Zoonotic Diseases Training Package

Zoonotic Diseases Training Package Zoonotic diseases Session Title 03/08/2010 Bangkok

Zoonotic diseases: Session # LEARNING OBJECTIVES • At the end of this module the participant should be able to: • Define terms (zoonosis, emerging disease….) • Classify zoonoses based on host, pathogen, transmission • Understand the importance of zoonoses to One Health • Discuss emerging and re-emerging zoonoses • Understand reasons for disease emergence and re-emergence • Describe selected zoonoses important in their region • Understand the principles of zoonosis prevention and control

ZOONOTIC DISEASE RESOURCES This presentation gives an overview of the importance of zoonotic diseases to human and animal health, their ecology and epidemiology, and measures used for their prevention and control. Examples used can be varied by trainers according to the relevance of zoonoses in their regions Further information on zoonotic diseases, e.g. statistical data, can be found in the following websites: http://www.oie.int http://www.who.int http://www.fao.org http://www.cdc.gov

Zoonotic diseases: Session # DEFINITION Zoonoses are infections which are naturally transmitted between vertebrate animals and people Derived from the Greek ZOON (animals) and NOSES (diseases) People, animals, birds, arthropods and the inanimate environment are all involved in cycles of zoonotic infection

Zoonotic diseases: Session # ZOONOSES DEFINITIONS Anthropozoonoses:Zoonoses where the main reservoir of infection is non-human vertebrate animals Most zoonoses are of this type e.g. bovine tuberculosis, rabies, leptospirosis Zooanthroponoses: Diseases that mainly affect people, which may be transmitted to animals, which then act as temporary reservoirs of infection Examples are Mycobacterium tuberculosis in dogs, infectious hepatitis in apes, H1N1 pandemic influenza in pigs

Zoonotic diseases: Session # ZOONOSES DEFINITIONS Vector: an organism, often an invertebrate arthropod, that transmits a pathogen from reservoir to host, e.g. mosquito and JEV Reservoir: a long-term host of a pathogen, e.g. mouse and hantavirus (in this instance the host can also be the vector as the virus is transmitted via mouse excreta) Fomite: an inanimate object that can transmit an infectious agent, e.g. medical equipment and Ebola virus

Zoonotic diseases: Session # Agent Environment Host Zoonotic diseases are multifactorial and their occurrence is affected by interactions between the host, the agent and the environment

Zoonotic diseases: Session # ZOONOSES • Approximately 1500 infectious diseases are recognized in humans • Of these 60% are due to zoonoses • however • 75% of recently emerging infectious diseases (EID) have been caused by zoonotic pathogens

Zoonotic diseases: Session # EMERGING DISEASES • WHO/FAO/OIE definition • “An emerging zoonosis is a zoonosis that is newly recognised or newly evolved, or that has occurred previously but shows an increase in incidence or expansion in geographical, host or vector range”

Zoonotic diseases: Session # THEREFORE EMERGING INFECTIOUS DISEASES CAN BE… A known agent appearing in a new geographic area A known agent or its close relative occurring in a hitherto unsusceptible species A previously unknown agent detected for the first time Wild animal reservoirs represent a more frequent source of ‘new’ agents

Zoonotic diseases: Session # REASONS FOR DISEASE EMERGENCE Factors explaining emergence are complex, e.g. genetic drift and shift (influenza) and modification of the immunological status of populations (change in susceptibility of populations; vaccination) Social and ecological conditions influencing population growth and movement, food habits and the environment may be more important Influence of changing environment on reservoirs, vectors and victim species Population expansion and urbanisation

Zoonotic diseases: Session # REASONS FOR ZOONOSIS EMERGENCE Increasing contact between human populations, wild and domestic animals expose people to zoonotic agents by direct or indirect contact Growing population of drug and alcohol impaired and immuno-suppressed people worldwide are at higher risk of zoonoses Many of the common, life threatening infections associated with HIV are zoonoses

Zoonotic diseases: Session # RECENT EMERGING ZOONOSES Some diseases associated with changing farming practices, trade and consumer habits (SalmonellaEnteritidis, E. coli O:157) Live animal trade introduced screwworm to Libya, Ebola-like virus in monkeys in quarantine in the USA and monkeypox to the USA Epidemics of BSEdue to many factors including use of ruminant protein as feed Adaptation of avian influenza strain H5N1 to people is a current cause of concern

Zoonotic diseases: Session # VULNERABLE AREAS AND PEOPLE Poverty affected communities People with low population immunity (HIV, age) Areas of altered climate and increased vector range Areas of political unrest and population migration Natural disaster affected areas Areas of deforestation and altered biodiversity People affected by global trade and travel

IMPACT OF ZOONOTIC DISEASES • Human health (death and disability) • Animal health (death and disability) • Economic losses due to livestock culling, deaths and decreased production • Cost of control programs • Trade implications • Indirect effects on people due to psychological trauma (loss of pets, culling, loss of valuable animals) and impact on cultural traditions, etc.

Zoonotic diseases: Session # CLASSIFICATION OF ZOONOSES Type of infectious agent (bacteria, fungus, virus, parasite) Mode of transmission Type of reservoir host

Zoonotic diseases: Session # MODE OF TRANSMISSION Transmission of infections may be direct, indirect via arthropod vectors, or from environmental foci • Direct zoonosis • Cyclozoonosis • Metazoonosis • Saprozoonosis • Combination (e.g. direct &metazoonosis) www.who.int

Zoonotic diseases: Session # MODES OF TRANSMISSION Metazoonosis (e.g. Rift valley fever, JE) Direct and indirect Cyclozoonosis Mosquito eggs • Leptospira in animal urine Taenia solium Mosquitoes Livestock • Contaminated water Pigs Humans Humans • Leptospirosis in humans

SAPROZOONOSIS Diseases of vertebrate animals which can affect people, the infectious agents of which are either capable of replicating in inanimate sites, or require an inanimate environment for the development of an infectious stage of their life cycle eg. histoplasmosis, Toxocara canis, certain food-borne diseases

Zoonotic diseases: Session # TYPE OF RESERVOIR HOST Most zoonoses have more than one reservoir species and can be transmitted to people from many different animal species e.g. salmonellosis, rabies, leptospirosis, Nipah virus however Zoonoses can be referred to by their association with a particular species e.g. zoonoses of cattle, zoonoses of bats

Zoonotic diseases: Session # SUMMARY OF SELECTED ZOONOSES BACTERIAL Anthrax Brucellosis Plague Leptospirosis

Zoonotic diseases: Session # ANTHRAX Bacillus anthracis, Gram-positive sporing rod Worldwide, Russia, Asia, Africa, South America ‘Hot spots’ in warm humid areas where natural cycles exist All mammals susceptible but pigs, dogs and cats relatively resistant Birds can disseminate spores, chickens resistant, some birds susceptible

Zoonotic diseases: Session # ANTHRAX Organisms enter via - Skin (cutaneous anthrax) Lungs (pulmonary anthrax, woolsorter’s disease) Gastrointestinal tract Clinical signs include - Eschar in humans (black necrotic skin lesion) Sudden death in ungulates, blood from the nose and other body orifices; septicemia in humans

Zoonotic diseases: Session # ANTHRAX http://www.extension.org/pages/Anthrax

Zoonotic diseases: Session # ANTHRAX TRANSMISSION AND HUMAN DISEASE Animal by-products, wool, hides, bone meal, meat, imported curios etc. involved in spore transmission Cutaneous infections most common, inhalation, intestinal, person-to-person rare 1-7d incubation, spores germinate, papules, vesicles, edema, fatal septicemia Agricultural workers, vets, rural communities, travellers etc. Bioterrorism agent – US postal workers affected

Zoonotic diseases: Session # BRUCELLOSIS B. melitensis - goats, sheep (cattle, camels, dogs, people). Asia, Africa, Mediterranean and South America B. abortus – bovines, (dogs, people). Worldwide B. suis – pigs (people). South America, Southeast Asia, United States, Australia B. canis - domestic and wild carnivores (people). Many countries worldwide Primary hosts susceptible, disease in other hosts varies in severity

Zoonotic diseases: Session # BRUCELLOSIS Vegetative endocarditis in a person, caused by brucellosis UfukYetkin 2007 Brucellosis transmitted in milk and causing orchitis WHO and FAO

Zoonotic diseases: Session # BRUCELLOSIS Chronic, long term infections, rarely fatal Ingestion, venereal Concentration of animals during calving, during milking, commoner in dairy cattle Organism persists in cool temperatures Abortion depends on stage of gestation Carnivores, birds aid in spread of fomites Flu-like symptoms in humans, including muscle and joint pains, fever, cough, (rarely endocarditis)

Case study for discussion of Brucellosis in India Small Ruminant Research, Volume 14, Issue 2, Pages 161-165 (August 1994), Occurrence of abortions and seroprevalence of brucellosis in goats and sheep, S.V. Singha, N. Singha, M.P. Singhb, H. Shankara, D.D. Lalwanib Abstract Occurrence of abortions, still births and seroprevalence of brucellosis were studied in native, unvaccinated and organised flocks of goats (Barbari, Jamunapari, Sirohi, Kutchi, Jakharana, and Marwari) and sheep (Muzaffaragri) with abortion problems during the period from 1985 to 1990. In 6 years, 8.4% lambs and 13.4% kids were lost due to abortions and still births. Incidence of abortions were recorded as 12.3% and 6.8% and still births 1.0% and 1.6% in goats and sheep, respectively. Serologically, 0.6% goats and 3.6% sheep were found to be positive for brucellosis by standard tube agglutination test (SAT). The regular screening of the flocks for Brucellosis and elimination of positive cases partially helped to lower the incidence of Brucellosis in these flocks. http://www.smallruminantresearch.com/article/0921-4488(94)90106-6/abstract

Zoonotic diseases: Session # PLAGUE Yersiniapestis, Gram-negative rod Rodent disease transmitted by fleas (carried by 30-40 species of rodent, 1500 types of fleas) Complex sylvatic (wild) cycle Rodents act as reservoir and amplifying host Humans accidental hosts Carnivores infected by ingestion

Zoonotic diseases: Session # PLAGUE Capture of rats in Indochina to prevent plague www.asnom.org/ en/423_peste.html

Zoonotic diseases: Session # PLAGUE Disease of poor living conditions, rats and fleas Spread by fleas, handling plague material Human-human transmission (pneumonic plague) Buboes (cutaneous lymphadenitis), septicemia, pneumonia Buboes in groin CDC.gov

Bubonic plague in Mongolia, October 4, 2004, a case study for discussion There have been several cases of Bubonic Plague (also know as Black Plague, Black Death, Pestilence) in Mongolia recently, resulting in two deaths so far this year. According to D. Tserennorov, vice director for the Center for Infectious Diseases with Natural Foci, two people in the DarbiSoum of Gobi-Altai Aimag were infected. One of the victims died on September 18th and 62 others who have had, or may have had direct contact with the man are now quarantined. On September 19, 2004, a woman from Ilbenkh in the BayankhongorAimag was infected after skinning a marmot. Seventy people who have had, or may have had direct contact with her have not shown any symptoms of the disease so far. The Mongolian government has declared a state of emergency in these, and surrounding areas. The State Disaster Protection Agency warns people not to hunt or eat marmots. The Plague is transmitted via several methods. They include: Bites from rodent fleas Exposure to humans with the pneumonic form of the plague Handling infected carcasses Scratches or bites from infected domestic cats Exposure to aerosols (small air-borne particles breathed in from infected animals and humans) (http://mongolia.usembassy.gov/tw_10042004.html)

Zoonotic diseases: Session # LEPTOSPIROSIS Disease described in dogs in 1850 Weil’s disease described in people in 1880 Organism first isolated in Japan in 1914 - now 7 pathogenic species & over 200 serovars recognised By 1940 leptospirosis established as a major animal and public health problem Occupational disease Associated with natural disasters e.g. floods

Zoonotic diseases: Session # LEPTOSPIROSIS Direct anthropozoonosis (or via fomites) Host-adapted serovars in maintenance hosts which act as reservoirs, inapparent infections in these animals Herbivores long shedding, carnivores short Severe infections in secondary hosts (non-reservoir) All serovars capable of infecting any animal. Dominant serovars vary between regions, e.g. serovarAutumnalis in Thailand Moist environmental conditions favor survival outside hosts, endemic zones worldwide

Zoonotic diseases: Session # LEPTOSPIROSIS • Occupational hazard: in rice-growing communities, e.g. July 2008 578 infections, 15 dead in Thailand. Cattle, pigs and rodents possible reservoirs, via urine contaminating paddy fields. • Recreational risks: Sabah, Malaysia, 2000 Eco-challenge race – 50 out of 80 athletes contracted leptospirosis • Natural disasters: Typhoon Ketsana, Manila, Philippines in 2009, approx 170 deaths, hundreds infected, 1 million doses of prophylactic doxycycline, hospitals coped poorly

Zoonotic diseases: Session # LEPTOSPIRA AND HUMAN DISEASE • Contact with infected urine or contaminated water, seasonal spring/summer in cooler climates • Entry via intact mucous membranes, aerosols or skin abrasions, occupational disease • Anicteric (without jaundice) disease iscommon form in Australia, vague symptoms, flu-like, fever, headache, myalgia • Icteric disease very severe, more common in Asia, rodent hosts of serovars • Person-person transmission rare, dead-end hosts

LEPTOSPIROSIS IN KAMPHAENG PHET, THAILAND (case study to discuss) Am. J. Trop. Med. Hyg., 76(1), 2007, pp. 135–8 (www.ajtmh.org/cgi/reprint/76/1/135.pdf) Kamphaeng Phe Province (gray area)

Zoonotic diseases: Session # SUMMARY OF SELECTED ZOONOSES VIRAL LYSSAVIRUSES (RABIES) FLAVIVIRUSES (JAPANESE ENCEPHALITIS) NIPAH VIRUS INFLUENZA VIRUSES SARS

Zoonotic diseases: Session # LYSSAVIRUSES Family Rhabdoviridae, Genus Lyssavirus 1. Classical rabies 2. Lagos bat virus 3. Mokola virus 4. Duvenhage virus 5. European bat virus 1 6. European bat virus 2 7. PteropusLyssavirus (Australian bat lyssavirus)

Zoonotic diseases: Session # CLASSICAL RABIES Virulent rabies spread from Europe to Asia and other regions by infected dogs; many countries worldwide Dogs most important domestic hosts, cats, cattle and other domestic animals commonly involved Many wild reservoirs which differ between regions; principally canids (foxes, wolves, jackals) but also mongooses, skunks, raccoons, bats Some countries free by eradication e.g. UK Direct zoonosis – bites, mucosal exposure, other routes e.g. corneal transplants

Zoonotic diseases: Session # PATHOGENESIS OF RABIES infection of neurons Furious spread to neurons in ganglia or spinal cord, spread to brain death Dumb clinical signs 2-3 days spread to salivary glands, skin Virus shedding

Zoonotic diseases: Session # RABIES • Transmission to people mainly by bites via virus in saliva, aerosol transmission extremely rare • Aerosol transmission, found in bat saliva in zoos • Incubation 4 days – 6 years, depends on bite site • Clinical rabies invariably fatal • Prodromal period (behavioural changes) • Excitative period (hydrophobia, aerophobia in people); a dog in India bit 40 people/9 dogs in 4 hours • Paralytic period (dumb rabies)

Zoonotic diseases: Session # BAT-ASSOCIATED LYSSAVIRUSES Haematophagous (blood sucking), insectivorous and frugivorous (fruit eating) bats all can transmit rabies and related viruses Spread by bites and scratches from infected animals Neurological signs in bats and humans similar to classic rabies Cases reported in Australia, Europe and USA Vampire bats are reservoirs of classical rabies, South America

Zoonotic diseases: Session # OTHER BAT-ASSOCIATED ZOONOSES Pteropus spp. fruit bats are known reservoirs of a number of other zoonotic viruses worldwide, including Nipah virus, Hendra virus, Ebola and SARS

HENIPAVIRUSES The genus Henipavirus is a newly described genus including 2 newly emerged viral agents, Nipah virus and Hendra virus, first identified in Malaysia and Australia respectively

Zoonotic diseases: Session # HENDRA VIRUS Named for a suburb in Brisbane, infected 23 horses and 3 people in Queensland in 1994 Survey identified infected fruit bats; postulated that bat to horse contact had occurred due to habitat changes Occupational hazard, with infections in veterinarians and horse-associated workers Disease has killed four of the seven people infected since its discovery

Zoonotic diseases: Session # NIPAH VIRUS Malaysia and Singapore 1998/9 Mild disease in pigs Encephalitis & respiratory infections in people, cats and dogs in contact with pigs Malaysia 257 human cases/105 deaths; Singapore 11/1 1.1m pigs slaughtered Pteropus spp. bats implicated, closelyrelated to Hendra virus Seasonal, may be linked to bats ‘birthing’ www.abc.net.au, AFP: Raul Arboleda

Zoonotic diseases: Session # NIPAH VIRUS Eight outbreaks in Bangladesh and India since 1998 have been associated with bats contaminating fresh date palm juice, collected overnight to make palm sugar (255 cases/136 deaths) Bats have been seen to drink from the containers used to collect the raw juice, contamination Humans commonly drink the raw juice in the villages associated with the industry Fruit bats are ‘anthropophilic’ in India and Bangladesh (live in close proximity to humans)

Case study of Nipah outbreak in Bangladesh The Daily Star, Wednesday, January 20, 2010 Nipah virus claims 3 in Faridpur Three members of a family under Bhanga upazila of the district died within a week after they contracted encephalitis caused by Nipah virus. Faridpur Civil Surgeon Dr Bashirul Islam stating the report of Institute of Epidemiology, Disease Control and Research and National Influenza Centre, Bangladesh (IEDCR) yesterday confirmed the death of the three from Nipah virus that spread from the swab of bats. The dead were identified as Karuna Biswas, 30, of Algi village under Bhanga upazila, her daughter Dipti Biswas, 11, and nephew Sanu Biswas, 10. All the three drank raw date juice before they contracted the disease, the family sources added. On information, a special team of the International Centre for Diarrhoeal Disease Research, Bangladesh (ICDDRB) led by Faridpur Civil Surgeon Dr Bashirul Islam visited the village on Saturday and collected the sample of blood of the three. After examining the blood sample the IEDCR authorities identified the disease as encephalitis, says Dr Bashirul, adding that the disease originated from raw date juice contaminated by the swab of bats. All people of the district were advised to collect date juice covering the mouth of jars with nets so that bats cannot sink their tongues into the jar, he said. While talking to The Daily Star, Director of the IEDCR Prof Mahmudur Rahman said this is the first incidence of death due to Nipah virus this year. Last year encephalitis broke out in Rajbari and Manikganj. But very few people died because of the government's early detection programme. Under the programme a regular surveillance has been in place in Faridpur, Rajbari and Madaripur since 2006. The major outbreak took place in Faridpur in 2004 causing death to at least 17 people of Laxmipur village under Sadar upazila. www.thedailystar.net/newDesign/news-details.php?nid=122688

Zoonotic Diseases Training Package