Fair use, etc http://www.express-news.net/auth/ennews/ap/texas/d0654.html Two more diagnosed with meningitis in suburban Houston "HOUSTON (AP) - Two more cases of spinal meningitis were confirmed this weekend in suburban Houston, bringing the number to at least 18 cases in the area since Oct. 9, health officials said. Two have died of the disease this month. The meningitis outbreak has been added to concerns raised late last year about Houston's potential for epidemic as the city with the lowest vaccination rate in the nation - a city officials say is already vulnerable to disease because of its role as major port and airline hub. Although meningitis hasn't been included in the traditional round of childhood shots, there has been growing worry among area health professionals about meningitis and hepatitis, as well as traditional childhood disease. Mass vaccinations were given to those between two and 24 Saturday at New Caney Junior High School. About 8,000 people from five counties parked along the highway and waited in line for hours to receive vaccines provided by the Texas Department of Health. The vaccination program was recommended in the community of about 2,700 by the Centers for Disease Control and Prevention and the Montgomery County Health Department, said H. Mark Guidry, Texas Department of Health regional director. Vaccinations are recommended when cases exceed one per 100,000 in a three-month period. The Texas Department of Health is trying to determine if it will give mass vaccinations in Conroe. Meningitis is a severe bacterial infection of tissue covering the brain and spinal cord and can result in blindness, deafness, amputations and permanent brain damage. It is not as contagious as the common cold or flu and is spread by direct contact, such as coughing, sneezing, kissing and immediate sharing of unwashed utensils. Symptoms may include fever, severe headache, stiff neck, nausea, vomiting, a rash, confusion, drowsiness and coma, according to the health department. A vaccine is effective against some of the bacteria that cause meningitis, but can't cure those already exposed, health officials said. On Thursday, the CDC declared an official meningitis outbreak in Montgomery County, just north of Houston. The two new cases are in Fort Bend county, in suburban southwest Houston. A 13-year-old boy from Magnolia, about 35 miles northwest of Houston and a 56-year-old woman from the Houston suburb of Humble, in Harris County, have died of the disease in the past two weeks. Over the weekend, officials confirmed an eighth-grade student at Lamar Junior High School in Fort Bend County was taken to the emergency room after developing symptoms of the disease. Christy Willman, Lamar Consolidated School District spokeswoman, said an elementary school student from Pink Elementary School in the Lamar district has been sick since early last week with the disease. The 11 cases in Montgomery County include the boy who died in Magnolia, five cases in Conroe, one in Porter and one in Spring. ``We have been concerned for a long time about the vaccination rate and the possibility of an epidemic in the Houston area,'' said Rosie Perez, a director of community health for St. Joseph's hospital in Houston Walt Orenstein, a physician who directs the CDC's national immunization program, visited Houston last fall and warned officials that the city's low immunization rate puts the entire nation at risk because it could serve as the portal for an epidemic. He said that a national resurgence of measles between 1989 and 1991 which infected 55,000 people and killed 120 started in Houston, the nation's fourth largest city. Houston's role as a hub of international travel and an immigrant city with more than 22 percent of its population foreign-born also can be factors in the unwelcome import of disease, Brock Lamont, chief of immunization for the Houston Department of Health and Human services has said. Residents in the New Caney school district can still receive the vaccine at local clinics Monday, officials said, and the Montgomery County Health Department in Conroe will also be administering the vaccine. Another immunization program is set this week for the 3,600 students in the Humble school district in northeast Harris County, where five cases have been reported.

-- tex (tex@tex.com), January 21, 2001

Answers

yahoo

A link from this page to KHOU, Houston, says 34 cases have now been confirmed. When Edmonton gets 3 or 4 cases confirmed, it vaccinates its entire youth population. The outbreak in Houston is sounding very serious.

-- Rachel Gibson (rgibson@hotmail.com), January 23, 2001.

Just to make clear, the current Texas outbreak involves the bacterium _Neisseria meningitidis_, also known as the "meningococcus," a bacterial cause of meningitis and other infections. (There are a variety of other bacterial causes of meningitis--one other serious type that has been largely eliminated through childhood vaccination is _Haemophilus influenzae_ type B, or "HiB.")

The newspaper article contains some information that even if true is not relevant, such as the poor overall immunization rate among kids in Houston--this outbreak would not be prevented by improving coverage with the routine childhood vaccines.

It may be helpful to keep in mind that many people carry the meningococcus in their nose and throat without ill effect (= colonization); in winter months well over 10% of people in the U.S. may carry it, even 25% at times. Why a relatively few people develop disease is not always clear, although causes may include prior carriage of less pathogenic strains, genetic predisposition or underlying immune problems (young age can be included here), "stress", and/or more virulent strain of the bacteria, among others.

Here is the latest CDC guideline for use of the meningococcal vaccine:

http://www.cdc.gov/mmwr/PDF/rr/rr4907.pdf (June 2000)

In general, the vaccine is thought to benefit the population at large (or a specific age group that appears at risk based on the specific scenario) only when there is evidence of an outbreak, i.e., on-going transmission of a strain of the meningococcus that is causing disease.

The vaccine is also helpful in certain situations where people are packed together under stress and there is epidemiologic evidence of generally increased risk-- for example, new military recruits crowded together in barracks; pilgrims to Mecca during the annual Haj; college freshmen living in college dorms (this last is a new recommendation).

Note that the meningococcal vaccine has relatively limited effectiveness compared for example to some of the common childhood viral vaccines such as measles. (As a general statement, it is harder to develop highly effective vaccines against bacterial infections than against viral infections.) The vaccine is limited in use by age of patient (particularly in that it doesn't work for kids < 2 years). Also, it is specific only for certain serogroups of the meningococcus. The U.S. vaccine covers serogroups A, C, W135, and Y; a particular problem (due to the underlying biology) has been in making a vaccine effective against serogroup B, although progress is being made and candidate vaccines exist.

For more information, here is a link to a short factsheet:

http://www.health.state.pa.us/hpa/CDI/bacmen.htm

or see the CDC website.

-- Andre Weltman (aweltman@state.pa.us), January 23, 2001.

Headline: Vaccine proves a failure; Left Quebec infants open to contracting meningitis

Source: The Montreal Gazette, Wednesday 10 January 2001, http://www.montrealgazette.com/ A mass vaccination campaign against meningitis in Quebec in the early 1990s proved useless in protecting infants who were the most at risk of contracting the disease, a study published today in a major U.S. medical journal reveals.

And the vaccine that was given probably would no longer be effective in immunizing the rest of the public should another meningitis outbreak strike the province, the lead researcher said yesterday.

Although an experimental vaccine currently in use in England has been shown to be highly effective, it's rarely used in the rest of Europe and not available in Quebec, said Dr. Philippe De Wals, an epidemiologist at the Universite de Sherbrooke.

Still, De Wals said Quebec is probably better prepared to deal with another epidemic of the potentially fatal meningococcal disease, in part because of the findings of his study.

Quebec public-health authorities, for example, now know it would not make sense to use the old vaccine again if an outbreak occurs.

"We found that the vaccine was effective in the first two years after it was administered, but we have no evidence that it worked later on," De Wals said in an interview. "In other words, it was a short- term vaccine."

At the time that it was introduced, authorities thought the vaccine would be effective for five years. The Quebec government commissioned De Wals to evaluate the long-term impact of the polysacharide vaccine after its mass immunization campaign of 1992- 93.

The results of the study are published in today's Journal of the American Medical Association.

The researchers discovered that the vaccine was virtually useless in immunizing children between 6 months and 2 years old. In fact, eight infants who were vaccinated later developed meningococcal disease - a bacterial infection that causes inflammation of the tissue in the brain and spine.

That raises the alarming scenario that the vaccine itself might have been responsible for infecting the infants.

But De Wals refused to jump to that conclusion: "We can't say whether the vaccine caused the illness in these children."

The vaccine was judged 40-per-cent effective in children between the ages of 2 and 9; 75-per-cent effective among those in the 10-to-14 range; and 85-per-cent effective among those 15 or older.

"It's a vaccine that's excellent for adults and the military, but much less effective among the youth," De Wals said.

Although the incidence of meningococcal disease is low, about one case per 100,000 population, news reports of outbreaks strike fear in the hearts of parents. It's a terrifying disease that can strike quickly and kill within hours if untreated.

The provincial government spent up to $30 million immunizing 1.6 million Quebecers, following clusters of the meningococcal disease reported in all age groups across the province in 1991-92.

It was the largest immunization effort since the polio-vaccination campaign of the 1950s. The researchers noted that the number of cases of the highly contagious disease dropped markedly in 1993 after the mass immunization, and remained low thereafter.

For the period covered under the study, Jan. 1, 1990, until Dec. 31, 1998, a total of 899 cases were reported.

The study compared the numbers of patients who developed meningitis despite being vaccinated with the statistics on those who also fell ill but had not been vaccinated.

De Wal's study was the first to examine the impact of a mass immunization against men-ingococcal disease.

More than 110,000 infants up to 2 years old were vaccinated, costing the government $1.7 million.

"In retrospect, we can see that it was probably unfounded to use this vaccine on infants," De Wals said. "At the time, there was a lot of uncertainty and a political decision was made."

Preliminary results indicate that the experimental conjugate vaccine in use in England since November 1999 is 80- per-cent effective for all age groups combined. By comparison, the polysacharide vaccine is considered to have an over-all success rate of 60 per cent.

"If we were to carry out another mass vaccination across Canada, it would make more sense to use the new vaccine, certainly for the most young," he said. "But the problem is that there's a shortage of the vaccine in England. It also costs 10 times more than old vaccine.

"I think that as a result of our study, the government and pharmaceutical companies should accelerate the process of producing the new vaccine," De Wals added.

Meningococcal disease is transmitted though contact with secretions from the nose and throat of an infected person. Symptoms include high fever, severe headaches, neck stiffness, nausea and vomiting.

There are two common types: meningococcal meningitis and meningococcal septicemia. Septicemia is the type that most often kills.

Across Canada each year, there are about 250 to 300 cases of meningococcal disease, usually during the winter months. Most are isolated cases.

-- Andre Weltman (aweltman@state.pa.us), January 24, 2001.