Clinical characteristics and outcome associated with pandemic (2009) H1N1 influenza infection in patients with hematologic malignancies: a retrospective cohort study

When Viruses Meet Fungi: Tackling the Enemies in Hematology

The association of invasive fungal infections (IFI) and viral infections has been described in patients with hematologic malignancies (HM), in particular in hematopoietic stem cell transplant recipients. Regrettably, the diagnosis is often challenging, making the treatment inappropriate in some circumstances. The present review takes into consideration the viral infections commonly associated with IFI. Clinical presentation of IFI and viral infections, risk factors, and impact on the outcome of HM patients are discussed throughout the paper.

Impact of Influenza Infection Among Adult and Pediatric Populations With Hematologic Malignancy and Hematopoietic Stem Cell Transplant: A Systematic Review and Meta-Analysis

PURPOSE

Influenza is increasingly recognized as a leading cause of morbidity and mortality in patients with hematologic malignancies and recipients of hematopoietic stem cell transplantation (HSCT). However, the impact of influenza on this population has not been previously evaluated in a systematic review. This study systematically reviewed and summarized the outcomes of influenza infection as to in-hospital influenza-related mortality, development of lower respiratory tract infection and acute respiratory distress syndrome, need for hospitalization, intensive care unit admission, and mechanical ventilation.

METHODS

We conducted a systematic search of literature using the PubMed and EMBASE databases for articles published from January 1989 through January 19, 2020, reporting laboratory-confirmed influenza in patients of any age with hematologic malignancies and HSCT. Time from transplantation was not included in the search criteria. The impact of antiviral therapy on influenza outcomes was not assessed due to heterogeneity in antiviral treatment provision across the studies. Patients with influenza-like illness, solid-tumor cancers, or nonmalignant hematologic diseases were excluded from the study. A random-effects meta-analysis was performed to estimate the prevalences and 95% CIs of each outcome of interest. A subgroup analysis was carried out to assess possible sources of heterogeneity and to evaluate the potential impact of age on the influenza infection outcomes. Heterogeneity was assessed using the I² statistic.

FINDINGS

Data from 52 studies providing data on 1787 patients were included in this analysis. During seasonal epidemics, influenza-related in-hospital mortality was 16.60% (95% CI, 7.49%-27.7%), with a significantly higher death rate in adults compared to pediatric patients (19.55% [95% CI, 10.59%-29.97%] vs 0.96% [95% CI, 0%-6.77%]; P < 0.001). Complications from influenza, such as lower respiratory tract infection, developed in 35.44% of patients with hematologic malignancies and HSCT recipients, with a statistically significant difference between adults and children (46.14% vs 19.92%; P < 0.001). However, infection resulted in a higher hospital admission rate in pediatric patients compared to adults (61.62% vs 22.48%; P < 0.001). For the 2009 H1N1 pandemic, no statistically significant differences were found between adult and pediatric patients when comparing the rates of influenza-related in-hospital mortality, lower respiratory tract infection, and hospital admission. Similarly, no significant differences were noted in any of the outcomes of interest when comparing H1N1 pandemic with seasonal epidemics.

IMPLICATIONS

Regardless of influenza season, patients, and especially adults, with underlying hematologic malignancies and HSCT recipients with influenza are at risk for severe outcomes including lower respiratory tract infection and in-hospital mortality.

How to Use a Prioritised Approach for Treating Hematological Disorders During the COVID-19 Pandemic in India?

The current pandemic coronavirus, SARS-CoV-2, is known to cause severe infection (COVID-19) in patients with comorbidities, particularly cancer or an immunosuppressed state. Most healthcare systems in the country are likely to be overwhelmed soon if the pandemic moves to a stage of community transmission. Currently, limited evidence is available for managing patients with hematological disorders during the COVID-19 pandemic. The current review summarises the possible challenges clinicians are likely to face, key considerations to guide decision making, and possible solutions to the anticipated challenges. Disease specific recommendations and possible guidance for decision making have been suggested for most hematologic diseases that are feasible in our health setup. It is not meant to replace individual clinical judgment, but to provide a template to formulate local policies.

Influenza in patients with cancer after 2009 pandemic AH1N1: An 8-year follow-up study in Mexico

BACKGROUND

Immunosupressed patients are at high risk of influenza-related complications. Influenza AH1N1 has been hypothesized to induce worse outcomes in patients with malignancies, but after the A(H1N1)pdm09 few publications have analyzed the presentation and complications related to influenza afterward.

OBJECTIVES

We aimed to describe the characteristics, risk factors, and outcomes of influenza in an oncologic center after the 2009 pandemic and to compare our case distribution to the National community acquired influenza databases in Mexico and the United States.

METHODS

We reviewed the cases of confirmed influenza in patients with cancer from an oncological center in Mexico from April 2009 to April 2017. Data on severity and influenza type, malignancy, comorbidities, and outcomes were recorded. We correlated data between the Centers for Disease Control and Prevention (CDC) in the United States and SISVEFLU (Influenza Surveillance Program) in Mexico.

RESULTS

One hundred eighty-eight patients were included; 75 (39.9%) had a solid neoplasm and 113 (60.1%) had hematologic malignancies. AH1N1 was the most frequent influenza type (54.2%). Patients with hematologic malignancies had more pneumonia (55% vs 25%, P < .001), needed more hospitalizations (75% vs 39% P < .001), had higher all-cause mortality at 30 days (20% vs 9% P = .048) and influenza-associated mortality (17% vs 7% P = .041). Thirty (16%) patients died within 30 days, and 24 (12.7%) were related to influenza. Influenza type was not associated with worse outcomes. Yearly occurrence of influenza reported by the CDC and SISVEFLU showed a significant correlation (ρ = 0.823, P = .006).

CONCLUSIONS

AH1N1 was the dominant serotype. Patients with hematologic malignancies had more severe influenza and presented worse outcomes. Annual SISVEFLU and CDC surveillance information showed a similar distribution of cases along time but influenza serotypes did not match for all seasons.

Are Community Acquired Respiratory Viral Infections an Underestimated Burden in Hematology Patients?

Despite a plethora of studies demonstrating significant morbidity and mortality due to community-acquired respiratory viral (CRV) infections in intensively treated hematology patients, and despite the availability of evidence-based guidelines for the diagnosis and management of respiratory viral infections in this setting, there is no uniform inclusion of respiratory viral infection management in the clinical hematology routine. Nevertheless, timely diagnosis and systematic management of CRV infections in intensively treated hematology patients has a demonstrated potential to significantly improve outcome. We have briefly summarized the recently published data on CRV infection epidemiology, as well as guidelines on the diagnosis and management of CRV infections in patients intensively treated for hematological malignancies. We have also assessed available treatment options, as well as mentioned novel agents currently in development.

Respiratory Virus Infections of the Stem Cell Transplant Recipient and the Hematologic Malignancy Patient

Respiratory virus infections in hematologic stem cell transplant recipients and patients with hematologic malignancies are increasingly recognized as a cause of significant morbidity and mortality. The often overlapping clinical presentation makes molecular diagnostic strategies imperative for rapid diagnosis and to inform understanding of the changing epidemiology of each of the respiratory viruses. Most respiratory virus infections are managed with supportive therapy, although there is effective antiviral therapy for influenza. The primary focus should remain on primary prevention infection control procedures and isolation precautions, avoidance of ill contacts, and vaccination for influenza.

Safety and effectiveness of neuraminidase inhibitors in situations of pandemic and/or novel/variant influenza: a systematic review of the literature, 2009-15

Objectives

To review systematically the published literature evaluating neuraminidase inhibitor (NI) safety and effectiveness in situations of pandemic and novel/variant influenza.

Methods

We searched six online databases using comprehensive search criteria for observational studies and randomized controlled trials investigating the effects of NI treatment, prophylaxis or outbreak control in patients of all ages.

Results

Overall, 165 studies were included (95% observational), which were generally of low methodological quality due to lack of adjustment for confounding variables. In studies reporting adjusted estimates in general populations, NI treatment appeared likely to be effective against mortality (primarily if administered within 48 h of symptom onset) and potentially effective in reducing pneumonia. NIs appeared effective in reducing secondary transmission when indicated for prophylaxis. Limited, low-quality data suggest NIs are likely safe in general populations and may be safe in pregnant women and children. Data are scarce regarding safety of NIs in adults and high-risk individuals.

Conclusions

Most included studies were observational, statistically underpowered and at high risk of reporting biased and/or confounded effect estimates. NI treatment appeared likely effective in reducing mortality (cause unspecified) and pneumonia in general populations, with increasing benefit when administered with 48 h of symptom onset. NI pre- or post-exposure prophylaxis is likely effective in reducing secondary transmission of influenza in a general population. Our evidence suggests NIs are likely safe to use in the general population; however, data for children and pregnant women are limited. Knowledge gaps persist in specific populations such as Aboriginals, high-risk individuals and the elderly.

Influenza in patients with hematological malignancies: Experience at two comprehensive cancer centers

The burden of influenza infections in patients with hematological malignancies (HMs) is not well defined. We describe the clinical presentation and associated outcomes of influenza at two comprehensive cancer centers (center 1 in the United States and center 2 in Mexico). Clinical and laboratory data on patients with HMs and influenza infection diagnosed from April 2009 to May 2014 at the two centers were reviewed retrospectively. A total of 190 patients were included, the majority were male (63%) with a median age of 49 years (range, 1-88 years), and had active or refractory HMs (76%). Compared to center 1, patients in center 2 were significantly sicker (active cancer, decreased albumin levels, elevated creatinine levels, or hypoxia at influenza diagnosis) and experienced higher lower respiratory tract infection (LRI) rate (42% vs 7%; P < 0.001). In multivariable logistic regression analysis (odds ratio, 95% confidence interval), leukemia, (3.09, 1.23-7.70), decreased albumin level (3.78, 1.55-9.20), hypoxia at diagnosis (14.98, 3.30-67.90), respiratory co-infection (5.87, 1.65-20.86), and corticosteroid use (2.71, 1.03-7.15) were significantly associated with LRI; and elevated creatinine level (3.33, 1.05-10.56), hypoxia at diagnosis (5.87, 1.12-30.77), and respiratory co-infection (6.30, 1.55-25.67) were significantly associated with 60 day mortality in both centers. HM patients with influenza are at high risk for serious complications such as LRI and death, especially if they are immunosuppressed. Patients with respiratory symptoms should seek prompt medical care during influenza season.

Outcomes of Influenza Infections in Hematopoietic Cell Transplant Recipients: Application of an Immunodeficiency Scoring Index

Hematopoietic cell transplant (HCT) recipients have lower immune response to influenza vaccination and are susceptible to lower respiratory tract infection (LRI) and death. We determined clinical characteristics and outcomes of laboratory-confirmed influenza, including 2014/H3N2 infection, in 146 HCT recipients. An immunodeficiency scoring index (ISI) was applied to identify patients at high risk for LRI and death. Thirty-three patients (23%) developed LRI and 7 (5%) died within 30 days of diagnosis. Most patients received antiviral therapy (83%); however, only 18% received it within 48 hours of symptom onset. The incidence of LRI was significantly higher in the ISI high-risk group than it was in the low-risk group (P < .001). Receiving early antiviral therapy was associated with a substantial reduction in LRI for all ISI risk groups with the greatest risk reduction observed in the high-risk group. When compared with previous seasons, no significant differences in patient outcomes were observed during the 2014/H3N2 season; however, antiviral therapy was more promptly initiated in the latter season. The ISI that was originally developed for respiratory syncytial virus may help identify HCT recipients at risk for progression to LRI and mortality after influenza infection. These patients should be monitored more closely. Early initiation of antiviral therapy for influenza in HCT recipients, regardless of the ISI risk group, may improve morbidity as well as mortality.

Pandemic 2009 Influenza A (H1N1) virus infection in cancer and hematopoietic stem cell transplant recipients; a multicenter observational study

BACKGROUND

During March 2009 a novel Influenza A virus emerged in Mexico. We describe the clinical picture of the pandemic Influenza A (H1N1) Influenza in cancer patients during the 2009 influenza season.

METHODS

Twelve centers participated in a multicenter retrospective observational study of cancer patients with confirmed infection with the 2009 H1N1 Influenza A virus (influenza-like illness or pneumonia plus positive PCR for the 2009 H1N1 Influenza A virus  in respiratory secretions). Clinical data were obtained by retrospective chart review and analyzed. 

RESULTS

From May to August 2009, data of 65 patients were collected. Median age was 51 years, 57 % of the patients were female. Most patients (47) had onco-hematological cancers and 18 had solid tumors. Cancer treatment mainly consisted of chemotherapy (46), or stem cell transplantation (SCT) (16). Only 19 of 64 patients had received the 2009 seasonal Influenza vaccine. Clinical presentation included pneumonia (43) and upper respiratory tract infection (22). Forty five of 58 ambulatory patients were admitted. Mechanical ventilation was required in 12 patients (18%). Treatment included oseltamivir monotherapy or in combination with amantadine for a median of 7 days. The global 30-day mortality rate was 18%. All 12 deaths were among the non-vaccinated patients. No deaths were observed among the 19 vaccinated patients. Oxygen saturation <96% at presentation was a predictor of mortality (OR 19.5; 95%CI: 2.28 to 165.9).

CONCLUSIONS

In our cancer patient population, the pandemic 2009 Influenza A (H1N1) virus was associated with high incidence of pneumonia (66%), and 30-day mortality (18.5%). Saturation <96% was significantly associated with death. No deaths were observed among vaccinated patients.

Pandemic 2009 Influenza A (H1N1) virus infection in cancer and hematopoietic stem cell transplant recipients; a multicenter observational study

BACKGROUND

During March 2009 a novel Influenza A virus emerged in Mexico. We describe the clinical picture of the pandemic Influenza A (H1N1) Influenza in cancer patients during the 2009 influenza season.

METHODS

Twelve centers participated in a multicenter retrospective observational study of cancer patients with confirmed infection with the 2009 H1N1 Influenza A virus (influenza-like illness or pneumonia plus positive PCR for the 2009 H1N1 Influenza A virus  in respiratory secretions). Clinical data were obtained by retrospective chart review and analyzed. 

RESULTS

From May to August 2009, data of 65 patients were collected. Median age was 51 years, 57 % of the patients were female. Most patients (47) had onco-hematological cancers and 18 had solid tumors. Cancer treatment mainly consisted of chemotherapy (46), or stem cell transplantation (SCT) (16). Only 19 of 64 patients had received the 2009 seasonal Influenza vaccine. Clinical presentation included pneumonia (43) and upper respiratory tract infection (22). Forty five of 58 ambulatory patients were admitted. Mechanical ventilation was required in 12 patients (18%). Treatment included oseltamivir monotherapy or in combination with amantadine for a median of 7 days. The global 30-day mortality rate was 18%. All 12 deaths were among the non-vaccinated patients. No deaths were observed among the 19 vaccinated patients. Oxygen saturation <96% at presentation was a predictor of mortality (OR 19.5; 95%CI: 2.28 to 165.9).

CONCLUSIONS

In our cancer patient population, the pandemic 2009 Influenza A (H1N1) virus was associated with high incidence of pneumonia (66%), and 30-day mortality (18.5%). Saturation <96% was significantly associated with death. No deaths were observed among vaccinated patients.

Changing face of vaccination in immunocompromised hosts

Infection prevention is a key component of care and an important determinant of clinical outcomes in a diverse population of immunocompromised hosts. Vaccination remains a fundamental preventative strategy, and clear guidelines exist for the vaccination of immunocompromised individuals and close contacts. Unfortunately, adherence to such guidelines is frequently suboptimal, with consequent missed opportunities to prevent infection. Additionally, vaccination of immunocompromised individuals is known to produce responses inferior to those observed in immunocompetent hosts. Multiple factors contribute to this finding, and developing improved vaccination strategies for those at high risk of infectious complications remains a priority of care providers. Herein, we review potential factors contributing to vaccine outcomes, focusing on host immune responses, and propose a means for applying modern, innovative systems biology technology to model critical determinants of vaccination success. With influenza vaccine in solid organ transplants used as a case in point, novel means for stratifying individuals using a host "immunophenotype" are explored, and strategies for individualizing vaccine approaches tailored to safely optimize vaccine responses in those most at risk are discussed.