COMMUNITY-ACQUIRED PNEUMONIA IN THE ELDERLY PATIENT

Community‐acquired pneumonia and its predictors of mortality in rural southwestern Nigeria: A‐five year retrospective observational study

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Majority of people in sub-Sahara Africa reside in rural areas.

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Many hospitals in rural and sub-urban centres do not have adequate personnel and infrastructures.

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There are limited dataoncommunity-acquired pneumonia and its predictors of mortality and were largely restricted to urban and suburban centres.

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The results of the present study would guide the stakeholders on how to reduce community- acquired pneumonia mortality in rural centres.

Introduction

The predictors of community-acquired pneumonia (CAP) mortality are important outcome measures in epidemiological studies and clinical trials. There is an observed paucity of data regarding the predictors of mortality of CAP in Nigeria. Few studies from the urban centres have been reported in the literature, with none from the rural centres. The objective of this study is to ascertain the clinical presentations, risk factors, and predictors of mortality among patients admitted for CAP in rural Southwestern Nigeria.

Methods

A retrospective observational study using a data form and a standardised questionnaire reviewed the 176 patients admitted to Southwestern Nigeria hospital between January 2015 and December 2019. The data were analysed using SPSS Version 22.0. The results were presented in descriptive and tabular formats.

Results

A total of 176 patients were studied. Their mean age was 53.3±16.8 years. There were more males, 112 (63.6%), than females. The most common clinical presentations were cough, fever and sputum expectoration. The case fatality rate was 9.1% and its predictors were older aged patients [Adjusted Odds Ration (AOR), 4.135: 95% Confidence Interval (CI) (1.389-12.315); p =0.005], hypoxia [AOR, 11.118: 95% CI (2.607-47.405); p<0.001], tobacco smoking [AOR, 3.632: 95% CI (1.459-9.039); p=0.008], chronic obstructive pulmonary disease (COPD) [AOR, 10.111: 95%CI (2.370-43.139); p <0.001], and human immunodeficiency virus (HIV) [AOR, 9.444: 95% CI (4.304-20.725), p<0.001].

Conclusion

The case -fatality rate was 9.1%, and its predictors were older age patients, patients with hypoxia, tobacco smoking, COPD, and HIV. This study strengthens the argument on the higher prevalence of CAP and its mortality in rural Southwestern Nigeria. The findings may provide an impetus for prospective research on these outcomes.

Factors That Affect Oral Care Outcomes for Institutionalized Elderly

The aim of this study was to evaluate the effect of an oral care intervention program on the incidence of pneumonia and fever as a surrogate endpoint. In addition, we tried to determine the oral care risk factors for the incidence of fever. We provided an oral care program for the elderly at one private nursing home in July 2013. The maximum capacity of the nursing home was 60 residents. The body temperatures of all residents were measured twice a day and were summarized as the incidence of fever over a one-month period, which was used as the dependent variable. The residents' life conditions, number of teeth, and prescribed diet were used as independent variables. The factors that affected the incidence of fever were the number of remaining teeth, a prescribed diet of sliced food, the meal care level, and the oral Candida levels. These risk factors affected the incidence of fever independently or interactively with oral care. Some risk factors for the incidence of fever were enhanced by the oral care program. It is important to evaluate and control these factors before the implementation of an oral care program.

Streptococcus pneumoniae's Virulence and Host Immunity: Aging, Diagnostics, and Prevention

Streptococcus pneumoniae is an infectious pathogen responsible for millions of deaths worldwide. Diseases caused by this bacterium are classified as pneumococcal diseases. This pathogen colonizes the nasopharynx of its host asymptomatically, but overtime can migrate to sterile tissues and organs and cause infections. Pneumonia is currently the most common pneumococcal disease. Pneumococcal pneumonia is a global health concern and vastly affects children under the age of five as well as the elderly and individuals with pre-existing health conditions. S. pneumoniae has a large selection of virulence factors that promote adherence, invasion of host tissues, and allows it to escape host immune defenses. A clear understanding of S. pneumoniae's virulence factors, host immune responses, and examining the current techniques available for diagnosis, treatment, and disease prevention will allow for better regulation of the pathogen and its diseases. In terms of disease prevention, other considerations must include the effects of age on responses to vaccines and vaccine efficacy. Ongoing work aims to improve on current vaccination paradigms by including the use of serotype-independent vaccines, such as protein and whole cell vaccines. Extending our knowledge of the biology of, and associated host immune response to S. pneumoniae is paramount for our improvement of pneumococcal disease diagnosis, treatment, and improvement of patient outlook.

Bacterial community-acquired pneumonia in older patients

Pneumonia in the elderly remains a major source of morbidity and mortality in an age group that is growing in numbers. It remains unclear whether the propensity of older adults to develop community-acquired pneumonia represents an aging of host defenses, secondary effects of comorbid disease, or both. The signs and symptoms of pneumonia in the elderly are more subtle than in younger populations, which may lead to a delay in diagnosis. Although therapy for community-acquired pneumonia in the elderly is the same as for younger populations, mortality is higher, leading to an important role for prevention.

Pulmonary Emergencies in the Elderly

The aging process results in changes in pulmonary physiology that make the elderly population more susceptible to pulmonary disease. These physiologic changes also alter the clinical presentation of such diseases, making the diagnosis and treatment of pulmonary disorders particularly challenging for the clinician. It is important for the clinician to have a high index of suspicion for pulmonary disorders to make the proper diagnosis. It is essential to keep in mind the subtle differences between pulmonary diseases in the elderly compared with younger patients.

Dual function of the long pentraxin PTX3 in resistance against pulmonary infection with Klebsiella pneumoniae in transgenic mice

The long pentraxin PTX3 is expressed during acute inflammation and appears to control nitric oxide (NO) and tumor necrosis factor (TNF)-alpha production. In the present study, the physiological function of PTX3 was investigated in a model of pulmonary infection caused by the Gram-negative bacterium Klebsiella pneumoniae. Transgenic mice expressing multiple copies of PTX3 under the control of its own promoter were used to assess lethality rates, bacterial counts and inflammatory indices following pulmonary infection of mice. Expression of PTX3 is enhanced during pulmonary infection in wild-type mice. In transgenic mice given a high inoculum, overt PTX3 expression was associated with faster lethality. Faster lethality correlated with enhanced nitrate in plasma, an inability of neutrophils to migrate to lung tissue and greater dissemination of bacteria to blood at 20h after infection. In contrast, transgenic PTX3 expression conferred protection to mice given lower pulmonary inocula. In the latter experiments, there was enhanced TNF-alpha production, greater neutrophil influx and phagocytosis of bacteria by migrated neutrophils. By controlling the production of TNF-alpha and NO, and depending on the intensity of the inflammatory response induced by a given inoculum, the expression of PTX3 may favor or disfavor the influx of neutrophils and the ability of the murine host to deal with pulmonary infection with K. pneumoniae. These experiments highlight the delicate balance that exists among the various mediators that control the inflammatory response and suggest that PTX3 is an essential part of the ability of a host to deal with bacterial infection.

Excessive matrix metalloproteinase-9 in the plasma of community-acquired pneumonia

BACKGROUND

It has been shown that matrix metalloproteinase-9 (MMP-9) is involved in the pathogenesis of various pulmonary inflammatory diseases. We determined the MMP-9 concentration in the plasma of community-acquired pneumonia (CAP) patients before and after antibiotic treatment.

METHODS

Gelatin zymography and ELISA analysis were used to measure MMP-9 activity and MMP-9 level, respectively, in 35 control subjects and 46 CAP patients.

RESULTS

WBC counts, neutrophils, MMP-9 activity and MMP-9 level were significantly higher in CAP patients compared with that of control subjects (P<0.001), while MMP-9 activity and MMP-9 level were returned to normal after the antibiotic treatment (P<0.001). In addition, MMP-9 level correlated positively with WBC counts and neutrophils number both before and after the antibiotic treatment.

CONCLUSIONS

MMP-9 may play an important role in the pathogenesis of CAP with a positive correlation with the number of neutrophils.

Pneumonia in elderly patients with preexisting respiratory disease

To evaluate the optimal duration of appropriate antibiotic therapy for pneumonia in elderly patients with preexisting respiratory disease, we studied improvement of infectious parameters in these patients. The medical record database was used to identify patients admitted with the following characteristics: primary diagnosis of benign respiratory disease; aged 65 years or over; no active malignant diseases in any organs; and at least one admission for pneumonia during April 2001 to May 2003. We observed 47 pneumonia episodes in 30 patients. Elevated CRP levels more than 8.0 mg/ml and leukocytosis more than 10.0 x 10(3) mm(-3) was seen in 21 and 29 pneumonia episodes, respectively. With appropriate intravenous antimicrobial therapy, average of CRP levels on day 0 (9.16 +/- 6.81 mg/dl) decreased to 5.18 +/- 4.67 mg/dl on day 3 (P = 0.0073). In more than 70% of pneumonia episodes, serum levels of CRP normalized on day 10. Average of leukocyte counts on day 0 ((12.3 +/- 4.7) x 10(3) mm(-3)) decreased to (8.1 +/- 3.5) x 10(3) mm(-3) on day 3 (P = 0.0001). In more than 80% of pneumonia episodes, leukocyte count normalized on day 7. The clinical response to appropriate antimicrobial therapy for pneumonia occurs within the first 3 days of therapy. Duration of intravenous antimicrobial therapy for pneumonia in these patients of 10 days would be sufficient and could prevent recurrent infection with resistant bacteria.

Impaired host defense to Klebsiella pneumoniae infection in mice treated with the PDE4 inhibitor rolipram

The increase in levels of cAMP in leukocytes by selective inhibitors of PDE4 may result in reduction of inflammation, and may be useful in the treatment of pulmonary inflammatory disorders in humans. Here, we have assessed whether oral treatment with the prototype PDE4 inhibitor, rolipram, interfered with the antibacterial host response following pulmonary infection of mice with Klebsiella pneumoniae. K. pneumoniae infection induced a marked increase in the recruitment of neutrophils to the lungs and the production of proinflammatory cytokines and chemokines, including tumor necrosis factor-alpha (TNF-alpha) and keratinocyte-derived chemokine (KC), in bronchoalveolar (BAL) fluid and lung tissue. There were also detectable amounts of interleukin-10 (IL-10) and significant lethality. Treatment with rolipram (3-30 mg kg-1) was associated with earlier lethality and significant inhibition of the TNF-alpha production. This was associated with enhanced production of IL-10 in lung tissue of rolipram-treated animals. Rolipram treatment did not affect KC expression and the recruitment of neutrophils in the lung tissue. Over 70% of neutrophils that migrated into the BAL fluid following K. pneumoniae infection ingested bacteria. Treatment with rolipram inhibited the percentage of neutrophils undergoing phagocytosis of K. pneumoniae in a dose-dependent manner. Maximal inhibition (62%) occurred at doses equal to or greater than 10 mg kg-1. Thus, treatment of mice with the PDE4 inhibitor rolipram is accompanied by earlier lethality, enhanced bacterial load and decreased capacity of the responding host to produce TNF-alpha and of neutrophils to phagocytose bacteria. It will be important to investigate whether the shown ability of PDE4 inhibitors to inhibit neutrophil phagocytosis and control experimental bacterial infection will translate into an inhibition of the ability of neutrophils to deal with infectious microorganisms in the clinical setting.

The challenge of nonresolving pneumonia. Knowing the norms of radiographic resolution is key

Pneumonia that fails to resolve after 10 to 14 days of antibiotic therapy can lead physicians to call for consultation or unnecessary invasive diagnostic procedures. Understanding the infectious and noninfectious causes of pneumonia and their normal times to resolution is enormously helpful in the judicious evaluation of and timely intervention in this very challenging condition.

[Community-acquired pneumonia in the elderly: prognostic factors]

The incidence and mortality rates of community-acquired pneumonia are far higher in the elderly than among younger populations. However, the explanation may lie in the presence of comorbidity rather than in age itself. We performed a retrospective study of 226 patients over the age of 65 years who were admitted to our hospital with a diagnosis of community-acquired pneumonia over a period of 36 months, with the objective of identifying factors predicting mortality and to describe clinical features. The patients' mean age was 78.71 (65-96) years. One hundred forty-two were men (63%) and 84 were women (37%). Upon admission, 27.4% showed signs of altered mental state. The crude mortality rate was 20.8%. Multivariate analysis demonstrated the following independent risk factors associated with higher mortality: serum creatinine > 1.2 mg/dL (RR = 13.93; 95% CI 8.14-16.08); patient previously bedridden (RR = 5.73; 95% CI 3.41-6.79), PaO2/FiO2 < 200 (RR = 5; 95% CI 2.67-6.62) and neoplastic disease (RR = 4.08; 95% CI 1.96-5.24). The presence of chest pain was associated with a lower risk of mortality (RR = 0.11; 95% CI 0.01-0.54). Age itself was not a risk factor. We conclude that pneumonia in the elderly requires hospitalization and that it commonly presents with severe symptoms and high risk of mortality. Risk factors such as those identified in this study may help in the diagnosis and treatment of patients requiring special care.

Pneumonia in the elderly

Pneumonia, including community-acquired, LTCF-acquired, and nosocomial infections, is a major cause of morbidity and mortality among the elderly. The aged with pneumonia often present with atypical features, including confusion, lethargy, and general deterioration of condition (silent infection). Further investigations, such as a chest radiograph frequently are required for diagnosis. The chest radiograph may be normal early on in the course of infection, particularly in dehydrated patients. The elderly are hospitalized more frequently for pneumonia, have a greater need for intravenous therapy, have a longer hospital stay, have a more prolonged course, have greater morbidity, and ultimately have a poorer outcome. Nevertheless, it may not be chronologic age per se that has a negative impact on the manifestations and outcome of pneumonia in the elderly, but rather the presence of underlying comorbid illness. The mainstay of therapy for pneumonia is antibiotics, and studies in the community and hospital have confirmed the important positive impact of early appropriate empiric therapy on outcome. Many relatively simple procedures, including attention to nutrition, influenza and pneumococcal vaccination, and avoidance of intubation, may help limit the occurrence of such infections.

[Community acquired pneumonia in patients older than 60 years. Incidence of atypical agents and clinical-radiological progression]

BACKGROUND

Seventy five patients older than 60 years with a community acquired pneumonia followed up in an outpatient clinic, were prospectively studied in order to determine the incidence of atypical agents, clinical-radiological characteristics, progression and the differences with pneumonia in younger patients.

METHOD

Clinical-radiological evaluation protocols were activated in the first visit and in two subsequent controls. Etiological diagnosis was made by means of serology (in the first visit and three weeks later).

RESULTS

Initially, 85 patients older than 60 years were included of which 75 non hospitalized were fully followed up. Also, in the comparative study, 216 outpatient clinic patients 60 years old or younger were followed up during the same period. In the first group the frequency of atypical agents was 33.3%. The most frequently isolated bacteria was Coxiella burnetii (13.3%)followed by virus and Legionella pneumophila. No case of Mycoplasma pneumoniae was diagnosed. The most frequent radiological onset was alveolar infiltrate (85%). The comparative study between the two populations (older or younger than 60 years), found few clinical differences (dyspnea more frequent in older,feverish chill in younger) and auscultation (crackles more frequent in older). We did not find differences remaining clinical-radiological or laboratory data. Most patients presented a favourable clinical and radiological progression. Only 2 patients needed hospital admission (2.7%).

CONCLUSIONS

In outpatient clinic patients older than 60 years with community acquired pneumonia a high number of atypical agents have been found. The clinical-radiological evolution was satisfactory for most of them. Age was not a decisive element in determining hospital admissions.

Etiology of severe pneumonia in the very elderly

The etiology of severe pneumonia requiring mechanical ventilation in the very elderly has been imprecise because of lack of comprehensive studies and low yield of diagnostic approach. Overall, 104 patients 75 yr of age and older with severe pneumonia were studied prospectively at two university-affiliated hospitals. Microbial investigation included blood culture, serology, pleural fluid, and bronchoalveolar secretions. Streptococcus pneumoniae (14%), gram-negative enteric bacilli (14%), Legionella sp. (9%), Hemophilus influenzae (7%), and Staphylococcus aureus (7%) were the predominant pathogens in community-acquired pneumonia (CAP). Staphylococcus aureus (29%), gram-negative enteric bacilli (15%), Streptococcus pneumoniae (9%), and Pseudomonas aeruginosa (4%) accounted for most isolates of nursing home-acquired pneumonia (NHAP). The case fatality rate was 55% (53% for CAP and 57% for NHAP; p > 0.5). Activity of Daily Living (ADL) Index, pulmonary, endocrine and central nervous system (CNS) comorbidities were associated with distinct microbial etiology. By multivariate analysis, hospital mortality was associated independently with 24-h urine output (odds ratio [OR], 5.6; 95% confidence interval [CI], 2.5 to 7.9; p < 0.001), septic shock (OR, 4.3; 95% CI, 1.9 to 8.9; p = 0.0059), radiographic multilobar involvement (OR, 3.7; 95% CI, 1.8 to 15.6; p = 0.02), and inadequate antimicrobial therapy (OR, 2.6; 95% CI, 1.4 to 23.9; p = 0.034). Further studies should focus on identifying effective antimicrobial regimens in randomized trials.

[Community-acquired pneumonia requiring hospital admission. A comparison of the clinical management, resource use and prognosis by different medical specialties]

OBJECTIVE

To evaluate whether there are differences regarding therapy, resource use and prognosis of inpatients due to community acquired pneumonia (CAP) in different clinical departments.

METHODS

One-year retrospective study, using the discharge abstract, of all patients aged over 7 years admitted to the general hospital with the diagnosis of CAP. Comparison of the appropriateness of antibiotic therapy, mean hospital stay, use of invasive procedures, intrahospital mortality rate, and readmissions between the different clinical departments.

RESULTS

A total of 511 patients were studied, 154 in Internal Medicine, 197 in Pneumology, 107 in Geriatrics and 53 in other departments, with moderate to severe underlying disease in 50.8%, severity criteria of CAP in 75%, and intrahospital mortality rate of 11.7%. No differences were observed regarding mean stay or appropriateness of antibiotic therapy. Invasive procedures were used most commonly in the Pneumology Department (12% vs 2%-7.5%; p = 0.001). In the Geriatrics Department readmissions were most common (10% vs 1%-4%; p = 0.006) and intrahospital mortality rate (19% vs 8.6%-13.2%; p = 0.029) than in the remaining departments. Intrahospital mortality was associated with a moderate or severe underlying disease, neurologic disease, severity criteria of CAP and ICU admission, and readmissions with a moderate or severe underlying disease.

CONCLUSIONS

There are relevant differences in intrahospital mortality rate and readmissions among patients with CAP in the different clinical departments, which seem to be associated with the underlying disease and the severity of the CAP.

Community-acquired pneumonia in the elderly: a practical guide to treatment

The incidence of community-acquired pneumonia (CAP), an infectious disease, sharply increases among the elderly and the main risk factor for CAP in this age group is chronic comorbidity. The use of the term CAP in the elderly population should be reserved for pneumonia acquired outside of the nursing home setting, since nursing home-acquired pneumonia differs from CAP in terms of its aetiology and clinical manifestations. The main aetiology for CAP is Streptococcus pneumoniae, but atypical pathogens also play an important role as causative agents. The clinical presentations of CAP in the elderly can be different from those in younger patients, and therefore it is important to be aware of and familiar with these differences to avoid unnecessary delays in reaching the correct diagnosis. Imaging is essential to diagnose CAP and to assess its severity. Clinical and laboratory indices can be used to identify elderly patients with CAP who are at low risk for mortality and who can be treated as outpatients. The decision not to hospitalise elderly patients with CAP is contingent on a good clinical condition and the existence of home support systems. The aetiology of CAP cannot be determined on the basis of clinical manifestations, imaging or routine laboratory test results, and the initial antibiotic therapy for elderly patients with CAP should be empirical, based on accepted guidelines. In the light of developments in recent years, elderly patients with CAP, except those who are severely ill, can be treated empirically with once-daily antibiotic monotherapy in the initial phase, using a third-generation fluoroquinolone preparation, such as sparfloxacin, levofloxacin or moxifloxacin, or a new macrolide such as clarithromycin, azithromycin or dirithromycin. In addition to antibiotic therapy, it is critically important to identify and treat the physiological disturbances that accompany CAP as well as decompensation of chronic comorbid conditions. As soon as the patient's condition permits, oral antibiotic therapy should replace intravenous therapy and early discharge from the hospital should be considered. Since influenza and pneumococcus immunisation can reduce morbidity and mortality from CAP, it is important to implement regular immunisation programmes in the primary care setting.

Measuring the impact of influenza on the hospital admission rates of the elderly in Ontario: a five-year admission rate analysis, 1988-1993

OBJECTIVE

A retrospective study was conducted to compare age- and sex-specific rates of hospital admission of the elderly in Ontario for five influenza seasons from 1988-1993 for pneumonia, congestive heart failure and chronic respiratory disease.

RESULTS

Significant increases in admissions were found for pneumonia in each influenza season for both sexes. Admissions were significantly increased for congestive heart failure for the oldest males in all years; and for four of five years for the youngest two age groups of males. For females significant increases in admissions occurred in the oldest two age groups in each influenza season; and for three of five seasons for the youngest age group. For chronic respiratory disease, significant increases in admissions were found for each influenza season for all years for the two youngest age groups of males and females.

CONCLUSION

The impact of influenza is substantial in terms of morbidity in the elderly.

Community-acquired pneumonia in the elderly. Clinical and nutritional aspects

Community-acquired pneumonia (CAP) in the elderly has a different clinical presentation than CAP in other age groups. Confusion, alteration of functional physical capacity, and decompensation of underlying illnesses may appear as unique manifestations. Malnutrition is also an associated feature of CAP in this population. We undertook a study to assess the clinical and nutritional aspects of CAP requiring hospitalization in elderly patients (over 65 yr of age). One hundred and one patients with pneumonia, consecutively admitted to a 1,000-bed teaching hospital over an 8-mo period, were studied (age: 78 +/- 8 yr, mean +/- SD). Nutritional aspects and the mental status of patients with pneumonia were compared with those of a control population (n = 101) matched for gender, age, and date of hospitalization. The main symptoms were dyspnea (n = 71), cough (n = 67), and fever (n = 64). The association of these symptoms with CAP was observed in only 32 patients. The most common associated conditions were cardiac disease (n = 38) and chronic obstructive pulmonary disease (COPD) (n = 30). Seventy-seven (76%) episodes of pneumonia were clinically classified as typical and 24 as atypical. There was no association between the type of isolated microorganism and the clinical presentation of CAP, except for pleuritic chest pain, which was more common in pneumonia episodes caused by classical microorganisms (p = 0.02). This was confirmed by a multivariate analysis (relative risk [RR] = 11; 95% confidence interval [CI]: 1.7 to 65; p = 0.0099). The prevalence of chronic dementia was similar in the pneumonia cohort (n = 25) and control group (n = 18) (p = 0.22). However, delirium or acute confusion were significantly more frequent in the pneumonia cohort than in controls (45 versus 29 episodes; p = 0.019). Only 16 patients with pneumonia were considered to be well nourished, as compared with 47 control patients (p = 0.001). Kwashiorkor-like malnutrition was the predominant type of malnutrition (n = 65; 70%) in the pneumonia patients as compared with the control patients (n = 31; 31%) (p = 0.001). The observed mortality was 26% (n = 26). Pleuritic chest pain is the only clinical symptom that can guide an empiric therapeutic strategy in CAP (typical versus atypical pneumonia). Both delirium and malnutrition were very common clinical manifestations of CAP in our study population.

LOWER RESPIRATORY TRACT INFECTIONS IN ELDERLY PATIENTS WITH ASTHMA

Infection plays a significant role in the morbidity and mortality of the elderly. One population in which infection has not been adequately studied is the elderly asthmatic. This article examines the problems of lower respiratory tract infections in elderly asthmatics in the context of their host defenses, the severity of infection, and their risk of infection with specific organisms. The role of infection in the pathogenesis of asthma and consideration of prophylaxis and therapy are presented.

Diagnosis and treatment of bacterial pneumonia in Korea

Even with advancements in knowledge the problem of pneumonia will not be eliminated. It should be understood who is at risk, why such people develop pneumonia, what causes the pneumonia, and respiratory infection should be managed and prevented. The relative frequency of the isolation of various etiologic agents that cause bacterial pneumonia differ according to age group, geography, socio-economic status, underlying disease, time of year, and possible concomitant viral illnesses. Prompt identification of the causative agent is vital in the management of pneumonia. The present status of elucidating the etiologic agent is far from complete and recently, newer techniques using DNA probes and polymerase chain reactions were used for the identification of microbial pathogens. The timely use of appropriate systemic antibacterial therapy eradicates the pathogens. Considering the alterations of the etiologic agents of bacterial pneumonia and antibiotic susceptibilities, attention should be directed to the usage of antimicrobial agents in order to maximize the efficacy and the therapeutic implications.

Host defenses against respiratory infection

The respiratory tract is protected from infection by its formidable mechanical and cellular defenses, supplemented when necessary by inflammatory and immune responses. Impairments in these defenses develop as a result of underlying disease and therapeutic interventions. Specific defects in host defenses often predispose to infection with particular etiologic agents. New opportunities for the therapeutic augmentation of defenses are emerging that may be particularly helpful in the care of immunocompromised patients.