Reservoir and Transmission

Leishmaniasis

Reservoirs include infected humans, domestic dogs, and various wild animals. It is usually transmitted via bite of an infected sandfly (Leishmania tropica). Transmission is via blood transfusion and person to person contact.

Scabies

The reservoir for scabies is humans. Scabies is highly contagious and spreads primarily through direct skin-to-skin contact.

Amebic Eye Infection

Amebas entered the eye with ameba-contaminated water. Infections have occurred primarily to people who wear contact lenses and use non-sterile solution, or infected by ameba contaminated water.

Toxoplasmosis

Definitive host is the cats and other felines that acquired the infection by eating rodents and birds. Intermediate hosts are rodents, birds, sheep, goats, swine, and cattle. Humans are usually infected by ingesting the cyst form of the parasites in uncooked meat or the oocyst from the feces of the cats.

Amebiasis

Reservoirs include asymptomatic and symptomatic humans and fecally contaminated food or water. Transmission occurs via ingestion of fecally contaminated food or water, by flies transporting cyst from feces to food, fecally soiled hands of infected food handlers, and anal intercourse.

Balantidiasis

Reservoirs include pig, and anything that might be contaminated with pig feces. Transmission is often via ingestion of Balantidium coli cysts in fecally contaminated food or water.

Cryptosporidiosis

Reservoirs include humans, cattle, and other domestic animals. Transmission is via fecal oral transmission or ingestion of contaminated water or food.

Cyclosporiasis

Reservoirs include fecally contaminated water. Transmission is primarily waterborne.

Giardiasis

Reservoirs include infected humans, beavers, and other wild and domestic animals that consumed water containing Giardia cysts. Transmission occurs via fecal oral route transmission.

Trichomoniasis

Reservoirs are infected humans. Transmission is via vaginal and urethral discharge of an infected person during sexual intercourse.

Primary Amebic Meningoencephalitis

Reservoirs are water and soil. The amebas usually enter at the nasal passage of a person when swimming in ameba-contaminated waters. After colonizing the nasal cavity, it will travel up to the brain and meninges through olfactory nerves.

African Trypanosomiasis (African Sleeping Sickness)

Reservoirs are infected humans of Trypanosoma brucei, gambiense. Primary reservoirs of Trypanosoma brucei, rhodesiense are the wild animals and domestic cattles. Tsetse flies serve as a paratenic host that carries the Trypanosomes. It matures in tsetse fly and infests humans by injecting it into the human bloodstream.

American Trypanosomiasis (Chagas' Disease)

Reservoirs are infected human, domestic animals, and wild animals. Kissing bug or reduviid bug act as a vector as it gets its blood meal with an infected animal or human. The bug feces will infect humans when the feces has been rubbed into the wounds or eyes. Transmission is via blood transfusion, and organ transplantation occurs.

Babesiosis

Rodents serve as reservoirs for Babesia microti, and cattles serve as reservoirs for Babesia divergens. Transmission occurs via tick bite and rarely by blood transfusion.

Malaria

Reservoirs are infected humans and infected mosquitoes. Most human infections occur as a result of an injection of sporozoites into the bloodstream by female Anopheles mosquitoes. Transmission may be using blood-contaminated needles and syringes.

Tinea barbae

Infection in the beard and mustache.

Tinea capitis

Scalps, eyebrows, and eyelashes.

Tinea corporis

Face, trunk, and major limbs.

Tinea cruris

Groin, perineal, and perianal areas.

Tinea pedis (Athlete's Foot)

Soles and between toes.

Tinea unguium

Nails.

Dermatophytosis

Infected human, soil, and animals as reservoirs. Transmission is via direct or indirect contact with the lesions of humans or animals, contact with fomites that have been infected.

Coccidioidomycosis

Soils as reservoirs of arthrospores. Transmission is via inhalation of arthrospores. Person to person is not occurring.

Histoplasmosis

Reservoirs include warm, moist soil, and bird droppings. Transmission via inhalation of conidia.

Pneumocystis Carinii Pneumonia

Infected humans as reservoirs. Transmission is unknown.

Zygomycosis

Humans are commonly infected via inhalation of spores but ingestion and direct inoculation may cause Zygomycosis.

Thrush

Infected humans as reservoirs. Transmission is via contact with secretions or excretions of mouth, skin, vagina, feces of patients.

Yeast Vaginitis

Infected humans as reservoirs. Transmission is via contact with secretions or excretions of mouth, skin, vagina, feces of patients.

Cryptococcosis

Reservoirs include bird droppings, and contaminated soil with bird droppings. Transmission is via inhalation of yeast. Person to person is not occurring.

Acne

Infected humans as reservoirs. It is not transmissible.

Anthrax (Woolsorter's Disease)

Anthrax infected animals as reservoirs as well as spores in soil, animal hair, animal skins, and products made from them. Transmission occurs via entry of endospores through breaks in skin, inhalation of spores, ingestion of bacteria thru contaminated meat.

Gas Gangrene (Clostridium Myonecrosis)

Soil is the primary reservoir of this disease. Humans are infected when the soil containing Clostridium spores enter the open wounds. Person to person transmission is not occurring.

Leprosy (Hansen Disease)

Infected humans as reservoirs. Transmission of leprosy is still not clearly established. It may gain entrance to the respiratory system or broken skin. It is not easily transmitted from person to person.

Staphylococcal Skin Infections

Infected humans as reservoirs. Transmission occurs by direct contact with a person having purulent lesion (discharging pus).

Streptococcal Skin Infections

Infected humans as reservoirs. Transmission occurs from person to person via large respiratory droplets or direct contact with patient or carrier.

Otitis Externa (Ear Canal Infection, Swimmer's Ear)

Reservoir includes contaminated swimming pool water, sometimes indigenous microflora or articles inserted to the ear when cleaning.

Otitis Media (Middle Ear Infection)

Otitis media is not a communicable disease.

Bacterial Conjunctivitis (Pink Eye)

Infected humans serve as reservoirs. Human to human transmission occurs via contact with eye and respiratory discharges, and contaminated fingers.

Chlamydial Conjunctivitis (Pana Trachoma)

Infected humans serve as reservoirs. Transmission occurs via contact with genital discharges of infected people, contaminated fingers, newborn via infected birth canal.

Trachoma (Chlamydia Keratoconjunctivitis)

Infected humans serve as reservoirs. Transmission is via direct contact with infectious ocular or nasal secretion or contaminated articles. It can be spread also by flies as a vector.

Gonococcal Conjunctivitis (Gonorrheal Ophthalmia Neonatorum)

Infected humans, specifical with infected maternal birth canal, serve as reservoirs. Transmission occurs via contact with infected birth canal during delivery. Also, it can be transmitted with finger to eye contact with infectious genital secretions.

Diphtheria

Infected humans serve as reservoirs. Transmission is via airborne, droplets, direct contact and contaminated fomites.

Streptococcal Pharyngitis (Strep Throat)

Infected humans serve as reservoirs. Transmission is via person to person by direct contact, usually by hands, aerosol droplets, secretions from infected patients and nasal carriers.

Psittacosis (Parrot Fever, Ornithosis)

Transmission is via birds to humans usually by inhalation of contaminated dust and aerosols.

Pneumonia

Infected humans serve as primary reservoirs, other reservoirs include psittacine birds (parrots and parakeets). Transmission is by droplet inhalation, direct oral contact, contact with contaminated hands and fomites, or inhalation of yeast and fungal spores.

Legionellosis (Legionnaires’ Disease, Pontiac Fever)

Environmental water sources as reservoirs. Transmission occurred via aerosols of Legionella spp. that have been produced by vegetable misting devices in supermarkets. Person to person transmission is not occurring.

Mycoplasma Pneumonia (Atypical Pneumonia, Walking Pneumonia)

Infected humans serve as reservoirs. Transmission via droplet inhalation or direct contact with infected persons, fomites with nasal secretion, and coughing patients.

Tuberculosis

Infected humans serve as primary reservoirs, rarely other mammals serve as reservoirs.Transmission via airborne droplets produced by infected people.

Whooping cough (Pertussis)

Infected humans serve as reservoirs. Transmission occurs via droplets produced by cough.

Bacterial Gastritis (Bacterial Gastritis and Gastric Ulcers)

Infected humans serve as reservoirs. Transmission occurs via ingestion; presumed to be oral to oral, or fecal-oral transmission.

Campylobacter Enteritis

Animals serve as reservoirs. Transmission is via ingestion of contaminated food.

Cholera

Reservoirs include humans and aquatic reservoirs (zooplanktons). Transmission is via fecal-oral route, contact with feces, and fecally contaminated water.

Salmonellosis

Reservoirs include a wide range of wild and domestic animals. Infected humans are also reservoirs. Transmission occurs via ingestion of contaminated food, fecal-oral transmission from person to person.

Typhoid Fever (Enteric Fever)

Infected humans serve as reservoirs, rarely domestic animals as reservoirs for paratyphoid.

Shigellosis (Bacillary Dysentery)

Infected humans serve as reservoirs. Transmission is via direct or indirect fecal-oral transmission, fecally contaminated hands, fecally contaminated food.

Clostridium difficile Associated Diseases

Hospital patients are the reservoir.

Enterohemorrhagic E. coli Diarrhea

Cattle and infected humans are the reservoirs. Transmission is via fecal-oral route, fecally contaminated water and food, and person to person contact.

Enterotoxigenic E. coli Diarrhea (Traveler's Disease)

Infected humans are the reservoirs. Transmission is via fecal-oral route, fecally contaminated water and food.

Genital Chlamydial Infections, Genital Chlamydiasis

Infected humans are the reservoirs. Transmission is via direct sexual contact or mother to neonate during birth.

Gonorrhea

Infected humans are the reservoirs. Transmission is via direct mucous membrane to mucous membrane contact, usually sexual contact.

Syphilis

Infected humans are the reservoirs. Transmission occurs via direct contact with lesions, body secretions, and saliva usually in sexual contact.

Rocky Mountain Spotted Fever (Tick Borne Typhus Fever)

Reservoirs include infected ticks in dogs, rodents, and other animals. Transmission is when feces of fleas rub into flea wounds.

Endemic Typhus (Murine Typhus, Flea Borne Typhus)

Reservoirs include mice, rats, possibly other types of mammals, and infected rat fleas. It is transmitted when infected fleas defecate and the feces rubbed into the bite wound. Person to person transmission is not occurring.

Epidemic Typhus

Reservoirs include infected humans and body lice. Transmission occurs from human to louse to human. Infected lice defecate while feeding and the feces rubbed into the bite wound.

Ehrlichiosis

Reservoirs are unknown. Transmission is via tick bite.

Lyme Disease

Ticks, rodents, and mammals serve as reservoirs. Transmission is via tick bite. Person to person does not occur.

Plague

Reservoirs include wild rodents, fleas, and rarely, rabbits, wild carnivores, and domestic rats. Transmission is via flea bite, droplet transmission from person to person (pneumonic plague), and handling of infected tissue of other wild animals.

Tularemia (Rabbit Fever)

Reservoirs include wild animals, some domestic animals, and hard ticks. Transmission is via tick bite, ingestion of contaminated meat or water, entry of organisms in wounds, and inhalation of dust. Person to person is not occurring.

Listeriosis

Reservoirs include soil, water, mud, silage, infected mammals, infected humans, and soft cheeses. Transmission is via ingestion of raw or contaminated milk, and vegetables.

Tetanus (Lockjaw)

Reservoirs include soil contaminated by feces of animals and humans. Spores of C. tetani are introduced in wounds and under anaerobic condition it will become vegetative C. tetani cells producing exotoxin in vivo. Person to person is not occurring.

Chickenpox (Varicella) and Shingles

Infected humans act as reservoirs but the transmission is from person to person by direct contact, droplet, airborne spread of vesicle fluid or secretions of the respiratory system of the person infected with chickenpox.

German Measles (Rubella)

Infected humans serve as reservoirs. Transmission occurs by droplet spread or direct contact with nasopharyngeal secretions.

Measles (Rubeola)

Infected humans serve as reservoirs. Airborne transmission occurs by spread of droplets, direct contact with nasal or throat secretion of the infected person.

Monkeypox

Infected animals serve as reservoirs. Transmission occurs via animal bite or contact with an infected animal's blood, body fluids or rash. Person to person transmission does occur.

Smallpox

Before smallpox has been eradicated, humans are the only source of this virus. Person to person transmission via respiratory tract (droplet spread) or skin inoculation.

Warts

Infected humans serve as reservoirs. Transmission usually occurs in direct contact. Genital warts are sexually transmitted.

Roseola

Roseola does not have an animal or environmental reservoir. The transmission is via direct contact, and droplets.

Adenoviral Conjunctivitis and Keratoconjunctivitis

Infected humans serve as reservoirs. Transmission occurs via direct contact with eye secretions or contact with contaminated surfaces.

Hemorrhagic Conjunctivitis

Infected humans serve as reservoirs. Transmission occurs direct or indirect contact with discharge from infected eyes.

Keratitis

A reservoir is any habitat (living or nonliving) where a pathogen resides, thrives, and reproduces. It serves as the source of infection. Infected humans serve as reservoirs. Transmission occurs direct or indirect contact with discharge from infected eyes.

Common Cold

Infected humans serve as reservoirs. Transmission is via respiratory secretions by way of hands and fomites or direct contact or inhalation of airborne droplets.

Acute, Febrile, Viral Respiratory Disease

Infected humans serve as reservoirs. Transmission occurs via direct oral contact or by droplets, fecal-oral route, and fomites.

Hanta Pulmonary Syndrome (HPS)

Rodents serve as reservoirs. Transmission is via inhalation of aerosolized rodent feces, urine, and saliva. Person to person does not occur.

Influenza (Flu)

Infected humans serve as primary reservoirs, pigs and birds also serve as reservoirs. Pig cells have receptors for both avian and human strains of influenza virus. Transmission is via airborne spread or direct contact.

Avian Influenza (Bird Flu)

Infected wild and domesticated birds serve as reservoirs. Bird to human transmission occurs via contact with infected poultry that have been contaminated with excretions from infectious birds.

Severe Acute Respiratory Syndrome (SARS)

Infected humans serve as reservoirs. Transmission occurs by respiratory droplets or by touching the mouth, nose, or eye after touching contaminated fomites.

Viral Gastroenteritis (Stomach Flu, 24-hour Flu)

Infected humans serve as reservoirs. Transmission is most often via fecal-oral route. Foodborne, waterborne, and shellfish transmission is reported. Airborne transmission and contact with contaminated fomites may cause epidemics in cruise ships and hospitals.

Type A hepatitis (HAV)

Fecal-oral transmission, from contaminated foods, person to person, acute.

Type B hepatitis (HBV)

Sexual or household contact with infected persons, mother to infant before birth, needles, chronic.

Type C hepatitis (HCV)

Primarily via parenterally transmitted (blood transfusion), rarely sexually transmitted, chronic.

Type D hepatitis (HDV)

Exposure to infected blood and body fluids, only appears if already infected with hepatitis B.

Type E hepatitis (HEV)

Fecal-oral transmission, and person to person, acute.

Type G hepatitis (HFV)

Parenteral, found alongside hepatitis C.

Anogenital Herpes (Genital Herpes)

Infected humans serve as reservoirs. Transmission via direct sexual intercourse during the presence of the lesions. Mother to fetus may occur during pregnancy and birth.

Genital Warts

Infected humans serve as reservoirs. Transmission via direct contact is usually sexual intercourse. Mother to fetus may occur during pregnancy and birth.

HIV Infection and AIDS

Infected humans serve as reservoirs. Transmission via direct sexual intercourse, sharing of used needles, and transfusions.

Infectious Mononucleosis (Kissing disease)

Infected humans serve as reservoirs. Transmission via person to person direct contact with saliva. Kissing facilitates spread among adolescents.

Mumps (Infectious Parotitis)

Infected humans serve as reservoirs. Transmission occurs via droplet spread and direct contact with the saliva of the infected person.

Viral Hemorrhagic Diseases

Infected humans serve as reservoirs and green monkeys of Africa as reservoirs of Marburg virus. Transmission is from person to person via direct contact with infected blood secretions, internal organs, or semen.

Lymphocytic Choriomeningitis

Infected rodents primarily the common house mice serve as reservoirs. Humans become infected if they are exposed to mouse urine, droppings, saliva, or nesting materials. It can enter broken skins, nose, eyes, mouth, and bite of infected rodents. Person to person transmission does not occur.