bowang0911/MedQuAD huggingface dataset:
Like all arenaviruses, Chapare virus has a rodent host as its reservoir. Humans can contract CHHF through contact with an infected rodent. Contact can be direct or through inhalation of aerosolized Chapare virus from the urine or feces of infected rodents. 
 
Although arenaviruses have been isolated from insects, neither they nor any other intermediary host appear to spread CHHF. 
 
Person-to-person transmission of arenaviruses through aerosolization, although possible, is rare. From the only observed cluster of cases of CHHF, there was no evidence of person-to-person transmission. 
 
Transmission, if it can occur with CHHF, is most likely the result of direct contact with an infected person.
The symptoms of CHHF, as reported in the only described patient, resemble those of other South American hemorrhagic fevers, such as Argentine HF or Bolivian HF. The incubation period is unknown, but for Argentine hemorrhagic fever (AHF) is 6 to 16 days. 
   
The CHHF clinical course included: 
    
    - fever 
    - headache 
    - articulation and muscle pain 
    - vomiting 
    
   
These symptoms were followed by deterioration with multiple hemorrhagic signs. The only described CHHF patient died 14 days after onset of symptoms. 
   
Since Arenaviruses may enter the fetus through infection of the mother, and anecdotal evidence suggests that infected pregnant women may suffer miscarriages, it is reasonable to assume that both infection of the fetus and miscarriage may be associated with CHHF infection in the mother.
CHHF virus has been successfully isolated from both blood and serum during the acute febrile phase of illness. Although not undertaken at the time of the initial cluster, virus can certainly be isolated from tissue obtained post-mortem if available. A subsequent complete genomic analysis of Chapare virus facilitated the development of specific molecular detection (RT-PCR) assays. 
   
Serologic diagnosis of CHHF can be made by indirect immunofluorescent assay and ELISA. However, individuals from endemic areas who show fever, dizziness, and myalgia, accompanied by laboratory findings of low white blood cell and platelet counts and excess protein in the urine, should be suspected of having one of the South American hemorrhagic fever viruses. Clinical specimens should be tested using specific assays.
Supportive therapy is important in CHHF. This includes: 
    
    - maintenance of hydration 
    - management of shock 
    - sedation 
    - pain relief 
    - usual precautions for patients with bleeding disorders 
    - transfusions (when necessary) 
    
   
Use of convalescent plasma therapy for treatment of AHF reduces mortality significantly and anecdotal evidence shows that the antiviral drug ribavirin may also hold promise for treating AHF. Ribavirin has also been considered for preventing development of disease in people exposed to other arenaviruses. 
   Recovery 
   
The precise mortality of CHHF is unknown and the only described case was fatal. 
   
Patients who have suffered from other arenaviruses may continue to excrete virus in urine or semen for weeks after recovery. For this reason, these fluids should be monitored for infectivity, since convalescent patients have the potential to infect others (particularly sexual partners) via these fluids.
Yersiniosis is an infectious disease caused by a bacterium of the genus Yersinia. In the United States, most human illness is caused by one species, Y. enterocolitica. Infection with Y. enterocolitica can cause a variety of symptoms depending on the age of the person infected. Infection with Y. enterocolitica occurs most often in young children. Common symptoms in children are fever, abdominal pain, and diarrhea, which is often bloody. Symptoms typically develop 4 to 7 days after exposure and may last 1 to 3 weeks or longer. In older children and adults, right-sided abdominal pain and fever may be the predominant symptoms, and may be confused with appendicitis. In a small proportion of cases, complications such as skin rash, joint pains, or spread of bacteria to the bloodstream can occur.
The Centers for Disease Control and Prevention (CDC) monitors the frequency of Y. enterocolitica infections through the foodborne disease active surveillance network (FoodNet). In addition, CDC conducts investigations of outbreaks of yersiniosis to control them and to learn more about how to prevent these infections. CDC has collaborated in an educational campaign to increase public awareness about prevention of Y. enterocolitica infections. The U.S. Food and Drug Administration inspects imported foods and milk pasteurization plants and promotes better food preparation techniques in restaurants and food processing plants. The U.S. Department of Agriculture monitors the health of food animals and is responsible for the quality of slaughtered and processed meat. The U.S. Environmental Protection Agency regulates and monitors the safety of our drinking water supplies.
There are three different filarial species that can cause lymphatic filariasis in humans. Most of the infections worldwide are caused by Wuchereria bancrofti. In Asia, the disease can also be caused by Brugia malayi and Brugia timori.
    
The infection spreads from person to person by mosquito bites. The adult worm lives in the human lymph vessels, mates, and produces millions of microscopic worms, also known as microfilariae. Microfilariae circulate in the person's blood and infect the mosquito when it bites a person who is infected. Microfilariae grow and develop in the mosquito. When the mosquito bites another person, the larval worms pass from the mosquito into the human skin, and travel to the lymph vessels. They grow into adult worms, a process that takes 6 months or more. An adult worm lives for about 5–7 years. The adult worms mate and release millions of microfilariae into the blood. People with microfilariae in their blood can serve as a source of infection to others.
    
     
    
    
A wide range of mosquitoes can transmit the parasite, depending on the geographic area. In Africa, the most common vector is Anopheles and in the Americas, it is Culex quinquefasciatus. Aedes and Mansonia can transmit the infection in the Pacific and in Asia.
    
Many mosquito bites over several months to years are needed to get lymphatic filariasis. People living for a long time in tropical or sub-tropical areas where the disease is common are at the greatest risk for infection. Short-term tourists have a very low risk.
    
Programs to eliminate lymphatic filariasis are under way in more than 50 countries. These programs are reducing transmission of the filarial parasites and decreasing the risk of infection for people living in or visiting these communities.
    Geographic distribution
    
     
    
    
Lymphatic filariasis affects over 120 million people in 73 countries throughout the tropics and sub-tropics of Asia, Africa, the Western Pacific, and parts of the Caribbean and South America.
    
In the Americas, only four countries are currently known to be endemic: Haiti, the Dominican Republic, Guyana and Brazil.
    
In the United States, Charleston, South Carolina, was the last known place with lymphatic filariasis. The infection disappeared early in the 20th century. Currently, you cannot get infected in the U.S.
The standard method for diagnosing active infection is the identification of microfilariae in a blood smear by microscopic examination. The microfilariae that cause lymphatic filariasis circulate in the blood at night (called nocturnal periodicity). Blood collection should be done at night to coincide with the appearance of the microfilariae, and a thick smear should be made and stained with Giemsa or hematoxylin and eosin. For increased sensitivity, concentration techniques can be used.
    
Serologic techniques provide an alternative to microscopic detection of microfilariae for the diagnosis of lymphatic filariasis. Patients with active filarial infection typically have elevated levels of antifilarial IgG4 in the blood and these can be detected using routine assays.
    
Because lymphedema may develop many years after infection, lab tests are most likely to be negative with these patients.
Patients currently infected with the parasite
    
Diethylcarbamazine (DEC) is the drug of choice in the United States. The drug kills the microfilaria and some of the adult worms. DEC has been used world-wide for more than 50 years. Because this infection is rare in the U.S., the drug is no longer approved by the Food and Drug Administration (FDA) and cannot be sold in the U.S. Physicians can obtain the medication from CDC after confirmed positive lab results. CDC gives the physicians the choice between 1 or 12-day treatment of DEC (6 mg/kg/day). One day treatment is generally as effective as the 12-day regimen. DEC is generally well tolerated. Side effects are in general limited and depend on the number of microfilariae in the blood. The most common side effects are dizziness, nausea, fever, headache, or pain in muscles or joints.
    
DEC should not be administered to patients who may also have onchocerciasis as  DEC can worsen onchocercal eye disease.  In patients with loiasis, DEC can cause serious adverse reactions, including encephalopathy and death. The risk and severity of the adverse reactions are related to Loa loa microfilarial density.
The drug ivermectin kills only the microfilariae, but not the adult worm; the adult worm is responsible for the pathology of lymphedema and hydrocele.
    
Some studies have shown adult worm killing with treatment with doxycycline (200mg/day for 4–6 weeks).  
    Patients with clinical symptoms
    
Lymphedema and elephantiasis are not indications for DEC treatment because most people with lymphedema are not actively infected with the filarial parasite.
    
To prevent the lymphedema from getting worse, patients should ask their physician for a referral to a lymphedema therapist so they can be informed about some basic principles of care such as hygiene, exercise and treatment of wounds.
    
Patients with hydrocele may have evidence of active infection, but typically do not improve clinically following treatment with DEC. The treatment for hydrocele is surgery.
    
More on: Resources for Health Professionals: Treatment
The best way to prevent lymphatic filariasis is to avoid mosquito bites. The mosquitoes that carry the microscopic worms usually bite between the hours of dusk and dawn. If you live in an area with lymphatic filariasis:
   
    - at night 
     
      - sleep in an air-conditioned room or
      - sleep under a mosquito net
     
    - between dusk and dawn 
     
      - wear long sleeves and trousers and
      - use mosquito repellent on exposed skin.
     
   
   
Another approach to prevention includes giving entire communities medicine that kills the microscopic worms -- and controlling mosquitoes. Annual mass treatment reduces the level of microfilariae in the blood and thus, diminishes transmission of infection. This is the basis of the global campaign to eliminate lymphatic filariasis.
   
Experts consider that lymphatic filariasis, a neglected tropical disease (NTD), can be eradicated and a global campaign to eliminate lymphatic filariasis as a public health problem is under way. The elimination strategy is based on annual treatment of whole communities with combinations of drugs that kill the microfilariae. As a result of the generous contributions of these drugs by the companies that make them, tens of millions of people are being treated each year. Since these drugs also reduce levels of infection with intestinal worms, benefits of treatment extend beyond lymphatic filariasis. Successful campaigns to eliminate lymphatic filariasis have taken place in China and other countries.
   
More on: Insect Bite Prevention
Loa loa parasites are found in West and Central Africa. Ten countries have areas where there are high rates of infection (i.e., where more than 40% of the people who live in that area report that they have had eye worm in the past). An estimated 14.4 million people live in these areas of high rates of infection. Another 15.2 live in areas where 20–40% of people report that they have had eye worm in the past.
    
More on: Where Loa Loa is Prevelant [WHO Map]
    
The people most at risk for loiasis are those who live in the certain rain forests in West and Central Africa. The deerflies that pass the parasite to humans usually bite during the day and are more common during the rainy season. They are attracted by the movement of people and by smoke from wood fires. Rubber plantations are areas where more deerflies may be found. The flies do not typically enter homes, but they might be attracted to homes that are well lit.
    
Travelers are more likely to become infected if they are in areas where they are bitten by deerflies for many months, though occasionally they get infected even if they are in an affected area for less than 30 days.
    
Your risk of infection depends on the number of bites received, the number of infected deerflies in the area you visit, and the length of your stay in the area.
In people who have been bitten by the flies that carry Loa loa in areas where Loa loa is known to exist, the diagnosis can be made in the following ways:
  
   - Identification of the adult worm by a microbiologist or pathologist after its removal from under the skin or eye
   - Identification of an adult worm in the eye by a health care provider
   - Identification of the microfilariae on a blood smear made from blood taken from the patient between 10AM and 2PM
   - Identification of antibodies against L. loa on specialized blood test
  
  
Diagnosis of loiasis can be difficult, especially in light infections where there are very few microfilariae in the blood. The specialized blood test is not widely available in the United States. A positive antibody blood test in someone with no symptoms means only that the person was infected sometime in his/her life. It does not mean that the person still has living parasites in his/her body.
Decisions about treatment of loiasis can be difficult and often require advice from an expert in infectious diseases or tropical medicine. Although surgical removal of adult worms moving under the skin or across the eye can be done to relieve anxiety, loiasis is not cured by surgery alone. There are two medications that can be used to treat the infection and manage the symptoms. The treatment of choice is diethylcarbamazine (DEC), which kills the microfilariae and adult worms. Albendazole is sometimes used in patients who are not cured with multiple DEC treatments. It is thought to kill adult worms. Certain people with heavy infections are at risk of brain inflammation when treated with DEC. This can cause coma or sometimes death. People with heavy infections need to be treated by experienced specialists.  Sometimes, other medical conditions need to be addressed first in order to make it safer to use DEC. Sometimes treatment is not recommended.
    
More on: Resources for Health Professionals: Treatment
There are no programs to control or eliminate loiasis in affected areas. Your risk of infection may be less in areas where communities receive regular treatment for onchocerciasis or lymphatic filariasis.
    
There are no vaccines that protect you from loiasis. If you are going to be in an area with loiasis for a long period of time, diethylcarbamazine (DEC)—300mg taken once a week—can reduce your risk of infection. Avoiding areas where the deerflies are found, such as muddy, shaded areas along rivers or around wood fires, may also reduce your risk of infection. You may reduce your risk of bites by using insect repellants that contain DEET (N,N-Diethyl-meta-toluamide) and wearing long sleeves and long pants during the day, which is when deerflies bite. Treating your clothes with permethrin may also help. For a description of CDC's information for preventing insect bites, see CDC's Yellow Book.
    
More on: Insect Bite Prevention
Humans can become infected through tick bites or through contact with the blood, feces, or urine of an infected, sick, or dead animal – most commonly, rodents. Occupational and recreational activities such as hunting or trapping may increase human risk of infection. 
 
Transmission may also occur with no direct tick or rodent exposure as OHFV appears to be extremely stable in different environments. It has been isolated from aquatic animals and water and there is even evidence that OHFV can be transmitted through the milk of infected goats or sheep to humans. 
 
No human-to-human transmission of OHFV has been documented but infections due to lab contamination have been described.
After an incubation period of 3-8 days, the symptoms of OHF begin suddenly with chills, fever, headache, and severe muscle pain with vomiting, gastrointestinal symptoms and bleeding problems occurring 3-4 days after initial symptom onset. Patients may experience abnormally low blood pressure and low platelet, red blood cell, and white blood cell counts.  
                
After 1-2 weeks of symptoms, some patients recover without complication. However, the illness is biphasic for a subset of patients who experience a second wave of symptoms at the beginning of the third week. These symptoms include fever and encephalitis (inflammation of the brain). 
                
The case fatality rate of OHF is low (0.5% to 3%).
Risk Factors
    
The people most likely to be infected with pinworm are children under 18, people who take care of infected children and people who are institutionalized. In these groups, the prevalence can reach 50%.
    
Pinworm is the most common worm infection in the United States. Humans are the only species that can transfer this parasite. Household pets like dogs and cats cannot become infected with human pinworms. Pinworm eggs can survive in the indoor environment for 2 to 3 weeks.
    Epidemiology
    
Pinworm infections are more common within families with school-aged children, in primary caregivers of infected children, and in institutionalized children.
    
A person is infected with pinworms by ingesting pinworm eggs either directly or indirectly. These eggs are deposited around the anus by the worm and can be carried to common surfaces such as hands, toys, bedding, clothing, and toilet seats. By putting anyone’s contaminated hands (including one’s own) around the mouth area or putting one’s mouth on common contaminated surfaces, a person can ingest pinworm eggs and become infected with the pinworm parasite. Since pinworm eggs are so small, it is possible to ingest them while breathing.
    
Once someone has ingested pinworm eggs, there is an incubation period of 1 to 2 months or longer for the adult gravid female to mature in the small intestine. Once mature, the adult female worm migrates to the colon and lays eggs around the anus at night, when many of their hosts are asleep. People who are infected with pinworm can transfer the parasite to others for as long as there is a female pinworm depositing eggs on the perianal skin. A person can also re-infect themselves, or be re-infected by eggs from another person.
A person infected with pinworm is often asymptomatic, but itching around the anus is a common symptom. Diagnosis of pinworm can be reached from three simple techniques. The first option is to look for the worms in the perianal reqion 2 to 3 hours after the infected person is asleep. The second option is to touch the perianal skin with transparent tape to collect possible pinworm eggs around the anus first thing in the morning. If a person is infected, the eggs on the tape will be visible under a microscope. The tape method should be conducted on 3 consecutive mornings right after the infected person wakes up and before he/she does any washing. Since anal itching is a common symptom of pinworm, the third option for diagnosis is analyzing samples from under fingernails under a microscope. An infected person who has scratched the anal area may have picked up some pinworm eggs under the nails that could be used for diagnosis.
    
Since pinworm eggs and worms are often sparse in stool, examining stool samples is not recommended. Serologic tests are not available for diagnosing pinworm infections.
The medications used for the treatment of pinworm are mebendazole, pyrantel pamoate, and albendazole. All three of these drugs are to be given in 1 dose at first and then another single dose 2 weeks later. Pyrantel pamoate is available without prescription. The medication does not reliably kill pinworm eggs. Therefore, the second dose is to prevent re-infection by adult worms that hatch from any eggs not killed by the first treatment.Health practitioners and parents should weigh the health risks and benefits of these drugs for patients under 2 years of age.
    
Repeated infections should be treated by the same method as the first infection. In households where more than one member is infected or where repeated, symptomatic infections occur, it is recommended that all household members be treated at the same time. In institutions, mass and simultaneous treatment, repeated in 2 weeks, can be effective.
Washing your hands with soap and warm water after using the toilet, changing diapers, and before handling food is the most successful way to prevent pinworm infection. In order to stop the spread of pinworm and possible re-infection, people who are infected should bathe every morning to help remove a large amount of the eggs on the skin. Showering is a better method than taking a bath, because showering avoids potentially contaminating the bath water with pinworm eggs. Infected people should not co-bathe with others during their time of infection.
    
Also, infected people should comply with good hygiene practices such as washing their hands with soap and warm water after using the toilet, changing diapers, and before handling food. They should also cut fingernails regularly, and avoid biting the nails and scratching around the anus. Frequent changing of underclothes and bed linens first thing in the morning is a great way to prevent possible transmission of eggs in the environment and risk of reinfection. These items should not be shaken and carefully placed into a washer and laundered in hot water followed by a hot dryer to kill any eggs that may be there.
    
In institutions, day care centers, and schools, control of pinworm can be difficult, but mass drug administration during an outbreak can be successful. Teach children the importance of washing hands to prevent infection.
    
More on: Handwashing
Diagnosing HPS
  
Diagnosing HPS in an individual who has only been infected a few days is difficult, because early symptoms such as fever, muscle aches, and fatigue are easily confused with influenza. However, if the individual is experiencing fever and fatigue and has a history of potential rural rodent exposure, together with shortness of breath, would be strongly suggestive of HPS. If the individual is experiencing these symptoms they should see their physician immediately and mention their potential rodent exposure.
  Treating HPS
  
    
      
     
   
  
  
There is no specific treatment, cure, or vaccine for hantavirus infection. However, we do know that if infected individuals are recognized early and receive medical care in an intensive care unit, they may do better. In intensive care, patients are intubated and given oxygen therapy to help them through the period of severe respiratory distress.
  
The earlier the patient is brought in to intensive care, the better. If a patient is experiencing full distress, it is less likely the treatment will be effective.
  
Therefore, if you have been around rodents and have symptoms of fever, deep muscle aches, and severe shortness of breath, see your doctor immediately. Be sure to tell your doctor that you have been around rodents—this will alert your physician to look closely for any rodent-carried disease, such as HPS.