The causes of disease in humans

Communicable diseases are those that are spread from one person to another person, from animal to animal, or from animal to person, or vice versa. It is likely that everyone will come down with a communicable disease at some point in their lives. It is important to learn about the causes of communicable diseases and ways to prevent their spread. For example, some may say that HIV is caused by sexual contact.

The causes of disease in humans

Tick-borne Diseases Colorado Tick Fever Colorado tick fever CTF is The causes of disease in humans acute and rather benign disease caused by a virus coltivirus that is transmitted to humans by ticks.

Symptoms are usually limited to high fever, headache, muscle aches, and lethargy, but the symptoms are frequently biphasic and recurring. The disease is confined to the mountains or highland regions of eight western states and western Canada Fig.

CTF is transmitted to humans during the spring and early summer by the bite of the adult stage of the Rocky Mountain wood tick Dermacentor andersoni or by D. The virus is maintained in nature through transmission by immature stages of ticks to various species of small mammals, particularly chipmunks, ground squirrels, and deer mice during the spring and summer months.

The virus survives the winter in infected tick nymphs and adults. The habitats that support the rodent hosts and tick vectors of the virus in the disease endemic region contain rocky surfaces with moderate shrub cover and scattered pines.

Avoid tick-infested habitats during spring and early summer and use personal protection against ticks. No vaccines or treatment are available. The disease is distinguished by a sudden onset of high fever, severe headache, muscle pain, and a red rash starting on the extremities about 3 to 6 days after onset of symptoms and extending to the palms of hands and soles of feet and then to the rest of the body.

The disease is transmitted to humans in the United States by several hard tick Ixodidae species; D. Incases of RMSF were reported from all regions of the United States, although more cases were reported in the south-Atlantic and south-central states Fig.

The natural hosts for the rickettsia are a variety of wild rodents, although rabbits and wild and domestic carnivores are involved in some cases.

The rickettsia survive the winter months in the tick vector and may be maintained by transovarial transmission from the female adult tick to its offspring. Avoid tick-infested areas and use personal measures to protect against tick bites. No vaccine is presently licensed for public use, but antibiotic treatment is effective and should be initiated without waiting for laboratory confirmation of clinical diagnosis.

Lyme Disease Lyme disease is caused by a spirochete bacterium Borrelia burgdorferi that is transmitted to humans by hard ticks. Early symptoms include a flu-like illness with headache, slight fever, muscle or joint pain, neck stiffness, swollen glands, jaw discomfort, and inflammation of the eye membranes.

The causes of disease in humans

The rapidly expanding red rash starts at the tick bite site and expands to a nearly circular lesion of about 1 to 8 inches 2 to 20 cm. Additional smaller skin lesions may appear at other sites of the body and may last for days or weeks. Later symptoms, including heart, nervous system, and joint manifestations, may develop in untreated individuals.

The joint pain and swelling usually occur one or more months after infection, may involve one or more joints, and may recur in different joints; the knee joint is most frequently affected. Domestic animals may be affected as well. In9, cases of Lyme disease were reported in 44 states Fig.

Most cases were reported in the northeastern and upper midwestern states where the vector is the deer tick Ixodes scapularis and where transmission is predominately in residential communities. Other vectors are I.

Transmission in these other regions of the United States may be more sporadic and occur during outdoor activities related to recreation and occupation. Acquisition of Lyme disease by humans peaks during the summer months when the tick nymphs are feeding on hosts. Because of its small size, the attached nymph frequently goes unnoticed and is not removed.

The transmission cycle of Lyme disease begins when larvae acquire spirochetes while feeding on infected white-footed mice, chipmunks, other rodents, and birds.

Engorged larvae drop to the ground, molt to the nymphal stage, and wait until the following summer to attach to and transmit spirochetes to susceptible rodents, birds, larger mammals, and humans. Uninfected larvae subsequently feed on these wild vertebrate hosts to complete the transmission cycle.

The engorged nymphs drop to the ground and molt into adult ticks which are active during the fall and following spring and feed on large mammals, primarily deer. Deciduous forest is the predominant habitat for the tick vector and vertebrate hosts in the Northeast and Midwest.

Other prime habitats include forested areas interspersed with residential development and grass and shrub areas, particularly along forest edges. Patients treated with appropriate antibiotics during the early stages of the disease usually have rapid and complete recovery.

Even patients treated during later stages generally respond well and recover. No vaccine is available except for domestic dogs. Avoid locations with ticks during seasonal activity periods, use personal measures to protect against ticks, become knowledgeable about the symptoms of Lyme disease, and seek medical care and treatment if infected.

Tularemia Tularemia is caused by the bacteria Francisella tularensis and is characterized by sudden onset of high fever and chills, joint and muscle pain, and prostration.

Slow-healing sores or lesions develop at the site of entry of the bacteria or arthropod bite. Inflammation and swelling of nearby lymph nodes follow.Diseases of wildlife or diseases present in their habitats can infect humans and some can cause serious illness or even death.

Becoming aware of the potential diseases present and taking precautions to decrease exposure will greatly reduce chances of becoming infected with one of these diseases. This disease is fairly damaging to the human body and can cause serious illness.

Symptoms of this disease include confusion, seizures, insomnia, personality changes, weight loss, slurred speech and trouble talking or walking. Inflammation: The Real Cause of All Disease and How to Reduce and Prevent It The Body Ecology Diet book addresses the sources of inflammation - one of the silent causes of aging and disease.

Get your copy to read how healing your digestion can reduce inflammation in your body and help you get well! There are two orders of Zygomycetes containing organisms that cause human disease, the Mucorales and the Entomophthorales.

The majority of human illness is caused by the Mucorales. While disease is most commonly linked to Rhizopus spp., other organisms are also associated with human infection, including Mucor, Rhizomucor, Absidia, Apophysomyces, Saksenaea, Cunninghamella, Cokeromyces, .

Specific Genetic Disorders. Many human diseases have a genetic component. Some of these conditions are under investigation by researchers at or associated with the National Human Genome Research Institute (NHGRI).

Below is a list of selected genetic, orphan and rare diseases. This list . athlete's feet,ringworm,candida Take your pick. Fungi in the body, whether in the stomach/gut or in the blood can cause a multitude of problems and symptoms, many of which are misdiagnosed or treated with antibiotics which itself is a fungus.

Birds and their droppings can carry over 60 diseases