Human pulmonary dirofilariasis presenting as a solitary pulmonary nodule: A case report and a brief review of literature

Development of New Recombinant DgK Antigen for Diagnosis of Dirofilaria immitis Infections in Dogs Using ELISA Technique and Its Comparison to Molecular Methods

Background

Dirofilaria immitis is a cosmopolitan zoonotic, vector-borne parasite of carnivorous animals causing dirofilariasis in human beings. Common commercial serodiagnostic tests for canine dirofilariasis usually lead to different results in their sensitivity and specificity. The present study reports development of recombinant DgK (rDgK) antigen of D. immitis for accurate immunodiagnosis of D. Immitis-infected dogs using indirect ELISA test.

Methods

The rDgK coding sequence was successfully sequenced, codon optimized and cloned into pET-24a(+) expression vector and then expressed in Escherichia coli. The recombinant DgK was affinity purified using Ni²+-charged HiTrap chelating column, followed by testing in Western blotting and enzyme-linked immunosorbent assays (ELISA) with dog sera from a dirofilariasis endemic area. The performance of rDgK ELISA was evaluated using 60 sera collected from suspected dogs, while molecular technique was used as a reference test.

Results

Sera from positive control D. immitis infection produced a strong IgG antibody response to rDgK both in ELISA and Western blotting tests. The sensitivity and specificity related to diagnostic potential of rDgK for ELISA were 92.5% and 87.5%, respectively. The results of rDgK ELISA showed a high agreement (0.764) with molecular identification.

Conclusion

The findings revealed that the developed new rDgK antigen is sensitive and specific for immunodiagnosis of canine dirofilariasis using ELISA test.

The roles of galectins in parasitic infections

Galectins is a family of multifunctional lectins. Fifteen galectins have been identified from a variety of cells and tissues of vertebrates and invertebrates. Galectins have been shown to play pivotal roles in host-pathogen interaction such as adhesion of pathogens to host cells and activation of host innate and adaptive immunity. In recent years, the roles of galectins during parasite infections have gained increasing attention. Galectins produced by different hosts can act as pattern recognition receptors detecting conserved pathogen-associated molecular patterns of parasites, while galectins produced by parasites can modulate host responses. This review summarizes some recent studies on the roles of galectins produced by parasitic protozoa, nematodes, and trematodes and their hosts. Understanding the roles of galectins in host-parasite interactions may provide targets for immune intervention and therapies of parasitic infections.

The Complexity of Zoonotic Filariasis Episystem and Its Consequences: A Multidisciplinary View

Vector-borne transmitted helminthic zoonosis affects the health and economy of both developing and developed countries. The concept of episystem includes the set of biological, environmental, and epidemiological elements of these diseases in defined geographic and temporal scales. Dirofilariasis caused by different species of the genus Dirofilaria is a disease affecting domestic and wild canines and felines and man, transmitted by different species of culicid mosquitoes. This complexity is increased because Dirofilaria species harbor intracellular symbiont Wolbachia bacteriae, which play a key role in the embryogenesis and development of dirofilariae and in the inflammatory pathology of the disease. In addition, the vector transmission makes the dirofilariasis susceptible to the influence of the climate and its variations. The present review addresses the analysis of dirofilariasis from the point of view of the episystem, analyzing the complex network of interactions established between biological components, climate, and factors related to human activity, as well as the different problems they pose. The progress of knowledge on human and animal dirofilariasis is largely due to the multidisciplinary approach. Nevertheless, different aspects of the disease need to continue being investigated and cooperation between countries and specialists involved should be intensified.

Subcutaneous and Pulmonary Dirofilariasis with Evidence of Splenic Involvement

Cases of human dirofilariasis have been reported in several countries around the world, including a large number in the Atlantic and Gulf Coast regions of the United States. Most commonly, these cases have subcutaneous or pulmonary involvement; however, there have been few reports of dirofilariasis involving structures such as large vessels, mesentery, the spermatic cord, and liver. We present a case of an unusual presentation of human dirofilariasis presenting as a shoulder abscess and what is presumed to be pulmonary and splenic involvement in a 55-year-old female.

A rare case of human pulmonary dirofilariasis with a growing pulmonary nodule after migrating infiltration shadows, mimicking primary lung carcinoma

INTRODUCTION

Pulmonary dirofilariasis is a rare pulmonary parasitic infection by the nematode Dirofilaria immitis. It is characterized by an asymptomatic pulmonary nodule usually seen on chest X-ray. The differential diagnosis of pulmonary dirofilariasis includes other pulmonary diseases, primary lung carcinoma and metastatic lung tumor.

CASE PRESENTATION

Pulmonary dirofilariasis was diagnosed in a woman who presented with interstitial pneumonia. Growth of the pulmonary nodule was detected subsequent to hemoptysis. The histological diagnosis was made based on a wedge resection performed under video-associated thoracic surgery (VATS).

CONCLUSION

Pulmonary dirofilariasis often varies in its clinical course. The diagnosis is best made using wedge resection under VATS.

Parasitic pneumonia and lung involvement

Parasitic infestations demonstrated a decline in the past decade as a result of better hygiene practices and improved socioeconomic conditions. Nevertheless, global immigration, increased numbers of the immunocompromised people, international traveling, global warming, and rapid urbanization of the cities have increased the susceptibility of the world population to parasitic diseases. A number of new human parasites, such as Plasmodium knowlesi, in addition to many potential parasites, have urged the interest of scientific community. A broad spectrum of protozoal parasites frequently affects the respiratory system, particularly the lungs. The diagnosis of parasitic diseases of airway is challenging due to their wide varieties of clinical and roentgenographic presentations. So detailed interrogations of travel history to endemic areas are critical for clinicians or pulmonologists to manage this entity. The migrating adult worms can cause mechanical airway obstruction, while the larvae can cause airway inflammation. This paper provides a comprehensive review of both protozoal and helminthic infestations that affect the airway system, particularly the lungs, including clinical and roentgenographic presentations, diagnostic tests, and therapeutic approaches.