Aspergillosis following influenza A infection]

An 83-year-old man had an influenza-like upper respiratory infection that progressed to pneumonia and respiratory insufficiency during a period two weeks. After admission, anti-influenza A antibody increased 32-fold and antibiotic treatment had little effect on the pneumonia. Aspergillus antigen was detected from his serum and pleural effusion, however, culture of sputum was negative for aspergillus. Administration of amphotericin B reduced the serum level of aspergillus antigen, however he died due to the progression of respiratory insufficiency and bloody sputum. Aspergillus infection is generally thought to occur in immunocompromised hosts, but this patient had no apparent immunosuppressive conditions except for his age before the influenza A infection. His WBC and lymphocyte count temporally decreased to 2,000 x 10(6)/L (lymphocytes 160 x 10(6)/L) followed by aspergillus infection. This temporally reduction of lymphocytes is thought to have been responsible for the aspergillus infection. Complications of influenza infection are sometimes fatal and vaccination against influenza seems necessary in high risk individuals such as elderly people.     

Extensive pyomyositis secondary to paronychia-related MRSA infection: A case report

Rationale:Pyomyositis is characterized by an insidious and multifactorial inflammatory process, which is often caused by hematogenous pathogen. Predisposing risk factors include immunodeficiency, diabetes, malignancy, or trauma. The spectrum of clinical presentation depends on disease severity, typically presented by fever and hip pain. We hereby present a case with extensive pyomyositis secondary to chronic paronychia infection.Patient concerns:A 14-year-old immunocompetent male presented with fever and hip pain. The patient was initially surveyed for common infectious etiologies prior to the presentation of acute limping, which led to image confirmation of extensive pyomyositis.Diagnosis:The patient presented with acute pain in the right hip accompanied by headache, myalgia of the right leg, and intermittent fever for a week. Physical examination disclosed limping gait, limited range of motion marked by restricted right hip flexion and right knee extension, and chronic paronychia with a nail correction brace of the left hallux. Diagnosis of pyomyositis was confirmed by magnetic resonance image. Methicillin-resistant strains of Staphylococcus aureus was isolated from the patient''s blood and urine cultures within 2 days of collection. The same strain was also isolated from the pus culture collected via sonography-guided aspiration.Interventions:Antibiotics treatment with oxacillin, teicoplanin, daptomycin, and fosfomycin were administered. Sonography-guided aspiration and computed tomography-guided pigtail drainage were arranged, along with nail extraction of his left hallux paronychia prior to discharge. Oral antibiotics fusidic acid was prescribed. Total antibiotics course of treatment was 4 weeks.Outcomes:The patient gradually defervesced and was afebrile after drainage. Followed limb doppler sonography showed regression of the abscess at his right lower limb. Gait and range of motion gradually recovered without sequelae.Lessons:Ambulation and quality of life are greatly affected by the inflammatory process of pyomyositis. Detailed evaluation of predisposing factors should be done, even in immunocompetent individuals. Timely diagnosis is vital to successful treatment.     

Parsonage-Turner syndrome following chikungunya virus infection:A case report

Rationale: Parsonage-Turner syndrome is a rare syndrome of unknown etiology, affecting mainly the lower motor neurons of the brachial plexus.Chikungunya fever is a mosquito-borne viral disease characterized by acute fever and polyarthritis/polyarthralgia.Patient concerns: A 54-year-old Brazilian male patient who presented with a 2-day history of fever(temperature 38.8 ℃), arthralgia, erythematous rash, diffuse osteomuscular pain and headache, which evolved into left shoulder pain associated with morning stiffness.Diagnosis: Parsonage-Turner syndrome and chikungunya fever.Interventions: Symptomatic treatment(a combination of short-acting dypirone(500 mg every 6 h) and slow-release opioids(tramadol 100 mg every 4 h) and physiotherapy/rehabilitation with improvement.Outcomes: The patient was improved and discharged, remaining with symptomatic treatment and physiotherapy/rehabilitation.Lessons: To the best of our knowledge, there were no reports of Parsonage-Turner syndrome following chikungunya virus infection.Awareness of the possibility of this rare association is important.The present case report highlights the importance of awareness of this association as a new cause of morbidity in patients with chikungunya virus infection.     

甲型H1N1流感1例报告

1病例报告 患者,男,69岁,因发热15h于2009年5月22日入院。患者于当地时间2009年5月15日乘机从加拿大蒙特利尔离开,经多伦多转机,2009年5月16日下午16时到达北京。5月21日10时许自觉头痛不适,测体温37．9℃,无其他不适,白服板兰根2袋,12时自测体温37．5℃,遂到我院发热门诊就诊。     

Rhabdomyolysis associated with influenza A virus infection

Rhabdomyolysis is characterized by local or generalized skeletal muscle neclosis. It is caused by many clinical conditions and drug or alcohol abuse. Clinical symptoms are muscle pain and muscle weakness. Laboratory investigations show a rise in serum creatine phosphokinase and electrolyte disturbances. The most serious complication is acute renal failure. We present a patient with rhabdomyolysis and renal failure associated with a recent Influenza A virus infection.     

A case of group B streptococcal pyomyositis

The group B streptococcus is an opportunistic pathogen that causes a variety of serious infections including bacteremias, puerperal sepsis, and neonatal meningitis. Group B streptococcal infections of muscle are rare. We report here an unusual case of group B streptococcal pyomyositis. Pyomyositis arises predominantly from infections caused by Staphylococcus aureus and, occasionally, Streptococcus pyogenes. Because of the rarity of pyomyositis in temperate climates, the common lack of localizing signs or symptoms, and the frequently negative blood cultures, considerable delay often precedes the diagnosis of pyomyositis; in fact, the infection has been initially misdiagnosed as muscle hematoma, cellulitis, thrombophlebitis, osteomyelitis, or neoplasm. Diagnosis may be greatly aided by radiologic techniques that can demonstrate the sites of muscle enlargement and the presence of fluid collections. The response to antibiotics is usually rapid, but resolution of the infection may require aspiration of deeply situated muscle abscesses. This report describes a diabetic patient with an unusual presentation of pyomyositis that mimicked an acute abdomen.     

Invasive pulmonary aspergillosis following influenza A infection]

A 55-year-old man with arc welder's pneumoconiosis who presented with bilateral pneumonia was admitted to our hospital. Streptococcus pneumoniae and Aspergillus fumigatus were cultured from sputum on admission. The patient was treated with antibiotics and an anti-fungal agent, but his chest radiograph shadows became exacerbated, and he died of respiratory failure on the fourth day of hospitalization. Histological examination of postmortem lung tissue revealed necrotizing aspergillous pneumonia. The results of hemagglutination inhibition tests for influenza A (H3 N2) were x16 in September 1999, and x512 on the third day of hospitalization. We diagnosed this patient's condition as invasive pulmonary aspergillosis associated with influenza A viral infection. The suppression of cellular immunity, lymphocytopenia, and destruction of airways-mucociliary transport induced by influenza A viral infection were suspected to have predisposed him to aspergillus superinfection.     

Bone marrow immunosuppression in Salmonella-infected mice is prolonged following influenza virus infection

OBJECTIVE: It has been shown previously that infection with diverse viruses induces alterations in bone marrow lineage-specific progenitor cells. As complications arising from secondary bacterial infections can adversely affect the host, we investigated whether virally induced hematological alterations could contribute to the enhanced illness observed in such cases. MATERIALS AND METHODS: Mice were infected with influenza virus alone or influenza virus followed by a vaccine strain of Salmonella typhimurium. The effects on hematopoiesis were analyzed by fluorescein-activated cell sorting analysis and immunohistology. RESULTS: Systemic Salmonella typhimurium infection induces depletion of bone marrow erythroid and lymphoid cells. The depletion lasted longer in mice that had been previously infected with influenza virus, compared with mice that had been previously treated with allantoic fluid. Although an increase in splenic lymphoid cells was apparent in the spleens of Salmonella-infected mice, the majority of cells in the enlarged spleens were found to be both immature and mature erythrocytes. CONCLUSION: These results show that bone marrow progenitor cell depletion induced by bacterial infection is prolonged following a viral infection. It is possible that hematological alterations may contribute to the enhanced clinical illness observed in consecutive viral:bacterial infections.     

A case of central diabetes insipidus following probable type A/H1N1 influenza infection

The major causes of central diabetes insipidus (CDI) are neoplastic or infiltrative lesions of the hypothalamus or pituitary gland, severe head injuries, or pituitary or hypothalamic surgery. Lymphocytic infundibuloneurophysitis (LINH) is associated with autoimmune inflammatory disease of the pituitary gland, but the exact etiology is unknown. CDI caused by viral infections has been rarely reported. Here, we describe the case of a 22-year-old man who was in good health until 2 months prior to admission, presented with acute development of polyuria and polydipsia, and showed increased urinary volume up to 9000 mL/day. The patient showed elevated serum osmolality and low urine osmolality, with a low level of antidiuretic hormone. Endocrinological findings revealed CDI, but his arterial pituitary function appeared normal. Magnetic resonance imaging revealed significant enlargement of the pituitary stalk. We suspected CDI due to LINH based on non-transsphenoidal biopsy findings. He was diagnosed as type A influenza,and given oral therapeutic agents. However, acute onset of polyuria and polydipsia occurred 10 days after the influenza diagnosis. The available epidemiological information regarding the outbreak of influenza around that time strongly suggested that the patient was infected with the A/H1N1 influenza virus, although this virus had not been detected on polymerase chain reaction testing. In the present case, the autoimmune mechanism of LINH may have been associated with novel influenza A/H1N1 virus infection.     

Two cases of successfully treated invasive pulmonary aspergillosis following influenza virus infection]

While invasive pulmonary aspergillosis usually occurs in immunocompromised hosts, it has been described after influenza virus infection in healthy individuals. The first case was a 76-year-old previously healthy woman admitted because of chest pain, cough, sputum, fever, and a chest radiograph abnormality. A transbronchial biopsy specimen showed fungal hyphae. Amphotericin B (AMPH) and Itraconazole (ITCZ) were given, and she improved gradually. A viral test showed a titre of 1/128 to influenza A. Case 2 was a 72-year-old previously healthy man admitted because of cough, fever, chest pain and a consolidation and cavitation on the chest radiograph. Antibiotics were ineffective. Cavitation with a halo sign appeared on the contralateral lung. Because his daughter was infected with Influenza B, we suspected he had been infected with IPA following influenza infection. AMPH and ITCZ and Micafungin sodium were given. His respiratory failure worsened, and on the tenth hospital day he required artificial ventilation; his condition improved gradually, (extubation after 40 days.) A viral test showed a titre of 1/128 to influenza B. IPA must be considered for the differential diagnosis of complications of influenza virus infection.     

Immunofluorescence determination of the pathogenesis of infection with influenza virus in mice following exposure to aerosolized virus.

The pathogenesis of infection with influenza A virus in mice was studied by exposure of specific pathogen-free mice to aerosols of influenza virus and by monitoring of mortality, viral titers in lung homogenates, and presence of viral antigens in respiratory cells as determined by immunofluorescence. In two experiments with different death rates (100% and 43%), viral antigen accumulated in the epithelial cells lining the airways, in alveolar macrophages, in alveolar cells, and in visceral pleura. By enumeration of the number of airways, alveolar macrophages, and alveolar cells containing influenza viral antigens at different intervals after exposure to the viral aerosol, it was determined that viral replication occurred initially in the epithelial cells lining the airways and later extended to the alveolar macrophages and alveolar cells. This semiquantitative survey of the dynamics of influenza viral infection by aerosol indicated that the viral infection in mice was a descending process.     

细胞因子在流感病毒感染中的免疫调节作用

流感病毒对呼吸道黏膜有亲嗜性,流感病毒通过感染呼吸道黏膜上皮细胞而入侵机体,引起机体免疫应答.多种细胞间的相互作用是通过细胞因子介导的.因此,不论在固有免疫应答还是适应性免疫应答中,细胞因子均表现出重要的功能.近年来,免疫分子、细胞因子在其中的作用逐步明确.本文将着重从细胞因子来源、分类来阐述细胞因子在流感病毒感染中的...     

Cardiovascular manifestations associated with influenza virus infection

Influenza accounts for 3 to 5 million cases of severe illness and up to 300,000 deaths annually. Cardiovascular involvement in acute influenza infection can occur through direct effects of the virus on the myocardium or through exacerbation of existing cardiovascular disease. Epidemiological studies have demonstrated an association between influenza epidemics and cardiovascular mortality and a decrease in cardiovascular mortality in high risk patients has been demonstrated following vaccination with influenza vaccine. Influenza is a recognised cause of myocarditis which can lead to significant impairment of cardiac function and mortality. With recent concerns regarding another potential global pandemic of influenza the huge potential for cardiovascular morbidity and mortality is discussed.     

Microbiota regulates immune defense against respiratory tract influenza A virus infection

Although commensal bacteria are crucial in maintaining immune homeostasis of the intestine, the role of commensal bacteria in immune responses at other mucosal surfaces remains less clear. Here, we show that commensal microbiota composition critically regulates the generation of virus-specific CD4 and CD8 T cells and antibody responses following respiratory influenza virus infection. By using various antibiotic treatments, we found that neomycin-sensitive bacteria are associated with the induction of productive immune responses in the lung. Local or distal injection of Toll-like receptor (TLR) ligands could rescue the immune impairment in the antibiotic-treated mice. Intact microbiota provided signals leading to the expression of mRNA for pro-IL-1β and pro-IL-18 at steady state. Following influenza virus infection, inflammasome activation led to migration of dendritic cells (DCs) from the lung to the draining lymph node and T-cell priming. Our results reveal the importance of commensal microbiota in regulating immunity in the respiratory mucosa through the proper activation of inflammasomes.     

Paravertebral pyomyositis in childhood following closed injury

Pyomyositis is an acute bacterial infection that affects striated muscle and is generally accompanied by the formation of an abscess. In most cases, the microorganism involved is Staphylococcus aureus. Clinical findings are characterized by pain, swelling and muscular edema, together with variable general symptoms. Complications include arthritis, osteomyelitis and even septic shock with a mortality of 1.8%. We report the case of an 8-year-old boy who sustained a closed lumbar injury on banging his shoulder while he was playing on a trampoline and who developed paravertebral pyomyositis complicated by sepsis. S. aureus was isolated in the blood culture. The boy subsequently developed a perivertebral abscess and finally contiguous osteomyelitis in the L3 spinous process. The patient received treatment with vancomycin and metronidazole for 6 weeks followed by cloxacillin therapy for 2 weeks (a total of 8 weeks of intravenous antibiotic therapy). Physical examination 3 months after discharge revealed no abnormalities. The possibility of pyomyositis should be borne in mind, especially in children with fever, localized muscular pain and a history of accidental or sports injuries. Early diagnosis and treatment are important to reduce the risk of possibly fatal complications.