细螺旋体抗体 z-bo 2020-09-22 334

　　Mice are often infected in the Powderima slum. The gutter was covered by footprints, and the roof was covered with black dung. The rats even left marks on the blood of residents of the Grand Slam in Brazil's third largest city. Many residents carry Leptspira antibodies. This bacteria is usually found in mouse urine and is a deadly "poison" to humans.

　　"The number of rats is incredible," Carlos Bautista said while sitting in the cabin and looking outside. Six years ago, Bautista's wife died of lung damage caused by tuberculosis. Soon, he sent his son to live in the country with his grandparents. Bautista said: "For him, living in the country is better than facing rats or getting sick here."

　　Rat disease

　　The mouse has always been one of the most widely distributed animals in the world. As an urban wild animal, it is always related to disease and pollution. But scientists are not interested in them. Many functions of the City Mouse (Gary Mouse) are still a mystery.

　　But with the rapid increase in the urban population, more and more people have poured into the rat-affected communities like PaudaLima. These rodents have attracted the attention of researchers and public health professionals. In the past decade, many scientists have initiated various projects to better understand the behavior and evolution of mice and their role in disease transmission. In Powderima, the research on the relationship between humans and mice is one of the longest and most in-depth. For 20 years, researchers have carefully examined the body, family and habits of residents here. Rats are similar to humans. The goal is to decipher the driving force of leptospirosis and find the best way to control the disease. The disease causes 60,000 deaths worldwide every year.

　　"When I was investigating the Grand Slams in Jakarta, Manila and Cali, the sight I saw in Powderima was the same," said Albert Coe, a doctor and infectious disease expert at Hyeres University in the United States. Ko is the founder of the Salvadoran Research Project in Brazil. "We need to find a ready-made solution in the urban slums."

　　Ko's interest in powdered mice can be traced back to 1996. At that time, his place of work in El Salvador accommodated many residents suffering from fatal diseases, many of whom suffered from kidney failure. At that time, leptospirosis was considered a rural disease. Spirulina usually parasitizes the kidneys and urinary system of rats and livestock. When human epidermis and mucous membranes come into contact with water contaminated by the urine of these animals, they may be infected with the disease. Many people may have no symptoms of infection, or just fever and pain. However, a small number of people suffer severe kidney damage and pulmonary hemorrhage, the cause of which is unclear.

　　Therefore, Ko and his colleagues from Brazil spent more than a year tracking the outbreak of Leptospyrosis. It turned out that the infection had moved to the city. They found 326 serious cases within 8 months, including 50 deaths. The culprit is a strain of Leptospyra, which mainly parasitises mice. They also noticed a sharp increase in the number of infections after heavy rains. In addition, most of the patients came from the suburbs of the city, and one of them was Powderima.

　　Since 2001, these suburbs have been the focus of research projects that integrate infectious diseases, urban ecology and community development. With the support of Brazilian and American funding agencies, scientists are working with local authorities and Grand Slam residents to jointly understand and fight the disease. Doctor Joseph Vinets of the University of California, San Diego, said: "As far as I know, the ongoing El Salvador project cannot be compared with systematic urban research."

　　Contrast Tokoobuyuki

　　One morning in April, the research team wore white robes and crowds moved. Shuttle between buildings on the street. They want to collect data in Powder Lima. In humid tropical regions, these coats can make people feel unhappy. But for safety reasons, researchers must wear white uniforms to show neutrality to those who control the blows.

　　Federal University of Bahia (UFBA) graduate student and ecologist Arsinoê Pertile crossed the slope to reach Valley No. 4 nominated by the scientist. The total area of this area and nearby valleys is less than 1/5 square kilometers, but it can accommodate more than 3,000 people. Approximately 90% of residents are illegal land occupiers, and their living expenses average only US$2.6 per day.

　　At the bottom of the valley, Pertile is a small outdoor market selling beer and other beverages in a narrow but walled courtyard. The researchers built a rat trap here to catch mice. The particles dissected the captured mice, recorded their size and sex, and extracted samples. The researchers also checked the mice’s urine to detect Leptospira. She said: "About 80% of mice have lean spirochetes." They also hope to correlate the age, sex and location of the mice with the level of lean spirochetes in the urine.

　　These traps are part of a large project to study the distribution of grand slam rats. The scientists placed the mice in the valley, covered with a mucous membrane coated with a mixture of soot and methanol, and recorded the footprints and tail marks of the mice passing by them. We have identified hot spots for our activities.

　　Pertile and his research partner Luciano Lima, an urban deratization expert, are very interested in the speed at which rats can "survive" in the "Fourth Valley" after the blame. .. Genetic studies have shown that the number of mice living in different Slam Valleys is relatively unique. This means that the mouse has not moved too far.

　　They set up traps at 60 locations in three valleys. Did the population recover because the rats arrived from the nearby Grand Slam or the surviving mice in the four valleys reproduced? I checked. The relevant conclusions provide suggestions for future rat prevention and treatment projects.

　　After 7 years of fighting with rats, Lima has rich experience and believes that water, food and dense vegetation will be the resting place for rats. He said that in the four months since the last rodent eradication, the valley was filled with rats again.

　　The declaration of rat war seems to be an effective way to solve rat-mediated diseases. However, according to PaudaLima's research, killing mice has no effect. The reason is that the researchers discovered that another important "murderer" is water, especially untreated sewage and runoff. It connects everything in a home run: rats, bacteria, and people.

　　Even in affluent cities, mice can cause mild infections, but humans are less infected. The powderima project leader and UFBA ecologist Federico Costa said the reason is that modern infrastructure keeps sewage and rainwater away from the population. But in the fourth valley, there are drains everywhere.

　　Looking for a better strategy

　　There are a lot of mice and spirochetes in the slums, why doesn’t everyone get sick? The Ko research team wants to know this. Researchers found that approximately 3.2% of Grand Slam residents are infected each year. Three out of ten infected people have mild symptoms, while one in 200 severely ill patients. Scientists also found that if a person’s daily income is $1, the chance of being infected will be reduced by half. In addition, the relationship between Leptspira infection and water suggests that killing mice is not enough to protect the Powderima population. "People are too close to sewage and rats." Costa Rica said, "I think it is possible to design a system that can collect most of the water and minimize infection."

　　At the beginning of the project, the scientific people and community leaders worked in the federal government. The government invested 36 million U.S. dollars to build roads and sewers, and built new houses for 271 residents. But so far, the project has only been partially completed. There is a row of new apartments beside the newly paved road, but there is still an open creek at the end of the drain. In addition, ongoing delays in the project are wasting money.

　　In order to solve

　　Due to the difficulties, scientists are looking for cheaper and faster ways to combat lipemia. They plan to investigate the effectiveness of coordinating rodent control, isolating some areas or distributing rubber boots to residents. Researchers first hope to use computer models to test the effectiveness of these interventions. At present, the model jointly developed by the University of Costa Andre and the University of Liverpool in the United Kingdom is still relatively rough, and researchers can only perform simulations at the valley level.

　　In any case, research on powdered powder is affecting the practice of local governments. Ko said, for example, 15 years ago, rodent control in El Salvador was very random and concentrated in affluent areas. Currently, the government is focusing on 11 suburbs where leptospirosis is high. In 2015, the rodent killer visited the five most severely damaged areas from house to house, leaving behind a rodent and found traces of rats.

　　However, Ko admitted that there is currently no data to prove that these strategies can reduce infections. He said: "But my intuition shows that this is what we need to solve the plague." However, the prevention and treatment of leptospirosis still has a long way to go. During the investigation, the investigation team learned that a 12-year-old boy had a fever and may have leptospirosis. In addition, Maria Gorete Magalhesodrigues (Maria Gorete Magalhesodrigues), who is in charge of the city’s rodent control work, said last year that there are five caravans and 120 staff working on rodent control. However, with the advent of ten viruses, four vehicles and 80 staff were transferred and killed the mosquitoes. Currently, her rodent control team only responds to infection reports.

　　"Skin pus disease has not caused much attention," she said, "but I am trying to beat it."