Disease spreading

The value of insecticides in controlling human and animal diseases spread by insects has been dramatic. It has been shown that between 1942 and 1952, the use of DDT in pubHc health measures to control the mosquito vectors of malaria and the human body louse vector of typhus saved five million hves and prevented 100 million illnesses (4). Insecticides have provided the means to control such important human diseases as filariasis transmitted by Culex mosquitoes and onchocerciasis transmitted by Simulium blackflies. 

Leprosy is a chronic, communicable disease spread by prolonged, intimate contact with an infected person. Peripheral nerves are affected, and skin involvement is present. Lesions may be confined to a few isolated areas or may be fairly widespread over the entire body. Treatment with the leprostatic drugs provides a good prospect for controlling the disease and preventing complications. 

To report to the WHO evidence of a public health risk identified outside their territory, which may cause international disease spread, manifested by exported/imported human cases, vectors carrying infection or contamination, or contaminated goods... 

Fungal disease spread by wind, insects, and rain-splash. It overwinters In the soil... 

Viral disease spread primarily by aphids it may also be spread by handling diseased plants, and on tools. Infection usually occurs when plants are about six weeks old. See also Viruses. 

Fungal disease spread by rain and wind, especially during a damp spring. 

Fungal disease spread by rain-splash, on hands, and on tools. Attacks are worst in warm, moist conditions. Overwinters on stems, fallen leaves and in soil. 

Under the intellectual leadership of Paul Ehrlich, the dye industry provided arsphenamine, the first effective agent against syphilis. Syphilis is an infectious disease spread by sexual contact. It is caused by the spirochete Treponema pallidum. Syphilis runs various courses over many years and can result in death if not treated. Penicillins are now the dmgs of choice for syphilis. Chemists discovered two other medicinal agents in the early years of the twentieth century tryparsamide for trypanosomiasis, a parasitic disease, and oxophenarsine, also for syphilis. 

Insecticide, used mostly to protect from diseases spread by insects. Also a byproduct in the production of dicofol, another insecticide. Limited use allowed under the Stockholm convention for areas where malaria is a significant health risk and economic constraints prevent the use of other pesticides... 

Methaqualone is an addictive, or habit-forming, synthetic drug that alters brain function. In their search for new medications to fight malaria, a potentially deadly tropical disease spread by mosquitoes, scientists in India first synthesized methaqualone in 1955. The drug was found to be hypnotic and a potent sedative, but it was then thought to be non-addictive. 

The above findings indicate that earthworms can provide a useful amount of protein for poultry. Concerns are that the earthworms may concentrate heavy metals and contaminants present in the soil and may act as intermediate hosts for cestode worms and disease vectors such as that causing blackhead in turkeys. This concern about disease spread is minimized in some tropical countries by collecting the earthworms and sun-drying them before feeding to poultry. 

Throughout the 3 weeks 1 was there, we only had one small outbreak of diarrhea, which was contained within 3 days, and some small outbreaks of viral upper respiratory infections. This was achieved by nearly daily reminders in loudspeaker announcements that clean hands would be about the only way to stop disease spread, and that residents had to be personally responsible and pretty determined about seeking hand cleansing opportunities to keep us all healthy. They rose to the occasion. 

Pathogen-Free Seed Stock—Production of clean seed stock is important in reducing plant disease spread. Often, seeds are grown in arid areas where the amount of moisture is controlled by an irrigation system. This... 

Disinfecting Equipment and Tools—Some plant diseases can be spread from plant to plant, field to field, and crop to crop by workers and their equipment. Disinfecting equipment, tools, and clothing before moving from an infected area to a disease-free area can prevent or delay disease spread. This method of disease spread is especially important in high humidity and wet... 

Because M. leprae almost exclusively infects humans, animal models for studying leprosy are few. Surprisingly, a few species of armadillo can also be infected with M. leprae. Recently, however, wild armadillos have been appearing with a naturally occurring form of leprosy. If the disease spreads in the armadillo population, researchers will not be able to use these animals for leprosy studies, sirKe study animals must be completely... 

Contamination of water by pathogens is another insidious route of disease spread. Water remains crystal clear until there are millions of bacteria present in each milliliter. Viruses, which are much smaller, can be present in even higher numbers without affecting the appearance of the liquid. Thus, water can be easily laced with enough pathogens to cause illness. 

New leaves with black centers growing tips wilted. Cause Mummy berry. This fun-gd disease spreads most easily in cold, wet spring weather. For more information, see Berries drop early mature berries turn gray, shriveled, and hard on page 45. 

Cause American gooseberry mildew. This fungal disease spreads most rapidly during periods of warm days followed by cool nights. Under these conditions the crop can be ruined overnight. For more information, see Leaves with powdery white patches leaves stunted and deformed" below. 

Leaves and flowers greenish yellow, distorted new growth spindly. Cause Aster yellows. Feeding leafhoppers may transmit this disease. There is no control for aster yellows. Remove and destroy infected plants do not compost them. Prevent the disease spread by controlling sucking pests such as leafhoppers and aphids. 

Leaves covered with white powder. Cause Powdery mildew. Powdery white or grayish fungal patches grow on upper leaf surfaces of plants subject to poor air circulation or hot, humid weather. As the disease spreads, leaves become distorted and ma drop off. Powdery mildew is more severe when growing conditions are unsatisfactory. 

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