Update on influenza and other viral pneumonias

Prolonged lymphopenia in a patient with lymphoma and severe Pandemic influenza A H1N1 2009 virus infection

Please cite this paper as:Ñamendys‐Silva et al. (2011) Prolonged lymphopenia in a patient with lymphoma and severe Pandemic influenza A H1N1 2009 virus infection. Influenza and Other Respiratory Viruses DOI: 10.1111/j.1750‐2659.2010.00193.x.

Objective  To describe the clinical course of a confirmed influenza A Pandemic (H1N1) 2009 virus infection in a patient with lymphoblastic lymphoma on chemotherapy.

Design  Case report.

Setting  Instituto Nacional de Cancerología located in Mexico City, a national referral center for cancer patients.

Patient and results  A 15‐year‐old boy, with lymphoblastic lymphoma on chemotherapy. Oseltamivir 75 mg BID was started within 24 hour of first symptoms. The patient developed respiratory failure despite oseltamivir therapy; he presented a prolonged clinical course with severe lymphopenia and deteriorated every time oseltamivir was stopped while lymphopenia persisted. Oseltamivir was reassumed twice; in the second course, rimatadine was added. Genetic study of the virus showed 100% identity for AH1N1SW, and no H274Y mutation for oseltamivir resistance was found. Clinical recovery was apparent until he presented lymphocyte reconstitution after 35 days of disease while still on antiviral therapy.

Conclusion  This case exemplifies the need to sustain antiviral therapy while patient continues with severe lymphopenia. Lymphocyte count could be used as a surrogate marker to prolong antiviral therapy in patients with severe lymphopenia and clinically symptomatic Pandemic (H1N1) 2009 infection. This case also highlights the importance of treating patients based on clinical grounds and the variability of rRt‐PCR test for H1N1.

Clinical implications of respiratory virus infections in solid organ transplant recipients: a prospective study

BACKGROUND

There is limited information about clinical consequences of respiratory virus infections (RVI) in solid organ transplant recipients. No prospective epidemiological study has been published previously.

METHODS

We selected a cohort of 152 transplant recipients (cardiac, hepatic and renal transplant recipients). Median time from transplantation was 17 months (range 1-50). They were prospectively followed-up for RVI during 7 months (October to April). Clinical and microbiological evaluation (cell culture, shell vial and polymerase chain reaction technique) of each RVI episode was made.

RESULTS

We detected 81 RVI (0.91 episodes/patient/year). Complications were detected in 15/81 episodes (18.5%): acute bronchitis (10 cases), pneumonia (three cases; 3.7% of RVI episodes) and bacterial sinusitis (2 cases). In 4 of 81 episodes (5%), patients needed hospitalization. A respiratory virus was isolated in 17 of 68 nasopharyngeal samples (six respiratory syncytial virus, six influenza, four picornavirus, one adenovirus). Fever presented an 83% positive predictive value for the diagnosis of influenza virus infection among those with a positive microbiological isolation. There were no episodes of acute rejection coincidentally with RVI. Only 54% of the subjects had been previously vaccinated against influenza.

CONCLUSIONS

Incidence of RVI among solid organ transplant recipients is similar to general population but complications are higher. A relationship between RVI and rejection was not detected. The rate of influenza vaccination was lower than expected. The presence of fever in a transplant recipient with RVI strongly suggests influenza infection.

Office pediatrics: current perspectives on the outpatient evaluation and management of lower respiratory infections in children

PURPOSE OF REVIEW

The outpatient evaluation and management of a child with lower respiratory infection (LRI) remain a challenge to clinicians worldwide. This update will discuss current problems and new developments in the outpatient evaluation and treatment of pediatric LRIs.

RECENT FINDINGS

The cause of pediatric LRIs remains partially defined. Mixed infections and 'unknown' organisms may be important sources of clinical illness. A wider incidence of atypical bacteria LRIs (notably Mycoplasma pneumoniae) in children is now recognized. Viral LRIs from rhinoviruses and human metapneumovirus are increasingly detected in children. Human metapneumovirus may compound the clinical severity of pediatric LRIs, specifically in combination with respiratory syncytial virus. Innovations in testing for viral LRIs offer a promising tool for the outpatient evaluation and management of pediatric LRIs.

SUMMARY

Neither clinical symptoms nor findings on chest radiographs can reliably distinguish children with bacterial LRIs from those with viral or atypical pathogens. The efficacy of outpatient antibiotic treatment of atypical bacteria LRIs remains unproven. Multiplex rapid viral testing may ultimately help to refine strategies for outpatient management. The outpatient treatment of viral LRIs remains limited to supportive care; the 'value' of bronchodilators, epinephrine, or corticosteroids for treatment of bronchiolitis is unconfirmed.

A review of the effectiveness of vaccine potency control testing

The use of potency control testing is a valuable tool for testing the actual relative strength of manufactured assembly lots of vaccine. Biological-based manufacturing methods are inherently variable and potency testing is a tool to ensure lot-to-lot consistency of commercial vaccines. A strong historical link to clinical efficacy has been established where correlation to efficacy and adequate test validation have been achieved. The link to immunogenicity and efficacy has traditionally been strongest with attenuated vaccines and toxoids. Control potency test failure does predict that a serial or batch of vaccine would most likely provide insufficient immunogenicity in typical field applications. Because of the complexity of pathogenic processes and associated immune responses, potency tests may not always directly predict the effectiveness of a vaccine. Thus, vaccines that pass control potency testing may not always provide adequate efficacy. This is particularly true of adjuvanted, inactivated vaccines. In the development of vaccine formulations and control tests for vaccines, the nature of the desired protective immune responses to the targeted pathogen (when known) should be considered. These considerations could provide better alternatives in the assays chosen as correlates of immunity and may more accurately predict efficacy and assure batch-to-batch consistency. Also, the effects of the dose and duration of antigen exposure as well as the nature of antigen presentation and generation of extrinsic cytokines could be characterised and correlated to vaccine potency as additional indicators of vaccine efficacy.

Lower respiratory infections in children

Lower respiratory infections (LRIs) continue to threaten the health of children worldwide and are exacerbated by global environmental problems such as air pollution [1]. In the developing world where nutrition remains poor and access to healthcare is scarce, LRIs are the most common cause of illness and death in children. Outcomes of LRI illness are far better in developed countries, but the overall morbidity of LRI is still high and may exceed that of other age groups [2]. The environmental "health" of our planet remains an issue closely linked to the health of children--particularly in terms of LRI disease. It is also clear that further progress in preventing, diagnosing, and treating LRI disease will have a significant impact on the health of children. The recent literature details both progress and clinical dilemmas of LRI-related illnesses in children. Lower respiratory infection disease is considered to include the following entities: acute lower respiratory infections, pneumonia, atypical pneumonia, bronchitis, and bronchiolitis. This update will review current reports on the evaluation of children with LRIs, bacterial and viral LRIs, and sequelae of LRIs.