Risk factors for human heartworm infections (dirofilariasis) in the South.

Human pulmonary dirofilariasis (HPD) is caused by the transmission of infective third stage larvae of the canine heartworm, Dirofilaria immitis, during blood-feeding by several species of infected mosquitoes. Since humans are incidental hosts and cannot support the parasite's life cycle, infective larvae die after migrating to the pulmonary vascular bed, where an initial subclinical inflammatory reaction is typically followed by a single pulmonary granuloma. The resulting nodular granuloma is described radiographically as a "coin lesion" that resembles a neoplastic lesion, which must be ruled out by invasive lung biopsy. Since HPD cases have been reported mainly from regions with high canine heartworm prevalence, such as the southern United States (US), the objectives of this review were (1) to describe the microbiology of the parasite; (2) to resolve any misconceptions regarding the pathophysiology and outcomes of canine versus human heartworm infections; (3) to describe the prevalence and parasite burden of canine dirofilariasis in the South compared to other areas; (4) to describe the prevalence of HPD in the South; (5) to identify the most important species of mosquito vectors of dirofilariasis based on seroprevalence rates of infection and transmission efficiency; (6) to identify the key risk factors for HPD in the South; and (7) to recommend new strategies for the diagnosis, management, control, and prevention of HPD. Future investigations should focus on targeting specific mosquito species for improved vector control of D. immitis transmission and on developing new immunologic and molecular methods for diagnosing HPD and eliminating the need for invasive diagnostics for differential diagnosis of innocuous, parasitic "coin lesions".

The Worm that Clogs the Lungs: Strongyloides Hyper-Infection Leading to Fatal Acute Respiratory Distress Syndrome (ARDS).

BACKGROUND Strongyloides stercoralis is an intestinal helminth. Parasitism is caused by penetration of the larvae through the skin. It is endemic in tropical and subtropical regions of the world and in the United States occurs in the southeastern region. It has a tendency to remain dormant or progress to a state of hyper-infection during immunosuppression. CASE REPORT We present the case of a 70-year-old Nigerian who developed fatal ARDS secondary to Strongyloides infection after been treated with steroids for treatment of autoimmune necrotizing myopathy. Despite adequate management with mechanical ventilation and appropriate antifungal therapy, the patient died on day 19 of hospitalization. CONCLUSIONS S. stercoralis is known to affect every organ in the body. ARDS is often an overlooked complication of Strongyloides hyper-infection, which is often deadly. Immediate diagnosis and treatment are important for patient survival.

Tropical parasitic lung diseases.

Though parasitic lung diseases are frequently seen in tropical countries, these are being increasingly reported from many parts of the world due to globalisation and travel across the continents. In addition, the emergence of human immunodeficiency virus (HIV) infection/acquired immunodeficiency syndrome (AIDS), the frequent use of immunosuppressive drugs in many diseases and the increasing numbers of organ transplantations have resulted in a renewed interest in many tropical parasitic lung diseases. This review outlines the recent developments in the pathogenesis, diagnosis and management of common and rare parasitic lung diseases.

Cardiac manifestations of parasitic infections part 3: pericardial and miscellaneous cardiopulmonary manifestations.

This is part three of a three-part series discussing parasites of the heart. In this section, we present an overview on parasitic diseases involving predominantly the pericardium and other miscellaneous cardiopulmonary manifestations such as some pulmonary hypertension syndromes and endomyocardial fibrosis.

[Diagnosis and treatment of Lophomonas blattarum infection in 26 patients with bacterial pneumonia].

The clinical features of Lophomonas blattarum infection in 26 patients with bacterial pneumonia were analyzed. Common manifestation included fever, cough and breathlessness. Computed tomography (CT) showed interstitial change and alveolar exudation. The parasites were found in sputum smear and from the bronchoalveolar lavage fluid (BALF). Metronidazole was effectively used to cure the pulmonary infection of L. blattarum.

Extracorporeal membrane oxygenation (ECMO) as salvage treatment for pulmonary Echinococcus granulosus infection with acute cyst rupture.

Extracorporeal membrane oxygenation (ECMO) has been used successfully for the treatment of patients with respiratory failure due to severe infections. Although rare, parasites can also cause severe pulmonary disease. Tapeworms of the genus Echinococcus give rise to the development of cystic structures in the liver, lungs, and other organs. Acute cyst rupture leads to potentially life-threatening infection, and affected patients may deteriorate rapidly. The case of a young woman from Bulgaria who was admitted to hospital with severe dyspnoea, progressive chest pain, and haemoptysis is described. Computed tomography of the chest was pathognomonic for cystic echinococcosis with acute cyst rupture. Following deterioration on mechanical ventilation, she was cannulated for veno-venous ECMO. The patient's condition improved considerably, and she was weaned successfully from ECMO and mechanical ventilation. Following lobectomy of the affected left lower lobe, the patient was discharged home in good condition. This appears to be the first report of the successful use of ECMO as salvage treatment for a severe manifestation of a helminthic disease. Due to recent migration to Western Europe, the number of patients presenting with respiratory failure due to pulmonary echinococcosis with cyst rupture is likely to increase.

[Mycological and parasitological examinations in the management of lung infections]. / Examens mycologiques et parasitologiques dans la prise en charge des infections pulmonaires.

Pulmonary parasitic diseases are rare whereas pulmonary fungal infections are increasing. The diversity of clinical presentations requires laboratory tests to confirm the diagnosis. Direct examination of lung samples and antibody detection are the basis of parasitological diagnosis. With regard to mycoses, the range of biological tests is broader. The conventional mycological examination allows identification of any type of fungus except Pneumocystis jirovecii. Its specificity is excellent but it lacks sensitivity. Detection of antibodies, antigens or nucleic acid complements the diagnostic tools. With regard to aspergillosis, there is a broad nosological set with variable prognosis. The choice of appropriate laboratory procedures depends on the clinical presentation and patient risk factors. The search for galactomannan antigen is effective and a new technique, "Lateral Flow Device", seems very promising. The detection of antibodies is also informative but various techniques are used. A good knowledge of the performance and limitations of these techniques allows targeted prescription. The use of PCR for the diagnosis of pulmonary fungal infections has limited indications. Biological and clinical co-operation is essential for the choice and interpretation of laboratory tests for parasitic or fungal pulmonary disease.

Eosinophilic Lung Diseases.

Eosinophilic lung diseases especially comprise eosinophilic pneumonia or as the more transient Löffler syndrome, which is most often due to parasitic infections. The diagnosis of eosinophilic pneumonia is based on characteristic clinical-imaging features and the demonstration of alveolar eosinophilia, defined as at least 25% eosinophils at BAL. Peripheral blood eosinophilia is common but may be absent at presentation in idiopathic acute eosinophilic pneumonia, which may be misdiagnosed as severe infectious pneumonia. All possible causes of eosinophilia, including drug, toxin, fungus related etiologies, must be thoroughly investigated. Extrathoracic manifestations should raise the suspicion of eosinophilic granulomatosis with polyangiitis.

[Worms and the lung]. / Der Wurm in der Lunge.

Due to international travel and migration helminthic infections are increasingly imported to countries were they are not endemic. A vast variety of helminthes may involve the lung. The lungs are either site of the infection or temporarily involved during maturation of helminthic larvae. In many affected patients the clinical picture is not specific and not typical. A thorough patient's history including a detailed travel history will lead to diagnosis, which must be confirmed by detecting the parasite either directly or with serological tests. The appropriate method depends on the parasite suspected and its life cycle within the human body. A combination of these methods will show the best results for most helminthes. As specific therapy is widely available for most helminthiases a precise diagnosis is important.

Antibody levels in reduced/alkylated intravenous immune globulin.

Antibody titers, found in representative lots of a reduced and alkylated intravenous immune globulin, against a variety of common microorganisms are presented. With the more frequently occurring pathogens the specific antibody level does not vary significantly between lots. Depending upon the type of assay used, antibody titers per se may or may not reflect the therapeutic activity of the preparation against a specific microorganism.

Dirofilaria immitis: a rare, increasing cause of pulmonary nodules.

Dirofilariasis is an unusual but increasing cause of solitary pulmonary nodules. In this study, we reviewed the entire experience with dirofilariasis at our institution. Five such patients were identified. In all patients, the Dirofilaria immitis infection manifested as a solitary pulmonary nodule, and all patients underwent thoracotomy for diagnosis. None required systemic treatment. D. immitis is found in dog, cat, wolf, coyote, and fox populations throughout the United States, but the highest concentrations have been noted in the eastern, southeastern, and southern coastal states. The distribution of human cases of D. immitis infection has a similar pattern. Pulmonary dirofilariasis should be included in the differential diagnosis of peripheral noncalcified pulmonary nodules, especially in endemic areas.

Paragonimiasis in the United States. A report of nine cases in Hmong immigrants.

Nine cases of paragonimiasis have been encountered in Laotian Hmong immigrants from Camp Ban Vinai in Thailand. Symptoms included cough, hemoptysis, and fever. Chest x-ray films showed segmental infiltrates and pleural effusions, often bilateral. The clinical presentation mimics tuberculosis. All Hmong patients with chronic infiltrates and pleural disease in whom tuberculosis has not been proven should have parasitologic and serologic evaluation to exclude paragonimiasis.

Management of infections of the lower respiratory tract in children.

Different microorganisms can cause similar clinical patterns of lower respiratory tract disease, and a variety of clinical presentations can be caused by the same organism. Nevertheless by considering such factors as epidemiology, patient age, manifestations of nonrespiratory diseases, state of nutrition and course of illness, the physician can make reasonable assumptions as to the etiology of a child's respiratory infection. On this basis he or she can make a rational choice of initial therapy. The patient's response to treatment, as well as information gained from laboratory and radiographic studies, if available, can be used to change the management plan as necessary.

Cryptosporidiosis after CD34-selected autologous peripheral blood stem cell transplantation (PBSCT). Treatment with paromomycin, azithromycin and recombinant human interleukin-2.

We report two cases of cryptosporidiosis after CD34-selected PBSCT for lymphoma. While the first patient died of pulmonary cryptosporidiosis, treatment with paromomycin, azithromycin and subcutaneous low-dose rhIL-2 to improve numerical and functional T lymphocyte defects completely eliminated infection in the second patient. We conclude, that the removal of mature T lymphocytes by positive selection of CD34+ cells bears the risk of a delayed immune reconstitution resulting in an increased incidence of severe and sometimes fatal opportunistic infections. IL-2 might be useful in this situation by accelerating immune reconstitution and reducing the danger of opportunistic infections.

Modulation of Schistosoma japonicum pulmonary egg granulomas with monoclonal antibodies.

We have examined the ability of various Schistosoma japonicum egg antigens to sensitize mice for subsequent secondary pulmonary egg granuloma formation. Further, we produced monoclonal antibodies (Mabs) specific for egg antigens and evaluated their abilities to modulate pulmonary granuloma formation and inhibit soluble egg antigen (SEA)-stimulated lymphocyte blastogenesis. A homogeneous, 140 Kd egg glycoprotein, SJe; 140-GP was nearly as effective as intact eggs in sensitizing for egg-focused pulmonary granuloma formation, while SEA, or the heterogeneous immunoaffinity (IA)-purified C10 antigens were ineffective. The in vivo administration of chronic infection serum (CIS) or Mabs reactive with SJe; 140-GP, to egg-sensitized/egg-challenged mice, modulated pulmonary granuloma formation. Two of these modulatory SJe; 140-GP-specific Mabs (1 A1-1 or 14B3-8), an IgG1, and an IgG3, respectively, did not alter the responses of SEA-stimulated lymph node cells from mice with acute or chronic schistosomiasis japonica. In contrast, another SJe; 140-GP-specific IgG3 Mab (7A6-5), CIS, immunoaffinity purified anti-SEA from CIS, or the non-SEA-binding fraction of CIS, all resulted in dose-related inhibition of SEA-induced proliferation. These data confirm the antibody-driven nature of some immunoregulatory networks in murine schistosomiasis japonica, and extend these observations to include certain Mabs. The immunogenic nature of SJe; 140-GP, and the modulatory and inhibitory activities of Mabs specific for this glycoprotein, indicate it may play a central role in granuloma formation and modulation in this infection.

Paragonimiasis: a Japanese perspective.

Paragonimiasis has been considered to be a foodborne zoonosis endemic only in limited areas in the world. Recently, however, patients have been seen almost all over the world because of the increase in number of overseas travelers and the popularization of ethnic dishes in developed countries. If paragonimiasis is misdiagnosed as tuberculosis or lung cancer patients suffer from a considerable burden of long-term hospitalization and unnecessary examinations and treatments. Clinicians should always be aware of the possibility of paragonimiasis when patients have pulmonary lesions with eosinophilia and an elevated serum IgE. For the diagnosis, rapid and reliable immunodiagnostic methods are now available. Highly effective drugs are also available for treatment.

Pulmonary schistosomiasis.

Schistosoma infection is one of the most common infectious diseases, limited in the past only to the endemic countries. With the enormous increase in migration and travel, we encounter more and more cases in developed, nonendemic countries. Although the disease has been known for many years from studies in the endemic countries, the new patient population of nonimmune travelers presents with a different clinical pattern that requires further investigation. One of the features of the disease in the nonendemic population is pulmonary involvement that seems to be much more common than previously suspected. The differences between the nonimmune population with the early pulmonary involvement and the population of endemic areas with late pulmonary involvement are summarized in Table 1. Clinicians in the Western countries have a higher chance of encountering the early (acute) form of the disease, although immigrants from endemic countries may present with late (chronic) schistosomiasis. In the differential diagnosis of pulmonary pathology, especially when accompanied by eosinophilia, schistosomal infection should be considered. The travel history of the patient is mandatory for an evaluation.

Paragonimiasis: a view from Columbia.

Paragonimiasis is a zoonosis caused by adult trematodes of the Paragonimus genus. The infection in humans is a result of a complex transmission cycle that includes two obligate intermediate hosts, a snail and a crustacean or a crayfish, and a definitive mammalian host. It has been shown that 9 of the more than 40 species of Paragonimus described affect humans in over 39 countries in Asia, Africa and America. It is estimated that 20.7 million people have paragonimiasis and it is calculated that 195 million people are at risk of being infected. The illness usually is caused once the parasite has settled in the lung at the site of the main clinical symptoms: cough, thoracic pain and hemoptysis. The diagnosis of paragonimiasis is based on the patient's history, the parasitological findings (ova in sputum and in feces), and the result of radiological and immunological tests. In severe cases, the patient may suffer from life-threatening hemoptysis or pneumothorax. Currently, praziquantel is the drug of choice.

Thoracic amebiasis.

Pleuropulmonary amebiasis is the common and pericardial amebiasis the rare form of thoracic amebiasis. Low socioeconomic conditions, malnutrition, chronic alcoholism, and ASD with left to right shunt are contributing factors to the development of pulmonary amebiasis. Although no age is exempt, it commonly occurs in patients aged 20 to 40 years, with an adult male to female ratio of 10:1. Children rarely develop thoracic amebiasis: when it does occur there is an equal sex distribution. The infection usually spreads to the lungs by extension of an amebic liver abscess. Infection may pass to the thorax directly from the primary intestinal lesion through hematogenous spread, however. Lymphatic spread is one possible route. Inhalation of dust containing cysts and aspiration of cysts or trophozoites of E histolytica in the lungs are some other hypothetical routes. The lung is the second most common extraintestinal site of amebic involvement after the liver. Usually the lower lobe, and sometimes the middle lobe of the right lung, are affected, but it may affect any lobe of the lungs. The patient develops fever and right upper quadrant pain that is referred to the tip of the right shoulder or in between the scapula. Hemophtysis is common. The diagnosis of thoracic amebiasis is suggested by the combination of an elevated hemidiaphragm (usually right), hepatomegaly, pleural effusion, and involvement of the right lung base in the form of haziness and obliteration of costophrenic and costodiaphragmatic angles. Infection is usually extended to the thorax by perforation of a hepatic abscess through the diaphragm and across an obliterated pleural space, producing pulmonary consolidation, abscesses, or broncho-hepatic fistula. Empyema develops when a liver abscess ruptures into the pleural space. Rarely, a posterior amebic liver abscess can burst into the inferior vena cava and develop an embolism of the inferior vena cava and thromboembolic disease of the lungs with congestive cardiac failure or corpulmonale. Diagnosis by finding E histolytica in stool specimens is of limited value. In a limited number of cases amebae might be found in aspirated pus or expectorated sputum. "Anchovy sauce-like" pus or sputum may be found. Presence of bile in sputum indicates that the pus is of liver origin. Serological tests are of immense value in diagnosis. Liver enzymes are usually normal and neutrophilic leucocytosis may or may not be found. ESR is invariably elevated. Anti-amebic antibodies can be detected by ELISA, IFAT, and IHA. Amebic antigen can be detected from serum and pus by ELISA. Detection of Entamoeba DNA in pus or sputum may be a sensitive and specific method. Pleuropulmonary amebiasis is easily confused with other illnesses and is treated as pulmonary TB, bacterial lung abscesses, and carcinoma of the lung. A single drug regimen with metronidazole with supportive therapy usually cures patients without residual anomalies. Aspiration of pus from empyema thoracis may be needed for confirmation and therapeutic purposes. The pericardium is usually involved by direct extension from the amebic abscess of the left lobe of the liver, sometimes from the right lobe of the liver, and rarely from the lungs or pleura. An initial accumulation of serous fluid due to reactive pericarditis followed by intrapericardial rupture may develop either (1) acute onset of severe symptoms with chest pain, dyspnea, and cardiac tamponade, shock, and death, or (2) progressive effusion with thoracic cage pain, progressive dyspnea, and fever. Chest radiograph, ultrasound examination, and CT scan usually confirm the presence of a liver abscess in continuity with the pericardium and fluid within the pericardial sac with or without the fistulous tract. Echocardiography may demonstrate fluid in the pericardial cavity. Patients should be cared for in the ICU and ambecides should be started without delay. Pericardiocentesis usually confirms the diagnosis and improves the general condition of the patient. Aspiration of the accumulated fluid should be performed urgently in cardiac tamponade; repeated aspiration may be needed. Surgical drainage should be done if needed. Acanthamoeba, a free-living ameba, may also infect the lungs in the form of pulmonary nodular infiltration and pulmonary edema in association with amebic meningoencephalitis in immunocompromised patients. It usually spreads to the meninges of the brain by way of the blood from its primary lesion in the lung or skin. Early diagnosis and institution of treatment may be life saving for these patients. A literature review shows that HIV/AIDS patients are not prone to infection with E histolytica. It is now clear that there are an increasing number of HIV-seropositive patients among amebic liver abscess patients, however, which suggests that although the incidence of intestinal infection is not high among HIV-seropositive or AIDS patients they are more susceptible to an invasive form of the disease.

Ascariasis pneumonitis: a potentially fatal complication in smoke inhalation injury.

Ascaris pneumonitis in areas of endemic infestation is considered a benign condition. Smoke inhalation with any burn injury can be potentially fatal. A heavy infestation of Ascaris could further exacerbate the smoke-induced lung injury. After ingested eggs hatch in the small intestine, the larvae penetrate the mucosa and invade the blood stream and are then carried to the lungs. The larvae break out into the aveolar spaces as they are too large to cross the capillary bed and are carried up the bronchial tree and eventually swallowed. This study describes three cases of Ascaris infection in thermally injured children. While the burns were < 30 per cent total body surface area, two patients who were injured in the same fire had a further complication of smoke inhalation which necessitated sophisticated therapy in order to promote survival. All patients were treated initially with Vermox. The one patient without smoke inhalation did not develop ascariasis pneumonitis even with positive stool samples and was discharged with no complications, whereas the two with smoke inhalation developed severe pneumonitis. One patient was placed on ECMO and did not receive a full course of the Vermox treatment. This patient died after several weeks of ECMO treatment. The third patient received a full course of Vermox, slowly recovered, and went home. Supportive therapy only is recommended during the lung migration phase of the Ascaris lifecycle. We feel that continuation of chemotherapy (Vermox) would have been beneficial in the fatal case based on the survival of the second patient.(ABSTRACT TRUNCATED AT 250 WORDS)