Community-acquired pneumonia

Stakeholder views on the acceptability of human infection studies in Malawi

BACKGROUND

Human infection studies (HIS) are valuable in vaccine development. Deliberate infection, however, creates challenging questions, particularly in low and middle-income countries (LMICs) where HIS are new and ethical challenges may be heightened. Consultation with stakeholders is needed to support contextually appropriate and acceptable study design. We examined stakeholder perceptions about the acceptability and ethics of HIS in Malawi, to inform decisions about planned pneumococcal challenge research and wider understanding of HIS ethics in LMICs.

METHODS

We conducted 6 deliberative focus groups and 15 follow-up interviews with research staff, medical students, and community representatives from rural and urban Blantyre. We also conducted 5 key informant interviews with clinicians, ethics committee members, and district health government officials.

RESULTS

Stakeholders perceived HIS research to have potential population health benefits, but they also had concerns, particularly related to the safety of volunteers and negative community reactions. Acceptability depended on a range of conditions related to procedures for voluntary and informed consent, inclusion criteria, medical care or support, compensation, regulation, and robust community engagement. These conditions largely mirror those in existing guidelines for HIS and biomedical research in LMICs. Stakeholder perceptions pointed to potential tensions, for example, balancing equity, safety, and relevance in inclusion criteria.

CONCLUSIONS

Our findings suggest HIS research could be acceptable in Malawi, provided certain conditions are in place. Ongoing assessment of participant experiences and stakeholder perceptions will be required to strengthen HIS research during development and roll-out.

[Community-acquired pneumonia]

CLINICAL ISSUE

The diagnosis of community-acquired pneumonia (CAP) is often not possible based only on the clinical symptoms and biochemical parameters.

STANDARD RADIOLOGICAL METHODS

For every patient with the suspicion of CAP, a chest radiograph in two planes should be carried out. Additionally, a risk stratification for the decision between outpatient therapy or hospitalization is recommended.

METHODICAL INNOVATIONS

Based on the evaluation of the different radiological patterns as well as their extent and distribution, a rough allocation to so-called pathogen groups as well as a differentiation between viral and bacterial infections are possible; however, because different pathogens cause different patterns an accurate correlation is not feasible by relying purely on imaging.

ACHIEVEMENTS/PRACTICAL RECOMMENDATIONS

The radiological findings serve as proof or exclusion of pneumonia and can also be used to evaluate the extent of the disease (e.g. monolobular, multilobular, unilateral or bilateral). In cases of prolonged disease, suspicion of complications (e.g. pleural effusion or empyema, necrotizing pneumonia or abscess) or comorbid conditions (e.g. underlying pulmonary or mediastinal diseases) computed tomography is an important diagnostic tool in addition to chest radiography. Ultrasound is often used to diagnose pleural processes (e.g. parapneumonic effusion or pleural empyema).

A Curious Case of Inhalation Fever Caused by Synthetic Cannabinoid

BACKGROUND

This case report describes inhalation fever as an uncommon pulmonary adverse effect of synthetic cannabinoids.

CASE REPORT

A 29-year-old man was brought in for severe agitation after smoking K2, a synthetic cannabinoid. He required multiple doses of lorazepam and haloperidol for sedation. His vital signs were notable for a mild fever and tachycardia. Otherwise, the rest of his exam was unremarkable. The laboratory test was significant for leucocytosis and diffuse reticular-nodular and interstitial infiltrates on chest radiograph. Urine drug toxicology was negative. Interestingly, his symptoms and pulmonary infiltrates on the chest radiograph resolved spontaneously after 24 hours of observation.

CONCLUSIONS

This patient developed transient pulmonary infiltrates and fever following the synthetic cannabinoid inhalation, as seen in self-limiting inhalation fever. Inhalation fever as a consequence of synthetic cannabinoid has not been described previously and there is a need for further research in this field.

Time trends in primary-care morbidity, hospitalization and mortality due to pneumonia

Most studies reporting pneumonia morbidity are restricted to hospitalized patients, although only a minority of pneumonia patients are admitted to hospital. To get a better understanding of the burden of disease in the general population, we conducted a population-based retrospective study to examine trends in pneumonia incidence in general practice, hospitalization, and mortality due to pneumonia in The Netherlands between 1997 and 2007. Between 2001/2002 and 2006/2007 there was an adjusted yearly increase of 12% in the clinical diagnosis of pneumonia in patients consulting general practitioners. Hospitalizations increased 5% per year between 1999/2000 and 2006/2007, while mortality annually decreased by 2% between 1997/1998 and 2006/2007. Our study suggests that the morbidity of pneumonia in the Dutch population increased considerably over this period, especially in primary-care settings, and that focusing only on hospitalization might underestimate the increasing public health burden of pneumonia.

Immunization with PspA incorporated into a poly(ethylene oxide) matrix elicits protective immunity against Streptococcus pneumoniae

CBA/N mice were immunized with PspA in a poly(ethylene oxide) matrix to examine its ability to deliver the antigen and modulate the immune response. All mice receiving PspA in the matrix survived a lethal pneumococcal challenge and had serum anti-PspA antibody levels statistically higher than mice receiving PspA alone (P < 0.009).

Sudden death due to asphyxia by esophageal polyp: two case reports and review of asphyxial deaths

Asphyxia, not an uncommon cause of sudden death, may result from numerous etiologies. Foreign-body aspiration and strangulation are 2 extrinsic causes. Airway obstruction may also be caused by laryngeal edema, asthma, infection, or anaphylaxis. Chronic causes of asphyxia include musculoskeletal diseases (eg, muscular dystrophy, amyotrophic lateral sclerosis), neurologic disorders (eg, myasthenia gravis, multiple sclerosis), respiratory disease (eg, emphysema, chronic bronchitis), or tumors. The manner of death in cases of asphyxiation may be natural, accidental, homicide, or suicide. For the death investigator, determining the cause and manner of death can often be quite challenging. We report here 2 cases of an esophageal fibrovascular polyp causing sudden asphyxial death, review of the literature, and discussion of other differential diagnoses in the case of asphyxial death.

Increased carrageenan-induced acute lung inflammation in old rats

Ageing is associated with increased susceptibility to lung infections and delayed resolution of pulmonary infiltrates. The purpose of this study was to investigate the effect of age on the onset of carrageenan-induced lung inflammation. When compared with carrageenan-treated young rats (3 months old), old rats (>18 months old) exhibited a preponderance of pleural exudation and polymorphonuclear cell infiltration. Lung myeloperoxidase activity, an index of neutrophil infiltration and activation, was significantly increased in old rats in comparison with young rats. Consistent with the biochemical markers of inflammation, increased lung damage, as assessed by nitrosative stress and lipid peroxidation, was observed in carrageenan-treated old rats. In the lung exudate obtained from old rats, a significant reduction in interleukin-10 (IL-10) was observed, while similar expression of monocyte chemotactic protein-1 was induced, suggesting that a decrease in IL-10 rather than increased chemotaxis may account for the preponderance of the inflammatory cellular infiltrate in old rats. Similar to the in vivo situation, freshly isolated alveolar macrophages obtained from old rats produced less IL-10. This defective IL-10 production could be explained by a reduction in the cAMP-dependent signalling pathway, which mediates IL-10 production. Indeed, we found decreased cAMP-responsive element binding protein (CREB) and phosphorous-CREB (P-CREB) expression in old rats, which may account for reduced IL-10 production in old rats.

Community-acquired bacteraemia in a rural area: predominant bacterial species and antibiotic resistance

The invasion of the bloodstream represents one of the most important sequelae of infection. This study was conducted over an 18-month period to determine the predominant bacterial agents of a community-acquired bacteraemia seen at health centres in a rural area of Jordan, and their antibiotic susceptibilities. Blood samples were collected and cultured from 215 patients who presented with fever and presumed diagnosis of a bacteraemia. Isolates were identified and tested for antibiotic susceptibility. The variables included the age and sex of the patients, aetiology, sources of the bacteraemia, risk factors, treatment and outcome. One hundred and twenty-six (58.6%) blood cultures were positive. Children less than 14 years old accounted for 34.9% of these, and 38% were from patients that were more than 50 years old. The most frequent aetiologic agents were Staphylococcus aureus, followed by Brucella melitensis and Streptococcus pneumoniae. A wide range of resistance to commonly used antimicrobial agents and multidrug resistance was documented in 44.4% of the isolates. The most frequent sources of the bacteraemia were urinary (15.9%), respiratory (14.3%), no source of the bacteraemia identified (primary bacteraemia) (13.5%), gastrointestinal (12.7%) and soft-tissue infection (7.9%). No identifiable risk factor for infection could be determined in 34% of the patients. The predominant pathogens identified and the relatively high prevalence of antibiotic resistance of the isolates are most probably due to the nature and lifestyle of this rural population and the use of empiric treatment. Characteristics permitting recognition of patients with such strains would aid infection control efforts in the community.

Once-daily oral gatifloxacin vs three-times-daily co-amoxiclav in the treatment of patients with community-acquired pneumonia

A double-blind, double-dummy, multicentre, multinational, parallel-group study was designed to establish proof of equivalence between oral gatifloxacin and oral co-amoxiclav in the treatment of 462 patients with mild-to-moderate community-acquired pneumonia. Eligible patients were randomised equally to either gatifloxacin 400 mg once-daily plus matching placebo for 5-10 days, or amoxycillin 500 mg + clavulanic acid 125 mg three-times-daily for 5-10 days. The primary efficacy endpoint was clinical response (clinical cure plus improvement) at the end of treatment. Overall, a successful clinical response was achieved in 86.8% of gatifloxacin-treated patients, compared with 81.6% of those receiving co-amoxiclav, while corresponding rates of bacteriological efficacy (eradication plus presumed eradication) were 83.1% and 78.7%, respectively. The safety and tolerability profile of gatifloxacin was comparable to that of co-amoxiclav, with adverse gastrointestinal events, e.g., diarrhoea and nausea, being the most common treatment-related adverse events in both groups. The study showed no evidence of gatifloxacin-induced phototoxicity, musculoskeletal disorders, or hepatic and renal problems. Overall, this study showed that gatifloxacin was equivalent clinically to a standard course of co-amoxiclav in patients with community-acquired pneumonia, and that gatifloxacin was safe and well-tolerated.

An update on community-acquired pneumonia in adults

Community-acquired pneumonia (CAP) is a leading cause of morbidity and mortality, despite effective therapies. Guidelines for CAP management vary widely in their approach. Resistance of S pneumoniae to penicillins and other antibiotics has prompted evaluation of the new fluoroquinolones.

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.

Sparfloxacin: a review

BACKGROUND

The continuing increase in the rate of penicillin and cephalosporin resistance among respiratory pathogens and of cross-resistance to macrolide antibiotics has led to the recommendation that fluoroquinolone antibiotics be used to treat high-risk patients with community-acquired pneumonia (CAP) and acute bacterial exacerbations of chronic bronchitis (ABECB).

OBJECTIVE

This review focuses on sparfloxacin, an oral fluoroquinolone, discussing its mechanism of action, activity, pharmacokinetic characteristics, safety, and efficacy in CAP and ABECB.

METHODS

Studies were identified by a MEDLINE search of the literature from 1990 to 1999, supplemented by educational materials from conferences and symposia.

RESULTS

Sparfloxacin is active against the major respiratory pathogens and against the atypical pathogens in pneumonia that are being reported with increasing frequency. Its long half-life permits once-daily dosing. In large trials in CAP and ABECB in which all isolates were susceptible to both comparators, sparfloxacin was found to have similar efficacy to erythromycin, cefaclor, amoxicillin, ofloxacin, and clarithromycin. Its safety profile is similar to that of the macrolides and other quinolone antimicrobial agents. Photosensitivity, nausea, and diarrhea are the most common adverse events reported in clinical trials of sparfloxacin. Its use is contraindicated in patients with QTc-interval prolongation.

CONCLUSION

The increasing prevalence of beta-lactam- and macrolide-resistant bacteria in respiratory infections emphasizes the need for newer agents such as the fluoroquinolones. The choice between agents should be based on activity against the relevant respiratory pathogens in high-risk patients.