Ear , nose and throat ( ENT ) involvement in zoonotic diseases : a systematic review

Introduction: Zoonoses are infections transmitted from animal to man, either directly (through direct contact or contact with animal products) or indirectly (through an intermediate vector, such as an arthropod). The causative agents include bacteria, parasites, viruses, and fungi. The purpose of this review is to make an accurate examination of all zoonotic diseases that can be responsible of ear, nose, and throat (ENT) involvement. Methodology: A PubMed search was performed combining the terms (otorhinolaryngology OR rhinology OR laryngology OR otology OR mastoiditis OR otitis OR sinusitis OR laryngitis OR rhinitis OR pharyngitis OR epiglottitis OR dysphonia OR ear OR larynx OR nose OR pharynx) with each one of the etiological agents of zoonoses for the period between January 1997 and August 2012 without language restrictions. Results: A total of 164 articles were selected and examined. Larynx was the most commonly involved ENT organ, followed by oral cavity, pharynx, and neck. Bacteria were the most representative microorganisms involved. Nose and major salivary glands were affected most frequently by protozoa; paranasal sinus, oral cavity, ear, neck, nerves and upper airway by bacteria; and larynx by fungi. Conclusions: ENT symptoms and signs may be present in many zoonotic diseases, some of which are also present in industrialized countries. Most zoonotic diseases are not commonly encountered by ENT specialists. Appreciation of the possible occurrence of these diseases is important for a correct microbiological approach, which often requires special culture media and diagnostic techniques.


Introduction
Although zoonotic infections are a major burden worldwide -both in terms of immediate and long-term morbidity and mortality [1,2] and in terms of socioeconomical, ecological, and political impact [3] scientific and public health interest and funding for these diseases remain relatively minor and inadequate [4].Zoonotic infections are defined, in general, as infections transmitted from animal to man (and, less frequently, vice versa), either directly (through direct contact or contact with animal products) or indirectly (through an intermediate vector, such as an arthropod) [5].Zoonotic disease may affect ENT districts.Unfortunately, literature is often limited to single case reports from different countries and does not allow adequate appreciation of the problem.Otorhinolaryngologists often lack in-depth knowledge of zoonotic diseases, which complicates etiological identification and treatment and control strategies.In the present review, we summarized scientific publications on zoonotic diseases that directly or indirectly involved the ENT area.

Bibliographical research
A PubMed Medline search for human cases of zoonotic diseases involving head and neck areas was performed combining the terms (otorhinolaryngology OR rhinology OR laryngology OR otology OR mastoiditis OR otitis OR sinusitis OR laryngitis OR rhinitis OR pharyngitis OR epiglottitis OR dysphonia OR ear OR larynx OR nose OR pharynx) with each one of the etiological agents of zoonoses indicated in Tables 1-4 for the period between January 1997 and August 2012 without language restrictions.A study was considered eligible for inclusion in the systematic review if it reported data on patients with zoonotic diseases who presented ENT signs and/or symptoms.Duplicate publications or papers not reporting clinical cases were excluded.The inclusion criteria were applied and the data were extracted by one reviewer and then checked by a second reviewer.

Results
After a scrupulous analysis, 164 papers were considered and examined.Most of the papers are listed on the basis of the etiological agent in Tables 1-4, and a brief note was reported for each paper if it was considered relevant.
Nasal involvement was found in 24 papers.Most of the studies reported cases of leishmaniasis and fungal infections (Tables 3 and 4); bacterial diseases were reported in two articles, and one case each of Hantavirus and echinococcosis was also reported (Tables 2 and 4).Common symptoms were nose bleeding and other symptoms resulting from inflammatory pseudotumor (Figure 1).Paranasal sinus involvement, commonly with sinusitis symptoms, was described in 13 articles.The etiological agents in seven articles were bacteria; protozoa, fungi, and helminths were each the etiological agents in two articles (Figure 1).
Involvement of the oral cavity or pharynx was found in 41 papers.Bacteria (in most of the cases, Francisella tularensis reported from Turkey) were detected as agents of these conditions in 25 articles (Table 1), followed by protozoa (eight articles), fungi (seven articles), and viruses.Pharyngitis, tonsillitis, pharyngotonsillitis, and dysphagia were found frequently, often associated with lymphadenopathy and fever (Figure 1).
Involvement of the larynx was described in 39 articles.Bacteria were the etiologic agents in eight articles, the Japanese encephalitis virus was the etiologic agent in one article, Leishmania spp in 11 articles (Table 4), fungi in 18 articles (Table 3), and helminths in one article (Table 4).Symptoms of larynx involvement were epiglottitis, dysphonia, or dyspnea (Figure 1).
Thirty-five articles documented ear involvement.Bacteria were identified in 21 articles (Table 1), viruses in four (Table 2), protozoa in one (Table 4), fungi in four (Table 3), and helminths in one article (Table 4).Otitis media, otomastoiditis, sensorineural loss of hearing, and vestibular dysfunction were the most frequently reported conditions (Figure 1).
Involvement of the neck was found in 33 articles.Bacteria were identified in 29 articles, fungi in two articles, viruses (Cowpox virus) in one article, and helminths (Echinococcus granulosus) in one article.The most frequent manifestation was lymphadenopathy.Rarely, retropharyngeal or neck abscess and necrotizing fasciitis were found (Figure 1).
Nerve disease was described in eight articles.The most frequently involved agents were bacteria: Bartonella henselae, Borrelia burgdorferi, and Campylobacter spp. in one case (Table 1), West Nile Virus in one case (Table 2), and Leishmania spp.were detected in one case (Table 4).The most frequent manifestation was facial or laryngeal nerve paralysis.
An involvement of the total upper airway was found in three papers, each one reporting cases of infection with Clostridium botulinum, Mycobactrium avium, and Corynebacterium ulcerans (Table 1).Only one article documented an involvement of facial tissue in the course of helminthiasis (dirofilariasis) (Table 4).
Involvement of major salivary glands was found in four articles.Etiologicals agents were in one case Crimean-Congo haemorrhagic fever virus, in two cases Toxoplasma gondii, and in one case Cryptococcus neoformans.Symptoms were parotitis or parotid mass (Figure 1).

Bacteria
[References] ENT manifestations and notes Bartonella spp.
[6] Atypical presentations of cat scratch disease in the head and neck; cat scratch disease presenting as acute mastoiditis; neck abscess secondary to cat-scratch disease; traveler's fever, cervical adenomegaly, Brazilian patient returning from South Africa; cat scratch disease presenting with peripheral facial nerve paralysis.Brucella spp.
Hantaviruses [43]    Five papers described cases occurring in travelers: two cases of leishmaniasis (Table 4), and a case each of paracoccidioidomycosis, histoplasmosis (Table 3), and bartonellosis (Table 1).Some cases were complicated by severe symptoms and death.Some papers reported cases in which the zoonotic lesions could have been misdiagnosed as cancer.These included three cases of leishmaniasis (Table 4), a case of laryngeal criptococosis (Table 3), two cases of laryngeal paracoccidiomicosis (Table 3), and one case of toxoplasmosis lymphadenitis presenting as a parotid mass (Table 4).

Discussion
On the basis of the present review, the larynx seem to be the most common ENT organ involved in zoonotic diseases, followed by the oral cavity, pharynx, and neck.Bacteria were the most frequently involved agents .The nose and major salivary glands seemed to be affected most frequently by protozoa [47][48][49]; paranasal sinus, oral cavity, ear, neck, nerves, and upper airway were most affected by bacteria, and the larynx was most affected by fungi [58][59][60].
Of all the microorganisms considered, some have a worldwide distribution, while others are restricted to certain geographic areas.Mucosal leishmaniasis is uncommon outside of Central and South America.Mucosal leishmaniasis contracted in southern Europe mostly affected adult males, of which half were immunodeficient.Clinical polymorphism makes diagnosis difficult.
It is important to note that the ENT manifestations in zoonoses can be an integral part of the disease for example, American mucocutaneous leishmaniasis (ACL) [46][47][48][49][50][51][52][53][54][55][56] and botulism -while in others, such as paracoccidiomicosis or tularemia, ENT involvement is only occasionally found.In addition, many diseases that usually do not produce ENT involvement (such as histoplasmosis, leishmaniasis of the Mediterranean region, and criptococcosis) can produce it in immunosuppressed patients.Histoplasmosis, an AIDS-defining disease, may present as a disseminated form in which oral lesions are found in 30% to 50% of patients.
The present work shows that ENT symptoms and signs may be present in many zoonotic diseases, some of which are also present in industrialized countries.Most of these diseases are not commonly encountered by ENT specialists who may confuse them occasionally for neoplastic conditions.Appreciation of the possible occurrence of these diseases is important for a correct microbiological approach, which often requires special culture media and diagnostic techniques.
Zoonotic diseases may be difficult to diagnose and can be capable of confusing even the most experienced physicians, especially if they occur in countries where the disease is not endemic.Because there are no common signs and symptoms of zoonotic diseases involving ENT districts, the practicing otorhinolaringologist, while attending to patients with ENT symptoms not responding to common therapy, should pay particular attention to anamnesis (immunosuppressive therapy; history of at-risk professional and recreational occupations such as hunter, ranger, farmer, and veterinarian; recent travel to endemic regions; particular environment of life of the patients and their partners; and eating habits) and consider the possibility of a zoonotic disease [3,4].
From the dawn of modern medicine, the understanding of infectious disease and how to treat it has been an integral part of the physician's craft in all fields.Undoubtedly, the impact of zoonotic diseases may vary in relationship to the socioeconomic context and to the public health system in different geographic areas.A greater threat exists in developing countries [3], which today is of utmost importance in the context of globalization.The practice of travel medicine with the possibility of imported cases from endemic regions is also of growing concern.Often, because of economic globalization and increased travel and migration (even forced, as occurs with refugees), agents are found in countries different from their source [61].Because this may cause serious diagnostic difficulties, it is important that physicians from both endemic and non-endemic zones increase their awareness of diseases that have been previously considered to be uncommon in their home countries.

Figure 1 .
Figure 1.Anatomical localization of zoonotic agents at ENT region.

Table 4 .
Fungal agents of zoonoses and ENT manifestations Tongue, Malaysia; retropharyngeal abscess; laryngitis, AIDS; vocal cord cyst; laryngitis simulating laryngeal carcinoma; colonization of a voice prosthesis; auricular cryptococcosis as the initial presentation of AIDS, USA; nasal cutaneous cryptococcosis AIDS; parotid gland; C. laurentii, oropharynx, erythroleukaemia, Belgium; otitis and cholesteatoma; meningitis, vestibular dysfunction; isolation of C. magnus and C. chernovii from nasal cavities of pediatric patients with acute lymphoblastic leukemia, Kuwait.