USGS - science for a changing world

U.S. Geological Survey Manual

Appendix 24-A

Part 445-2-H, Chapter 24

Recommended Practices for Preventing Infectious Diseases in Field Work

The following is a list of infectious diseases, risk factors, and applicable treatment and preventive measures that are recommended for USGS field personnel. Additional information can be found on the Centers for Disease Control and Prevention (CDC) website: and

Due to the ever changing landscape of emerging diseases, the reader should periodically refer to the CDC website,, United States Department of Agriculture Animal and Plant Health Inspection Service (USDA APHIS) or contact their local safety officer or their cost center’s occupational health service provider for additional information on infectious diseases in their workplace. Information on traveler immunizations can be found in SM 445-2-H.23 Occupational Medicine Program.

Occupational Disease: Avian Influenza A

Risk Factors and Symptoms: Avian influenza A refers to the disease caused by infection with avian (bird) influenza (flu) Type A viruses. These viruses occur naturally among wild aquatic birds worldwide and can infect domestic poultry and other bird and animal species. Avian flu viruses rarely infect humans, are inefficient, and not sustained. However, sporadic human infections with avian flu viruses have occurred from close contact with sick or dead infected poultry. Avian influenza A viruses that have infected humans include both highly pathogenic avian influenza (HPAI) and low pathogenic avian influenza (LPAI) A viruses.

Although Avian Influenza A viruses usually do not infect humans, rare cases of human infection with avian influenza A viruses have been reported. Most human infections with avian influenza A viruses have occurred following direct or close contact with infected birds, contact with surfaces contaminated with feces, oral or nasal discharge from infected birds. Illness in humans has ranged from mild to severe.

Symptoms of HPAI H5N1 avian influenza A virus infections of humans: range from conjunctivitis only, to influenza-like illness, to severe respiratory illness (e.g. shortness of breath, difficulty breathing, pneumonia, acute respiratory distress, viral pneumonia, respiratory failure) with multi-organ disease, sometimes accompanied by nausea, abdominal pain, diarrhea, vomiting and sometimes neurologic changes (altered mental status, seizures). Symptoms of LPAI are similar to HPAI H5N1and may range from conjunctivitis to influenza-like illness (e.g., fever, cough, sore throat, muscle aches) to lower respiratory disease (pneumonia) requiring hospitalization. HPAI Asian H5N1and LPAI H7N9 have been responsible for most human illness worldwide to date, including the most serious illnesses and deaths.

Treatment: If an employee develops a fever, respiratory symptoms, and/or conjunctivitis within 10 days after last exposure to avian influenza-infected or exposed birds; or after contact with avian influenza-contaminated environmental surfaces, or after contact with people suspected to be ill with avian influenza, the employee should have prompt telephone access to a health care provider and access to medical care within 48 hours after the onset of symptoms. Employees are advised to follow the guidance of the health care provider.


 1. Where avian influenza is not known or suspected in wild birds or poultry. Handling healthy, sick, or dead birds the following measures shall apply:

2.  Where avian influenza is confirmed or presumed to be present in wild birds or poultry, the following additional work practices shall apply during the handling, investigations, or disposal of any healthy, sick, live or dead wild birds:

3.  Where avian influenza is confirmed or presumed to be present in wild birds or poultry, the following additional work practices shall apply when cleaning and disinfecting potentially contaminated equipment:

4.  It is recommended that employees handling wild birds get the seasonal flu vaccine, monitor their health for symptoms, and seek medical treatment immediately from a health care provider (within 48 hours from onset of symptoms).

For detailed guidance refer to Updated Employee Health and Safety Guidance for Avian Influenza Surveillance and Control Activities in Wild Bird Populations, 2014, Department of the Interior.

Centers for Disease Control (CDC) Reference:

World Health Organization (WHO) Reference:

Occupational Disease: Baylisascariasis

Risk Factors and Symptoms: Baylisascaris infection is caused by a roundworm found in raccoons. This roundworm can infect people as well as a variety of other animals, including dogs. Human infections are rare, but can be severe if the parasites invade the eye (ocular larva migrans), organs (visceral larva migrans) or the brain (neural larva migrans).

Baylisascaris infection is not spread from one person to another. People become infected when they accidentally ingest the roundworm eggs in soil, water, or on objects that have been contaminated with raccoon feces. When humans ingest these eggs, they hatch into larvae in the person's intestine and travel throughout the body, affecting the organs and muscles.

Signs and symptoms can be asymptomatic, but larvae tend to invade spinal cord and eye of humans causing permanent neurological damage, blindness, or death.

Treatment: Employees working with raccoons, raccoon feces, or in contact with contaminated soil who experience symptoms, should seek treatment from a health care provider. No drug has been shown to be totally effective for the treatment of Baylisascaris infection. Albendazole, a broad spectrum anthelmintic, has been recommended for specific cases.

Prevention: Baylisascaris infection can be prevented by avoiding contact with raccoons, their feces, or soil contaminated with raccoon feces. Prompt removal and incineration of raccoon feces will reduce the risk for exposure and infection. Wear gloves and wash hands after contact with raccoons, feces, and surfaces contaminated with feces. Disinfect surfaces with 10% bleach solution.

CDC Reference:

Occupational Disease: Encephalitis

Risk Factors and Symptoms: Encephalitis (e.g., EEE, WEE, VEE) is a mosquito-borne viral disease. As the name suggests, Eastern Equine Encephalitis (EEE) occurs predominantly in the eastern half of the U.S. Because of the high case fatality rate, it is regarded as one of the more serious mosquito-borne diseases in the United States. Encephalitis virus is transmitted to humans through the bite of an infected mosquito. The main EEE transmission cycle is between birds and mosquitoes. Several species of mosquitoes can become infected with the EEE virus. The most important mosquito in maintaining the enzootic (animal-based, in this case bird-mosquito-bird) transmission cycle is Culiseta melanura.

Symptoms range from mild flu-like illness to encephalitis (inflammation of the brain), coma and death. The EEE case fatality rate (the percentage of people who develop the disease who will die) is 35%, making it one of the most pathogenic mosquito-borne diseases in the US. It is estimated that 35% of people who survive EEE will have mild to severe neurological deficits.

States with largest number of cases are Florida, Georgia, Massachusetts, and New Jersey. The enzootic (animal-based) transmission cycle is most common to coastal areas and freshwater swamps. Human cases occur relatively infrequently, largely because the primary transmission cycle takes place in swamp areas where populations tend to be limited.

Those most at risk are: residents of and visitors to endemic areas (areas with an established presence of the virus); people who engage in outdoor work and recreational activities; and people over age 50 or younger than age 15.

Treatment: Employees with suspected EEE should be evaluated by a healthcare provider. There are no effective therapeutic drugs. Supportive care by the health care provider is the treatment.

Prevention: There are no licensed vaccines for human use. Employees should avoid mosquito bites by using personal and household protection measures, such as using insect repellent containing N,N-diethyl-meta-toluamide (DEET) on skin and clothes, wearing protective clothing, taking precautions from dusk to dawn when mosquitoes are most likely to bite, and controlling standing water that can provide mosquito breeding sites.

CDC Reference:

Occupational Disease: Echinococcosis

Risk Factors and Symptoms: Echinococcosis is a parasitic disease caused by infection with tiny tapeworms of the genus Echinocococcus. Echinococcosis is classified as either cystic echinococcosis (E. granulosus) or alveolar echinococcosis (E. multilocularis). Eggs are shed through the feces of foxes, wolves, dogs, and cats. The most common mode of transmission to humans is by the accidental consumption of soil, water, or food that has been contaminated by the fecal matter containing the eggs.

Cysts or tumors mainly form in the liver and lungs but can also appear in the spleen, kidneys, heart, bone, and central nervous system, including the brain and eyes. Symptoms depend on the location of the cyst or tumor and may include discomfort, pain, nausea, and vomiting. Left untreated there is a high mortality in patients.

Treatment: Surgery and/or long-term chemotherapy.

Prevention: Avoid contact with wild canidae such as foxes, coyotes and stray dogs and cats. Wash your hands with soap and warm water after handling animals and before handling food. Do not consume any food or water that may have been contaminated by fecal matter.

Wear disposable rubber gloves, follow safety precautions during necropsies of wild canidae, deep freeze carcasses for one week prior to necropsy to kill eggs and do not open intestines unless necessary.

CDC Reference:

Occupational Disease: Ehrlichiosis

Risk Factors and Symptoms: Ehrlichiosis is caused by several bacterial species in the genus Ehrlichia. The disease occurs primarily in the southeastern and south central regions of the country and is primarily transmitted by the lone star tick, Amblyomma americanum. The symptoms caused by infection usually develop 1-2 weeks after being bitten by an infected tick and include fever, headache, chills, malaise, muscle pain, nausea, vomiting, diarrhea, confusion, red eyes, and sometimes a rash. Ehrlichiosis is a serious illness that can be fatal if not treated correctly, even in previously healthy people. Severe clinical presentations may include difficulty breathing, or bleeding disorders.

Treatment: The antibiotic doxycycline is the first line treatment and should be initiated immediately whenever ehrlichiosis is suspected.

Prevention: Limiting exposure to ticks reduces the likelihood of ehrlichial infection. In people exposed to tick-infested habitats, prompt careful inspection and removal of crawling or attached ticks is an important method of preventing disease. It may take several hours of attachment before microorganisms are transmitted from the tick to the host. Prevention measures:

CDC Reference:

Occupational Disease: Giardiasis (Giardia)

Risk Factors and Symptoms: Giardiasis is the most frequently diagnosed intestinal parasitic disease in the United States and among travelers with chronic diarrhea. It is a diarrheal disease caused by the microscopic protozoan flagellate Giardia intestinalis. The parasite lives in the intestines and is passed in feces. People become infected with Giardia by swallowing Giardia cysts (hard shells containing Giardia) found in contaminated food or water. Cysts are instantly infectious once they leave the host through feces.

Signs and symptoms may vary and can last for 1 to 2 weeks or longer. In some cases, people infected with Giardia have no symptoms. Some symptoms include diarrhea, gas, stomach or abdominal cramps, upset stomach, nausea, vomiting, and dehydration.

Treatment: Several drugs that can be used to treat Giardia infection include metronidazole, tinidazole, and nitazoxanide, paromomycin, quinacrine, and furazolidone.

Prevention: Minimize contact with the feces of all animals. Wear disposable rubber gloves when cleaning up animal feces and when in contact with animals and their living areas. Wash hands after contact with animals, their living areas, and feces.

Avoid drinking poorly treated or untreated water. Protect water supplies from contamination with feces. Filter water with NSF Standard 58 for cyst and oocyst reduction. Filtered tap water will need additional treatment to kill or weaken other microorganisms. Drink bottled water. Avoid eating food that may be contaminated.

CDC Reference:

Occupational Disease: Hantavirus Pulmonary Syndrome

Risk Factors and Symptoms: Hantavirus Pulmonary Syndrome (HPS) is a severe, sometimes fatal, respiratory disease in humans caused by infection with a Hantavirus. Hantavirus is transmitted by infected rodents through urine, droppings, or saliva containing Hantavirus.

Early symptoms include fatigue, fever and muscle aches, especially in the large muscle groups—thighs, hips, back, and sometimes shoulders. These symptoms are universal.

Four to ten days after the initial phase of illness, the late symptoms of HPS appear. These include coughing and shortness of breath, with the sensation of constriction around the chest and suffocation, as fluid builds in the lungs.

Humans can contract the disease when these materials are disturbed and people breathe in contaminated air. It is also believed that people can be infected by touching something that has been contaminated with rodent urine, droppings, or saliva, and then touch their nose or mouth. Workers handling infected rodents in laboratory or in the field or working in the rodent’s habitat; and people working in infested buildings are at increased risk to this disease, particularly during dusty clean-up activities. HPS was first recognized in 1993 and has since been identified throughout the United States. Although rare, HPS is potentially deadly.

Treatment: There is no specific treatment for Hantavirus infection. Supportive care is given.

Prevention: There are no vaccines for HPS.

Eliminate or minimize contact with rodents in your home, workplace, or campsite. Seal up holes inside and outside to prevent entry by rodents. Trap rodents to help reduce the population. Take precautions before and while cleaning rodent-infested areas. Before cleaning a space, ventilate the area by opening the doors and windows for at least 30 minutes to diffuse potentially infectious aerosolized material. Use cross-ventilation and leave the area during the airing-out period.

Disinfect contaminated surfaces with 10% bleach and water solution. Wet down, with bleach solution, dust and fecal materials when cleaning infested sites or contaminated surfaces.

Wear a N100 or P100 respirator, impermeable gloves and protective clothing, as appropriate, when handling infected animals and bedding, cleaning cages, and cleaning infested or dusty spaces.

CDC Reference:

Occupational Disease: Heartland Virus Disease

Risk Factors and Symptoms: Heartland virus belongs to a family of viruses called Phleboviruses. Viruses in this family are found all over the world. Some of these viruses can cause people to get sick. Most of the phleboviruses that cause people to become ill are passed through the bite of a mosquito, tick, or sand-fly. It is not yet fully known how people become infected with Heartland virus. However, recent studies suggest that ticks, namely Lone Star ticks, may transmit the virus. Heartland virus disease has been identified among residents of Missouri and Tennessee. It is unknown at this time if the virus may be found in other areas of the United States.

Patients who have been diagnosed with Heartland virus disease became sick between May-September. They all had a fever and felt very tired. Some also complained of headaches, muscle aches, diarrhea, loss of appetite, or feeling sick to their stomach. Patients had low numbers of cells that fight infection and that help blood clot. Most patients required hospitalization for their illness.

Treatment and Prevention: Employees should consult their health care provider if they experience any symptoms that concern them. Currently, no tests are routinely available to tell if a person is infected with Heartland virus. Tests that will help a doctor diagnose Heartland virus infection are being developed.

There is no specific treatment for Heartland virus disease. Antibiotics are not effective against viruses. Supportive therapy can treat some symptoms. Some patients may need to be hospitalized for intravenous fluids and treatment for pain or fever.

Apply repellants to discourage tick attachment and prevent mosquito bites. Repellents containing DEET or permethrin can be sprayed on boots and clothing, and will last for several days. Repellents containing DEET (n, n-diethyl-m-toluamide) can be applied to the skin, but will last only a few hours before reapplication is necessary. Use DEET with caution on children because adverse reactions have been reported. Preventing bites from ticks and mosquitoes may prevent this and other infections. Wear long sleeves and pants. Use of tick gaiters is recommended. Avoid bushy and wooded areas if possible. Perform thorough tick checks after spending time outdoors.

CDC Reference:

Occupational Disease: Hepatitis A (HAV)

Risk Factors and Symptoms: Hepatitis A is a liver disease caused by the hepatitis A virus. Hepatitis A can affect anyone. In the United States, hepatitis A can occur in situations ranging from isolated cases of disease to widespread epidemics.

Good personal hygiene and proper sanitation can help prevent hepatitis A. Vaccines are also available for long-term prevention of hepatitis A virus infection in people 12 months of age and older. Immune globulin is available for short-term prevention of hepatitis A virus infection in individuals of all ages.

Employees who travel to developing countries are at substantial risk for acquiring hepatitis A. No work-related instances of HAV transmission have been reported among sewage workers in the United States.

HAV is found in the stool of people with hepatitis A. It is usually spread by close personal contact and sometimes by eating food or drinking water containing HAV.

Hepatitis A can cause: mild “flu-like” illness, jaundice (yellow skin or eyes), severe stomach pains and diarrhea. Sometimes, hepatitis A causes death (about 100 per year in the U.S.). A person who has hepatitis A can easily pass the disease to others within the same household. The disease is self-limiting and lasts from a few weeks to several months.

Treatment: Employees who are at risk and concerned they have been exposed to the HAV, should consult with a health care provider. The disease is self-limiting though a health care provider may decide whether or not to treat with a post exposure prophylaxis or Hepatitis A vaccine.

Prevention: The hepatitis A vaccination is for employees who travel to certain countries and others at risk, such as people who work with HAV-infected primates, who work with HAV in research laboratories, or work with sewage or in sewage-containing environments.

Depending on conditions, HAV can be stable in the environment for months. Heating foods at temperatures greater than 185 F (85 C) for one minute or disinfecting surfaces with a 10% bleach solution is necessary to inactivate HAV.

CDC References: and

Occupational Disease: Hepatitis B HBV

Risk Factors and Symptoms: Hepatitis B is a serious disease caused by a virus that attacks the liver. The virus, which is called hepatitis B virus (HBV), can cause lifelong infection, cirrhosis (scarring) of the liver, liver cancer, liver failure, and death.

Transmission occurs with contact with infectious blood, semen, and other potentially infectious materials (OPIM) as defined in the OSHA Bloodborne Pathogens standard.

People at risk for HBV infection might also be at risk for infection with hepatitis C virus (HCV) or human immunodeficiency virus HIV.

Treatment: No medication is available; best addressed through supportive treatment. Periodically monitor liver disease progression.

Prevention: Hepatitis B vaccine. Wear disposable rubber gloves, eye and face protection, and protective clothing, as appropriate, when handling human blood and OPIM. Refer to M-445-2-H.25, Bloodborne Pathogens Protection Program for additional requirements.

CDC References: and

Occupational Disease: Histoplasmosis

Risk Factors and Symptoms: Histoplasmosis is a disease caused by the fungus Histoplasma capsulatum. The fungus lives in the environment, usually in association with large amounts of bird or bat droppings. It mainly lives in the central and eastern United States, especially areas around the Ohio and Mississippi River valleys. The fungus also lives in parts of Central and South America, Africa, Asia, and Australia. Lung infection can occur after a person inhales airborne, microscopic fungal spores from the environment; however, many people who inhale the spores do not get sick. The symptoms of histoplasmosis are similar to pneumonia, and the infection can sometimes become serious if it is not treated.

Treatment: The mild pulmonary (lung) form of histoplasmosis will generally resolve within about a month without treatment. Prescription antifungal medications are needed to treat severe cases of acute histoplasmosis and all cases of chronic or disseminated disease.

Prevention: There is no vaccine to prevent histoplasmosis. It is not always possible to prevent exposure to the fungus in areas where the fungus is endemic. However, employees should avoid areas with accumulations of bird or bat droppings, especially if one has a weakened immune system. Areas with accumulations of bird or bat droppings should be cleaned up by professional companies that specialize in the removal of hazardous waste. If employees are required to clean up bird or bat droppings in the area, use dust control methods such as wetting down droppings and contaminated soil before removal. In addition, wear PPE to include rubber gloves, disposable coveralls with hoods and shoe coverings. The minimum respiratory protection is based on the level of contamination. Consult with the local industrial hygienist. Employees should also wear appropriate protective clothing and the appropriate respirator when entering environments containing bird and bat droppings such as bird and bat nesting or roosting areas and caves. Also prevent birds and bats from nesting in buildings and lodgings.

Before starting a job or activity where there is a possibility of being exposed to H. capsulatum, consult the NIOSH/NCID document Histoplasmosis: Protecting Workers at Risk.

CDC Reference:

Occupational Disease: Lyme disease

Risk Factors and Symptoms: Lyme disease is caused by the bacterium Borrelia burgdorferi and is transmitted to humans by the bite of infected blacklegged ticks. Typical symptoms include fever, headache, fatigue, and a characteristic skin rash called erythema migrans. If left untreated, infection can spread to the joints, heart, and nervous system. Lyme disease is diagnosed based on symptoms, physical findings (e.g., expanding “bull's-eye” rash or a non-descript around the site of tick bite), and the possibility of exposure to infected ticks; laboratory testing is helpful if used correctly and performed with validated methods.

Treatment: Employees who discover a tick lodged in their skin should carefully remove it with tweezer by grabbing the tick as close to the skin as possible. Tick bites are to be reported in the DOI Safety Management and Information System (SMIS). Employees should be vigilant and watch for signs and symptoms of infection. Seek medical attention if any of these symptoms presents itself after a tick bite. Most cases of Lyme disease can be treated successfully with a few weeks of antibiotics.

Prevention: Reducing exposure to ticks is the best defense against Lyme disease and other tick-borne infections. Steps to prevent Lyme disease include using insect repellent with 20%-30% DEET or permethrin. Use products that contain DEET or permethrin on clothing. Treat clothing and gear, such as boots, pants, socks and tents, removing ticks promptly with tweezers, landscaping, and integrated pest management. Wear long sleeves and pants. Use of tick gaiters is recommended. Avoid bushy and wooded areas if possible. Perform thorough tick checks after spending time outdoors. Use of tick gaiters is recommended.

A Lyme disease vaccine is no longer available. The vaccine manufacturer discontinued production in 2002, citing insufficient consumer demand. Protection provided by this vaccine diminishes over time. Therefore, if you received the Lyme disease vaccine before 2002, you are probably no longer protected against Lyme disease.

CDC Reference:

Occupational Disease: Malaria

Risk Factors and Symptoms: Infection with malaria parasites may result in a wide variety of symptoms, including fever, chills, general malaise, nausea, vomiting, headaches, body aches, and flu-like illness. Left untreated, they may develop severe complications and die. Malaria disease can be categorized as uncomplicated or severe (complicated). In general, malaria is a curable disease if diagnosed and treated promptly and correctly.

Following the infective bite by the Anopheles mosquito, first symptoms usually appear after 7 to 30 days. Antimalarial drugs taken for prophylaxis by travelers can delay the appearance of malaria symptoms by weeks or months, long after the traveler has left the malaria-endemic area. (This can happen particularly with Plasmodium vivax and P. ovale, both of which can produce dormant liver stage parasites; the liver stages may reactivate and cause disease months after the infective mosquito bite.) Such long delays between exposure and development of symptoms can result in misdiagnosis or delayed diagnosis because of reduced clinical suspicion by the health-care provider. Returned travelers should always remind their health-care providers of any travel in malaria-risk areas during the past 12 months.

Treatment: Oral medications or continuous intravenous infusion of antimalarial drugs such as chloroquine and quinine.

Prevention: Employees should avoid mosquito bites by employing personal and household protection measures, such as using insect repellent containing DEET applied to skin and clothing, wearing protective clothing, taking precautions from dusk to dawn when mosquitoes are most likely to bite, and controlling standing water that can provide mosquito breeding sites.

Use antimalarial drugs prophylactically, prior to traveling to certain countries. The drugs do not prevent initial infection through a mosquito bite, but they prevent the development of malaria parasites in the blood, which are the forms that cause disease. This type of prevention is also called "suppression."

Employees preparing for international travel should conduct an individual risk assessment along with their supervisor, taking into account not only the destination country, but also the detailed itinerary, including specific cities, types of accommodation, season, and style of travel. In addition, conditions such as pregnancy or the presence of antimalarial drug resistance at the destination may modify the risk assessment. A risk assessment from CDC can be found here:

CDC References: and

Occupational Disease: Plague

Risk Factors and Symptoms: Plague is an infectious disease of animals and humans caused by a bacterium named Yersinia pestis.

People usually get plague from being bitten by a rodent flea that is carrying the plague bacterium or by handling an infected animal. Today, modern antibiotics are effective against plague, but if an infected person is not treated promptly, the disease is likely to cause illness or death. When a person has plague pneumonia and cough, droplets containing plague bacteria can be spread into the air. If a non-infected person inhales these infectious droplets, they also can become infected. In occupational environments, the disease can be transmitted to humans through handling rodents and rabbits with infected fleas, handling tissue or fluids of infected animals, inhaling or ingesting such fluids and materials.

Plague symptoms depend on how the patient was exposed to the plague bacteria. Plague can take different clinical forms, but the most common are bubonic, pneumonic and septicemic. Bubonic: fever, headache, chills, and weakness and one or more swollen, tender and painful lymph nodes (called buboes); Septicemic: may develop from untreated bubonic plague; Pneumonic: Pneumonic plague may develop from inhaling infectious droplets or may develop from untreated bubonic or septicemic plague after the bacteria spread to the lungs as a rapidly developing pneumonia.

Treatment: Employees working with infected or suspected infected rodents or tissues should seek medical treatment from a healthcare provider if experiencing symptoms. Plague is treatable with commonly available antibiotics.

Prevention: A plague vaccine is no longer available in the United States. Preventive antibiotic treatment may be given when transmission is suspected.

CDC References:

Occupational Disease: Rabies

Risk Factors and Symptoms: Rabies is a preventable viral disease of mammals most often transmitted through the bite of a rabid animal. It is also possible, but quite rare, that people may get rabies if infectious material from a rabid animal, such as saliva, gets directly into their eyes, nose, mouth, or a wound. Inhalation of aerosolized rabies virus is also a potential non-bite route of exposure, but except for laboratory workers, most people won't encounter an aerosol of rabies virus. The vast majority of rabies cases reported to the Centers for Disease Control and Prevention (CDC) each year occur in wild animals like raccoons, skunks, bats, and foxes.

Rabies virus infects the central nervous system, causing encephalopathy and ultimately death. Early symptoms of rabies in humans are nonspecific, consisting of fever, headache, and general malaise. As the disease progresses, neurological symptoms appear and may include insomnia, anxiety, confusion, slight or partial paralysis, excitation, hallucinations, agitation, hypersalivation, difficulty swallowing, and hydrophobia (fear of water). Death usually occurs within days of the onset of symptoms.

Treatment: There is no treatment for rabies after symptoms of the disease appear. Post-exposure prophylaxis which includes a human rabies immunoglobulin and vaccine are administered.

Prevention: Pre-exposure vaccination is recommended for people in high-risk groups, such as veterinarians, animal handlers, and certain laboratory workers. Other people whose activities bring them into frequent contact with rabies virus or potentially rabid bats, raccoons, skunks, cats, dogs, or other species at risk of having rabies should also be considered for pre-exposure prophylaxis. In addition, international travelers likely to come in contact with animals in areas of enzootic dog rabies which lack immediate access to appropriate medical care, including biologics, should be considered for pre-exposure prophylaxis.

People who work with live rabies virus in research laboratories or vaccine production facilities are at the highest risk of inapparent exposures. Such people should have a serum (blood) sample tested for antibody every 6 months and receive booster vaccine, when necessary. Routine pre-exposure prophylaxis for other situations may generally not be indicated. Vaccinate animals.

Wear protective clothing, disposable rubber gloves, and eye and face protection, as appropriate, when handling high risk animals and infectious materials.

CDC Reference:

Occupational Disease: Relapsing Fever

Risk Factors and Symptoms: Relapsing Fever is a disease characterized by relapsing or recurring episodes of fever, often accompanied by headache, muscle and joint aches and nausea lasting several days, followed by an interval without fever, followed by another episode of fever. Symptoms can reoccur, producing a telltale pattern of fever lasting roughly 3 days, followed by 7 days without fever, followed by another 3 days of fever. Without antibiotic treatment, this process can repeat several times.

It is caused by certain species of Borrelia spirochetes (cork-screw shaped bacteria. There are two forms of relapsing fever: Tick-borne relapsing fever (TBRF) and Louse-borne relapsing fever (LBRF). TBRF is caused by Borrelia hermsii, B. parkeri, and B. turicatae that are transmitted to humans through the bite of infected soft ticks. Most cases occur in the summer months and are associated in particular with sleeping in rustic, rodent-infested cabins in mountainous areas of the Western United States.

LBRF is caused by another spiral-shaped bacterium, B. recurrentis that is transmitted from human to human by the body louse. LBRF still causes sporadic illness and outbreaks in Africa. Illness can be severe, with mortality of 30% to 70% in outbreaks. In the United States, TBRF most often occurs after staying in a rustic cabin where rodents have made their nests.

Treatment: Seek medical treatment if you show repeated patterns of symptoms followed by periods of no fever, especially after lodging in rustic cabins in the mountainous area of the Western United States. TBRF spirochetes are susceptible to multiple doses of penicillin and other beta-lactam antimicrobials, as well as tetracyclines, macrolides, and possibly fluoroquinolones. In contrast to TBRF, LBRF caused by B. recurrentis can be treated effectively with a single dose of antibiotics.

Prevention: Avoid sleeping in rodent infested buildings. Limit tick bites by using insect repellent containing DEET (on skin or clothing) or permethrin (applied to clothing and equipment). Permethrin can be applied on boots and clothing, and will last for several days. Repellents containing DEET (n, n-diethyl-m-toluamide) can be applied to the skin, but will last only a few hours before reapplication is necessary. Use DEET with caution on children because adverse reactions have been reported. Wear long sleeves and pants. Use of tick gaiters outside is recommended. Avoid bushy and wooded areas if possible. Perform thorough tick checks after spending time outdoors.

Rodent-proof buildings in areas where the disease is known to occur. Identify and remove any rodent nesting material from walls, ceilings and floors. In combination with removing the rodent material, fumigate the building with preparations containing pyrethrins and permethrins. More than one treatment is often needed to effectively rid the building of the vectors, the soft-ticks. Always follow product instructions, and consider consulting a licensed pest control specialist.

CDC Reference:

Occupational Disease: Rocky Mountain Spotted Fever

Rocky Mountain spotted fever (RMSF) is a tickborne disease caused by the bacterium Rickettsia rickettsii. This organism is a cause of potentially fatal human illness in North and South America, and is transmitted to humans by the bite of infected tick species. In the United States, these include the American dog tick (Dermacentor variabilis), Rocky Mountain wood tick (D. andersoni), and brown dog tick (Rhipicephalus sanguineus).

Risk Factors and Symptoms: Symptoms include fever, headache, abdominal pain, vomiting, and muscle pain. A rash may also develop, but is often absent in the first few days, and in some patients, never develops. Rocky Mountain Spotted Fever can be a severe or even fatal illness if not treated in the first few days of symptoms.

Treatment: Seek medical treatment from a health care provider if symptoms occur after bitten by a tick. Doxycycline is the first line treatment for adults and children of all ages and should be initiated immediately whenever RMSF is suspected (within 5 days after symptoms start).

Prevention: No vaccine or prophylaxis treatment is available. Limiting exposure to ticks is the most effective way to reduce the likelihood of Rocky Mountain spotted fever infection. In people exposed to tick-infested habitats, prompt careful inspection and removal of crawling or attached ticks is an important method of preventing disease. Limit tick bites by using insect repellent containing DEET (on skin or clothing) or permethrin (applied to clothing and equipment). Permethrin can be applied on boots and clothing, and will last for several days. Repellents containing DEET (n, n-diethyl-m-toluamide) can be applied to the skin, but will last only a few hours before reapplication is necessary. Use DEET with caution on children because adverse reactions have been reported. Wear long sleeves and pants. Use of tick gaiters outside is recommended. Avoid bushy and wooded areas if possible.

Perform thorough tick checks after spending time outdoors. Currently, no licensed vaccine is available for the prevention of Rocky Mountain spotted fever.

CDC Reference:

Occupational Disease: Salmonellosis

Risk Factors and Symptoms: Salmonellosis is an infection with bacteria of genus Salmonella. Salmonella species have been known to cause illness for over 100 years. Most people infected with Salmonella develop diarrhea, fever, and abdominal cramps 12 to 72 hours after infection. The illness usually lasts 4 to 7 days, and most people recover without treatment. However, in some people, the diarrhea may be so severe that the patient needs to be hospitalized. In these cases, the person is treated promptly with antibiotics.

Salmonella is usually transmitted to humans by eating foods contaminated with animal feces, such as beef, poultry, milk, eggs, and vegetables. Transmission also occurs from inadequate hand washing after handling infected animals, including birds and reptiles.

Treatment: Most do not require treatment other than oral fluids and supportive care. People with severe diarrhea may require rehydration with intravenous fluids.

Prevention: There is no vaccine to prevent salmonellosis. People should wash their hands after contact with animal or animal feces. Wear personal protective clothing when handling animals, feces, and contaminated items.

CDC Reference:

Occupational Disease: Southern Tick-Associated Rash Illness (STARI)

Risk Factors and Symptoms: The rash of STARI is a red, expanding “bull's-eye” lesion that develops around the site of a lone star tick bite. The rash usually appears within 7 days of a tick bite and expands to a diameter of 8 centimeters (3 inches) or more. Patients may also experience fatigue, headache, fever, and muscle pains. The saliva from lone star ticks can be irritating; redness and discomfort at a bite site does not necessarily indicate an infection.

Treatment: Seek medical treatment if symptoms appear after being bitten by a tick. It is not known whether antibiotic treatment is necessary or beneficial for patients with STARI. Nevertheless, because STARI resembles early Lyme’s Disease, physicians will often treat patients with oral antibiotics.

Prevention: Wear long pants and sleeved shirts. Tuck your pants legs into your socks so that ticks cannot crawl up the inside of your pants legs. Apply repellants to discourage tick attachment. Repellents containing DEET or permethrin can be sprayed on boots and clothing, and will last for several days. Repellents containing DEET (N, N-diethyl-meta-toluamide) can be applied to the skin, but will last only a few hours before reapplication is necessary. Use DEET with caution on children because adverse reactions have been reported. Use of tick gaiters is recommended. Avoid bushy and wooded areas if possible. Perform thorough tick checks after spending time outdoors.

Conduct a body check upon return from potentially tick-infested areas by searching your entire body for ticks. Use a hand-held or full-length mirror to view all parts of your body. Remove any tick you find on your body carefully with tweezers.

CDC Reference:

Occupational Disease: Tetanus

Risk Factors and Symptoms: Tetanus is an infection caused by bacteria called Clostridium tetani. When the bacteria invade the body, they produce a poison (toxin) that causes painful muscle contractions. Another name for tetanus is "lockjaw" because it often causes a person's neck and jaw muscles to lock, making it hard to open the mouth or swallow.

Tetanus bacteria are everywhere in the environment, including soil, dust and manure. The bacteria can get into the body through broken skin, usually through injuries from contaminated objects. Certain breaks in the skin that are more likely to get infected with tetanus bacteria include wounds contaminated with dirt, feces, or saliva, puncture wounds, burns, crush injuries, injuries with dead tissue.

Symptoms include headache, jaw cramping, sudden, involuntary muscle tightening often in the stomach, painful muscle stiffness all over the body, trouble swallowing, jerking or staring (seizures), fever and sweating, high blood pressure and fast heart rate. Symptoms can progress and may lead to death.

Treatment: Tetanus is a medical emergency requiring hospitalization, immediate treatment with human tetanus immune globulin, tetanus vaccine, drugs to control muscle spasms, aggressive wound care, and antibiotics. Depending on how severe the infection is, a machine to help you breathe may be required.

Prevention: Tetanus-Diphtheria Vaccine (all adults, every 10 years but it can also be given earlier after a severe and dirty wound or burn). Immediate and proper wound care can also help prevent infection.

CDC Reference:

Occupational Disease: Tularemia

Risk Factors and Symptoms: Tularemia is a disease of animals and humans caused by the bacterium Francisella tularensis. Humans can become infected through several routes, including tick and deer fly bites, skin contact with infected animals, ingestion of contaminated water, laboratory exposure, and inhalation of contaminated dusts or aerosols.

Symptoms of tularemia could include: sudden fever, chills, headaches, diarrhea, muscle aches, joint pain, dry cough, and progressive weakness. People can also catch pneumonia and develop chest pain, bloody sputum and can have trouble breathing and even sometimes stop breathing. Other symptoms of tularemia depend on how a person was exposed to the tularemia bacteria. These symptoms can include ulcers on the skin or mouth, swollen and painful lymph glands, swollen and painful eyes, and a sore throat.

Treatment: Antibiotics used to treat tularemia include streptomycin, gentamicin, doxycycline, and ciprofloxacin. Treatment usually lasts 10 to 21 days depending on the stage of illness and the medication used.

Prevention: Use insect repellent containing DEET on your skin, or treat clothing with repellent containing permethrin or picaridin to prevent insect bites. Wear long pants, long sleeves, and long socks to keep tick and deer flies off your skin. Tuck in pant legs into your socks so that ticks cannot crawl up inside your pant leg. Remove attached ticks promptly with fine-tipped tweezers. Do not drink untreated surface water.

Wear rubber gloves and other personal protective equipment as needed to protect against direct skin contact with infected animal carcasses. Wash your hands often, using soap and warm water, especially after handling animal carcasses. Be sure to cook your food thoroughly and that your water is from a safe source.

Note any change in the behavior of your pets (especially rodents, rabbits, and hares) or livestock, and consult a veterinarian if they develop unusual symptoms.

CDC Reference:

Occupational Disease: Typhoid Fever

Risk Factors and Symptoms: Typhoid Fever is a life-threatening illness caused by the bacterium Salmonella typhi. In the United States about 400 cases occur each year, and 75% of these are acquired while traveling internationally.

Salmonella typhi lives only in humans. People with typhoid fever carry the bacteria in their bloodstream and intestinal tract. In addition, a small number of people, called carriers, recover from typhoid fever but continue to carry the bacteria. Both ill people and carriers shed S. typhi in their feces (stool).

You can get typhoid fever if you eat food or drink beverages contaminated by an infected person or if contaminated sewage gets into the drinking water. Typhoid Fever is more common in areas of the world where handwashing is less frequent and water is likely to be contaminated with sewage.

Symptoms include lasting high fevers, weakness, stomach pains, headache, and loss of appetite. Some patients have constipation, and some have a rash. Internal bleeding and death can occur but are rare.

Treatment: Employees should seek medical treatment immediately from a health care provider if they have high fever and feel very ill. If traveling in a foreign country, employees can usually call the U.S. consulate for a list of recommended doctors.

Typhoid fever can be prevented and can usually be treated with antibiotics.

Prevention: Two basic actions can protect you from Typhoid Fever:

 1. Avoid risky foods and drinks.

 2. Get vaccinated against typhoid fever.

Watching what you eat and drink during travel is as important as being vaccinated. This is because the vaccines are not completely effective. Avoiding risky foods will also help protect you from other illnesses including travelers' diarrhea, cholera, dysentery, and hepatitis A.

CDC References: and

Occupational Disease: West Nile Virus

Risk Factors and Symptoms: West Nile virus is an arthropod-borne virus (arbovirus) most commonly spread by infected mosquitoes. West Nile virus can cause febrile illness, encephalitis (inflammation of the brain) or meningitis (inflammation of the lining of the brain and spinal cord).

Most people get infected with West Nile virus by the bite of an infected mosquito. Mosquitoes become infected when they feed on infected birds. Infected mosquitoes can then spread the virus to humans and other animals. In a very small number of cases, West Nile virus has been spread through blood transfusions, organ transplants, and from mother to baby during pregnancy, delivery, or breastfeeding.

West Nile virus has been detected in all lower 48 states (not in Hawaii or Alaska). The incubation period is usually 2 to 6 days but ranges from 2 to 14 days. This period can be longer in people with certain medical conditions that affect the immune system. No symptoms in most people. Most people (70-80%) who become infected with West Nile virus do not develop any symptoms.

Febrile illness in some people. About 1 in 5 people who are infected will develop a fever with other symptoms such as headache, body aches, joint pains, vomiting, diarrhea, or rash. Most people with this type of West Nile virus disease recover completely, but fatigue and weakness can last for weeks or months.

Severe symptoms in a few people. Less than 1% of people who are infected will develop a serious neurologic illness such as encephalitis or meningitis (inflammation of the brain or surrounding tissues). The symptoms of neurologic illness can include headache, high fever, neck stiffness, disorientation, coma, tremors, seizures, or paralysis.

Recovery from severe disease may take several weeks or months. Some of the neurologic effects may be permanent. About 10 percent of people who develop neurologic infection due to West Nile virus will die.

Treatment: Currently there is no West Nile virus vaccine available for people.

Prevention: The easiest and best way to avoid West Nile Virus is to prevent mosquito bites:

CDC References: and

Occupational Disease: Zika Virus

Risk Factors and Symptoms: The Zika virus is a disease transmitted to people by infected mosquitoes through the Aedes species (Aedes aegypti and Ae. Albopictus). Aedes mosquitoes are endemic in the U.S. Virgin Islands, Puerto Rico, Hawaii, Guam and American Samoa. Aedes mosquitoes are also established in the continental United States, as far north as Iowa and New York, west to Texas, and in scattered areas of California, Arizona and New Mexico. This type of mosquito typically breeds in domestic water-holding containers, and is an aggressive daytime biter that feeds both indoors and outdoors near dwellings.

The Zika virus remains in the blood of an infected person for about a week, but in some people it may be longer. During the first week of infection, the virus can be passed from an infected person to a mosquito through a mosquito bite. The infected mosquito can then spread the virus to other people. In a small number of cases, the Zika virus has been transmitted sexually and through blood transfusions.

The local transmission of Zika virus has been reported in the U.S. Territories of the U.S. Virgin Islands, Puerto Rico and American Samoa, as well as in Mexico, Caribbean, and Central and South America. While there have not been any locally transmitted cases in the Continental United States to date, there have been multiple cases where people have become infected from traveling in areas with Zika virus. Thus the Centers for Disease Control and Prevention (CDC) has issued Travel Health Notices for countries with ongoing Zika virus transmission.

Treatment: Currently, no vaccine or medication exists to prevent or treat Zika virus infection. When Zika virus does cause illness, symptoms are generally mild and do not require medical treatment. If you develop the symptoms described above and have recently visited or live in an area where the Zika virus is found, consult with your doctor. A preliminary diagnosis is based on symptoms, travel history and or area of residence. Specialized blood tests are used to confirm the diagnosis of Zika virus. Care is generally focused on relieving the symptoms and includes:

Prevention: Persons traveling to or residing in areas of active Zika virus transmission should take steps to prevent infection through prevention of mosquito bites such as:

The CDC recommends that all pregnant women consider postponing travel to areas where Zika virus transmission is ongoing. Pregnant women traveling to an area with Zika virus transmission are advised to strictly follow steps to avoid mosquito bites.

CDC and DOI References: and

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Last modification: 22-Aug-2017@14:31