Alert for Seniors
Older people threatened by new diarrhea superbug
resistant to preventive drug
Young children, gay men are most common victims of
this diarrhea; threat may increase amount adults due to this bugs
resistance to preventive drug for adults
2, 2015 – A new variety of a bug that already causes about
half-a-million cases of diarrhea each year in the U.S. is proving
resistant to drugs usually prescribed to protect adults. This new
superbug is being imported by international travelers and has sickened
at least 243 people, with large recent outbreaks in Massachusetts,
Pennsylvania and California.
“These outbreaks show a troubling trend in
Shigella infections in the United
States,” said Dr. Tom Frieden, Director of the Centers for Disease
Control and Prevention (CDC).
“Drug-resistant infections are harder to treat and
because Shigella spreads so easily
between people, the potential for more – and larger – outbreaks is a
real concern. We’re moving quickly to implement a national strategy to
curb antibiotic resistance because we can’t take for granted that we’ll
always have the drugs we need to fight common infections.”
bacteria resistant to the antibiotic ciprofloxacin sickened 243 people
in 32 states and Puerto Rico between May 2014 and February 2015.
Research by the CDC found that the drug-resistant illness was being
repeatedly introduced as ill travelers returned and was then infecting
other people in a series of outbreaks around the country.
CDC and public health partners investigated several
recent clusters of shigellosis in Massachusetts, California and
Pennsylvania and found that nearly 90 percent of the cases tested were
resistant to ciprofloxacin (Cipro), the first choice to treat
shigellosis among adults in the United States. Shigellosis can spread
very quickly in groups like children in childcare facilities, homeless
people and gay and bisexual men, as occurred in these outbreaks.
In the United States, most
Shigella is already resistant to the
antibiotics ampicillin and trimethoprim/sulfamethoxazole. Globally,
Shigella resistance to Cipro is
increasing. Cipro is often prescribed to people who travel
internationally, in case they develop diarrhea while out of the United
States. More study is needed to determine what role, if any, the use of
antibiotics during travel may have in increasing the risk of
antibiotic-resistant diarrhea infections among returned travelers.
“The increase in drug-resistant
Shigella makes it even more critical
to prevent shigellosis from spreading,” said Anna Bowen, M.D., M.P.H., a
medical officer in CDC’s Waterborne Diseases Prevention Branch and lead
author of the study.
“Washing your hands with soap and water is
important for everyone. Also, international travelers can protect
themselves by choosing hot foods and drinking only from sealed
CDC’s PulseNet lab network identified an increase
in Shigella sonnei infections with an
uncommon genetic fingerprint in December 2014. Further testing at CDC’s
National Antimicrobial Resistance Monitoring System (NARMS) lab found
that the bacteria were resistant to Cipro.
PulseNet detected several large clusters: 45 cases
in Massachusetts; 25 cases in California; and 18 cases in Pennsylvania.
About half of the PulseNet cases with patient
information were associated with international travel, mostly to the
Dominican Republic and India. The San Francisco Department of Public
Health reported another 95 cases (nine of them among those identified by
PulseNet), with almost half occurring among the homeless or people
living in single-room occupancy hotels.
an estimated 500,000 cases of diarrhea in the United States every year.
It spreads easily and rapidly from person to person and through
contaminated food and recreational water.
It can cause watery or bloody diarrhea, abdominal
pain, fever, and malaise. Although diarrhea caused by
Shigella typically goes away without
treatment, people with mild illnesses are often treated with antibiotics
to stop the diarrhea faster.
Until recently, Cipro resistance has occurred in
just 2 percent of Shigella infections
tested in the United States, but was found in 90 percent of samples
tested in the recent clusters.
Shigella is spreading, CDC recommends
doctors use lab tests to determine which antibiotics will effectively
treat shigellosis. Doctors and patients should consider carefully
whether an infection requires antibiotics at all.
To prevent the spread of shigellosis, CDC
recommends that people wash their hands often with soap and water,
especially after using the toilet and before preparing food or eating;
keep children home from childcare and other group activities while they
are sick with diarrhea; avoid preparing food for others while ill with
diarrhea; and avoid swimming for a few weeks after recovering. Improving
access to toilets and soap and water for washing hands may help prevent
Shigella transmission among the
Travelers to developing countries can take
additional precautions to avoid diarrhea and minimize infection with
resistant bacteria. Choose safe foods and beverages, such as food that
is steaming hot and drinks from sealed containers (download CDC’s app “Can
I Eat This?” to help you make safer food and beverage choices when
Wash hands frequently, particularly before eating
and after using the toilet. Take bismuth subsalicylate to prevent
travelers’ diarrhea and treat it with over-the-counter drugs like
bismuth subsalicylate or loperamide. Try to reserve antibiotics for
severe cases of travelers’ diarrhea.
Health care providers should test stool samples
from patients with symptoms consistent with shigellosis, re-test stool
if patients do not improve after taking antibiotics, and test bacteria
for antibiotic resistance.
For more information on
Shigella, please visit:
Travelers can learn more about food and water
precautions to prevent Shigella at: