Parasitic infections of the lung: a guide for the respiratory physician

Utilizing metagenomic next-generation sequencing for pathogen detection and diagnosis in lower respiratory tract infections in real-world clinical practice

BACKGROUND

Infectious etiologies of lower respiratory tract infections (LRTIs) by the conventional microbiology tests (CMTs) can be challenging. Metagenomic next-generation sequencing (mNGS) has great potential in clinical use for its comprehensiveness in identifying pathogens, particularly those difficult-to-culture organisms.

METHODS

We analyzed a total of 205 clinical samples from 201 patients with suspected LRTIs using mNGS in parallel with CMTs. mNGS results were used to guide treatment adjustments for patients who had negative CMT results. The efficacy of treatment was subsequently evaluated in these patients.

RESULTS

mNGS-detected microorganisms in 91.7% (188/205) of the clinical samples, whereas CMTs demonstrated a lower detection rate, identifying microorganisms in only 37.6% (77/205) of samples. Compared to CMT results, mNGS exhibited a detection sensitivity of 93.5% and 95.4% in all 205 clinical samples and 180 bronchoalveolar lavage fluid (BALF) samples, respectively. A total of 114 patients (114/201; 56.7%) showed negative CMT results, among which 92 received treatment adjustments guided by their positive mNGS results. Notably, 67.4% (62/92) of patients demonstrated effective treatment, while 25% (23/92) experienced a stabilized condition. Subgroup analysis of cancer patients revealed that 41.9% (13/31) exhibited an effective response to treatment, and 35.5% (11/31) maintained a stable condition following medication adjustments guided by mNGS.

CONCLUSION

mNGS demonstrated great potential in identifying microorganisms of clinical significance in LRTIs. The rapid turnaround time and reduced susceptibility to the impact of antimicrobial administration make mNGS a valuable supplementary tool for diagnosis and treatment decision-making for suspected LRTIs in clinical practice.

Unusual pediatric lung infections: imaging findings

Pediatric lung infections continue to be a leading cause of pediatric morbidity and mortality. Although both pediatric and general radiologists are familiar with typical lung infections and their imaging findings in children, relatively rare lung infections continue to present a diagnostic challenge. In addition, the advances in radiological imaging and emergence of several new lung infections in recent years facilitated the need for up-to-date knowledge on this topic. In this review article, we discuss the imaging findings of pediatric lung infections caused by unusual/uncommon and new pathogens. We review the epidemiological, clinical, and radiological imaging findings of viral (coronavirus disease 2019, Middle East respiratory syndrome, bird flu), bacterial (Streptococcus anginosus, Francisella tularensis, Chlamydia psittaci), and parasitic lung infections (echinococcosis, paragonimiasis, amoebiasis). Additional disorders whose clinical course and imaging findings may mimic lung infections in children (hypersensitivity pneumonitis, pulmonary hemorrhage, eosinophilic pneumonia) are also presented, to aid in differential diagnosis. As the clinical presentation of children with new and unusual lung infections is often non-specific, imaging evaluation plays an important role in initial detection, follow-up for disease progression, and assessment of potential complications.

Strongyloidiasis

Strongyloidiasis is a neglected tropical disease caused primarily by the roundworm Strongyloides stercoralis. Strongyloidiasis is most prevalent in Southeast Asia and the Western Pacific. Although cases have been documented worldwide, global prevalence is largely unknown due to limited surveillance. Infection of the definitive human host occurs via direct skin penetration of the infective filariform larvae. Parasitic females reside in the small intestine and reproduce via parthenogenesis, where eggs hatch inside the host before rhabditiform larvae are excreted in faeces to begin the single generation free-living life cycle. Rhabditiform larvae can also develop directly into infectious filariform larvae in the gut and cause autoinfection. Although many are asymptomatic, infected individuals may report a range of non-specific gastrointestinal, respiratory or skin symptoms. Autoinfection may cause hyperinfection and disseminated strongyloidiasis in immunocompromised individuals, which is often fatal. Diagnosis requires direct examination of larvae in clinical specimens, positive serology or nucleic acid detection. However, there is a lack of standardization of techniques for all diagnostic types. Ivermectin is the treatment of choice. Control and elimination of strongyloidiasis will require a multifaceted, integrated approach, including highly sensitive and standardized diagnostics, active surveillance, health information, education and communication strategies, improved water, sanitation and hygiene, access to efficacious treatment, vaccine development and better integration and acknowledgement in current helminth control programmes.

Risk factors and clinical features for pulmonary paragonimiasis-associated pneumothorax

BACKGROUND

Pulmonary paragonimiasis, a food-borne zoonotic helminthiasis, is a parasitic disease of the lung caused by infection with trematodes species of the genus Paragonimus. Although pneumothorax has been reported as occuring with paragonimiasis, to date no study has been performed concerning the clinical features and predictive risk factors for this condition.

METHODS

This retrospective study, which aims to fill this gap, was conducted at Jeonbuk National University Hospital. All patients (aged ≥19 years) were diagnosed with paragonimiasis between May 2011 and December 2021. Medical records were reviewed and information concerning age, sex, vital signs, underlying diseases, clinical signs and symptoms, laboratory findings, radiologic findings, treatment, and clinical outcomes was collected. An odds ratio (OR) for the risk factors associated with pneumothorax was calculated using the binary logistic regression model.

RESULTS

Among 179 consecutive patients diagnosed with pulmonary paragonimiasis, the postive rate of pneumothorax was 10.6% (19/179). Pneumothorax occurred mostly in the right lung (78.9%, 15/19), and intrapulmonary parenchymal lesions showed an ipsilateral relationship with pneumothorax (94.7%, 18/19). Fifteen patients (78.9%, 15/19) of pneumothorax associated with pulmonary paragonimiasis are accompanied by pleural effusion. Most of patients with pneumothorax (89.5%, 17/19) underwent chest tube insertion as a first treatment. Three patients (15.8%) showed relapses but in no case was a death recorded. Asthma (odds ratio [OR] 8.10, 95% confidence interval [CI] 1.43-45.91), chest pain (OR 8.15, 95% CI 2.70-24.58), and intrapulmonary lesions (OR 8.94, 95% CI 1.12-71.36) were independent risk factors for pulmonary paragonimiasis-associated pneumothorax.

CONCLUSIONS

Our findings suggest that clinicians should keep in mind the possibility of pneumothorax when approached by patients with pulmonary paragonimiasis complaining of chest pain, accompanied by intrapulmonary lesions or with asthma as an underlying disease.

Food Allergies and Parasites in Children

The dynamically growing incidence of food allergies forces the scientific community to develop new methods for their diagnosis, differentiation, and effective treatment. Parasitoses appear much less frequently in the scientific literature, as well as among the presumed causes of numerous conditions. The similarity of inflammatory mechanisms in allergies and parasitosis necessitates a revision of current diagnostic standards. A lack of specificity and the coincidence of symptoms at an early stage of disease can lead to misdiagnosis. In this paper, we attempted to perform a comparative analysis of the similarities and differences in symptoms for these two types of diseases. We described the molecular mechanisms and metabolic pathways of food allergy and parasitosis. We presented the available research methods and directions of ongoing studies aimed at implementing precise medical techniques for differential diagnosis. We discussed the allergenic properties of certain parasite proteins, using the example of myofibrillar tropomyosins from the nematode Anisakis simplex. The literature in the fields of allergology and parasitology leads to the conclusion that it is reasonable to run parallel allergological and parasitological diagnostics in patients with non-specific symptoms. This approach will facilitate accurate and early diagnosis and implementation of effective therapy.

Eosinophilic Lung Diseases

The eosinophilic lung diseases may manifest as chronic eosinophilic pneumonia, acute eosinophilic pneumonia, or as the Löffler syndrome (generally of parasitic etiology). The diagnosis of eosinophilic pneumonia is made when both characteristic clinical-imaging features and alveolar eosinophilia are present. Peripheral blood eosinophils are generally markedly elevated; however, eosinophilia may be absent at presentation. Lung biopsy is not indicated except in atypical cases after multidisciplinary discussion. The inquiry to possible causes (medications, toxic drugs, exposures, and infections especially parasitic) must be meticulous. Idiopathic acute eosinophilic pneumonia may be misdiagnosed as infectious pneumonia. Extrathoracic manifestations raise the suspicion of a systemic disease especially eosinophilic granulomatosis with polyangiitis. Airflow obstruction is frequent in allergic bronchopulmonary aspergillosis, idiopathic chronic eosinophilic pneumonia, eosinophilic granulomatosis with polyangiitis, and hypereosinophilic obliterative bronchiolitis. Corticosteroids are the cornerstone of therapy, but relapses are common. Therapies targeting interleukin 5/interleukin-5 are increasingly used in eosinophilic lung diseases.

Immunocompromised Host Pneumonia: Definitions and Diagnostic Criteria: An Official American Thoracic Society Workshop Report

Pneumonia imposes a significant clinical burden on people with immunocompromising conditions. Millions of individuals live with compromised immunity because of cytotoxic cancer treatments, biological therapies, organ transplants, inherited and acquired immunodeficiencies, and other immune disorders. Despite broad awareness among clinicians that these patients are at increased risk for developing infectious pneumonia, immunocompromised people are often excluded from pneumonia clinical guidelines and treatment trials. The absence of a widely accepted definition for immunocompromised host pneumonia is a significant knowledge gap that hampers consistent clinical care and research for infectious pneumonia in these vulnerable populations. To address this gap, the American Thoracic Society convened a workshop whose participants had expertise in pulmonary disease, infectious diseases, immunology, genetics, and laboratory medicine, with the goal of defining the entity of immunocompromised host pneumonia and its diagnostic criteria.

Parasitic lung diseases

Parasitic lung diseases are caused by a number of parasites as a result of transient passage in the lung or as a result of an immunologic reaction. The clinical presentation may be in the form of focal or cystic lesions, pleural effusion or diffuse pulmonary infiltrates. With increasing globalisation, it is important to consider parasitic infections in the differential diagnosis of lung diseases. This is particularly important since early identification and prompt therapy result in full cure of these conditions. In this review, we summarise the most common parasitic lung diseases.

Efficacy and safety of video-assisted thoracoscopic surgery and thoracotomy in the treatment of pulmonary hydatid disease in the Tibetan Plateau: a retrospective study

Background

Although video-assisted thoracoscopic surgery (VATS) plays an increasingly significant part in treating thoracic disease, the role of thoracotomy is not replaced in cystic echinococcosis. The aim of this study was to demonstrate the application of VATS and traditional thoracotomy in the treatment of pulmonary hydatid disease in Shigatse of the Tibet Plateau and to compare the clinical safety and efficacy of these two surgical approaches.

Methods

A total of 53 patients with pulmonary hydatid who received thoracoscopic cystectomy with needle aspiration from January 2015 to December 2020 were enrolled in the study, and 126 patients who received thoracotomy during the same period were matched as the control group. The clinical characteristics, operative time, incidence of perioperative complications, length of stay, and hospitalization cost of the VATS and thoracotomy groups were analyzed to compare the safety and efficacy. Patients were followed up through telephone and outpatient service. In order to balance potential confounding baseline factors, propensity-score matching (PSM) was applied to establish a 1:1 VATS to thoracotomy group ratio.

Results

There were statistically significant differences between the VATS group and the thoracotomy group in operative time, blood loss, drainage volume, and postoperative hospital stay (P<0.05), with the VATS group being superior to the thoracotomy group. There were no significant differences in postoperative complications, adverse imaging outcomes, or recurrence rates between the 2 groups. In terms of complications, there was no significant difference in the incidence of postoperative air leakage, atelectasis, or other common complications between the 2 groups, while the frequency of postoperative fever and incision infection in the thoracotomy group was significantly higher than that in the VATS group (P<0.05). Moreover, the postoperative recurrence rate between the 2 groups showed no significant difference after a 3-year follow-up.

Conclusions

Compared to traditional thoracotomy, VATS had acceptable efficacy and safety and it could further accelerate postoperative recovery and reduce the cost in the treatment of pulmonary hydatid disease in the Tibetan Plateau. Thus, VATS should be promoted more widely to other Tibetan regions.

First molecular approach to diagnose paediatric pulmonary lophomoniasis: A case series

A prospective study was conducted from 2017 to 2021 at Bouali Hospital in Mazandaran province, Sari, Iran. Out of 58 patients who were enrolled in our study, lophomoniasis was diagnosed in bronchoalveolar lavage fluid of nine patients, for the first time, using an in‐house polymerase chain reaction technique. All patients were treated with metronidazole at 7.5 mg/kg/day every 12 h for 14 days. After 6 months of follow‐up, symptoms were fully resolved.

Rapidly progressive respiratory failure after helminth larvae ingestion

BACKGROUND

Self-administration of helminths has gained attention among patients as a potential but unproven therapy for autoimmune disease. We present a case of rapidly progressive respiratory failure in a patient with systemic sclerosis (SSc) and pulmonary arterial hypertension (PAH) as a result of self-administration of parasitic organisms.

CASE

A 45-year-old woman with a history of interstitial lung disease and PAH due to limited cutaneous SSc presented to pulmonary clinic with worsening dyspnea, cough, and new onset hypoxemia. Three months prior to presentation she started oral helminth therapy with Necator americanus as an alternative treatment for SSc. Laboratory evaluation revelaed eosinophilia and elevated IgE levels. IgG antibodies to Strongyloides were detected. High resolution computed tomography of the chest revealed progressive ILD and new diffuse ground glass opacities. Transthoracic echocardiogram and right heart catheterization illustrated worsening PAH and right heart failure. The patient was admitted to the hospital and emergently evaluated for lung transplantation but was not a candidate for transplantation due to comorbidities. Despite aggressive treatment for PAH and right heart failure, her respiratory status deteriorated, and the patient transitioned to comfort-focused care.

CONCLUSION

Although ingestion of helminths poses a risk of infection, helminth therapy has been investigated as a potential treatment for autoimmune diseases. In this case, self-prescribed helminth ingestion precipitated fatal acute worsening of lung inflammation, hypoxemia, and right heart dysfunction, highlighting the risk of experimental helminth therapy in patients, especially those with underlying respiratory disease.

Case Report: Clonorchis sinensis Infection Associated with Eosinophilic Pneumonia: A Case Report and Review of the Literature

Clonorchis sinensis, a trematode prevalent in East Asia, causes hepatobiliary infection. Exposure typically occurs through ingestion of raw or undercooked fish containing the encysted larval form of the parasite. Extrahepatobiliary disease has not commonly been described. In this case report, we describe an unusual case of C. sinensis infection associated with eosinophilic pneumonia. A middle-aged man from China presented with subacute cough and was found to have a bilateral diffuse eosinophilic pneumonia with associated peripheral eosinophilia. Stool microscopy revealed C. sinensis eggs, and the patient improved after treatment with prednisone and praziquantel. Pulmonary clonorchiasis should be considered in patients with eosinophilic pneumonia from areas highly endemic for this pathogen.

Immunological underpinnings of Ascaris infection, reinfection and co-infection and their associated co-morbidities

Human ascariasis is the most common and prevalent neglected tropical disease and is estimated that ~819 million people are infected around the globe, accounting for 0.861 million years of disability-adjusted life years in 2017. Even with the existence of highly effective drugs, the constant presence of infective parasite eggs in the environment contribute to a high reinfection rate after treatment. Due to its high prevalence and broad geographic distribution Ascaris infection is associated with a variety of co-morbidities and co-infections. Here, we provide data from both experimental models and humans studies that illustrate how complex is the interaction of Ascaris with the host immune system, especially, in the context of reinfections, co-infections and associated co-morbidities.

Pulmonary Manifestations of Parasitic Diseases in Children

Parasites can cause respiratory symptoms through focal or diffuse lung involvement, depending on the location of the parasite and the host's immune response. Pulmonary involvement can be a major feature of some parasitic infections or a complication during transpulmonary larval migration. Parasites should be included in the differential diagnosis of common lung diseases, especially in the presence of peripheral eosinophilia or extrapulmonary symptoms (abdominal pain, diarrhea, jaundice, skin lesions).

Parasitic necrotizing pneumonia in an immunocompetent patient in United States

A 59-year-old Baltimore native female, with a history of asthma and no history of travel outside of the USA, presented with productive cough and shortness of breath. Computed tomography scan showed left upper lobe consolidation of the lung with multiple tiny cavitations. She was empirically treated without improvement. Later, strongyloides were found in the sputum gram stain and she was treated with ivermectin. Pulmonary strongyloidiasis has been mainly described in patients who are immunosuppressed and have a history of travel to endemic areas, both of which were absent in our patient. Our case underlines the importance of considering strongyloides necrotizing pneumonia as a differential diagnosis of community-acquired pneumonia even in immunocompetent patients in the USA, especially if not responding to empiric treatment.

Host Immunity and Inflammation to Pulmonary Helminth Infections

Helminths, including nematodes, cestodes and trematodes, are complex parasitic organisms that infect at least one billion people globally living in extreme poverty. Helminthic infections are associated with severe morbidity particularly in young children who often harbor the highest burden of disease. While each helminth species completes a distinct life cycle within the host, several helminths incite significant lung disease. This impact on the lungs occurs either directly from larval migration and host immune activation or indirectly from a systemic inflammatory immune response. The impact of helminths on the pulmonary immune response involves a sophisticated orchestration and activation of the host innate and adaptive immune cells. The consequences of activating pulmonary host immune responses are variable with several helminthic infections leading to severe, pulmonary compromise while others providing immune tolerance and protection against the development of pulmonary diseases. Further delineation of the convoluted interface between helminth infection and the pulmonary host immune responses is critical to the development of novel therapeutics that are critically needed to prevent the significant global morbidity caused by these parasites.

Approach to Eosinophilia Presenting With Pulmonary Symptoms

Eosinophilia with pulmonary involvement is characterized by the presence of peripheral blood eosinophilia, typically ≥500 cells/mm³, by pulmonary symptoms and physical examination findings that are nonspecific, and by radiographic evidence of pulmonary disease and is further supported by histopathologic evidence of tissue eosinophilia in a lung or pleura biopsy specimen and/or increased eosinophils in BAL fluid, usually >10%. Considering that there are a variety of underlying causes of eosinophilia with pulmonary manifestations and overlapping clinical, laboratory, and radiologic features, it is essential to approach the evaluation of eosinophilia with pulmonary findings systematically. In this review, we will describe a case presentation and discuss the differential diagnosis, a directed approach to the diagnostic evaluation and supporting literature, the current treatment strategies for pulmonary eosinophilia syndromes, and the levels of evidence underlying the recommendations, where available. Overall, optimal management of eosinophilic lung disease presentations are directed at the underlying cause when identifiable, and the urgency of treatment may be guided by the presence of severe end-organ involvement or life-threatening complications. When an underlying cause is not easily attributable, management of eosinophilia with pulmonary involvement largely relies on eosinophil-directed interventions, for which biologic therapies are increasingly being used.

Seltene parasitäre Infektionen der Lunge

Pulmonale parasitäre Infektionen kommen weltweit vor, werden jedoch aufgrund der Seltenheit in Deutschland in den wenigsten Fällen differenzialdiagnostisch in Betracht gezogen. Parasitäre Lungenerkrankungen können unterschiedlichste pulmonale Manifestationen hervorrufen und sollten bei unklaren Befunden oder fehlendem Therapieansprechen differenzialdiagnostisch mit bedacht werden, um diese heilbaren Erkrankungen so früh wie möglich zu erkennen.

Cribra orbitalia and porotic hyperostosis are associated with respiratory infections in a contemporary mortality sample from New Mexico

OBJECTIVES

Cribra orbitalia (CO) and porotic hyperostosis (PH) are porous cranial lesions (PCLs) classically associated with iron-deficiency anemia in bioarchaeological contexts. However, recent studies indicate a need to reassess the interpretation of PCLs. This study addresses the potential health correlates of PCLs in a contemporary sample by examining relationships between the known cause of death (COD) and PCL presence/absence.

METHODS

This study includes a sample of 461 juvenile individuals (6 months to 15 years of age) who underwent examination at the University of New Mexico's Office of the Medical Investigator between 2011 and 2019. The information available for each individual includes their sex, age at death, and their COD and manner of death.

RESULTS

Odds ratio of having CO (OR = 3.92, p < .01) or PH (OR = 2.86, p = .02) lesions are increased in individuals with respiratory infections. Individuals with heart conditions have increased odds of having CO (OR = 3.52, p = .03) lesions, but not PH.

CONCLUSION

Individuals with respiratory infection are more likely to have CO and/or PH. CO appears to have a greater range of health correlates than PH does, as indicated by the heart condition results. However, individuals with congenital heart defects are at higher risk for respiratory infections, so bony alterations in cases of heart conditions may be due to respiratory illness. Since respiratory infection remains a leading cause of mortality today, CO and PH in bioarchaeological contexts should be considered as potential indicators of respiratory infections in the past.

Intravital imaging of host-parasite interactions in organs of the thoracic and abdominopelvic cavities

Infections with protozoan and helminthic parasites affect multiple organs in the mammalian host. Imaging pathogens in their natural environment takes a more holistic view on biomedical aspects of parasitic infections. Here, we focus on selected organs of the thoracic and abdominopelvic cavities most commonly affected by parasites. Parasitic infections of these organs are often associated with severe medical complications or have health implications beyond the infected individual. Intravital imaging has provided a more dynamic picture of the host-parasite interplay and contributed not only to our understanding of the various disease pathologies, but has also provided fundamental insight into the biology of the parasites.

Infectious Lung Disease

Infectious diseases are one of the main causes of morbidity and mortality worldwide. With new pathogens continuously emerging, known infectious diseases reemerging, increasing microbial resistance to antimicrobial agents, global environmental change, ease of world travel, and an increasing immunosuppressed population, recognition of infectious diseases plays an ever-important role in surgical pathology. This becomes particularly significant in cases where infectious disease is not suspected clinically and the initial diagnostic workup fails to include samples for culture. As such, it is not uncommon that a lung biopsy becomes the only material available in the diagnostic process of an infectious disease. Once the infectious nature of the pathological process is established, careful search for the causative agent is advised. This can often be achieved by examination of the hematoxylin and eosin-stained sections alone as many organisms or their cytopathic effects are visible on routine staining. However, ancillary studies such as histochemical stains, immunohistochemistry, in situ hybridization, or molecular techniques may be needed to identify the organism in tissue sections or for further characterization, such as speciation.

Regulatory T Cells in Respiratory Health and Diseases

Respiratory diseases compromise the health of millions of people all over the world and are strongly linked to the immune dysfunction. CD4+FOXP3+ T regulatory cells, also known as Tregs, have a central role maintaining tissue homeostasis during immune responses. Their activity and clinical impact have been widely studied in different clinical conditions including autoimmune diseases, inflammatory conditions, and cancer, amongst others. Tregs express transcription factor forkhead box P3 (FOXP3), which allows regulation of the immune response through anti-inflammatory cytokines such as IL-10 or transforming growth factor beta (TGF-β) and direct cell-to-cell interaction. Maintenance of immune tolerance is achieved via modulation of effector CD4+ T helper 1, 2 or 17 (Th1, Th2, Th17) cells by Tregs. This review highlights the recent progress in the understanding of Tregs in different disorders of the respiratory system.

Eosinophils: Nemeses of Pulmonary Pathogens?

PURPOSE OF REVIEW

Eosinophils are short-lived granulocytes that contain a variety of proteins and lipids traditionally associated with host defense against parasites. The primary goal of this review is to examine more recent evidence that challenged this rather outdated role of eosinophils in the context of pulmonary infections with helminths, viruses, and bacteria.

RECENT FINDINGS

While eosinophil mechanisms that counter parasites, viruses, and bacteria are similar, the kinetics and impact may differ by pathogen type. Major antiparasitic responses include direct killing and immunoregulation, as well as some mechanisms by which parasite survival/growth is supported. Antiviral defenses may be as unembellished as granule protein-induced direct killing or more urbane as serving as a conduit for better adaptive immune responses to the invading virus. Although sacrificial, eosinophil DNA emitted in response to bacteria helps trap bacteria to limit dissemination. Herein, we discuss the current research redefining eosinophils as multifunctional cells that are active participants in host defense against lung pathogens. Eosinophils recognize and differentially respond to invading pathogens, allowing them to deploy innate defense mechanisms to contain and clear the infection, or modulate the immune response. Modern technology and animal models have unraveled hitherto unknown capabilities of this surreptitious cell that indubitably has more functions awaiting discovery.

Surgery for parasitic lung infestations: roles in diagnosis and treatment

Pulmonary parasitic infestations are a worldwide problem associated with significant morbidity and socioeconomic impact. They are known to have varied clinical presentations and radiological appearances. Prevention of parasite transmission and medical treatment of cases form the two pillars of control of these diseases. The role of surgery is limited to the diagnosis and definitive treatment of the minority of pulmonary parasitic afflictions, most notably hydatidosis. Despite surgery being established as the treatment of choice in pulmonary hydatid cysts (PHCs) for over half a century, variations and unresolved controversies persist regarding the best surgical technique. Complications brought on by cyst rupture, multiplicity and multi-organ involvement add complexity to treatment decisions. The development of video-assisted thoracoscopic surgery (VATS) brings the promise of reduced peri-operative morbidity but is yet to be universally accepted as a safe technique. In this review, we endeavor to discuss the common pulmonary infestations focusing on the current trends and controversies surrounding surgery for PHC.

Real-Time Polymerase Chain Reaction Assay on Bronchoalveolar Lavage: An Alternative Method for Diagnosing Chronic Pulmonary Schistosomiasis?

Schistosomiasis causes mainly hepatic and genitourinary damage. Although lung nodules have been commonly described in acute phase, they are presumably underdiagnosed in chronic schistosomiasis. We previously reported a series of patients with chronic pulmonary schistosomiasis confirmed by the histological examination of the lung biopsies. In the present work, we retrospectively tested an in-house real-time polymerase chain reaction for Schistosoma (currently validated for diagnosis on stool and on urine) in the bronchoalveolar lavage (BAL) of a couple of those patients, and both resulted positive. The possibility of testing BAL with molecular methods targeting a wide spectrum of pathogens, including parasites, is appealing. Further studies are needed to validate this technique that might reduce unnecessary biopsies.

Influence of Parasitic Worm Infections on Allergy Diagnosis in Sub-Saharan Africa

Epidemiological studies from Sub-Saharan Africa indicate that allergies are on the rise in this region especially in urban compared to rural areas. This increase has been linked to improved hygiene, lifestyle changes, and lower exposure to pathogens in childhood. Reduced exposure to parasitic worm (helminth) infections and allergy outcomes has been the focus of a number of population studies over the years. Paradoxically, there are parallels in the immune responses to helminths and to allergies. Both conditions are associated with elevated levels of immunoglobulin E, high numbers of T helper 2 cells, eosinophils, and mast cells. These immune parallels have meant that the diagnosis of allergies in parts of the world where helminths are endemic can be hampered. The aim of this review is to examine observations from population studies conducted in Sub-Saharan Africa that demonstrate how helminth infections influence the parameters used to diagnose allergy outcomes in this region. We explore specifically how helminth infections hinder the in vitro diagnosis of allergic sensitization, influence the clinical manifestations of allergy, and also the effect of anthelmintic treatment on allergy outcomes. Advancing our understanding of how helminths influence allergy diagnosis is imperative for the development of improved tools to assess, diagnose, and treat allergic disorders in both helminth-endemic and non-endemic countries worldwide.

Cardiopulmonary and Gastrointestinal Manifestations of Eosinophil- associated Diseases and Idiopathic Hypereosinophilic Syndromes: Multimodality Imaging Approach

Eosinophil-associated diseases (EADs) are a diverse group of disorders characterized by an increase in circulating or tissue eosinophils. Cardiopulmonary and gastrointestinal system involvement can be due to primary EAD with no known cause or can be secondary to known systemic disease. The cardiopulmonary spectrum of EADs comprises simple pulmonary eosinophilia, acute eosinophilic pneumonia, chronic eosinophilic pneumonia, Churg-Strauss syndrome, allergic bronchopulmonary aspergillosis, bronchocentric granulomatosis, parasitic infections, and idiopathic hypereosinophilic syndrome. Eosinophilic gastrointestinal disorders include eosinophilic esophagitis, eosinophilic gastroenteritis, and eosinophilic colitis. Diagnosis is often challenging and requires a combination of clinical and imaging features along with laboratory findings. The absolute eosinophil count in peripheral blood and the percentage of eosinophils in bronchoalveolar lavage fluid are crucial in evaluation of various eosinophilic lung diseases. Although chest radiography is the initial imaging modality used in suspected cases of pulmonary EAD, multidetector computed tomography may demonstrate more characteristic pulmonary patterns, nodules, and subtle parenchymal abnormalities. Barium esophagography is used to assess mucosal abnormalities and the length and diameter of esophageal strictures. Magnetic resonance imaging is superior in providing valuable information in select patients, especially in evaluation of cardiac and gastrointestinal system involvement. Many patients require a multimodality imaging approach to enable diagnosis, guide treatment, and assess treatment response. Knowledge of the clinical features and imaging findings of the spectrum of EADs involving the lungs, heart, and gastrointestinal tract permits optimal patient care.

Pulmonary infections in the returned traveller

Pulmonary infections in the returned traveller are a common presentation. A wide variety of infections may present with pulmonary symptoms. It is important for clinicians to differentiate the cause of these symptoms. The risk of contracting certain travel-related pulmonary diseases depends on travel destination, length of stay, activities undertaken and co-morbidities. Some pathogens are found worldwide, whilst others are related to specific locations. This review article will discuss the approach to diagnosing and treating pulmonary infections in the returned traveller.

Severe Anemia and Lung Nodule in an Immunocompetent Adopted Girl with Strongyloides stercoralis Infection

Strongyloides stercoralis is a soil-transmitted helminth widely diffused in tropical areas. Chronic infection is usually characterized by absent or mild symptoms, but immunocompromised subjects are at risk of developing a severe syndrome that can be fatal if not promptly treated. We report a case of S. stercoralis infection causing severe anemia (hemoglobin 4.9 g/dL) and a lung nodule in a 14-year-old girl of Ethiopian origin adopted by an Italian couple. Severe anemia due to strongyloidiasis has been rarely reported, and mostly in severely ill patients, whereas our patient was immunocompetent and in good general conditions. Also, lung nodules have been only occasionally described in absence of respiratory symptoms. We discuss the management of patients with these findings, and we suggest to update the screening of immigrants from countries endemic for strongyloidiasis, including serology.

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.

Parasitic infestation of lung: An unusual cause of interstitial pneumonitis

Parasite infections are increasing worldwide due to increasing migration and traveling. Parasitic infections can affect lungs and present as a focal or diffuse lung diseases. High index of suspicion and detailed history are most important. We present a case of interstitial pneumonitis caused by parasite infestation, which was diagnosed on transbronchial lung biopsy.

Pulmonary dirofilariasis in a 59-year-old man

We present a case of a human pulmonary dirofilariasis in a 59-year-old man. At the medical examination, a chest computed tomography (CT) revealed a mass, measuring 18 × 15 mm in diameter, with an irregular margin on the bottom of the right lower lobe. We could not neglect the possibility of a primary lung cancer, and therefore, a lung partial resection was performed under video-assisted thoracoscopic surgery. The intra-operative pathological findings revealed inflammatory granuloma with coagulation necrosis and no malignant cells. The permanent pathological examination showed occlusion of the peripheral pulmonary artery by worms and formation of a necrotic mass surrounded by reactive inflammation and hemorrhage. Human pulmonary dirofilariasis is an extremely rare zoonotic infection, and sometimes it is difficult to distinguish it from a primary lung cancer on radiographic findings.

Update on immunologic and molecular diagnosis of human strongyloidiasis

Human strongyloidiasis is an intestinal parasitosis that may affect 100 million individuals. However, the prevalence rates of this infection may represent smaller values than the actual data, mainly due to difficulties in its diagnosis. The aim of this study was to update the immunological and molecular methods applied to the diagnosis of human strongyloidiasis. There is a great diversity of techniques used in the diagnosis of this parasitosis, such as immunofluorescence antibody test (IFAT), enzyme-linked immunosorbent assay (ELISA), immunoblotting, luciferase immunoprecipitation system (LIPS), dispstick and polymerase chain reaction (PCR), all with advantages and disadvantages, and with unique features for specific purposes. Considering the magnitude of strongyloidiasis and the importance of early diagnosis, due to the possibility of chronicity and hyperinfection, this study analyzes the different methods currently employed, and demonstrates the necessity of developing innovative methodologies, which also maintain diagnostic accuracy, particularly for regions with limited technological resources.

Active chi-like sequences are present in the ITS1 region of polyembryonic adult Collyriclum faba trematodes encysted in pairs

Collyriclum faba (Plagiochiida: Collyriclidae) adults occur in pairs within subcutaneous cysts. Here, we tested the extensive C. faba infrapopulation for five DNA loci known to display variability among Central European C. faba individuals. The infrapopulation tested shared 100% similarity in four of the five mitochondrial and nuclear DNA loci tested. Contrariwise, the internal transcribed spacer 1 (ITS1) loci in all but one individual differed from each other. We found only 0.0-1.5 base substitutions per 1,000 sites within the cysts, while we found 0.7-9.0 substitutions between the cysts of the single host and 3.0-9.0 substitutions when comparing C. faba individuals isolated from different host individuals. We observed the most of the ITS1 variability within 48 bp repetitive sequences featured by the chi-like sequence 5'-GCTTGTCTGCC-3' at their beginning. Similarly to the extensive C. faba infrapopulation examined, we determined the presence of highly variable number of repetitive sequences within the ITS1 locus of C. faba isolated from multiple host species and from various geographic locations. While similar variability was observed earlier in mutually unrelated specimens of several Schistosomatidae and Microphallidae species, here, we for the first time document it among multiple individuals of a single infracommunity possessing single mitochondrial haplotype. Lower ITS1 evolutionary divergence rates observed between individuals within the cysts when compared to those between the cysts suggest that the recombination occurs at multiple stages of the life cycle. We propose DNA recombination involving chi-like sequences to serve as a general feature shared by multiple families of digenetic trematodes to increase genetic diversity of their polyembryonic populations infecting their definitive hosts.

[Parasitosis (I). Imported heart and lung lesions]

Imported parasitoses are an uncommon condition in our setting, although recently, the increase of migratory flow has been leading to an increase in the detected cases of these diseases. This fundamentally occurs in immigrants from tropical zones where these conditions are generally endemic. However, imported parasitoses are being increasingly diagnosed in Western persons who have lived in the tropics for different reasons. When examining a subject with cardiovascular syndromes with a possible parasitic origin, it could be useful to classify the possible geographic zone of origin in order to perform disease screening. Then, if the problem is mainly respiratory, it would be well to first rule out the existence of tuberculosis in the case of long stays and to individual the diagnosis according to the geographic area, season of the year, type of exposure and symptoms presented, in the case of shorter stays.