Cold, Flu, or Allergy?

Know the Difference for Best Treatment

You’re feeling pretty lousy. You’ve got sniffles, sneezing, and a sore throat. Is it a cold, flu, or allergies? It can be hard to tell them apart because they share so many symptoms. But understanding the differences will help you choose the best treatment.

“If you know what you have, you won’t take medications that you don’t need, that aren’t effective, or that might even make your symptoms worse,” says NIH’s Dr. Teresa Hauguel, an expert on infectious diseases that affect breathing.

Cold, flu, and allergy all affect your respiratory system, which can make it hard to breathe. Each condition has key symptoms that set them apart.

Colds and flu are caused by different viruses. “As a rule of thumb, the symptoms associated with the flu are more severe,” says Hauguel. Both illnesses can lead to a runny, stuffy nose; congestion; cough; and sore throat. But the flu can also cause high fever that lasts for 3-4 days, along with a headache, fatigue, and general aches and pain. These symptoms are less common when you have a cold.

“Allergies are a little different, because they aren’t caused by a virus,” Hauguel explains. “Instead, it’s your body’s immune system reacting to a trigger, or allergen, which is something you’re allergic to.” If you have allergies and breathe in things like pollen or pet dander, the immune cells in your nose and airways may overreact to these harmless substances. Your delicate respiratory tissues may then swell, and your nose may become stuffed up or runny.

“Allergies can also cause itchy, watery eyes, which you don’t normally have with a cold or flu,” Hauguel adds.

Allergy symptoms usually last as long as you’re exposed to the allergen, which may be about 6 weeks during pollen seasons in the spring, summer, or fall. Colds and flu rarely last beyond 2 weeks.

Most people with a cold or flu recover on their own without medical care. But check with a health care provider if symptoms last beyond 10 days or if symptoms aren’t relieved by over-the-counter medicines. For more about when to see a doctor, go to CDC's Flu Page .

To treat colds or flu, get plenty of rest and drink lots of fluids. If you have the flu, pain relievers such as aspirin, acetaminophen, or ibuprofen can reduce fever or aches. Allergies can be treated with antihistamines or decongestants. See the “Wise Choices” box for more details.

Be careful to avoid “drug overlap” when taking medicines that list 2 or more active ingredients on the label. For example, if you take 2 different drugs that contain acetaminophen—one for a stuffy nose and the other for headache—you may be getting too much acetaminophen.

“Read medicine labels carefully—the warnings, side effects, dosages. If you have questions, talk to your doctor or pharmacist, especially if you have children who are sick,” Hauguel says. “You don’t want to overmedicate, and you don’t want to risk taking a medication that may interact with another.”

Brain Eating Amoeba

What Is a Brain-Eating Amoeba?

Amoebas are single-celled organisms. The so-called brain-eating amoeba is a species discovered in 1965. It's formal name is Naegleria fowleri. Although first identified in Australia, this amoeba is believed to have evolved in the U.S.

There are several species of Naegleria but only the fowleri species causes human disease. There are several fowleri subtypes. All are believed equally dangerous.

N. fowleri is microscopic: 8 micrometers to 15 micrometers in size, depending on its life stage and environment. By comparison, a hair is 40 to 50 micrometers wide.

Like other amoebas, Naegleria reproduces by cell division. When conditions aren't right, the amoebas become inactive cysts. When conditions are favorable, the cysts turn into trophozoites -- the feeding form of the amoeba.

To reach their food, N. fowleri trophozoites temporarily grow tails (flagella) that allow them to swim. In this form they cannot eat, so they soon go back to the trophozoite stage.

Where Are Brain-Eating Amoebas Found?

Naegleria loves very warm water. It can survive in water as hot as 113 degrees Fahrenheit.

These amoebas can be found in warm places around the globe. N. fowleri is found in:

• Warm lakes, ponds, and rock pits
• Mud puddles
• Warm, slow-flowing rivers, especially those with low water levels
• Untreated swimming pools and spas
• Untreated well water or untreated municipal water
• Hot springs and other geothermal water sources
• Thermally polluted water, such as runoff from power plants
• Aquariums
• Soil, including indoor dust

Naegleria can't live in salt water. It can't survive in properly treated swimming pools or in properly treated municipal water.

Most cases of N. fowleri disease occur in Southern or Southwestern states. Over half of all infections have been in Florida and Texas.

How Do People Get Infected With Brain-Eating Amoeba?

The term "brain-eating amoeba" makes the amoeba sound like a tiny zombie stalking your skull. But brains are accidental food for them.

According to the CDC, N. fowleri normally eats bacteria. But when the amoeba gets into humans, it uses the brain as a food source.

The good news is that if you were to drink a glass of water infested with N. fowleri amoeba, you would not get a brain infection. It infects people by getting into your nose.

This happens most often when people are diving, water skiing, or performing water sports in which water is forced into the nose. But infections have occurred in people who dunked their heads in hot springs or who cleaned their nostrils with neti pots filled with untreated tap water.

A person infected with N. fowleri amoeba cannot spread the infection to another person.

How Do Amoebas Get in the Brain?

Studies suggest that N. fowleri amoebas are attracted to the chemicals that nerve cells use to communicate with one another. Once in the nose, the amoebas travel through the olfactory nerve (the nerve connected with sense of smell) into the frontal lobe of the brain.

How Frequently Do People Get Infected by Brain-Eating Amoeba?

Even though N. fowleri amoebas are relatively common, they only rarely cause brain disease. N. fowleri disease is known as primary amoebic meningoencephalitis (PAM). It occurs from zero to eight times a year, almost always from July to September.

It's considered a rare infection. But some cases may be unreported. A study in Virginia that looked at more than 16,000 autopsy records from patients who died of meningitis found five previously unreported cases of PAM.

Studies show that many people may have antibodies to N. fowleri. That suggests that they became infected with the amoeba but that their immune systems fought it off.

It's not at all clear whether N. fowleri is a rare infection that always causes PAM and is almost always fatal, or a more common infection that only sometimes causes PAM.

In a 2009 study, CDC researchers suggested that the common finding of antibodies to the amoeba in humans and the frequent finding of N. fowleri in U.S. waters indicates "that exposure to the amoeba is much more common than the incidence of PAM suggests."

How Long Until Symptoms of Brain-Eating Amoeba Appear?

It takes two to 15 days for symptoms to appear after N. fowleri amoebas enter the nose. Death usually occurs three to seven days after symptoms appear. The average time to death is 5.3 days from symptom onset. Only a handful of patients worldwide have been reported to have survived an infection.

What Are the First Symptoms Someone Might Have?

Symptoms of PAM are not specific to this disease. At first, PAM may seem like viral meningitis. Symptoms include:

• headache
• fever
• stiff neck
• loss of appetite
• vomiting
• altered mental state
• seizures
• coma

There may also be hallucinations, drooping eyelid, blurred vision, and loss of the sense of taste.

Is There a Treatment for Infection With Brain-Eating Amoeba?

The right treatment isn't clear. A number of drugs kill N. fowleri amoebas in the test tube. But even when treated with these drugs, very few patients survive.

Is There a Rapid Test for Infection With Brain-Eating Amoeba?

There is no rapid test for infection with brain-eating amoeba. But researchers are working to develop one. Until such tests come along, it can take weeks to identify the amoeba.

How Do Amoebas Dissolve Brain Tissue?

One study suggests that N. fowleri amoebas produce two proteases -- enzymes that dissolve protein.

There is also evidence that this particular species of amoeba is attracted to the olfactory nerve and then to the brain by the chemical messengers nerve and brain cells use to communicate with one another.

Are Certain Groups Affected More Than Others?

Over 60% of U.S. cases are in children age 13 or younger. About 80% of cases are in males.

It's not at all clear whether children or males are more susceptible to the amoeba, or whether young males are more likely to engage in activities that expose them to the amoeba.

How Can I Protect Myself Against Brain-Eating Amoeba?

It makes sense to avoid swimming underwater, diving, water skiing, and jumping in warm, still waters during the late summer. It also makes sense to wear a nose clip when swimming, boating, or playing in or on warm waters.

It's also a good idea to avoid stirring up mud while taking part in such activities.

And if you are cleansing your nostrils, be sure to fill your neti pot or squeeze bottle with distilled or sterile water and not tap water. You can also use water that has been boiled for one minute (three minutes at high elevations) and then cooled. And you can filter the water using filters with pores no larger than 1 micron (1 micrometer).

Sexual health

Sexual health basics

Sexuality is part of being human. Love, affection and intimacy all play a role in healthy relationships from childhood through old age.

You often hear about the importance of physical health, mental health and spiritual health, but feeling confident about your sexual health also is very important. Achieving sexual health allows for:

• Healthy relationships
• Planned pregnancies
• Avoidance of disease

That's why it's essential to be well-informed about all aspects of sexual health and what it takes to have a fulfilling sex life. Similarly, it's important to be aware of factors that can complicate your sexual health. Don't let embarrassment keep you from bringing up concerns or asking questions of your doctor or other health care providers.

STD prevention

Sexually transmitted diseases (STDs) are infections acquired by sexual contact. You can get an STD by having unprotected sex with a partner who's infected. You can't always tell if someone is infected, however, because many STDs cause no symptoms, at least at first. In fact, a person may have an STD without knowing it.

That's why you have to be vigilant about STD prevention. If you're sexually active, your best bet for STD prevention is to have just one sex partner who doesn't have any STDs and who has sex only with you. If you're not in an exclusive relationship, you can still protect yourself by learning about and consistently practicing STD prevention, such as using condoms

Women's sexual health

Women's sexual health is an important aspect of women's health, whether you're trying to prevent pregnancy and sexually transmitted infections or you're worried about low sex drive or other women's sexual health problems.

Learn how to achieve a fulfilling sexual relationship, and know how to protect yourself from sexually transmitted infections. As you get older, understand common changes in women's sexual health — and how to maintain a healthy and enjoyable sex life at any age.

Men's sexual health

Men's sexual health is an important aspect of men's health, whether you're trying to prevent pregnancy and sexually transmitted infections or you're worried about erectile dysfunction or other men's sexual health problems.

For some men, worries about penis size top the list of their sexual health concerns. However, you're probably more normal than you think — and penis-enlargement products and procedures aren't likely to be effective.

As you get older, understand common changes in men's sexual health — and how to maintain a healthy and enjoyable sex life at any age.

Sex and aging

Are sex and aging like oil and water? No! Many older adults desire and enjoy an active sex life. And an active interest in sex, as well as satisfaction with the frequency and quality of sexual activity, is positively associated with health in later life. So don't let anyone tell you that sex is only for the young.

Of course, there are some challenges when it comes to sex and aging. Physical changes, illness, disabilities and some medicines can make sex challenging or difficult to enjoy. Yet, many resources are available to older adults to help them achieve a satisfying sex life. Don't be afraid to bring up concerns with your doctor or other health care provider.

And remember, whatever your age, take precautions to protect yourself from sexually transmitted infections.

Talking to kids about sex

Kids and sexuality — those words strike fear into the hearts of many parents. But talking to kids about sex is an important part of parenting. Children and adolescents need your guidance to help them make healthy and appropriate decisions about their sexual behavior.

When it comes to talking to kids about sex, there's no set script. And sex education needn't be a single tell-all discussion. Instead, look for everyday opportunities and let your child set the pace with his or her questions. Provide just the information that your child is asking for and is able to understand. As your child matures and asks more-detailed questions, you can provide more-detailed responses.

It's normal to feel uncomfortable when talking to kids about sex. But remember that by providing accurate and open communication, you increase the odds that your child will understand your values and make appropriate choices about sex.

Hepatitis C

Symptoms

Hepatitis C infection usually produces no signs or symptoms during its earliest stages. When signs and symptoms do occur, they're generally mild and flu-like and may include:

• Fatigue
• Fever
• Nausea or poor appetite
• Muscle and joint pains
• Tenderness in the area of your liver

When to see a doctor 

Make an appointment with your doctor if you have any signs and symptoms that worry you.

Causes

Hepatitis C infection is caused by the hepatitis C virus (HCV). HCV is spread when you come in contact with contaminated blood.

Examples of how HCV can be spread include:

• Blood transfusions and organ transplants before 1992.Improved blood-screening tests became available in 1992. Before that year, it was possible to unknowingly contract hepatitis C through a blood transfusion or organ transplant.
• Shared needles. HCV can also spread through sharing contaminated needles when injecting drugs.
• Childbirth. A small number of babies born to mothers with hepatitis C acquire the infection during childbirth.
• Sexual contact. In rare cases, HCV may be transmitted sexually.

Risk factors

Your risk of hepatitis C infection is increased if you:

• Are a health care worker who has been exposed to infected blood
• Have ever injected illicit drugs
• Have HIV
• Received a piercing or tattoo in an unclean environment using unsterile equipment
• Received a blood transfusion or organ transplant before 1992
• Received clotting factor concentrates before 1987
• Received hemodialysis treatments for a long period of time
• Were born to a woman with a hepatitis C infection

Complications

Hepatitis C infection that continues over many years can cause significant complications, such as:

• Scarring of the liver tissue (cirrhosis). After 20 to 30 years of hepatitis C infection, cirrhosis may occur. Scarring in your liver makes it difficult for your liver to function.
• Liver cancer. A small number of people with hepatitis C infection may develop liver cancer.
• Liver failure. A liver that is severely damaged by hepatitis C may be unable to function.

Preparing for your appointment

Who to see 

If you think you may have a risk of hepatitis C, see your family doctor or a general practitioner. Once you've been diagnosed with hepatitis C infection, your doctor may recommend you see a specialist. Specialists who see people with hepatitis C infection include:

• Doctors who specialize in infectious diseases
• Doctors who specialize in liver diseases (hepatologists)

How to prepare 

Because appointments can be brief and because there's often a lot of ground to cover, it's a good idea to be well prepared. To prepare, try to:

• Be aware of any pre-appointment restrictions. At the time you make the appointment, be sure to ask if there's anything you need to do in advance, such as restrict your diet.
• Write down any symptoms you're experiencing, including any that may seem unrelated to the reason for which you scheduled the appointment.

Tests and diagnosis

Screening for hepatitis C 

Testing for hepatitis C infection in people who have a high risk of coming in contact with the virus may help doctors begin treatment or recommend lifestyle changes that may slow liver damage. This is recommended because hepatitis C infection often begins damaging the liver before it causes signs and symptoms.

People who may want to talk to their doctors about screening for hepatitis C infection include

Treatments and drugs

Treatment isn't always necessary 

A diagnosis of hepatitis C infection doesn't necessarily mean you need treatment. If you have only slight liver abnormalities, you may not need treatment, because your risk of future liver problems is very low. Your doctor may recommend follow-up blood tests to monitor for liver problems.

Antiviral medications 

Hepatitis C infection is treated with antiviral medications intended to clear the virus from your body. Your doctor may recommend a combination of medications taken over several weeks. Once you complete a course of treatment, your doctor will test your blood for the hepatitis C virus. If hepatitis C is still present, your doctor may recommend a second round of treatment.

Antiviral medications can cause depression and flu-like signs and symptoms, such as fatigue, fever and headache. Some side effects can be serious enough that treatment must be delayed or stopped in certain cases.

Liver transplant 

If your liver has been severely damaged, a liver transplant may be an option. During a liver transplant, the surgeon removes your damaged liver and replaces it with a healthy liver. Most transplanted livers come from deceased donors, though a small number come from living donors who donate a portion of their livers.

For people with hepatitis C infection, a liver transplant is not a cure. Treatment with antiviral medications usually continues after a liver transplant, since hepatitis C infection is likely to recur in the new liver.

Vaccinations to protect against other forms of viral hepatitis 

Your doctor will likely recommend that you receive vaccines against the hepatitis A and B viruses. These are separate viruses that also can cause liver damage and complicate treatment of hepatitis C.

Hepatitis C

Definition

Hepatitis C is an infection caused by a virus that attacks the liver and leads to inflammation. Most people infected with the hepatitis C virus (HCV) have no symptoms. In fact, most people don't know they have the hepatitis C infection until liver damage shows up, decades later, during routine medical tests.

Hepatitis C is one of several hepatitis viruses and is generally considered to be among the most serious of these viruses. Hepatitis C is passed through contact with contaminated blood — most commonly through needles shared during illegal drug use.

What are dengue fever symptoms and signs?

After being bitten by a mosquito carrying the virus, the incubation period ranges from three to 15 (usually five to eight) days before the signs and symptoms of dengue appear. Dengue starts with chills, headache, pain upon moving the eyes, and low backache. Painful aching in the legs and joints occurs during the first hours of illness. The temperature rises quickly as high as 104 F (40 C), with relative low heart rate (bradycardia) and low blood pressure (hypotension). The eyes become reddened. A flushing or pale pink rash comes over the face and then disappears. The glands (lymph nodes) in the neck and groin are often swollen.

Fever and other signs of dengue last for two to four days, followed by a rapid drop in body temperature (defervescence) with profuse sweating. This precedes a period with normal temperature and a sense of well-being that lasts about a day. A second rapid rise in temperature follows. A characteristic rash appears along with the fever and spreads from the extremities to cover the entire body except the face. The palms and soles may be bright red and swollen.

What is the treatment for dengue fever?

Because dengue fever is caused by a virus, there is no specific medicine or antibiotic to treat it. For typical dengue, the treatment is purely concerned with relief of the symptoms (symptomatic). Rest and fluid intake for adequate hydration is important. Aspirin and nonsteroidal anti-inflammatory drugs should only be taken under a doctor's supervision because of the possibility of worsening hemorrhagic complications. Acetaminophen (Tylenol) and codeine may be given for severe headache and for the joint and muscle pain (myalgia).

Dengue and dengue haemorrhagic fever

Key facts

• Dengue is a mosquito-borne infection that causes a severe flu-like illness, and sometimes a potentially lethal complication called dengue haemorrhagic fever.
• Global incidence of dengue has grown dramatically in recent decades.
• About two fifths of the world's population are now at risk.
• Dengue is found in tropical and sub-tropical climates worldwide, mostly in urban and semi-urban areas.
• Dengue haemorrhagic fever is a leading cause of serious illness and death among children in some Asian countries.
• There is no specific treatment for dengue, but appropriate medical care frequently saves the lives of patients with the more serious dengue haemorrhagic fever.
• The only way to prevent dengue virus transmission is to combat the disease-carrying mosquitoes.

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Dengue is a mosquito-borne infection that in recent decades has become a major international public health concern. Dengue is found in tropical and sub-tropical regions around the world, predominantly in urban and semi-urban areas.

Dengue haemorrhagic fever (DHF), a potentially lethal complication, was first recognized in the 1950s during dengue epidemics in the Philippines and Thailand. Today DHF affects most Asian countries and has become a leading cause of hospitalization and death among children in the region.

There are four distinct, but closely related, viruses that cause dengue. Recovery from infection by one provides lifelong immunity against that virus but confers only partial and transient protection against subsequent infection by the other three viruses. There is good evidence that sequential infection increases the risk of developing DHF.

Global burden of dengue

The incidence of dengue has grown dramatically around the world in recent decades. Some 2.5 billion people – two fifths of the world's population – are now at risk from dengue. WHO currently estimates there may be 50 million dengue infections worldwide every year.

In 2007 alone, there were more than 890 000 reported cases of dengue in the Americas, of which 26 000 cases were DHF.

The disease is now endemic in more than 100 countries in Africa, the Americas, the Eastern Mediterranean, South-east Asia and the Western Pacific. South-east Asia and the Western Pacific are the most seriously affected. Before 1970 only nine countries had experienced DHF epidemics, a number that had increased more than four-fold by 1995.

Not only is the number of cases increasing as the disease is spreading to new areas, but explosive outbreaks are occurring. In 2007, Venezuela reported over 80 000 cases, including more than 6 000 cases of DHF.

Some other statistics:

• During epidemics of dengue, infection rates among those who have not been previously exposed to the virus are often 40% to 50%, but can reach 80% to 90%.
• An estimated 500 000 people with DHF require hospitalization each year, a very large proportion of whom are children. About 2.5% of those affected die.
• Without proper treatment, DHF fatality rates can exceed 20%. Wider access to medical care from health providers with knowledge about DHF - physicians and nurses who recognize its symptoms and know how to treat its effects - can reduce death rates to less than 1%.

The spread of dengue is attributed to expanding geographic distribution of the four dengue viruses and their mosquito vectors, the most important of which is the predominantly urban species Aedes aegypti. A rapid rise in urban mosquito populations is bringing ever greater numbers of people into contact with this vector, especially in areas that are favourable for mosquito breeding, e.g. where household water storage is common and where solid waste disposal services are inadequate.