DOCSLIB.ORG

The Ceylon Medical 2006 Jan..Pmd

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
The Ceylon Medical 2006 Jan..Pmd Leading articles with funding contributions from the professional colleges, International Council of Medical Journal Editors. New Ministry of Health, and the WHO (which has already taken England Journal of Medicine 2004; 351: 1250–1 (Editorial). some promotive and facilitatory initial actions in this regard 2. Angelis CD, Drazen JM, Frizelle FA, Haug C, Hoey J, et [4,8]. Our Journal already has a policy decision in place al. Is this clinical trial fully registered?—A statement from not to consider for publication papers reporting clinical the International Council of Medical Journal Editors. New trials that have not received approval from an acceptable England Journal of Medicine 2005; 352: 2436–8. ethical review committee, before the trial started enrolling (Editorial). participants. When a suitable trials registry has been 3. Abbasi K. Compulsory registration of clinical trials. British established, we will fall in line with the recent recommendation Medical Journal 2004; 329: 637–8 (Editorial). of the ICMJE [1–4]. 4. Abbasi K, Godlee F. Next steps in trial registration. British Meanwhile, we urge all medical professional bodies Medical Journal. 2005; 330: 1222–3 (Editorial). and all editors of journals publishing biomedical research in Sri Lanka to support this ICMJE concept, and the Sri 5. Macklin R. Double Standards in Medical Research. Lanka Medical Association to take all necessary steps, as Cambridge: Cambridge University Press, 2004. a matter of priority, to establish a registry of clinical trials. 6. Simes RJ. Publication bias: the case for an international To demur or delay now would place in peril the status of registry of clinical trials. Journal of Clinical Oncology 1986; our biomedical journals, the international standing of our 4: 1529–41. profession, and much more importantly, the altruism of our 7. Horton R, Smith R. Time to register randomised trials. people who volunteer for clinical trials, as well as the trust British Medical Journal 1999; 319: 865–6. and confidence patients have reposed in us. 8. World Health Organisation. The international clinical trials registry platform (ICTRP). www.who.int/ictrp/en (accessed References 26 May 2005). 1. De Angelis C, Drazen JM, Frizelle FA, Haug C, Hoey J, et al. Clinical trial registration: a statement from the Colvin Goonaratna, Editor, Ceylon Medical Journal, 6 Wijerama Mawatha, Colombo; e-mail: <[email protected]>. Intra-ocular nematode worms: rare but important Clinicians need help from a parasitologist for accurate identification Migration of nematode larvae in the human body is a lymphatics, but has also been recovered and clearly normal part of the life cycle of many parasites. Ocular identified from intra-ocular locations in humans. Fernando disease caused by the abnormal migration of human or [2] described the first local case of adult W. bancrofti in animal, juvenile or adult nematode worms in the eye is the anterior chamber of the human eye. Although uncommon, but important as they induce visual impairment numerous reports of filarial infection of the human and pose diagnostic and management challenges. The conjunctiva and the anterior chamber have been published detection of a worm, in or near the eye, is always a dramatic [3–5], infections of the vitreous are rare. This issue of the occurrence for both patient and clinician. Such patients journal (page 167) reports an instance of a W. bancrofti frequently complain of the sensation of movement of an juvenile female worm extracted from the vitreous of eye— object in the eye, and the clinician can occasionally see the first report of such a case in the world [6]. It is difficult the worm in the conjunctiva, on the eye itself, or in the to identify a female specimen of a filarioid with certainty, anterior or posterior chambers. but the position of the vulval opening in relation to the The nematodes that have been isolated from the oesophagus is an indication of the species [7]. human eye are of human or animal origin and belong to Loa loa is a subcutaneous filarial parasite of humans, different groups, including filariae, strongylids, endemic in west and central Africa. It is reported metastrongylids and ascarids [1]. Parasites infect the eye sporadically from other parts of the world in travellers either by extension from the infected adjacent tissues, or returning from endemic areas. This parasite has been by haematogenous dissemination to the eye. reported in Sri Lanka in an expatriate girl who had been The adult worm of Wuchereria bancrofti, the infected in Nigeria, hence classified as an imported causative agent of lymphatic filariasis, is found in the infection [8]. Eye infections may occur when the adult Vol. 50, No. 4, December 2005 141 Leading articles worm meanders into the subconjunctival tissue prompting Ocular angiostrongyliasis results from ocular the appellation “eye worm”. migration of Parastrongylus (=Angiostrongylus), a rodent Onchocerciasis (river blindness) is a chronic parasitic lung worm, found in bandicoots in Sri Lanka. It has been infection of humans caused by the nematode Onchocerca isolated in the eye on three occasions from the anterior volvulus. The major feature of the disease is ocular and chamber and once from the vitreous [19–22]. Of a total of dermatological pathology, of which itching is the 17 authentic ocular infections reported, four have been commonest and blindness the most serious. Discussion from Sri Lanka. The infection may not necessarily have of this filarial parasite is outside the scope of this article. been acquired by eating raw or undercooked intermediate or paratenic hosts, but rather by accidental ingestion of Almost all infections of the human conjunctiva with infective larvae liberated from damaged mollusks filarial worms of animal origin represent infections of contaminating raw leafy vegetables [20, 21]. A larva Dirofilaria species from dogs, cats and related carnivores. isolated from the anterior chamber of the eye in 1925, may This zoonotic infection is now widely recognised by not only be the first case in the world of ocular infection clinicians, pathologists and parasitologists worldwide, and reported, but also the first report of the genus unless there is some unusual presentation about the case, Parastrongylus in humans [23, 24]. they may not be routinely published. D. (Nochtiella) repens, the subcutaneous worm of dogs is incriminated Gnathastomiasis is a significant cause of ocular as the aetiologic agent infecting humans in Sri Lanka, and disease in east Asia, with sporadic cases being reported is associated with subcutaneous migration and nodule worldwide. It is the second most common ocular parasite formation. The second largest number of cases of in Thailand [25]. No cases of ocular gnathastomiasis have D. repens in the world has been reported from Sri Lanka, been reported from Sri Lanka, although two have been the largest number being reported from Italy [9, 10]. In Sri diagnosed in subcutaneous tissue [26]. As humans can Lanka, contributory factors could be the high prevalence get infected by drinking water containing infected Cyclops, of D. repens in dogs—up to 60% [11]—and availability of it is a potentially threatening eye infection. efficient vectors of this nematode, Aedes aegypti and Diagnosis of worms isolated from the eye is usually Anopheles subalbatus, found as peri-domestic species in based on identification of the parasite on morphological urban areas [12, 13]. Ocular dirofilariasis usually involves criteria in cross-section and specific serology. The a migrating worm, most frequently invading the eyelid or presence or absence of the head bulb, the number of conjunctiva [9]. cephalic papillae, and the pattern of the cuticle and the longitudinal and transverse striations seen on transverse The more unusual zoonotic infections, such as ocular sections of the worm are important in identification, disease caused by Brugia species, a zoonotic infection specially in filarioids [7]. The ends of the worm, male or acquired from dogs, still hold sufficient interest to merit female, contain the greatest amount of morphologic publication. The world’s second case of Brugia species, information, and every effort should be made to collect probably B. ceylonensis, was isolated from the conjunctiva and preserve the entire specimen. The clinician who of a Sri Lankan man [7]. removes an intact worm from the eye, must make an Nematodes of zoonotic origin, namely the heart worm accurate identification with the help of a specialist in of dogs (Dirofilaria immitis) [14] and adult Ancylostoma parasitology. When it is necessary to distinguish between (probably A. tubaeformae) have been isolated from the similar species, the application of molecular technology vitreous [1]. Humans may act as a definitive host in will be useful. The development of species specific probes hookworm infections caused by Necator americanus or allows identification where microscopic diagnosis is Ancylostoma duodenale. They may also be dead-end hosts virtually impossible. However, because the number of for canine hookworms (e.g. A. braziliense, A. caninum and specific probes needed to accomplish the task is large A. ceylanicum) [11, 15, 16], or A. braziliense and A. caninum and its application is limited, it is unlikely that a significant (now regarded as A. tubaeforme) from cats [15]. number will be generated and made available for routine use. Ocular toxocariasis is caused by the nematode larvae Emerging zoonotic infections continue to be recognized of Toxocara
Load more

Recommended publications
  • Gnathostoma Spinigerum Was Positive
    Department Medicine Diagnostic Centre Swiss TPH Winter Symposium 2017 Helminth Infection – from Transmission to Control Sushi Worms – Diagnostic Challenges Beatrice Nickel Fish-borne helminth infections Consumption of raw or undercooked fish - Anisakis spp. infections - Gnathostoma spp. infections Case 1 • 32 year old man • Admitted to hospital with severe gastric pain • Abdominal pain below ribs since a week, vomiting • Low-grade fever • Physical examination: moderate abdominal tenderness • Laboratory results: mild leucocytosis • Patient revealed to have eaten sushi recently • Upper gastrointestinal endoscopy was performed Carmo J, et al. BMJ Case Rep 2017. doi:10.1136/bcr-2016-218857 Case 1 Endoscopy revealed 2-3 cm long helminth Nematode firmly attached to / Endoscopic removal of larva with penetrating gastric mucosa a Roth net Carmo J, et al. BMJ Case Rep 2017. doi:10.1136/bcr-2016-218857 Anisakiasis Human parasitic infection of gastrointestinal tract by • herring worm, Anisakis spp. (A.simplex, A.physeteris) • cod worm, Pseudoterranova spp. (P. decipiens) Consumption of raw or undercooked seafood containing infectious larvae Highest incidence in countries where consumption of raw or marinated fish dishes are common: • Japan (sashimi, sushi) • Scandinavia (cod liver) • Netherlands (maatjes herrings) • Spain (anchovies) • South America (ceviche) Source: http://parasitewonders.blogspot.ch Life Cycle of Anisakis simplex (L1-L2 larvae) L3 larvae L2 larvae L3 larvae Source: Adapted to Audicana et al, TRENDS in Parasitology Vol.18 No. 1 January 2002 Symptoms Within few hours of ingestion, the larvae try to penetrate the gastric/intestinal wall • acute gastric pain or abdominal pain • low-grade fever • nausea, vomiting • allergic reaction possible, urticaria • local inflammation Invasion of the third-stage larvae into gut wall can lead to eosinophilic granuloma, ulcer or even perforation.
    [Show full text]
  • The Functional Parasitic Worm Secretome: Mapping the Place of Onchocerca Volvulus Excretory Secretory Products
    pathogens Review The Functional Parasitic Worm Secretome: Mapping the Place of Onchocerca volvulus Excretory Secretory Products Luc Vanhamme 1,*, Jacob Souopgui 1 , Stephen Ghogomu 2 and Ferdinand Ngale Njume 1,2 1 Department of Molecular Biology, Institute of Biology and Molecular Medicine, IBMM, Université Libre de Bruxelles, Rue des Professeurs Jeener et Brachet 12, 6041 Gosselies, Belgium; [email protected] (J.S.); [email protected] (F.N.N.) 2 Molecular and Cell Biology Laboratory, Biotechnology Unit, University of Buea, Buea P.O Box 63, Cameroon; [email protected] * Correspondence: [email protected] Received: 28 October 2020; Accepted: 18 November 2020; Published: 23 November 2020 Abstract: Nematodes constitute a very successful phylum, especially in terms of parasitism. Inside their mammalian hosts, parasitic nematodes mainly dwell in the digestive tract (geohelminths) or in the vascular system (filariae). One of their main characteristics is their long sojourn inside the body where they are accessible to the immune system. Several strategies are used by parasites in order to counteract the immune attacks. One of them is the expression of molecules interfering with the function of the immune system. Excretory-secretory products (ESPs) pertain to this category. This is, however, not their only biological function, as they seem also involved in other mechanisms such as pathogenicity or parasitic cycle (molting, for example). Wewill mainly focus on filariae ESPs with an emphasis on data available regarding Onchocerca volvulus, but we will also refer to a few relevant/illustrative examples related to other worm categories when necessary (geohelminth nematodes, trematodes or cestodes).
    [Show full text]
  • Toxocariasis: a Rare Cause of Multiple Cerebral Infarction Hyun Hee Kwon Department of Internal Medicine, Daegu Catholic University Medical Center, Daegu, Korea
    Case Report Infection & http://dx.doi.org/10.3947/ic.2015.47.2.137 Infect Chemother 2015;47(2):137-141 Chemotherapy ISSN 2093-2340 (Print) · ISSN 2092-6448 (Online) Toxocariasis: A Rare Cause of Multiple Cerebral Infarction Hyun Hee Kwon Department of Internal Medicine, Daegu Catholic University Medical Center, Daegu, Korea Toxocariasis is a parasitic infection caused by the roundworms Toxocara canis or Toxocara cati, mostly due to accidental in- gestion of embryonated eggs. Clinical manifestations vary and are classified as visceral larva migrans or ocular larva migrans according to the organs affected. Central nervous system involvement is an unusual complication. Here, we report a case of multiple cerebral infarction and concurrent multi-organ involvement due to T. canis infestation of a previous healthy 39-year- old male who was admitted for right leg weakness. After treatment with albendazole, the patient’s clinical and laboratory results improved markedly. Key Words: Toxocara canis; Cerebral infarction; Larva migrans, visceral Introduction commonly involved organs [4]. Central nervous system (CNS) involvement is relatively rare in toxocariasis, especially CNS Toxocariasis is a parasitic infection caused by infection with presenting as multiple cerebral infarction. We report a case of the roundworm species Toxocara canis or less frequently multiple cerebral infarction with lung and liver involvement Toxocara cati whose hosts are dogs and cats, respectively [1]. due to T. canis infection in a previously healthy patient who Humans become infected accidentally by ingestion of embry- was admitted for right leg weakness. onated eggs from contaminated soil or dirty hands, or by in- gestion of raw organs containing encapsulated larvae [2].
    [Show full text]
  • Molecular Identification of the Etiological Agent of Human
    Jpn. J. Infect. Dis., 73, 44–50, 2020 Original Article Molecular Identification of the Etiological Agent of Human Gnathostomiasis in an Endemic Area of Mexico Sylvia Paz Díaz-Camacho1, Jesús Ricardo Parra-Unda2, Julián Ríos-Sicairos2, and Francisco Delgado-Vargas2* 1Research Unit in Environment and Health, Autonomous University of Occident, Sinaloa; and 2Public Health Research Unit "Dra. Kaethe Willms", School of Chemical and Biological Sciences, Autonomous University of Sinaloa, University city, Culiacan, Sinaloa, Mexico SUMMARY: Human gnathostomiasis, which is endemic in Mexico, is a worldwide health concern. It is mainly caused by the consumption of raw or insufficiently cooked fish containing the advanced third-stage larvae (AL3A) of Gnathostoma species. The diagnosis of gnathostomiasis is based on epidemiological surveys and immunological diagnostic tests. When a larva is recovered, the species can be identified by molecular techniques. Polymerase chain reaction (PCR) amplification of the second internal transcription spacer (ITS-2) is useful to identify nematode species, including Gnathostoma species. This study aims to develop a duplex-PCR amplification method of the ITS-2 region to differentiate between the Gnathostoma binucleatum and G. turgidum parasites that coexist in the same endemic area, as well as to identify the Gnathostoma larvae recovered from the biopsies of two gnathostomiasis patients from Sinaloa, Mexico. The duplex PCR established based on the ITS- 2 sequence showed that the length of the amplicons was 321 bp for G. binucleatum and 226 bp for G. turgidum. The amplicons from the AL3A of both patients were 321 bp. Furthermore, the length and composition of these amplicons were identical to those deposited in GenBank as G.
    [Show full text]
  • Gnathostomiasis: an Emerging Imported Disease David A.J
    RESEARCH Gnathostomiasis: An Emerging Imported Disease David A.J. Moore,* Janice McCroddan,† Paron Dekumyoy,‡ and Peter L. Chiodini† As the scope of international travel expands, an ous complication of central nervous system involvement increasing number of travelers are coming into contact with (4). This form is manifested by painful radiculopathy, helminthic parasites rarely seen outside the tropics. As a which can lead to paraplegia, sometimes following an result, the occurrence of Gnathostoma spinigerum infection acute (eosinophilic) meningitic illness. leading to the clinical syndrome gnathostomiasis is increas- We describe a series of patients in whom G. spinigerum ing. In areas where Gnathostoma is not endemic, few cli- nicians are familiar with this disease. To highlight this infection was diagnosed at the Hospital for Tropical underdiagnosed parasitic infection, we describe a case Diseases, London; they were treated over a 12-month peri- series of patients with gnathostomiasis who were treated od. Four illustrative case histories are described in detail. during a 12-month period at the Hospital for Tropical This case series represents a small proportion of gnathos- Diseases, London. tomiasis patients receiving medical care in the United Kingdom, in whom this uncommon parasitic infection is mostly undiagnosed. he ease of international travel in the 21st century has resulted in persons from Europe and other western T Methods countries traveling to distant areas of the world and return- The case notes of patients in whom gnathostomiasis ing with an increasing array of parasitic infections rarely was diagnosed at the Hospital for Tropical Diseases were seen in more temperate zones. One example is infection reviewed retrospectively for clinical symptoms and confir- with Gnathostoma spinigerum, which is acquired by eating uncooked food infected with the larval third stage of the helminth; such foods typically include fish, shrimp, crab, crayfish, frog, or chicken.
    [Show full text]
  • Angiostrongylus Cantonensis: a Review of Its Distribution, Molecular Biology and Clinical Significance As a Human
    See discussions, stats, and author profiles for this publication at: https://www.researchgate.net/publication/303551798 Angiostrongylus cantonensis: A review of its distribution, molecular biology and clinical significance as a human... Article in Parasitology · May 2016 DOI: 10.1017/S0031182016000652 CITATIONS READS 4 360 10 authors, including: Indy Sandaradura Richard Malik Centre for Infectious Diseases and Microbiolo… University of Sydney 10 PUBLICATIONS 27 CITATIONS 522 PUBLICATIONS 6,546 CITATIONS SEE PROFILE SEE PROFILE Derek Spielman Rogan Lee University of Sydney The New South Wales Department of Health 34 PUBLICATIONS 892 CITATIONS 60 PUBLICATIONS 669 CITATIONS SEE PROFILE SEE PROFILE Some of the authors of this publication are also working on these related projects: Create new project "The protective rate of the feline immunodeficiency virus vaccine: An Australian field study" View project Comparison of three feline leukaemia virus (FeLV) point-of-care antigen test kits using blood and saliva View project All content following this page was uploaded by Indy Sandaradura on 30 May 2016. The user has requested enhancement of the downloaded file. All in-text references underlined in blue are added to the original document and are linked to publications on ResearchGate, letting you access and read them immediately. 1 Angiostrongylus cantonensis: a review of its distribution, molecular biology and clinical significance as a human pathogen JOEL BARRATT1,2*†, DOUGLAS CHAN1,2,3†, INDY SANDARADURA3,4, RICHARD MALIK5, DEREK SPIELMAN6,ROGANLEE7, DEBORAH MARRIOTT3, JOHN HARKNESS3, JOHN ELLIS2 and DAMIEN STARK3 1 i3 Institute, University of Technology Sydney, Ultimo, NSW, Australia 2 School of Life Sciences, University of Technology Sydney, Ultimo, NSW, Australia 3 Department of Microbiology, SydPath, St.
    [Show full text]
  • Rat Lungworm Disease) in Hawaii
    Preliminary Guidelines for the Diagnosis and Treatment of Human Neuroangiostrongyliasis (Rat Lungworm Disease) in Hawaii Authors: Clinical Subcommittee* of the Hawaii Governor’s Joint Task Force on Rat Lungworm Disease *Members of the Clinical Subcommittee and their affiliations are listed at the end of the document. August 29, 2018 Preliminary Clinical Guidelines: Neuroangiostrongyliasis Table of Contents Introduction............................................................................................................ 2 Key Points............................................................................................................. 3 Life Cycle of Angiostrongylus cantonensis............................................................ 4 Illustrative Case..................................................................................................... 5 Diagnosis of Neuroangiostrongyliasis....................................................................6 Characteristic Symptoms.............................................................................. 6 Signs on Physical Examination..................................................................... 7 Exposure History........................................................................................... 7 The Importance of the Lumbar Puncture...................................................... 8 Real-Time Polymerase Chain Reaction Test for Confirming Cases............. 8 Reporting Neuroangiostrongyliasis to DOH.................................................
    [Show full text]
  • Lecture 5: Emerging Parasitic Helminths Part 2: Tissue Nematodes
    Readings-Nematodes • Ch. 11 (pp. 290, 291-93, 295 [box 11.1], 304 [box 11.2]) • Lecture 5: Emerging Parasitic Ch.14 (p. 375, 367 [table 14.1]) Helminths part 2: Tissue Nematodes Matt Tucker, M.S., MSPH [email protected] HSC4933 Emerging Infectious Diseases HSC4933. Emerging Infectious Diseases 2 Monsters Inside Me Learning Objectives • Toxocariasis, larva migrans (Toxocara canis, dog hookworm): • Understand how visceral larval migrans, cutaneous larval migrans, and ocular larval migrans can occur Background: • Know basic attributes of tissue nematodes and be able to distinguish http://animal.discovery.com/invertebrates/monsters-inside- these nematodes from each other and also from other types of me/toxocariasis-toxocara-roundworm/ nematodes • Understand life cycles of tissue nematodes, noting similarities and Videos: http://animal.discovery.com/videos/monsters-inside- significant difference me-toxocariasis.html • Know infective stages, various hosts involved in a particular cycle • Be familiar with diagnostic criteria, epidemiology, pathogenicity, http://animal.discovery.com/videos/monsters-inside-me- &treatment toxocara-parasite.html • Identify locations in world where certain parasites exist • Note drugs (always available) that are used to treat parasites • Describe factors of tissue nematodes that can make them emerging infectious diseases • Be familiar with Dracunculiasis and status of eradication HSC4933. Emerging Infectious Diseases 3 HSC4933. Emerging Infectious Diseases 4 Lecture 5: On the Menu Problems with other hookworms • Cutaneous larva migrans or Visceral Tissue Nematodes larva migrans • Hookworms of other animals • Cutaneous Larva Migrans frequently fail to penetrate the human dermis (and beyond). • Visceral Larva Migrans – Ancylostoma braziliense (most common- in Gulf Coast and tropics), • Gnathostoma spp. Ancylostoma caninum, Ancylostoma “creeping eruption” ceylanicum, • Trichinella spiralis • They migrate through the epidermis leaving typical tracks • Dracunculus medinensis • Eosinophilic enteritis-emerging problem in Australia HSC4933.
    [Show full text]
  • Hookworm-Related Cutaneous Larva Migrans with Exceptional Multiple Cutaneous Entries
    Open Access Case Report J Clin Investigat Dermatol June 2017 Volume 5, Issue 1 © All rights are reserved by Vega et al. Journal of Hookworm-related Cutaneous Clinical & Investigative Larva Migrans with Exceptional Dermatology Luis J. Borda1, Penelope J. Kallis1, Robert D. Griffith1, Alessio Giubellino1 and Jeong Hee Cho-Vega2* Multiple Cutaneous Entries 1Department of Dermatology and Cutaneous Surgery, University of Miami Miller School of Medicine, Miami, FL, United States Keywords: Hookworm-related Cutaneous Larva Migrans; 2Dermatopathology Division, Department of Pathology and Laboratory Hookworm; Serpiginous multiple tracks; Tropical area; Anti-parasite Medicine, Sylvester Comprehensive Cancer Center and University of agent Miami Miller School of Medicine, Miami, FL, United States Abstract *Address for Correspondence Jeong Hee Cho-Vega, Dermatopathology Division, Department of Hookworm-related Cutaneous Larva Migrans (HrCLM) is a pruritic Pathology and Laboratory Medicine Sylvester Comprehensive Cancer serpiginous cutaneous eruption caused by animal hookworms Center and University of Miami Miller School of Medicine 1120 NW commonly found in tropical and subtropical areas, especially the 14th Street, Holtz ET, Suite 2146 Miami, FL 33136, USA, Tel: (305)- Southeastern United States. We describe here a very exceptional 243-6433; Fax: (305)-243-1624; E-mail: [email protected] HrCLM case showing multiple larva entries/lesions in a 63-year- old white male living in Miami. Clinically he presented with multiple Submission: 25 May, 2017 pruritic erythematous serpiginous tracks on his left anterior leg, left Accepted: 15 June, 2017 calf, and right thigh. While skin biopsies failed to demonstrate larva Published: 22 June, 2017 itself, the overall histological features supported multiple larva tracks Copyright: © 2017 Borda LJ, et al.
    [Show full text]
  • Dr. Donald L. Price Center for Parasite Repository and Education College of Public Health, University of South Florida
    Dr. Donald L. Price Center For Parasite Repository and Education College of Public Health, University of South Florida PRESENTS Sources of Infective Stages and Modes of Transmission of Endoparasites Epidemiology is the branch of science that deals with the distribution and spread of disease. How diseases are transmitted, i.e. how they are passed from an infected individual to a susceptible one is a major consideration. Classifying and developing terminology for what takes place has been approached in a variety of ways usually related to specific disease entities such as viruses, bacteria, etc. The definitions that follow apply to those disease entities usually classified as endoparasites i.e. those parasites that reside in a body passage or tissue of the definitive host or in some cases the intermediate host. When the definition of terms for the “Source of Infection” or “Mode of Infection” relate to prevention and/or control of an endoparasitic disease, they should be clearly described. For the source of infection, the medium (water, soil, utensils, etc.) or the host organism (vector, or intermediate host) on which or in which the infective stage can be found should be precisely identified. For the mode of transmission, the precise circumstances and means by which the infective stage is able to come in contact with, enter, and initiate an infection in the host should be described. SOURCE OF INFECTION There are three quite distinct and importantly different kinds of sources of the infective stage of parasites: Contaminated Sources, Infested Sources, and Infected Sources. CONTAMINATE SOURCES Contaminated Source, in parasitology, implies something that has come in contact with raw feces and is thereby polluted with feces or organisms that were present in it.
    [Show full text]
  • A Parasite of Red Grouse (Lagopus Lagopus Scoticus)
    THE ECOLOGY AND PATHOLOGY OF TRICHOSTRONGYLUS TENUIS (NEMATODA), A PARASITE OF RED GROUSE (LAGOPUS LAGOPUS SCOTICUS) A thesis submitted to the University of Leeds in fulfilment for the requirements for the degree of Doctor of Philosophy By HAROLD WATSON (B.Sc. University of Newcastle-upon-Tyne) Department of Pure and Applied Biology, The University of Leeds FEBRUARY 198* The red grouse, Lagopus lagopus scoticus I ABSTRACT Trichostrongylus tenuis is a nematode that lives in the caeca of wild red grouse. It causes disease in red grouse and can cause fluctuations in grouse pop ulations. The aim of the work described in this thesis was to study aspects of the ecology of the infective-stage larvae of T.tenuis, and also certain aspects of the pathology and immunology of red grouse and chickens infected with this nematode. The survival of the infective-stage larvae of T.tenuis was found to decrease as temperature increased, at temperatures between 0-30 C? and larvae were susceptible to freezing and desiccation. The lipid reserves of the infective-stage larvae declined as temperature increased and this decline was correlated to a decline in infectivity in the domestic chicken. The occurrence of infective-stage larvae on heather tips at caecal dropping sites was monitored on a moor; most larvae were found during the summer months but very few larvae were recovered in the winter. The number of larvae recovered from the heather showed a good correlation with the actual worm burdens recorded in young grouse when related to food intake. Examination of the heather leaflets by scanning electron microscopy showed that each leaflet consists of a leaf roll and the infective-stage larvae of T.tenuis migrate into the humid microenvironment' provided by these leaf rolls.
    [Show full text]
  • Visceral and Cutaneous Larva Migrans PAUL C
    Visceral and Cutaneous Larva Migrans PAUL C. BEAVER, Ph.D. AMONG ANIMALS in general there is a In the development of our concepts of larva II. wide variety of parasitic infections in migrans there have been four major steps. The which larval stages migrate through and some¬ first, of course, was the discovery by Kirby- times later reside in the tissues of the host with¬ Smith and his associates some 30 years ago of out developing into fully mature adults. When nematode larvae in the skin of patients with such parasites are found in human hosts, the creeping eruption in Jacksonville, Fla. (6). infection may be referred to as larva migrans This was followed immediately by experi¬ although definition of this term is becoming mental proof by numerous workers that the increasingly difficult. The organisms impli¬ larvae of A. braziliense readily penetrate the cated in infections of this type include certain human skin and produce severe, typical creep¬ species of arthropods, flatworms, and nema¬ ing eruption. todes, but more especially the nematodes. From a practical point of view these demon¬ As generally used, the term larva migrans strations were perhaps too conclusive in that refers particularly to the migration of dog and they encouraged the impression that A. brazil¬ cat hookworm larvae in the human skin (cu¬ iense was the only cause of creeping eruption, taneous larva migrans or creeping eruption) and detracted from equally conclusive demon¬ and the migration of dog and cat ascarids in strations that other species of nematode larvae the viscera (visceral larva migrans). In a still have the ability to produce similarly the pro¬ more restricted sense, the terms cutaneous larva gressive linear lesions characteristic of creep¬ migrans and visceral larva migrans are some¬ ing eruption.
    [Show full text]