Twenty-seven more people have tested positive for tuberculosis at Olathe Northwest High School, state and county health officials said Wednesday, but so far none has shown any symptoms of active disease.
The 27 were among 304 students and staff members the Johnson County Department of Health and Environment tested last week after a student was diagnosed earlier this month with an active case of TB. Only people with active TB can infect others.
Health officials on Monday began calling people who had tested positive; letters were mailed to those with no sign of the infection, the health officials said. People who tested positive will receive antibiotic treatment through the health department.
With many people away on spring break, not everyone who tested positive has been contacted yet.
“The number of individuals with TB infection does not exceed what we would anticipate in this setting,” health department director Lougene Marsh said. “Of course, we had hoped we wouldn’t find any additional TB cases, but we knew this was a possibility. That’s why we took such thorough steps to test everyone who might have been in close contact with the first confirmed case of TB disease.”
The health department also tested about 40 to 50 other people who were “close personal contacts” of the student but were not associated with the school, Marsh said. Some of these people also tested positive, but Marsh declined to say how many. “It might get much too close to identifying individuals,” she said.
Because it can take up to eight weeks for tuberculosis to show up positive in a blood test, a second round of tests will be provided May 5 for people whose initial tests were negative.
While those who tested positive last week have not shown any symptoms, they will still have to undergo chest X-rays to confirm that they do not have active TB.
Tuberculosis is caused by bacteria that can remain dormant, often in the lungs of infected people, for years, even a lifetime. Only about 10 percent of people infected with it develop the disease. When TB becomes active, people may develop fevers and night sweats, cough up blood, lose weight and become weak and fatigued. Left untreated, it can be fatal.
Tuberculosis is spread through the air by coughing, laughing, singing and sneezing. A person would have to be in close contact for several hours a day with an infected person to contract the disease. It cannot be spread by a handshake or a drinking glass, desk or other surfaces.
“It’s not enough just walking in the room and walking out. It takes some time in the vicinity of the patient,” said Dana Hawkinson, an infectious disease specialist at the University of Kansas Hospital.
The course of antibiotic treatment for tuberculosis depends on whether it’s active, Hawkinson said. Patients with active TB typically receive a battery of four drugs for two months, then two drugs for an additional four months. After several weeks of treatment, they are no longer able to transmit the disease to others.
Patients who have been exposed to TB but do not have active disease usually take a single antibiotic every day for nine months. “It significantly reduces the chance of getting active disease later in life,” Hawkinson said.
The Olathe Northwest student who was initially diagnosed had developed TB symptoms in early December, Marsh said. The health department was notified early this month when the student was diagnosed with active disease.
Marsh said the student was started immediately on medication and was placed in home isolation as a precaution. The student remained in isolation Wednesday.
The health department’s usual protocol for active tuberculosis is called directly observed treatment. A health care worker watches as patients take their medications to make sure they are taken correctly.
Except for a brief uptick in the early 1990s, tuberculosis has been declining steadily in the United States, from 84,304 active cases in 1953 to 9,582 in 2013, according to the U.S. Centers for Disease Control and Prevention.
From 2012 through 2014, Johnson County has averaged seven or eight active cases each year. During that time, the county has had a total of 109 probable or confirmed TB infections.
Olathe Northwest officials got some calls from curious parents Wednesday, but not a great deal of them, district spokeswoman Maggie Kolb said.
What callers learned is that the district is continuing to work with health officials to get information out to those who were tested for the disease, but there is no cause for alarm.
No special sanitation measures are necessary, as the germ doesn’t live on hand rails, doorknobs and other surfaces, Kolb said.
Also, no change in routine is planned when staff returns from spring break on Monday, or when students return to classes the following day.
“At this point, it will be business as usual,” Kolb said.
In a statement Wednesday, school officials said they would continue to rely on the expertise of the county health department.
“Both of our organizations are committed to protecting the safety and wellness of our students and staff,” the district said, “and also in providing accurate and timely information for all of the impacted families.”
What is tuberculosis?
Tuberculosis is caused by Mycobacterium tuberculosis. The bacteria usually attack the lungs but can attack any part of the body, including the kidney, spine and brain. If not treated properly, TB can be fatal.
How do the bacteria spread?
Through the air. When a person with TB disease of the lungs or throat coughs, sneezes, speaks or sings, people nearby may breathe in the bacteria and become infected.
How do TB bacteria lead to disease?
The bacteria become active if a person’s immune system can’t stop them from growing. When TB bacteria are active (multiplying in the body), this is called TB disease. People with TB disease may be able to spread the bacteria to others.
Does everyone with the infection get the disease?
No. Most will have a latent TB infection, in which TB bacteria live in the body without making a person sick. People with latent TB infection do not feel sick and do not have symptoms. They are not infectious and cannot spread TB bacteria to others. However, if TB bacteria become active in the body, the person will go from having latent TB infection to being sick with TB disease.
What are symptoms of TB disease?
Bad cough that lasts three weeks or longer; pain in the chest; coughing up blood or sputum; weakness or fatigue; weight loss; lack of appetite; chills; fever; sweating at night.
What is the treatment?
For TB disease, several drugs are taken, usually for six to nine months. For latent TB infection, treatment reduces the risk that TB infection will progress to TB disease. The decision about taking treatment for latent TB infection will be based on a person’s chances of developing TB disease.
How many cases of tuberculosis are reported in the U.S. each year?
In 2013, a total of 9,582 TB cases were reported. That’s a rate of 3 cases per 100,000 persons.
Is the rate of TB declining in the U.S.?
Yes. The number of cases has declined since 1992, which was the peak year in a resurgence of the disease.
How do TB rates in the U.S. compare between U.S.-born and foreign-born persons?
In 2013, almost two-thirds of reported TB cases in the United States occurred among foreign-born persons.
How many people die from TB in the United States?
There were 536 deaths from TB in 2011, the most recent year for which numbers are available. Since 1992, the number of TB deaths reported annually has decreased by 69 percent.
Source: U.S. Centers for Disease Control and Prevention