Food Borne Infections Organisms do not have to grow in the food before it is eaten: Organisms do not have to grow in the food before it is eaten:

Food Borne Infections Organisms do not have to grow in the food before it is eaten: Organisms do not have to grow in the food before it is eaten: Bacteria Typhoid Cholera TB Brucellosis Q-fever Anthrax Anthrax Viruses Hepatitis A Polio Anual incidence Rotavirus Enteroviruses Parasites Amoeboid disentry Toxoplasmosis Giardia lamblia Cryptosporidium Nematode Helminths Parasites Amoeboid disentry Toxoplasmosis Giardia lamblia Cryptosporidium Nematode Helminths

Typhoid fever –Diagnosis of typhoid fever  Blood cultures are positive during the first week and after the second week  Stool cultures and sometimes urine cultures are positive after the second week  The Widal test is a serological test for antibodies against Salmonella typhi.  10% of those infected become short term carriers and a smaller % become long-term carriers due to persistence of the bacteria in the gallbladder or urinary bladder.

Typhoid fever Salmonellosis

Other Bacteria TBBrucellosisQ-feverAnthrax

Incidence of TB Tuberculosis (TB) remains the leading cause of death worldwide from a single infectious disease agent. Indeed up to 1/2 of the world's population is infected with TB. Tuberculosis (TB) remains the leading cause of death worldwide from a single infectious disease agent. Indeed up to 1/2 of the world's population is infected with TB. The registered number of new cases of TB worldwide roughly correlates with economic conditions: The registered number of new cases of TB worldwide roughly correlates with economic conditions: the highest incidences are seen in those countries with the lowest gross national products. the highest incidences are seen in those countries with the lowest gross national products. WHO estimates that eight million people get TB every year, of whom 95% live in developing countries. WHO estimates that eight million people get TB every year, of whom 95% live in developing countries. An estimated 2 million people die from TB every year. An estimated 2 million people die from TB every year.

Mortality It is estimated that between 2000 and 2020, nearly one billion people will be newly infected, 200 million people will get sick, and 35 million will die from TB It is estimated that between 2000 and 2020, nearly one billion people will be newly infected, 200 million people will get sick, and 35 million will die from TB After a century of decline TB is increasing and there are strains emerging which are resistant to antibiotics. After a century of decline TB is increasing and there are strains emerging which are resistant to antibiotics. This excess of cases is attributable to the changes in the social structure in cities, the human immunodeficiency virus epidemic, and failure of most cities to improve public health programs, and the economic cost of treating. This excess of cases is attributable to the changes in the social structure in cities, the human immunodeficiency virus epidemic, and failure of most cities to improve public health programs, and the economic cost of treating.

HISTORY TB is an ancient infectious disease caused by Mycobacterium tuberculosis. TB is an ancient infectious disease caused by Mycobacterium tuberculosis. It has been known since 1000 B.C., It has been known since 1000 B.C., Since TB is a disease of respiratory transmission, optimal conditions for transmission include: Since TB is a disease of respiratory transmission, optimal conditions for transmission include: – overcrowding – poor personal hygiene – poor public hygiene

1/2 of the world's population is infected With the increased incidence of AIDS, TB has become more a problem in the U.S., and the world. With the increased incidence of AIDS, TB has become more a problem in the U.S., and the world. It is currently estimated that 1/2 of the world's population (3.1 billion) is infected with Mycobacterium tuberculosis. It is currently estimated that 1/2 of the world's population (3.1 billion) is infected with Mycobacterium tuberculosis. Mycobacterium avium complex is associated with AIDS related TB. Mycobacterium avium complex is associated with AIDS related TB.

Center for Food Security and Public Health Iowa State University Brucella spp. Gram negative, coccobacilli bacteria Gram negative, coccobacilli bacteria Facultative, intracellular organism Facultative, intracellular organism Environmental persistence Environmental persistence –Temp, pH, humidity –Frozen and aborted materials Multiple species Multiple species

Center for Food Security and Public Health Iowa State University SpeciesBiovar/ Serovar Natural HostHuman Pathogen B. abortus1-6, 9cattleyes B.melitensis1-3goats, sheepyes B. suis1, 3swineyes 2haresyes 4reindeer, caribou yes 5rodentsyes B. canisnonedogs, other canids yes B. ovisnonesheepno B. neotomaenoneDesert wood rat no B. marismarine mammals ?

Center for Food Security and Public Health Iowa State University The Many Names of Brucellosis Human Disease Malta Fever Malta Fever Undulant Fever Undulant Fever Mediterranean Fever Mediterranean Fever Rock Fever of Gibraltar Rock Fever of Gibraltar Gastric Fever Gastric Fever Animal Disease Bang’s Disease Bang’s Disease Enzootic Abortion Enzootic Abortion Epizootic Abortion Epizootic Abortion Slinking of Calves Slinking of Calves Ram Epididymitis Ram Epididymitis Contagious Abortion Contagious Abortion

Center for Food Security and Public Health Iowa State University Sir David Bruce ( ) British Army physician and microbiologist who discovered Micrococcus melitensis Professor FEG Cox. The Wellcome Trust, Illustrated History of Tropical Diseases

Center for Food Security and Public Health Iowa State University Transmission to Humans Conjunctiva or broken skin contacting infected tissues Conjunctiva or broken skin contacting infected tissues –Blood, urine, vaginal discharges, aborted fetuses, placentas Ingestion Ingestion –Raw milk & unpasteurized dairy products –Rarely through undercooked meat

Center for Food Security and Public Health Iowa State University Transmission to Humans Inhalation of infectious aerosols Inhalation of infectious aerosols –Pens, stables, slaughter houses Inoculation with vaccines Inoculation with vaccines –B. abortus strain 19, RB-51 –B. melitensis Rev-1 –Conjunctival splashes, injection Person-to-person transmission is very rare Person-to-person transmission is very rare Incubation varies Incubation varies –7-21 days to several months

Center for Food Security and Public Health Iowa State University

B. melitensis Latin America, Middle East, Mediterranean, eastern Europe, Asia, and parts of Africa Latin America, Middle East, Mediterranean, eastern Europe, Asia, and parts of Africa Accounts for most human cases Accounts for most human cases –In the Mediterranean and Middle East Up to 78 cases/100,000 people/year Up to 78 cases/100,000 people/year Arabic Peninsula 20% seroprevalence Arabic Peninsula 20% seroprevalence Recent emergence in cattle on Middle Eastern intensive dairy farms Recent emergence in cattle on Middle Eastern intensive dairy farms

Center for Food Security and Public Health Iowa State University B. abortus Worldwide Worldwide Some countries have eradicated Some countries have eradicated Notifiable disease in many countries Notifiable disease in many countries –Poor surveillance and reporting due to lack of recognition –Fever of Unknown Origin (FUO)

Center for Food Security and Public Health Iowa State University B. suis Biovars 1 and 3 Biovars 1 and 3 –Worldwide problems where swine are raised Free Free –United Kingdom, Canada Eradicated Eradicated –Holland, Denmark Low Incidence Low Incidence –Middle East, North Africa

Center for Food Security and Public Health Iowa State University B. canis Poorly understood Poorly understood 1-19% prevalence in United States 1-19% prevalence in United States Rarely causes disease in humans Rarely causes disease in humans

Center for Food Security and Public Health Iowa State University Brucellosis in U.S.: Year Reported Cases

Center for Food Security and Public Health Iowa State University Brucellosis United States United States –Approximately 100 cases per year –Less than 0.5 cases/100,000 people –Mostly California, Florida, Texas, Virginia –Many cases associated with consumption of foreign cheeses

Center for Food Security and Public Health Iowa State University Prognosis May last days, months or years May last days, months or years Recovery is common Recovery is common Disability is often pronounced Disability is often pronounced About 5% of treated cases relapse About 5% of treated cases relapse Failure to complete the treatment regimen Failure to complete the treatment regimen Sequestered infection requiring surgical drainage Sequestered infection requiring surgical drainage Case-fatality rate: <2% ( untreated) Case-fatality rate: <2% ( untreated) –Endocarditis caused by B. melitensis

Center for Food Security and Public Health Iowa State University Human Disease Neurological Neurological –Depression, mental fatigue Cardiovascular Cardiovascular –Endocarditis resulting in death Chronic brucellosis is hard to define Chronic brucellosis is hard to define –Length, type and response to treatment variable –Localized infection Blood donations of infected should not be accepted Blood donations of infected should not be accepted

Q Fever Q Fever

Center for Food Security and Public Health Iowa State University The Organism Coxiella burnetii Coxiella burnetii –Rickettsial agent –Obligate intracellular parasite –Stable and resistant –Killed by pasteurization –Two antigenic phases Phase 1: virulent Phase 1: virulent Phase 2: less pathogenic Phase 2: less pathogenic

Center for Food Security and Public Health Iowa State University History –1st described in Queensland, Australia –Found in ticks in Montana Outbreaks Outbreaks –Among military troops When present in areas with infected animals When present in areas with infected animals –Cities and towns Downwind from farms Downwind from farms By roads traveled by animals By roads traveled by animals

Center for Food Security and Public Health Iowa State University Transmission Aerosol Aerosol –Parturient fluids 10 9 bacteria per gram of placenta 10 9 bacteria per gram of placenta –Urine, feces, milk –Wind-borne Direct contact Direct contact Fomites Fomites Ingestion Ingestion Arthropods (ticks) Arthropods (ticks)

Center for Food Security and Public Health Iowa State University Transmission Person-to-person (rare) Person-to-person (rare) –Transplacental (congenital) –Blood transfusions –Bone marrow transplants –Intradermal inoculation –Possibly sexually transmitted

Center for Food Security and Public Health Iowa State University Epidemiology Worldwide Worldwide –Except New Zealand Reservoirs Reservoirs –Domestic animals Sheep, cattle, goats Sheep, cattle, goats Dogs, cats Dogs, cats –Birds –Reptiles –Wildlife

Center for Food Security and Public Health Iowa State University Epidemiology Occupational and environmental hazards Occupational and environmental hazards –Farmers, producers –Veterinarians and technicians –Meat processors, abattoir –Laboratory workers

Center for Food Security and Public Health Iowa State University Human Disease Incubation: 2-5 weeks Incubation: 2-5 weeks One organism may cause disease One organism may cause disease Humans are dead-end hosts Humans are dead-end hosts –Usually show clinical signs of illness Disease Disease –Asymptomatic (50%) –Acute –Chronic

Center for Food Security and Public Health Iowa State University Acute Infection Flu-like, self limiting Flu-like, self limiting Atypical pneumonia (30-50%) Atypical pneumonia (30-50%) –Non-productive cough, chest pain –Acute respiratory distress possible Hepatitis Hepatitis Skin rash (10%) Skin rash (10%) Other signs (< 1%) Other signs (< 1%) –Myocarditis, pericarditis, meningoencephalitis Death: 1-2% Death: 1-2%

Center for Food Security and Public Health Iowa State University Chronic Disease 1-5% of those infected 1-5% of those infected –Prior heart disease, pregnant women, immunocompromised Endocarditis Endocarditis Other Other –Osteomyelitis –Granulomatous hepatitis –Cirrhosis 50% relapse rate after antibiotic therapy 50% relapse rate after antibiotic therapy

Center for Food Security and Public Health Iowa State University Risk to Pregnant Women Most asymptomatic Most asymptomatic Transplacental transmission Transplacental transmission Reported complications Reported complications –In-utero death –Premature birth –Low birth weight –Placentitis –Thrombocytopenia

Center for Food Security and Public Health Iowa State University Prognosis Overall case-fatality rate < % Overall case-fatality rate < % 50% cases self-limiting 50% cases self-limiting Only 2% develop severe disease Only 2% develop severe disease Active chronic disease Active chronic disease –Usually fatal if left untreated –Fatality for endocarditis: 35-55% –50-60% need valve replacement

Center for Food Security and Public Health Iowa State University Case Male dairy farmer Male dairy farmer –Age 46 –Sudden onset Fever, chills, cough Fever, chills, cough Weight loss Weight loss –Initially thought it was influenza –Symptoms persisted for 2 weeks –Presented to emergency room Again influenza was the diagnosis Again influenza was the diagnosis

Center for Food Security and Public Health Iowa State University Large Animal Case Referral to infectious disease specialist Referral to infectious disease specialist –Tested positive for Q fever –Antibiotics for 5 days –Resolved in 2 weeks Epidemiology Epidemiology –No recent calvings on his farm –Two beef cattle herds across the road 2 out of 14 tested positive for Q fever 2 out of 14 tested positive for Q fever

Center for Food Security and Public Health Iowa State University Small Animal Case 1985, Nova Scotia, Canada 1985, Nova Scotia, Canada –33 cases of Q fever 25 were exposed to cat 25 were exposed to cat 17 developed cough 17 developed cough 14 developed pneumonia 14 developed pneumonia –Most common symptoms Fever, sweats, chills, fatigue, myalgia, headache Fever, sweats, chills, fatigue, myalgia, headache –Cat tested positive for C. burnetii 1:152 to phase I antigen 1:152 to phase I antigen 1:1024 to phase II antigen 1:1024 to phase II antigen

Center for Food Security and Public Health Iowa State University Animal Disease Sheep, cattle, goats Sheep, cattle, goats –Usually asymptomatic –Reproductive failure Abortions, stillbirths Abortions, stillbirths Retained placenta Retained placenta Infertility Infertility Weak newborns Weak newborns Low birth weights Low birth weights Mastitis in dairy cattle Mastitis in dairy cattle –Carrier state

Center for Food Security and Public Health Iowa State University Animal Disease Other animal species Other animal species –Dogs, cats, horses, pigs, camels, buffalo, pigeons, other fowl –Asymptomatic –Reproductive failure Laboratory Animals Laboratory Animals –Rats, rabbits, guinea pigs, hamsters –Varies from asymptomatic to fever, granulomas, or death

Center for Food Security and Public Health Iowa State University Morbidity and Mortality Prevalence unknown Prevalence unknown –Endemic areas 18-55% of sheep with antibodies 18-55% of sheep with antibodies 82% of dairy cattle 82% of dairy cattle Morbidity in sheep: 5-50% Morbidity in sheep: 5-50%

Center for Food Security and Public Health Iowa State University Prevention and Control Pasteurization Pasteurization Vaccination Vaccination –Human and animal –Not available in U.S. Eradication not practical Eradication not practical –Too many reservoirs –Constant exposure –Stability of agent in environment

Center for Food Security and Public Health Iowa State University Prevention and Control Education Education –Sources of infection Good husbandry Good husbandry –Disposal of birth products (incinerate) Lamb indoors in separate facilities Lamb indoors in separate facilities –Disinfection 0.05% chlorine 0.05% chlorine 1:100 Lysol 1:100 Lysol Isolate new animals Isolate new animals

Anthrax How heat resistant is Bacillus anthracis (B. Anthracis)? Spores Moist heat resistance D value at 90ºC (194ºF) minutes D value at 95ºC (203ºF) minutes Not That much killed with thorough cooking

Epidemiology of Anthrax in Animal and Human Hosts

Clinical Presentation of Anthrax Gastrointestinal (Ingestion) Anthrax  Virtually 100% fatal  Abdominal pain  Hemorrhagic ascites  Paracentesis fluid may reveal gram-positive rods

Treatment & Prophylaxis  Treatment Penicillin is drug of choice Erythromycin, chloramphenicol acceptable alternatives Doxycycline now commonly recognized as prophylactic  Vaccine (controversial)  Laboratory workers  Employees of mills handling goat hair  Active duty military members  Potentially entire populace of U.S. for herd immunity