prophylaxis

PrEP and PEP are medicines to prevent HIV. Each type is used in a different situation:

• PrEP stands for pre-exposure prophylaxis. It is for people who don't already have HIV but are at risk of getting it. PrEP is medicine that can reduce this risk. It can either be a pill that you take every day or an injection that you get every two months. With PrEP, if you do get exposed to HIV, the medicine can stop HIV from taking hold and spreading throughout your body.
• PEP stands for post-exposure prophylaxis. PEP is for people who have possibly been exposed to HIV. It is only for emergency situations. PEP must be started within 72 hours after a possible exposure to HIV.

PrEP can help protect you if you don't have HIV and any of these applies to you:

• You have had anal or vaginal sex in the past 6 months and:
  • Have a sexual partner with HIV,
  • Have not consistently used a condom, OR
  • Have been diagnosed with a sexually transmitted infection (STI) in the past 6 months
• You inject drugs and:
  • Share needles or other equipment to inject drugs OR
  • Have an injection partner with HIV
• You have been prescribed PEP and:
  • Continue engaging in high-risk behaviors OR
  • Have used multiple courses of PEP

If you have a partner who is HIV-positive and are considering getting pregnant, talk to your health care provider about PrEP. Taking it may help protect you and your baby from getting HIV infection while you try to get pregnant, during pregnancy, or while breastfeeding.

PrEP is very effective when you take it consistently. It reduces the risk of getting HIV from sex by about 99%. In people who inject drugs, it reduces the risk of HIV by at least 74%. PrEP is much less effective if you do not take it consistently.

PrEP does not protect against other STIs, so you should still use latex condoms every time you have sex. If your or your partner is allergic to latex, you can use polyurethane condoms.

You must have an HIV test every 3 months while taking PrEP, so you'll have regular follow-up visits with your provider. If you are having trouble taking PrEP every day or if you want to stop taking PrEP, talk to your provider.

Some people taking PrEP may have side effects, like nausea. The side effects are usually not serious and often get better over time. If you are taking PrEP, tell your provider if you have a side effect that bothers you or that does not go away.

If you are HIV-negative and you think you may have been recently exposed to HIV, contact your health care provider immediately or go to an emergency room right away.

You may be prescribed PEP if you are HIV negative or don't know your HIV status, and in the last 72 hours you may have been exposed to HIV:

• During sex, for example if a condom broke during sex with someone who could have HIV,
• Through the sharing of needles or drug preparation equipment, OR
• Through sexual assault

Your provider or emergency room doctor will help to decide whether PEP is right for you.

PEP may also be given to a health care worker after a possible exposure to HIV at work, for example, from a needlestick injury.

PEP must be started within 72 hours (3 days) after a possible exposure to HIV. The sooner you start it, the better; every hour counts.

You need to take the PEP medicines every day for 28 days. You will have to see your provider at certain times during and after taking the PEP, so you can have an HIV screening test and other testing.

Some people taking PEP may have side effects, like nausea. The side effects are usually not serious and often get better over time. If you are taking PEP, tell your provider if you have a side effect that bothers you or that does not go away.

PEP medicines may also interact with other medicines that a person is taking (called a drug interaction). So it's important to tell your provider about any other medicines that you take.

PEP is only for emergency situations. It is not the right choice for people who may be exposed to HIV frequently - for example, if you often have sex without a condom with a partner who is HIV-positive. In that case, you should talk to your health care provider about whether PrEP (pre-exposure prophylaxis) would be right for you.

HIV stands for human immunodeficiency virus. HIV harms your immune system by destroying a type of white blood cell that helps your body fight infection. This puts you at risk for other infections and diseases.

AIDS stands for acquired immunodeficiency syndrome. It is the final stage of infection with HIV. It happens when the body's immune system is badly damaged because of the virus. Not everyone with HIV develops AIDS.

HIV is spread through certain body fluids from a person who has HIV. This can happen:

• By having unprotected vaginal or anal sex with a person who has HIV. "Unprotected" means not using condoms or medicine to treat or prevent HIV. This is the most common way that it spreads.
• By sharing drug needles.
• Through contact with the blood of a person with HIV.
• From mother to baby during pregnancy, childbirth, or breastfeeding.

Anyone can get HIV, but certain groups have a higher risk of getting it:

• People who have another sexually transmitted infection (STI). Having an STI can increase your risk of getting or spreading HIV.
• People who inject drugs with shared needles.
• Gay and bisexual men.
• Black/African Americans and Hispanic/Latino Americans. They make up a higher proportion of new HIV diagnoses and people with HIV, compared to other races and ethnicities.
• People who engage in risky sexual behaviors, such as not using condoms or medicine to prevent or treat HIV.

Factors such as stigma, discrimination, income, education, and geographic region can also affect people's risk for HIV.

The first signs of HIV infection may be flu-like symptoms:

• Fever
• Chills
• Rash
• Night sweats (heavy sweating during sleep)
• Muscle aches
• Sore throat
• Fatigue
• Swollen lymph nodes
• Mouth ulcers

These symptoms may come and go within two to four weeks. This stage is called acute HIV infection.

If the infection is not treated, it becomes chronic HIV infection. Often, there are no symptoms during this stage. If it is not treated, eventually the virus will weaken your body's immune system. Then the infection will progress to AIDS. This is the late stage of HIV infection. Because your immune system is badly damaged, your body cannot fight off other infections, called opportunistic infections (OIs). OIs are infections that happen more frequently or are more severe in people who have weakened immune systems.

Some people may not feel sick during the earlier stages of HIV infection. So the only way to know for sure whether you have HIV is to get tested.

A blood test can tell if you have HIV infection. Your health care provider can do the test, or you can use a home testing kit. You can also use the CDC Testing Locator to find free testing sites.

There is no cure for HIV infection, but it can be treated with medicines. This is called antiretroviral therapy (ART). ART can make HIV infection a manageable chronic condition. It also reduces the risk of spreading the virus to others.

Most people with HIV live long and healthy lives if they get ART as soon as possible and stay on it. It's also important to take care of yourself. Making sure that you have the support you need, living a healthy lifestyle, and getting regular medical care can help you enjoy a better quality of life.

You can reduce the risk of getting or spreading HIV by:

• Getting tested for HIV.
• Choosing less risky sexual behaviors. This includes limiting the number of sexual partners you have and using latex condoms every time you have sex. If your or your partner is allergic to latex, you can use polyurethane condoms.
• Getting tested and treated for sexually transmitted infections (STIs).
• Not injecting drugs.
• Talking to your health care provider about medicines to prevent HIV:
  • PrEP (pre-exposure prophylaxis) is for people who don't already have HIV but are at very high risk of getting it. PrEP is daily medicine that can reduce this risk.
  • PEP (post-exposure prophylaxis) is for people who have possibly been exposed to HIV. It is only for emergency situations. PEP must be started within 72 hours after a possible exposure to HIV.

NIH: National Institutes of Health

HIV stands for human immunodeficiency virus. It harms your immune system by destroying CD4 cells. These are a type of white blood cells that fight infection. The loss of these cells makes it hard for your body to fight off infections and certain HIV-related cancers.

Without treatment, HIV can gradually destroy the immune system and advance to AIDS. AIDS stands for acquired immunodeficiency syndrome. It is the final stage of infection with HIV. Not everyone with HIV develops AIDS.

The treatment of HIV with medicines is called antiretroviral therapy (ART). It involves taking a combination of medicines every day. ART is recommended for everyone who has HIV. The medicines do not cure HIV infection, but help people with HIV live longer, healthier lives. They also reduce the risk of spreading the virus to others.

HIV medicines reduce the amount of HIV (viral load) in your body, which helps by:

• Giving your immune system a chance to recover. Even though there is still some HIV in your body, your immune system should be strong enough to fight off infections and certain HIV-related cancers.
• Reducing the risk that you will spread HIV to others.

There are many different types (called classes) of HIV medicines. Some work by blocking or changing enzymes that HIV needs to make copies of itself. This prevents HIV from copying itself, which reduces the amount of HIV in the body. Several types of medicines do this:

• Nucleoside reverse transcriptase inhibitors (NRTIs) block an enzyme called reverse transcriptase
• Non-nucleoside reverse transcriptase inhibitors (NNRTIs) bind to and later change reverse transcriptase
• Integrase inhibitors, also called integrase strand transfer inhibitors (INSTIs), block an enzyme called integrase
• Protease inhibitors (PIs) block an enzyme called protease

Some types of HIV medicines interfere with HIV's ability to infect CD4 immune system cells:

• Fusion inhibitors block HIV from entering the cells
• CCR5 antagonists and post-attachment inhibitors block different molecules on the CD4 cells. To infect a cell, HIV has to bind to two types of molecules on the cell's surface. Blocking either of these molecules prevents HIV from entering the cells.
• Attachment inhibitors bind to a specific protein on the outer surface of HIV. This prevents HIV from entering the cell.

Pharmacokinetic enhancers are another type of medicine. They are sometimes taken along with certain other HIV medicines. Pharmacokinetic enhancers increase the effectiveness of the other medicine. They work by slowing the breakdown of the other medicine. This allows that medicine to stay in the body longer at a higher concentration.

There are also multidrug combinations, which include a combination of two or more different types of HIV medicines.

It's important to start taking HIV medicines as soon as possible after your diagnosis, especially if you:

• Are pregnant
• Have AIDS
• Have certain HIV-related illnesses and infections
• Have an early HIV infection (the first 6 months after infection with HIV)

You and your health care provider will work together to come up with a personal treatment plan. This plan will be based on many factors, including:

• The possible side effects of HIV medicines
• Potential drug interactions with any other medicines you take
• How many medicines you will need to take every day
• Any other health problems you may have

It's important to take your medicines every day, according to the instructions from your provider. If you miss doses or don't follow a regular schedule, your treatment may not work, and the HIV virus may become resistant to the medicines.

HIV medicines can cause side effects. Most of these side effects are manageable, but a few can be serious. Tell your provider about any side effects that you are having. Don't stop taking your medicine without first talking to your provider. There may be steps you can take to help manage the side effects. In some cases, your provider may decide to change your medicines.

HIV medicines are not just used for treatment. Some people take them to prevent HIV. PrEP (pre-exposure prophylaxis) is for people who don't already have HIV but are at very high risk of getting it. PEP (post-exposure prophylaxis) is for people who have possibly been exposed to HIV.

NIH: Office of AIDS Research

Leukemia is a term for cancers of the blood cells. Leukemia starts in blood-forming tissues such as the bone marrow. Your bone marrow makes the cells which will develop into white blood cells, red blood cells, and platelets. Each type of cell has a different job:

• White blood cells help your body fight infection
• Red blood cells deliver oxygen from your lungs to your tissues and organs
• Platelets help form clots to stop bleeding

When you have leukemia, your bone marrow makes large numbers of abnormal cells. This problem most often happens with white blood cells. These abnormal cells build up in your bone marrow and blood. They crowd out the healthy blood cells and make it hard for your cells and blood to do their work.

Acute lymphocytic leukemia is a type of acute leukemia. It's also called ALL and acute lymphoblastic leukemia. "Acute" means that it usually gets worse quickly if it's not treated. ALL is the most common type of cancer in children. It can also affect adults.

In ALL, the bone marrow makes too many lymphocytes, a type of white blood cell. These cells normally help your body fight infection. But in ALL, they are abnormal and cannot fight infection very well. They also crowd out the healthy cells, which can lead to infection, anemia, and easy bleeding. These abnormal cells can also spread to other parts of the body, including the brain and spinal cord.

ALL happens when there are changes in the genetic material (DNA) in bone marrow cells. The cause of these genetic changes is unknown. However, there are certain factors that raise your risk of ALL.

The factors that raise your risk of ALL include:

• Being male
• Being white
• Being over age 70
• Having had chemotherapy or radiation therapy
• Having been exposed to high levels of radiation
• Having certain genetic disorders, such as Down syndrome

The signs and symptoms of ALL include:

• Weakness or feeling tired
• Fever or night sweats
• Easy bruising or bleeding
• Petechiae, which are tiny red dots under the skin. They are caused by bleeding.
• Shortness of breath
• Weight loss or loss of appetite
• Pain in the bones or stomach
• Pain or feeling of fullness below the ribs
• Swollen lymph nodes - you may notice them as painless lumps in the neck, underarm, stomach, or groin
• Having had many infections

Your health care provider may use many tools to diagnose ALL and figure out which subtype you have:

• A physical exam
• A medical history
• Blood tests, such as
  • Complete blood count (CBC) with differential
  • Blood chemistry tests such as a basic metabolic panel (BMP), comprehensive metabolic panel (CMP), kidney function tests, liver function tests, and electrolyte panel
  • Blood smear
• Bone marrow tests. There are two main types - bone marrow aspiration and bone marrow biopsy. Both tests involve removing a sample of bone marrow and bone. The samples are sent to a lab for testing.
• Genetic tests to look for gene and chromosome changes

If you are diagnosed with ALL, you may have additional tests to see whether the cancer has spread. These include imaging tests and a lumbar puncture, which is a procedure to collect and test cerebrospinal fluid (CSF).

Treatments for ALL include:

• Chemotherapy
• Radiation therapy
• Chemotherapy with stem cell transplant
• Targeted therapy, which uses drugs or other substances that attack specific cancer cells with less harm to normal cells

Treatment is usually done in two phases:

• The goal of the first phase is to kill the leukemia cells in the blood and bone marrow. This treatment puts the leukemia into remission. Remission means that the signs and symptoms of cancer are reduced or have disappeared.
• The second phase is known as post-remission therapy. Its goal is to prevent a relapse (return) of the cancer. It involves killing any remaining leukemia cells that may not be active but could begin to regrow.

Treatment during both phases also usually includes central nervous system (CNS) prophylaxis therapy. This therapy helps prevent the spread of leukemia cells to the brain and spinal cord. It may be high dose chemotherapy or chemotherapy injected into the spinal cord. It also sometimes includes radiation therapy.

NIH: National Cancer Institute

If you are pregnant or planning to get pregnant, it's important to get tested for HIV as soon as possible. If you find out that do have HIV, you can start treatment right away to protect your health and the health of your baby.

If you are pregnant and have HIV, there is a risk of passing HIV to your baby. It can happen in three ways:

• During pregnancy
• During childbirth, especially if it is vaginal childbirth
• During breastfeeding

But having HIV doesn't mean that you can't have children. Treatment with a combination of HIV medicines can help prevent passing HIV to your baby and protect your own health.

There are several different steps you can take to help prevent passing HIV to your baby:

• Taking HIV medicines. HIV medicines reduce the amount of HIV in the body (viral load) to a very low level. The goal is to get your viral load so low that a standard lab test can't detect it. This is called having an "undetectable viral load." Having an undetectable viral load is the best thing you can do to stay healthy and prevent your baby from getting HIV. These medicines will also help protect your health. Most HIV medicines are safe to use during pregnancy. They don't usually raise the risk of birth defects. But it is important to talk with your health care provider about the risks and benefits of the different medicines. Together you can decide which medicines are right for you. Then you need to make sure you take your medicines regularly.
• If needed, having a cesarean delivery. If your viral load is not reduced enough by the medicines, having a cesarean delivery (C-Section) can help prevent passing HIV to your baby.
• Giving HIV medicines to the baby. Your baby will get HIV medicines as soon as possible after birth. The medicines protect your baby from infection from any HIV that passed from you during childbirth. Which medicine your baby gets depends on several factors, including what your viral load was just before you gave birth. Your baby will need to take medicines for 4 to 6 weeks. He or she will get several HIV tests over the first few months.
• Not breastfeeding. Breast milk can have HIV in it. In the United States, infant formula is safe and readily available. So the Centers for Disease Control and Prevention and the American Academy of Pediatrics recommend that if you have HIV, you should feed your baby formula instead of breastfeeding.

If you are trying to get pregnant, it's important for your partner to also get tested for HIV.

If your partner does have HIV and you do not, talk to your provider about taking PrEP. PrEP stands for pre-exposure prophylaxis. This means taking medicines to prevent HIV. The PrEP helps to protect both you and your baby from HIV.

Meningococcal disease is the name for any illness that is caused by Neisseria meningitidis bacteria (also called meningococcal bacteria). These illnesses are often severe and can sometimes be deadly. They include infections of the lining of the brain and spinal cord (meningitis) and in the bloodstream (sepsis). Vaccines can help prevent the disease.

Some people have Neisseria meningitidis, the bacteria that cause the disease, in the back of their nose and throat. They usually have the bacteria but don't get sick. This is called being a "carrier." But sometimes the bacteria can spread to other parts of the body and cause meningococcal disease.

The bacteria can spread from person to person through saliva (spit). It usually happens through close or lengthy contact with a person who has it. Close contact can include things like kissing and coughing.

You cannot catch the bacteria through casual contact with someone who has the disease. For example, you cannot get it by breathing air where that person has been.

Anyone can get meningococcal disease, but you are more likely to get it if someone you live with has it. You are also more likely to get it if you have direct contact with the saliva of someone who has it (like through kissing).

Also, certain groups of people are more likely to get the disease. They include:

• Children younger than 1 year old.
• Teens and young adults ages 16 through 23 years old.
• Adults 65 years and older.
• People with medical conditions that weaken their immune system, including those with HIV and certain rare immune system diseases.
• People who either don't have a spleen or have a spleen that does not function well.
• People who take complement inhibitor. These are immunotherapy medicines that are given to people with certain rare conditions.
• People who live in crowded settings, such as college dorms or military barracks.
• People who travel to areas where the disease is more common, such as certain parts of sub-Saharan Africa.

There are different types of meningococcal disease. The most common types are meningitis and septicemia. Both types are very serious and can be deadly in a matter of hours.

Meningococcal meningitis is a meningococcal infection of the lining of the brain and spinal cord. The most common symptoms include:

• Fever
• Headache
• Stiff neck

It can also cause symptoms such as:

• Nausea and vomiting
• Photophobia (your eyes being more sensitive to light)
• Confusion

It may be hard to notice these symptoms in newborns and babies. They can also have different symptoms. They may:

• Be slow or inactive
• Be irritable
• Vomit
• Feed poorly
• Have a bulging of the soft spot of their skull

Meningococcal septicemia is a meningococcal infection of the bloodstream. It's also called meningococcemia. When someone has this disease, the bacteria enter the bloodstream and multiply. This damages the walls of the blood vessels and causes bleeding into the skin and organs. The symptoms may include:

• Fever and chills
• Fatigue
• Vomiting
• Cold hands and feet
• Severe aches or pain in the muscles, joints, chest, or abdomen (belly)
• Rapid breathing
• Diarrhea
• A dark purple rash (in the later stages of the disease)

Because it is so serious, you need to seek immediate medical attention if you or your child develops the symptoms of meningococcal disease.

The signs and symptoms of meningococcal disease are often similar to those of other illnesses. This can make it hard to diagnose.

If your (or your child's) health care provider thinks that you or your child could have meningococcal disease, they will order tests that take samples of blood and/or cerebrospinal fluid (fluid near the spinal cord). They will send the samples to a lab for testing. The testing will include bacteria culture testing, which can identify the specific type of bacteria that is causing the infection. Knowing this can help the provider decide on the best treatment.

Certain antibiotics can treat meningococcal disease. It is important that treatment is started as soon as possible. So if the provider thinks you have meningococcal disease, they will give you antibiotics right away (before the test results come back).

People with serious disease may need additional treatments, such as:

• Breathing support
• Medicines to treat low blood pressure
• Surgery to remove dead tissue
• Wound care for parts of the body with damaged skin

Some people with meningococcal disease will have long-term health problems and disabilities. These may include:

• Loss of limb(s)
• Deafness
• Nervous system problems
• Brain damage

Even with treatment, 10 to 15 in 100 people will die from the disease.

The best way to prevent meningococcal disease is to get vaccinated. The U.S. Centers for Disease Control and Prevention (CDC) recommends meningococcal vaccination for:

• All preteens and teens
• Children at higher risk for meningococcal disease
• Adults at higher risk for meningococcal disease

If you are a close contact of a person with meningococcal disease, you will likely be given antibiotics to prevent you from getting sick. This is called "prophylaxis." Close contacts include people who are living together. They also include people who had direct contact with the saliva of a person who has the disease (such as from kissing).

Although it's rare, you can get meningococcal disease more than once.

Centers for Disease Control and Prevention

Rabies is a deadly animal disease caused by a virus. It can happen in wild animals, including raccoons, skunks, bats and foxes, or in dogs, cats or farm animals. People get it from the bite of an infected animal.

In people, symptoms of rabies include fever, headache and fatigue, then confusion, hallucinations and paralysis. Once the symptoms begin, the disease is usually fatal. A series of shots can prevent rabies in people exposed to the virus. You need to get them right away. If an animal bites you, wash the wound well; then get medical care.

To help prevent rabies:

• Vaccinate your pet. Rabies vaccines are available for dogs, cats and farm animals
• Don't let pets roam
• Don't approach stray animals. Animals with rabies might be aggressive and vicious, or tired and weak

Centers for Disease Control and Prevention