Preventing pneumonia: the role for pneumococcal and influenza vaccines

Seasonal Incidence of Community-acquired Pneumonia: A Retrospective Study in a Tertiary Care Hospital in Kathmandu, Nepal

Introduction

Community-acquired pneumonia (CAP) is the major cause of death in adult and elderly persons with a variety of presentations. Seasonal variation in the incidence of the disease is essential for clinicians and epidemiologists who deal with such diseases. The study was aimed at analysing the clinical profile and outcomes of community-acquired pneumonia during different seasons of the year in a tertiary care hospital, Manmohan Memorial Teaching Hospital (MMTH), of Kathmandu, Nepal.

Method

The aetiology and clinical profile of 378 patients with CAP who were admitted to MMTH over a period of one year were taken into account in this retrospective cross-sectional hospital-based study. Data were retrieved from the hospital medical records section and the Department of Pathology. All patients with a primary diagnosis of CAP admitted to the hospital were included in the study. Monthly and seasonal trends, aetiology, comorbidities, and mortality rates were analysed.

Results 

Of 378 patients with CAP, 160 patients (42.3%) had associated chronic obstructive pulmonary disease (COPD), 92 patients (24.3%) had hypertension (HTN), 59 patients (15.6%) had diabetes, 12 patients (3.1%) had active pulmonary tuberculosis, seven patients (1.85%) had kidney disease, and the remaining 48 patients (12.6%) had only CAP. Seasonal variation of CAP was noted in 131 patients (35%) in the winter, 98 (26%) in autumn, 86 (23%) in spring, and 63 patients (16%) in summer seasons. None of the patients were vaccinated against influenza and pneumococcus. The most common organism isolated in CAP was Acinetobacter calcoaceticus baumannii (ACB) complex (4.7%), which was more distinguished in the winter season. The second most isolated organism was Pseudomonas aeruginosa (2.6%). The most common clinical presentation was fever (63%), followed by cough (47%) and shortness of breath (47%). Sputum culture was found to be positive in 51 cases (13.4%). Among 378 patients, 78 patients (20.6%) received treatment in the Intensive Care Unit (ICU) and the rest of the patients received treatment in the general medical ward. The mortality rate was found to be 6.6%.

Conclusion

An incidence of sputum-positive CAP was found in 51 cases (13.4%). The most common organism was ACB complex, followed by Pseudomonas aeruginosa, which were sensitive to polymyxins. Both of them were predominant in the winter and spring.

Pharmacokinetic and Pharmacodynamic Efficacy of Intrapulmonary Administration of Ciprofloxacin for the Treatment of Respiratory Infections

The pharmacokinetic and pharmacodynamic efficacy of intrapulmonary administration of ciprofloxacin (CPFX) for the treatment of respiratory infections caused by pathogenic microorganisms resisting sterilization systems of alveolar macrophages (AMs) was evaluated by comparison with an oral administration. The time-courses of the concentration of CPFX in AMs and lung epithelial lining fluid (ELF) following intrapulmonary administration of CPFX solution to rats (200 microg/kg) were markedly higher than that following oral administration (10 mg/kg). The time-course of the concentrations of CPFX in plasma following intrapulmonary administration was markedly lower than that in AMs and ELF. These results indicate that intrapulmonary administration is more effective in delivering CPFX to AMs and ELF, compared with oral administration, in spite of a low dose and it avoids distribution of CPFX to the blood. In addition, the antibacterial effects of CPFX in AMs and ELF following intrapulmonary administration were evaluated by pharmacokinetics/pharmacodynamics analysis. The concentration of CPFX in AMs and ELF-time curve (AUC)/minimum inhibitory concentration of CPFX (MIC) ratio and the maximum concentration of CPFX in AMs and ELF (Cmax)/MIC ratio were markedly higher than the effective values. The present study indicates that intrapulmonary administration of CPFX is an effective technique for the treatment of respiratory infections.

Comparative transcriptional profiling of the lung reveals shared and distinct features of Streptococcus pneumoniae and influenza A virus infection

Pneumonia is the most common cause of death from infectious disease in the western hemisphere. Pathophysiological and protective processes are initiated by pattern recognition of microbial structures. To provide the molecular framework for a better understanding of processes relevant to host defence in pneumonia, we performed pulmonary transcriptome analysis in mice infected with the major bacterial and viral agents of community-acquired pneumonia, Streptococcus pneumoniae and influenza A virus. We detected differential expression of 1300 genes after infection with either pathogen. Of these, approximately 36% or 30% were specific for pneumococcal or influenza infection, respectively, yielding pathogen-specific as well as shared inflammatory transcriptional signatures. These results not only reveal a differential response on the cytokine and chemokine levels but also emphasize the important role of genes implicated in regulation and fine tuning of inflammation. As one, albeit unexpected, key feature of pneumococcal pneumonia we discovered down-regulation of B-cell responses, probably reflecting a pneumococcal virulence strategy. The pathophysiological consequences of influenza A virus infection were reflected by the emerging protective T-cell response and differential induction of genes involved in tissue regeneration and proliferation. These data provide new insights into pathogenesis of the most common forms of pneumonia, highlighting the value of transcriptional profiling for the elucidation of underlying mechanisms.

Statin treatment and reduced risk of pneumonia in patients with diabetes

BACKGROUND

Recent prognostic studies have shown that previous treatment with statins is associated with a better outcome in patients admitted to hospital with pneumonia. Because of an increased risk of pneumonia in patients with diabetes, we assessed the effects of statin use on the occurrence of pneumonia in adult diabetic patients.

METHODS

All patients with a diagnosis of diabetes (types 1 and 2) enlisted in the UK General Practice Research Database between 1 June 1987 and 21 January 2001 were included. A case-control study was performed with cases defined as patients with a first recorded diagnosis of pneumonia. For each case up to four controls were matched by age, sex, practice, and index date. Patients were classified as current users when the index date was between the start and end date of statin treatment. Conditional multiple logistic regression analysis was used to estimate the strength of the association between statin treatment and the occurrence of pneumonia.

RESULTS

Statins were used in 1.1% of 4719 cases and in 2.1% of 15 322 matched controls (crude odds ratio (OR) 0.51, 95% CI 0.37 to 0.68). After adjusting for potential confounders, treatment with statins was associated with a significant reduction in the risk of pneumonia (adjusted OR 0.49, 95% CI 0.35 to 0.69). The association was consistent among relevant subgroups (cardiovascular diseases, pulmonary diseases) and independent of the use of other prescription drugs.

CONCLUSIONS

The use of statins is associated with a considerable reduction in the risk of pneumonia in diabetic patients. In addition to lowering the risk of cardiovascular disease, statins may be useful in preventing respiratory infections.

Influenza: incidence, symptoms and treatment

Influenza is a common respiratory condition that has a history of developing into epidemics and pandemics. Individuals at risk of influenza and related complications include older people, young children and individuals with chronic renal, cardiac and respiratory diseases. Influenza can begin suddenly and is accompanied by fever, chills, aches, pains, headaches, fatigue, cough and generalized weakness that can last up to 14 days. Complications of influenza include secondary bacterial pneumonia, post-influenza encephalitis, changes in cardiac electrocardiogram and secondary bacterial infections, such as Staphylococcus aureus-induced myositis. The influenza vaccine is the main form of treatment. Suitably qualified nurse prescribers and nurses who supply and administer the vaccine under patient group directions should be sufficiently knowledgeable about the virus and how its transmission can be prevented in order to educate patients at risk of developing influenza about the role of the vaccine in the prevention of the disease.