HUMAN PARAINFLUENZA 2 RELATED ILLNESS AND A DEATH IN A GROUP OF CAPTIVE WESTERN LOWLAND GORILLAS (GORILLA GORILLA GORILLA).

An onset of respiratory disease in a captive bachelor group (n = 3) of western lowland gorillas (Gorilla gorilla gorilla) was concomitant with peak attendance of visitors at the institution and with unwanted occurrences of food items being thrown in the gorillas' enclosure. While the condition of two individuals improved with supportive therapy and antibiotics, the third gorilla died three days following initiation of treatment. A fatal bacterial pneumonia, secondary to an infection by a human parainfluenza virus 2 (HIPV-2), was considered to be the cause of death based on histopathology, lung cultures, and reverse transcription PCR. HPIV-2 activity in the human population of the province was detected for that period, including the same viral strain. This report confirms a HPIV-2 respiratory illness and associated death in a gorilla. Clinical presentation and context suggest conspecifics were also affected and that contaminated food thrown by visitors may have been the source of infection.

Residues in the heptad repeat a region of the fusion protein modulate the virulence of Sendai virus in mice.

While the molecular basis of fusion (F) protein refolding during membrane fusion has been studied extensively in vitro, little is known about the biological significance of membrane fusion activity in parainfluenza virus replication and pathogenesis in vivo. Two recombinant Sendai viruses, F-L179V and F-K180Q, were generated that contain F protein mutations in the heptad repeat A region of the ectodomain, a region of the protein known to regulate F protein activation. In vitro, the F-L179V virus caused increased syncytium formation (cell-cell membrane fusion) yet had a rate of replication and levels of F protein expression and cleavage similar to wild-type virus. The F-K180Q virus had a reduced replication rate along with reduced levels of F protein expression, cleavage, and fusogenicity. In DBA/2 mice, the hyperfusogenic F-L179V virus induced greater morbidity and mortality than wild-type virus, while the attenuated F-K180Q virus was much less pathogenic. During the first week of infection, virus replication and inflammation in the lungs were similar for wild-type and F-L179V viruses. After approximately 1 week of infection, the clearance of F-L179V virus was delayed, and more extensive interstitial inflammation and necrosis were observed in the lungs, affecting entire lobes of the lungs and having significantly greater numbers of syncytial cell masses in alveolar spaces on day 10. On the other hand, the slower-growing F-K180Q virus caused much less extensive inflammation than wild-type virus, presumably due to its reduced replication rate, and did not cause observable syncytium formation in the lungs. Overall, the results show that residues in the heptad repeat A region of the F protein modulate the virulence of Sendai virus in mice by influencing both the spread and clearance of the virus and the extent and severity of inflammation. An understanding of how the F protein contributes to infection and inflammation in vivo may assist in the development of antiviral therapies against respiratory paramyxoviruses.

Verification of genetic loci responsible for the resistance/susceptibility to the Sendai virus infection using congenic mice.

Sendai virus (SeV) is one of the most important pathogens in the specific-pathogen free rodents. It is known that there are some inbred mouse strains susceptible or resistant to SeV infection. The C57BL/6 (B6) and DBA/2 (D2) mice are representative of the resistant and susceptible strains, respectively. Previous study with the quantitative trait locus (QTL) analysis identified three QTLs responsible for resistance or susceptibility to SeV infection on different chromosomes and indicated that resistance or susceptibility to SeV infection was almost predicted by genotypes of these three QTLs. In this paper, to verify the above hypothesis, congenic lines were generated as follows; B6-congenic lines carrying one of the D2 alleles of three QTLs and combination of these three QTLs, and D2-congenic lines carrying single or combination of B6 alleles of three QTLs. All these congenic lines were then challenged with SeV infection. D2 congenic lines introgressed single or combination of B6 alleles of QTLs changed to resistance to SeV infection. Especially, a D2 triple-congenic line became resistant as similar level to B6-parental strain. However, B6-congenic lines introgressed single or combination of D2 alleles of QTLs all remained to be resistant to SeV infection. Both IL-6 and TNF-α in broncho-alveolar lavage fluid of D2 triple-congenic line were decreased to the similar level of B6 mice, suggesting that this is a part of factors that D2 triple-congenic line became resistant to the similar level of B6 mice. Data obtained from these congenic mice verified that three QTLs identified previously were indeed responsible for the resistance/susceptibility to SeV infection in B6 and D2 mice.

Lower Respiratory Tract Diseases Caused by Common Respiratory Viruses among Stem Cell Transplantation Recipients: A Single Center Experience in Korea.

PURPOSE: To describe the incidence, clinical courses, and risk factors for mortality of lower respiratory tract diseases (LRDs) caused by common respiratory viruses (CRVs) in stem cell transplantation (SCT) recipients. MATERIALS AND METHODS: We retrospectively reviewed the medical records of 1038 patients who received SCT between January 2007 and August 2011 at a single center in Korea. RESULTS: Seventy-one CRV-LRDs were identified in 67 (6.5%) patients. The human parainfluenza virus (HPIV) was the most common causative pathogen of CRV-LRDs at 100 days [cumulative incidence estimate, 23.5%; 95% confidence interval (CI), 3.3-43.7] and 1 year (cumulative incidence estimate, 69.2%; 95% CI, 45.9-92.5) following SCT. The 30-day overall mortality rates due to influenza-LRDs, respiratory syncytial virus-LRDs, HPIV-LRDs, and human rhinovirus-LRDs were 35.7, 25.8, 31.6, and 42.8%, respectively. Co-pathogens in respiratory specimens were detected in 23 (33.8%) patients. The overall mortality at day 30 after CRV-LRD diagnosis was 32.8% (22/67). High-dose steroid usage (p=0.025), a severe state of immunodeficiency (p=0.033), and lymphopenia (p=0.006) were significantly associated with death within 30 days following CRV-LRD diagnosis in a univariate analysis. Multivariate logistic regression analysis revealed that high-dose steroid usage [odds ratio (OR), 4.05; 95% CI, 1.12-14.61; p=0.033] and lymphopenia (OR, 6.57; 95% CI, 1.80-24.03; p=0.004) were independent risk factors for mortality within 30 days of CRV-LRDs. CONCLUSION: CRV-LRDs among SCT recipients showed substantially high morbidity and mortality rates. Therefore, the implement of an active diagnostic approaches for CRV infections is required for SCT recipients with respiratory symptoms, especially those receiving high-dose steroids or with lymphopenia.

Parainfluenza type 3 infection post stem cell transplant: high prevalence but low mortality.

Parainfluenza type 3 (PIV 3) is a well-recognized cause of respiratory illness after stem cell transplantation (SCT), with an estimated incidence of 2-7% and a high mortality rate associated with lower respiratory tract infection (LRTI). A 12-month retrospective study was undertaken in which 23 positive cases of PIV 3 occurred in SCT recipients. The frequency of infection was 36.1% in matched unrelated donor SCT recipients, 23.8% in sibling allogeneic SCT recipients and 2.3% in autologous transplant recipients. Seventeen cases were outpatient or community acquired despite standard infection control measures. Eleven patients only developed upper respiratory tract symptoms. LRTI symptoms developed in 12 patients, of whom eight had a new infiltrate on chest X-ray. Overall mortality at 30 days from PIV 3 diagnosis was 4% (one patient). Four patients died within 100 days of PIV 3 diagnosis, but PIV 3 was not believed to be the primary cause of death in any of these patients. Early ribavirin was used in eight patients and only one patient who received ribavirin died. These results suggest a higher prevalence of PIV 3 but a lower mortality than documented previously, particularly in allogeneic transplant recipients. The authors propose that the high prevalence reflects the unit's policy of active surveillance for respiratory viruses and the difficulty in preventing transmission of PIV 3, especially in the outpatient setting during an outbreak period. Ribavirin treatment may improve outcome in patients with LRTI but is not required in all patients with PIV 3.

Respiratory syncytial virus-induced acute lung injury in adult patients with bone marrow transplants: a clinical approach and review of the literature.

Acute lung injury induced by respiratory syncytial virus (RSV) is a major cause of morbidity and mortality in patients who have undergone bone marrow transplantation. Twenty-nine of the 74 patients who received bone marrow transplants at the University of Minnesota during a 1-year period developed evidence of acute lung injury, and RSV was identified as the cause in 8. We discuss the clinical course of these 8 patients and offer a clinical approach to RSV infection occurring after bone marrow transplantation. We also review the immune response to infection with RSV and relate this information to the nature and degree of immunosuppression present in patients undergoing this type of transplantation. We found bronchoalveolar lavage with rapid antigen detection to be particularly useful for the prompt diagnosis of this serious infection. The virus was obtained from the lower respiratory tract of each patient and was identified in lavage effluent by culture and by antigen detection (ELISA). The mean time to a positive culture was 6 days, while detection of antigens of respiratory syncytial virus by ELISA was completed within 18 hours in all cases. The clinical progression of the illness in immunocompromised patients appears to be the same as in non-immunocompromised persons: upper respiratory tract infection and illness precede lower respiratory tract infection and acute lung injury. Seven of our 8 patients had upper respiratory tract symptoms or abnormal sinus radiographs, and upper respiratory specimens (cultures and ELISA from nasopharynx, throat, and sputum) were positive in 5 of 8 patients. Six patients developed RSV-induced lung injury before marrow engraftment; 4 of them had respiratory failure requiring mechanical ventilation and died, including 3 in whom RSV was eliminated from the lower respiratory tract following treatment with ribavirin aerosol. Two additional pre-engraftment patients had only relatively mild lung injury 4 days after beginning treatment with ribavirin for RSV infection in the upper respiratory tract. Their recovery suggests that early treatment may ameliorate RSV-induced lung injury. The remaining 2 patients developed lung injury after marrow engraftment. Both of these patients had clear chest radiographs, responded clinically to ribavirin, and survived. RSV is a potentially treatable cause of life-threatening lung injury, if the physician is aggressive in identifying the virus in the upper respiratory tract before evidence of lung injury appears. Rapid detection methods are essential when bone marrow transplant patients have fever along with signs, symptoms, or radiographic indications of nasal or sinus disorders.(ABSTRACT TRUNCATED AT 400 WORDS)

Low mortality rates related to respiratory virus infections after bone marrow transplantation.

Respiratory viruses (RVs) frequently cause severe respiratory disease in bone marrrow transplant (BMT) recipients. To evaluate the frequency of RV, nasal washes were collected year-round from BMT recipients with symptoms of upper respiratory tract infection (URI). Direct immunofluorescence assay was performed for respiratory syncytial virus (RSV), influenza (Flu) A and B, adenovirus and parainfluenza (Paraflu) virus. Patients with RSV pneumonia or with upper RSV infection, but considered at high risk for developing RSV pneumonia received aerosolized ribavirin. Oseltamivir was given to patients with influenza. A total of 179 patients had 392 episodes of URI. In all, 68 (38%) tested positive: RSV was detected in 18 patients (26.4%), Flu B in 17 (25%), Flu A in 11 (16.2%) and Paraflu in 7 (10.3%). A total of 14 patients (20.6%) had multiple RV infections or coinfection. RSV pneumonia developed in 55.5% of the patients with RSV-URI. One of the 15 patients (6.6%) with RSV pneumonia died. Influenza pneumonia was diagnosed in three patients (7.3%). RSV and influenza infections peaked in fall-winter and winter-spring months, respectively. We observed decreased rates of influenza and parainfluenza pneumonia and low mortality because of RSV pneumonia. The role of antiviral interventions such as aerosolized ribavirin and new neuraminidase inhibitors remains to be defined in randomized trials.

Mass mortality in seals caused by a newly discovered morbillivirus.

During a recent disease outbreak among harbour seals (Phoca vitulina) in the North and Baltic seas, more than 17,000 animals have died. The clinical symptoms and pathological findings were similar to those of distemper in dogs. Based on a seroepizootiological study, using a canine distemper virus (CDV) neutralization assay, it was shown that CDV or a closely related morbillivirus (phocid distemper virus-PDV) was the primary cause of the disease. The virus was isolated in cell culture from the organs of dead seals and characterized as a morbillivirus by serology (immunofluorescence neutralization and enzyme-linked immunosorbent assays) and by negative contrast electron microscopy. Experimental infection of SPF dogs resulted in the development of mild clinical signs of distemper and CDV-neutralizing antibodies. The disease was reproduced in seals by experimental inoculation of organ material from animals that had died during the outbreak. However, seals that had been vaccinated with experimental inactivated CDV vaccines were protected against this challenge. This fulfilled the last of Koch's postulates, confirming that the morbillivirus isolated from the seal organs, was the primary cause of the disease outbreak. The recent demonstration of the presence of a similar virus in Lake Baikal seals (Phoca sibirica), which infected these Siberian seals 1 year before the northwestern European seals were infected, raises new questions about the origin of this infectious disease in pinnipeds.

Protective effect of passive immunization against TNF-alpha in mice infected with Sendai virus.

TNF-alpha has been reported to be induced in mice infected with Sendai virus. We evaluated the role of TNF-alpha in the virus infection. TNF-alpha was induced locally in proportion to virus titers in the lung. The activity was correlated with suppression of body weight gain. Passive immunization against TNF-alpha improved body weight gain and ameliorated pneumonic lesions in infected mice, and prevented them from lethal infection, but lung virus induced emaciation, pneumonic lesions and death were mediated by TNF-alpha.

Serologic study of phocine distemper in a population of harbor seals in Scotland.

A serologic survey of the prevalence of morbillivirus antibodies was conducted in a population of harbor seals (Phoca vitulina) from northeastern Scotland, where mortality was comparatively low during the 1988 phocine distemper virus outbreak. None of the 12 seals sampled before the epizootic were seropositive. Thirty-five (52%) of 68 seals sampled after the beginning of the epizootic were seropositive, although there were significant age-related differences in both the number of seropositive individuals and in antibody levels. Marking studies showed that most seropositive seals caught during the peak of the epizootic survived for several months. Thus, the low mortality observed in this population did not appear to result from a lack of contact with the virus.

[Virus excretion and changes in virulence of type 1 paramyxovirus of pigeons following passage through chickens]. / Virusuitscheiding en virulentiewijziging van het paramyxovirus type 1 van de duif bij kuikenpassage.

Paramyxovirus type 1 of pigeons (strain PMV1-D) was transmitted by sequential contact over nine groups of SPF chicks. The first and last (9th) passages were made in 12-day-old SPF chicks, whereas the others were made in day-old chicks. Mortality was much higher in the last passage group than it was in the first group. None of the day-old chicks survived the PMV1-D infection. Increased virulence of PMV1-D for chickens following passages was also found to be present by the virus characterisation indexes, the EID50, the ICPI and the IVPI in particular.

A parainfluenza-3 outbreak in a SCT unit: sepsis with multi-organ failure and multiple co-pathogens are associated with increased mortality.

The estimated frequency of parainfluenza virus 3 (PIV-3) infections following haematopoietic SCT (HSCT) is 2-7%, whereas reported mortality ranges from 18 to 33%. We report a retrospective outcome analysis following an outbreak of PIV-3 infection in our transplant unit. A total of 16 HSCT patients developed PIV-3 infection. All patients had upper respiratory tract infection, whereas lower respiratory tract infection occurred in 8 patients. Overall, 13 patients were treated with aerosolised Ribavirin (2 g t.d.s. for 5 days) and i.v. Ig (0.5 g/kg) as per standard protocol. One patient refused treatment, whereas two patients with full immune reconstitution were not treated. Overall mortality was 62.5%. Sepsis with multi-organ failure and the presence of pulmonary co-pathogens were both significantly associated with PIV-3-related mortality. Our series confirms that high mortality is associated with PIV-3 infection in HSCT recipients. In patients who develop PIV-3 infection, despite strict enforcement of infection control policies, the best strategy might be careful risk assessment, with effective broad-spectrum anti-microbials in those who are at risk of secondary infection.

Airway epithelial versus immune cell Stat1 function for innate defense against respiratory viral infection.

The epithelial surface is often proposed to actively participate in host defense, but evidence that this is the case remains circumstantial. Similarly, respiratory paramyxoviral infections are a leading cause of serious respiratory disease, but the basis for host defense against severe illness is uncertain. Here we use a common mouse paramyxovirus (Sendai virus) to show that a prominent early event in respiratory paramyxoviral infection is activation of the IFN-signaling protein Stat1 in airway epithelial cells. Furthermore, Stat1-/- mice developed illness that resembled severe paramyxoviral respiratory infection in humans and was characterized by increased viral replication and neutrophilic inflammation in concert with overproduction of TNF-alpha and neutrophil chemokine CXCL2. Poor control of viral replication as well as TNF-alpha and CXCL2 overproduction were both mimicked by infection of Stat1-/- airway epithelial cells in culture. TNF-alpha drives the CXCL2 response, because it can be reversed by TNF-alpha blockade in vitro and in vivo. These findings pointed to an epithelial defect in Stat1-/- mice. Indeed, we next demonstrated that Stat1-/- mice that were reconstituted with wild-type bone marrow were still susceptible to infection with Sendai virus, whereas wild-type mice that received Stat1-/- bone marrow retained resistance to infection. The susceptible epithelial Stat1-/- chimeric mice also exhibited increased viral replication as well as excessive neutrophils, CXCL2, and TNF-alpha in the airspace. These findings provide some of the most definitive evidence to date for the critical role of barrier epithelial cells in innate immunity to common pathogens, particularly in controlling viral replication.

Molecular investigations of an outbreak of parainfluenza virus type 3 and respiratory syncytial virus infections in a hematology unit.

A large simultaneous outbreak of respiratory syncytial virus (RSV) and parainfluenza type 3 (PIV-3) infections occurred on an adult hematology unit. Implementation of enhanced infection control was complicated by cocirculation of the two different viruses, with prolonged viral shedding from infected patients, and placed great pressure on health care staff; of 27 infected hematopoietic stem cell transplant patients, 9 died, and the unit was closed for 2 months. Retrospective molecular investigation of the virus strains involved in the outbreak was performed by analyzing part of the fusion gene of PIV-3 and part of the glycoprotein gene of RSV. Reverse transcription-PCR on nasopharyngeal aspirates from patients infected before and during the simultaneous outbreak generated amplicons for sequence analysis. A single strain of RSV and a single strain of PIV-3 had spread from person to person within the unit; 7 patients were infected with RSV, 22 were infected with PIV-3, and 4 were infected with both viruses. The PIV-3 outbreak had started at the beginning of August 3 months before the RSV outbreak; it had arisen when PIV-3 was introduced from the community by a patient and passed to another patient, who became chronically infected with the identical strain and, in spite of being nursed in isolation, was most likely the source from which widespread infection occurred in November. Had these early cases been linked to a common PIV-3 strain at the time of diagnosis, enhanced infection control precautions might have prevented the eventual extensive spread of PIV-3, making it much easier to deal with the later RSV outbreak.

Contamination of a specific-pathogen-free rat breeding colony with Human parainfluenzavirus type 3.

Routine antibody surveillance for Sendai virus in a breeding colony suggested viral invasion into laboratory rats. A more specific haemagglutination-inhibition test implied that the agent was related closely to Human parainfluenza virus type 3 (hPIV3), rather than Sendai virus. To isolate this virus, Vero cells were inoculated with lung homogenates of 30 young animals from the colony. One of the cultures became positive at the second passage by RT-PCR directed to the hPIV3 NP and L genes. Cytopathic effect with cell fusion was observed at the third passage. The HN gene of this virus (KK24) had >93 % similarity to those of other hPIV3 isolates, suggesting a human origin of KK24. Experimental intranasal inoculation of KK24 into SD rats showed virus replication in the lungs at 3-5 days post-infection (p.i.). Pathological examination of the lungs at day 5 p.i. indicated a moderate detachment, degradation and apoptosis of bronchial epitheliocytes with peribronchial mononuclear infiltrations. At day 7 p.i., these changes became less prominent, and no lesions were apparent at day 10 p.i. or later. The infected rats seroconverted at day 7 p.i. On the contrary, none of the 30 experimentally infected ICR mice showed any pathological lesions in their lungs, despite seroconversion at 7 days p.i. These results suggest that hPIV3 can invade rat colonies and has a moderate and transient pathogenicity in rats. This is the first report of non-experimental hPIV3 infection in laboratory rats, unexpectedly detected by antibody screening for Sendai virus.

The novel parainfluenza virus hemagglutinin-neuraminidase inhibitor BCX 2798 prevents lethal synergism between a paramyxovirus and Streptococcus pneumoniae.

An association exists between respiratory viruses and bacterial infections. Prevention or treatment of the preceding viral infection is a logical goal for reducing this important cause of morbidity and mortality. The ability of the novel, selective parainfluenza virus hemagglutinin-neuraminidase inhibitor BCX 2798 to prevent the synergism between a paramyxovirus and Streptococcus pneumoniae was examined in this study. A model of secondary bacterial pneumonia after infection with a recombinant Sendai virus whose hemagglutinin-neuraminidase gene was replaced with that of human parainfluenza virus type 1 [rSV(hHN)] was established in mice. Challenge of mice with a sublethal dose of S. pneumoniae 7 days after a sublethal infection with rSV(hHN) (synergistic group) caused 100% mortality. Bacterial infection preceding viral infection had no effect on survival. The mean bacterial titers in the synergistic group were significantly higher than in mice infected with bacteria only. The virus titers were similar in mice infected with rSV(hHN) alone and in dually infected mice. Intranasal administration of BCX 2798 at 10 mg/kg per day to the synergistic group of mice starting 4 h before virus infection protected 80% of animals from death. This effect was accompanied by a significant reduction in lung viral and bacterial titers. Treatment of mice 24 h after the rSV(hHN) infection showed no protection against synergistic lethality. Together, our results indicate that parainfluenza viruses can prime for secondary bacterial infections. Prophylaxis of parainfluenza virus infections with antivirals might be an effective strategy for prevention of secondary bacterial complications in humans.

Predictors of outcome of severe respiratory syncytial virus-associated respiratory failure treated with extracorporeal membrane oxygenation.

OBJECTIVE: To examine the Extracorporeal Life Support Organization registry data base for all infants and children with respiratory syncytial virus-associated respiratory failure managed with extracorporeal life support, to delineate predictors of outcome. DESIGN: Retrospective cohort study. SETTING: Extracorporeal Life Support Organization data registry. PATIENTS: All pediatric patients treated in the United States with extracorporeal life support for severe pediatric respiratory syncytial virus-associated respiratory failure reported to the registry, from 1982 through June 1992. INTERVENTIONS: Venoarterial or venovenous extracorporeal life support. MEASUREMENTS AND MAIN RESULTS: As of June 1992, fifty-three pediatric patients meeting study entry criteria were reported to the Pediatric Respiratory Failure Registry (n = 412) as having received extracorporeal membrane oxygenation (ECMO) for severe respiratory syncytial virus infection with pulmonary failure. Forty-nine percent (26/53) were successfully managed and survived to hospital discharge. The mean patient age was 5.0 +/- 8.6 months. Duration of mechanical ventilation before institution of extracorporeal life support was 8.1 +/- 6.2 days. Multivariate logistic regression analysis found four variables to be associated with patient nonsurvival at the p < 0.05 level: male gender, longer duration of mechanical ventilation before ECMO, higher peak inspiratory pressure, and lower ratio of arterial oxygen tension to fraction of inspired oxygen. Era of treatment was not associated with outcome. Receiver operator characteristic curve analysis of this multivariate model resulted in cutoff points of r = 0.5 and 0.1 that resulted in 92% sensitivity and 81% specificity (false-positive ratio 19%) and 96% sensitivity and 73% specificity (false-positive ratio 27%), respectively. CONCLUSIONS: Predictors of outcome of severe respiratory failure caused by respiratory syncytial virus infection managed with ECMO exist, and multivariate predictive models with high sensitivity and low false-positive risk are possible. Similar mathematical models may be helpful in establishing criteria for future trials of ECMO versus conventional respiratory support.