The majority of healthy people with normal immunity may never become ill with TB, unless they are heavily exposed to infectious cases who are not treated or who have been on treatment for less than about one week. Even then, 90% of people infected with TB bacteria never develop TB disease. This applies to XDR-TB as well as to "ordinary" TB. People with HIV infection, however, in close contact with a TB patient, are more likely to catch TB and fall ill.

People who are ill with pulmonary TB (i.e. TB of the lungs, the site most commonly affected) are often infectious and can spread the disease by coughing, or sneezing, or simply talking, as this propels TB bacteria into the air. A person needs only to breathe in a small number of these germs to become infected (although only a small proportion of people will become infected with TB disease).

XDR-TB is the abbreviation for extensively drug-resistant tuberculosis (TB). One in three people in the world is infected with dormant TB germs (i.e. TB bacteria). Only when the bacteria become active do people become ill with TB. Bacteria become active as a result of anything that can reduce the person's immunity, such as HIV, advancing age, or some medical conditions. TB can usually be treated with a course of four standard, or first-line, anti-TB drugs.

The most important thing is for a patient to continue taking all their treatment exactly as prescribed. No doses should be missed, but this is especially important if the course of treatment is meant to be taken every other day: so-called "intermittent treatment". Above all, the treatment should be taken right through to the end.

Extensively drug resistant TB (XDR TB) is a rare type of MDR TB. XDR TB is defined as TB that is resistant to isoniazid and rifampin, plus resistant to any fluoroquinolone and at least one of three injectable second-line drugs (i.e., amikacin, kanamycin or capreomycin). Because XDR TB is resistant to first-line and second-line drugs, patients are left with treatment options that are much less effective.

Yes, in some cases. Several countries with good TB control programmes have shown that cure is possible for up to 30% of affected people. But successful outcomes also depend greatly on the extent of the drug resistance, the severity of the disease and whether the patient's immune system is compromised.

This depends on the patient's access to health-care services. If TB bacteria are found in the sputum, the diagnosis of TB can be made in a day or two, but this finding will not be able to distinguish between drug-susceptible and drug-resistant TB. To evaluate drug susceptibility, the bacteria need to be cultivated and tested in a suitable laboratory. Final diagnosis in this way for TB, and especially for XDR-TB, may take from 6 to 16 weeks.

A blood test can determine whether or not a person is infected with HIV. The most commonly used test detects antibodies (disease-fighting proteins) against HIV. It may take as long as three to six months for HIV antibodies to reach levels that are measurable in standard blood tests.

TB Infection (Latent TB) means that the bacteria are inside your body but they are not active. Typically, these people have strong immune systems and consequently, never have TB symptoms nor develop the disease. What's more, they do not pass the disease on to other people. People with TB infection usually have positive skin test reactions and can develop the active disease at any point if they do not receive preventative therapy.

Sometimes the TB bacteria are resistant to the medicines used to treat TB disease. This means that the medicine can no longer kill the bacteria. Multidrug-resistant TB, or MDR TB, is bacteria that are resistant to two or more of the most important TB medicines: INH and RIF. A more serious form of MDR TB is called extensively drug-resistant TB (XDR TB). XDR TB is a rare type of TB that is resistant to nearly all medicines used to treat TB disease.

The BCG vaccine prevents severe forms of TB in children, such as TB meningitis. It would be expected that BCG would have the same effect in preventing severe forms of TB in children, even if they were exposed to XDR-TB, but it may be less effective in preventing pulmonary TB in adults, the commonest and most infectious form of TB. The effect of BCG against XDR-TB would therefore likely be very limited.

XDR-TB has been found in every region of the world, though it is still very rare. People who are at most risk, if they do come into contact with someone with XDR-TB, are those with reduced immunity to infectious diseases, such as those with HIV infection or other medical conditions that can weaken a person's immunity. It is also advised that such people should avoid high-risk areas where there are no infection control measures in place.

People whose resistance is low due to conditions such as HIV infection, diabetes, some cancers, and chemotherapy

estimated 33% of the 40 million people living with HIV/AIDS worldwide are co-infected with TB. Furthermore, without proper treatment, approximately 90% of people living with HIV/AIDS die within months of contracting TB. The majority of people who are co-infected with both diseases live in sub-Saharan Africa.

No. TB bacteria are spread from person to person through the air only. TB infection cannot be acquired by handling food or objects.

Studies of families of HIV-infected people have found that HIV is not spread through sharing utensils, towels, bedding, or toilet facilities. Behaviors that increase the likelihood of contact with blood from an HIV-infected person, such as sharing a razor or toothbrush, should be avoided.

Mumps virus has been found in respiratory secretions 3 days before the start of symptoms until 9 days after onset. Although mumps virus has been detected on rare occasions for up to 9 days after symptom onset, the patient is most infectious within the first 5 days.

Tuberculosis, or TB, is a disease caused by a germ (called the tubercle bacterium or Mycobacterium tuberculosis). TB usually affects the lungs, but can affect other parts of the body, such as the lymph nodes (glands), the bones and (rarely) the brain. Infection with the TB germ may not develop into TB disease.

The bacteria that causes trachoma can be spread easily on an infected person's hands or clothing, or may be carried by flies that have come into contact with discharge from the eyes or nose of an infected person. Because trachoma is transmitted through close personal contact, it tends to occur in clusters, often infecting entire families and communities.

Yes. The survivability rate of a person infected with anthrax through either the cutaneous or gastrointestinal form of the infection, if caught early, is promisingly high. Antibiotics, such as ciprofloxacin (Cipro, manufactured by Bayer who currently holds the patent), doxycycline or penicillin, are used to treat the infected person for a period of about sixty (60) days to allow all of the anthrax spores to germanate and die.

People are infected with WNv by being bitten by an infected mosquito. The risk level in the province is expected to vary by region and to flare up in the summer and fall depending on climate conditions. The public will be notified by public health officials if birds or mosquitoes in the province test positive for the virus. When people are exposed to mosquitoes in an area the WN virus has been detected they are at risk for infection.

People have not been known to transmit the infection to others, so infected persons do not need to be isolated.

If treatment is recommended, consider your options and work with your doctor/clinician and local support system to prepare a treatment plan.

The "contagious" period varies, but it probably begins the day before symptoms appear and extends for about one week after the first symptoms appeared.

Because influenza is spread from person to person through the air, individuals who have an influenza-like illness should remain home until they have recovered from their illness.

This can vary, depending on the age and health of the infected person. In general, healthy adults can infect others from 1 day before they begin to feel sick to about 5 days after they first develop symptoms. Young children and people with chronic illnesses can infect others for about a week or more.

Using such facilities does not put a person at risk for HIV infection. Only activities that cause intimate contact with blood, vaginal secretions, semen, pre-ejaculation fluid, or breast milk of an HIV-infected person can transmit HIV.

the present time, the risk of becoming infected with H5N1 virus from bird feeders is low. Generally, perching birds (Passeriformes) are the predominate type of birds at feeders. While there are documented cases of H5N1 causing death in some Passeriformes (e.g., house sparrow, Eurasian tree-sparrow, house finch), most of the wild birds that are traditionally associated with avian influenza viruses are waterfowl and shore birds.