clinical features of viral pneumonia in developing countries

Pneumonia is still the number one killer of young children globally, accounting for 18% of mortality in children under 5 years of age. An estimated 120 million new cases of pneumonia occur globally each year. In developing countries, management and prevention efforts against pneumonia have traditionally focused on bacterial pathogens. More recently however, viral pathogens have gained attention as a result of improved diagnostic methods, such as polymerase chain reaction, outbreaks of severe disease caused by emerging pathogens, discovery of new respiratory viruses as well as the decrease in bacterial pneumonia as a consequence of the introduction of highly effective conjugate vaccines. Although the epidemiology, etiology and clinical characterization of viral infections are being studied extensively in the developed world, little data are available from low- and middle-income countries. In this paper, we review the epidemiology, etiology, clinical and radiological features of viral pneumonia in developing countries.

Epidemiology of virus-induced asthma exacerbations: with special reference to the role of human rhinovirus

Viral respiratory infections may be associated with the virus-induced asthma in adults as well as children. Particularly, human rhinovirus is strongly suggested a major candidate for the associations of the virus-induced asthma. Thus, in this review, we reviewed and focused on the epidemiology, pathophysiology, and treatment of virus-induced asthma with special reference on human rhinovirus. Furthermore, we added our preliminary data regarding the clinical and virological findings in the present review.