WHONET: An Information System for Monitoring
Antimicrobial Resistance

WHONET is an information system developed to support The
World Health Organization's (WHO) goal of global
surveillance of bacterial resistance to antimicrobial
agents. Microbiologists, clinicians and infection control
workers may use its software to enhance monitoring of
drug resistance in their hospitals and communities and to
merge their files into national, regional, and global
networks for surveillance of drug resistance. WHONET
software can be installed on personal computers and be
configured for the locations of the patients a laboratory
serves and for the antimicrobial agents it tests. The
program accepts susceptibility test results and allows
printing of reports and logbooks and retrieval of data.
If the laboratory already has a computerized reporting
system, a translation program can be created to download
the laboratory's files into WHONET. Either way, the
microbiologists and other infectious disease specialists
gain new analytical tools to monitor and manage
susceptibility test quality and the spread of drug
resistance locally and outside their area.

WHONET can also analyze stored data. From a single
screen, a WHONET user selects the type of analysis to
run, the species of bacteria to analyze, the subsets of
isolates to include (e.g., all, isolates from urine only,
and isolates resistant to gentamicin and from certain
locations), and the antimicrobial agents and period to
examine. Types of analyses include percentage of data
categorized as resistant, intermediate, or susceptible by
standard or other breakpoints; distributions of test
measurements (zone diameter, minimal inhibitory
concentration) in the form of histograms; scatterplots
comparing measurements for different agents or methods
for the same isolates; and line listings of isolates
grouped by combinations of agents to which they are
resistant (antibiotypes) to trace distinctive strains.
Isolates with uncommon antibiotypes can also be flagged
on entry so that they may be rechecked while still
available, and local outbreaks can be detected early.

Although test results are entered and monitored locally
on software configured for local use, they are filed in
a universal file format so that any copy of the program
can analyze the files of any laboratory. This feature has
enabled groups of users in 10 countries to set up passive
surveillance systems by pooling and analyzing their files
collaboratively. WHONET assists such initiatives by
providing file encryption options to ensure
confidentiality before data are pooled and analyzed.

Ongoing local analysis by local workers is the foundation
of the system. It detects local problems in testing,
which no laboratory can avoid entirely, and thus improves
the overall quality of the files. It delineates local
spread of drug-resistant strains, which aids infection
control and can explain and correct uncommon prevalence
of certain types of drug resistance at certain sites. It
allows local workers to distinguish their problems from
those of other sites and focus on infection control or
antimicrobial use that might be related to those
problems.

Expansion of the system has been recommended by the WHO
Scientific Working Group on Monitoring and Management of
Bacterial Resistance to Antimicrobial Agents. For more
information or for participation contact 

Thomas F. O'Brien and John M. Stelling
WHO Collaborating Center for Surveillance of 
Resistance to Antimicrobial Agents
Microbiology, Brigham and Women's Hospital
Boston, MA 02115, USA
tel (1-617) 732-6803
fax (1-617) 732-4144
Internet: whonet@bustoff.bwh.harvard.edu
-----


Recommendations for Preventing the Spread of Vancomycin
Resistance

CDC's Hospital Infection Control Practices Advisory
Committee (HICPAC) has published "Recommendations for
Preventing the Spread of Vancomycin Resistance." The
recommendations focus on vancomycin-resistant enterococci
(VRE).

The reported incidence of infection and colonization with
VRE in U.S. hospitals has increased rapidly in the last
5 years. This increase has compounded the need for
antimicrobial drugs to treat VRE infections. Most VRE are
also resistant to multiple other drugs (e.g.,
aminoglycoside and ampicillin), which have been used for
treating VRE infections. In addition, the possibility
that the vancomycin-resistance genes present in VRE may
be transferred to other gram-positive microorganisms,
especially Staphylococcus aureus, is a serious public
health concern.

Although the epidemiology of VRE has not been fully
elucidated, and most enterococcal infections have been
attributed to the patient's endogenous flora, recent
studies have demonstrated that enterococci, including
VRE, can be spread directly from patient to patient or
indirectly by transient carriage on the hands of
personnel or contaminated environmental surfaces and
patient-care equipment.

In its recommendations, HICPAC stresses that the
prevention and control of vancomycin resistance will
require a coordinated, concerted effort from various
departments of a hospital. Because the recommendations
were developed with limited data and further research is
needed to find cost-effective ways to control the spread
of vancomycin resistance, HICPAC strongly encourages
hospitals to develop their own institution-specific
plans, which should stress the following elements: 1)
prudent vancomycin use by clinicians, 2) education of
hospital staff regarding vancomycin resistance, 3) early
detection and prompt reporting of vancomycin resistance
in enterococci and other gram-positive microorganisms by
the hospital microbiology laboratory, and 4) immediate
implementation of appropriate infection-control measures
to prevent person-to-person transmission of VRE.

The recommendations were developed by HICPAC's
Subcommittee on the Prevention and Control of
Antimicrobial-Resistant Microorganisms in Hospitals and
subject-matter experts and representatives of the
American Hospital Association, American Society for
Microbiology, Association for Professionals in Infection
Control and Epidemiology, Infectious Diseases Society of
America, Society for Healthcare Epidemiology of America,
and Surgical Infection Society. The recommendations were
published in February in Infection Control and Hospital
Epidemiology 1995;16:105-13 and will also be published in
the April 1995 issue of the American Journal for
Infection Control.

Hospital Infection Control 
Practices Advisory Committee
National Center for Infectious Diseases
Centers for Disease Control and Prevention
Atlanta, Georgia, USA
-----


Waterborne Cryptosporidiosis Threat Addressed

Cryptosporidium parvum was first recognized as a cause of
human illness in 1976. From 1976 to 1982, the disease was
reported rarely in the United States, primarily among the
immunocompromised. In 1982, the number of reported cases
began to increase dramatically along with the number of
HIV-infected persons; outbreaks among immunocompetent
populations also were reported. Recent municipal
waterborne outbreaks of cryptosporidiosis in Texas
(1984), Georgia (1987), and Oregon (1992), and a massive
outbreak in Wisconsin in 1993 that affected more than
400,000 persons have raised awareness about the
waterborne transmission of cryptosporidiosis. Since 1993,
several smaller cryptosporidiosis outbreaks were reported
in the United States: two were related to drinking water,
six were linked to recreational water, and one was
foodborne.

Cryptosporidiosis is caused by ingestion of the
environmentally tough oocysts of the protozoan parasite
C. parvum, an intracellular organism that can replicate
in the gut epithelial cells of most mammals. Its oocyst
is extremely resistant to chlorine, which is commonly
used to treat municipal water.

In healthy persons, the disease lasts 1 to 2 weeks and
can have considerable economic impact through absenteeism
of those affected. In the immunocompromised, the disease
is often severe, lifelong, and life-threatening. No
effective therapy is available.

The magnitude of the 1993 Wisconsin outbreak and its
association with a municipal water plant operating within
existing state and federal regulations underlined the
need for improved surveillance and coordination among
public health agencies and spurred efforts for regulatory
standards for Cryptosporidium in drinking water. During
1995-1996, the U.S. Environmental Protection Agency (EPA)
intends to implement the Information Collection Rule,
which requires utilities that serve populations of
100,000 or more and use surface water (lakes, rivers,
streams) to test that water routinely for Cryptosporidium
oocysts. If oocysts are found, the utility may also have
to test finished water (tap water). Utilities that serve
populations of 10,000 to 99,000 will also have to test
source water, but for a shorter period. They will not be
required to test tap water, even if oocysts are found.
Authority to issue boil water advisories if oocysts are
found varies from state to state. The health risks from
ingesting low levels of Cryptosporidium are unknown. More
than 300 representatives from 40 states and more than 25
regulatory, public health, water utility, and advocacy
groups met at the Centers for Disease Control and
Prevention (CDC) in Atlanta in September 1994 to discuss
the prevention and control of waterborne
cryptosporidiosis. Recommendations from the CDC workshop
will be published in the next 2 to 3 months.

CDC held the first meeting of the Working Group on
Waterborne Cryptosporidiosis in November 1994. The
working group convenes biweekly by teleconference. For
more information about the group, contact Margaret Hurd
(phone: 404-488-7769, fax: 404-488-7761).

The working group has three main purposes: 1) promote a
regular exchange of ideas, goals, activities, and
proposals among individual scientists, agencies, and
organizations interested in waterborne cryptosporidiosis;
2) make decisions on public health issues related to
waterborne cryptosporidiosis; and 3) assemble smaller,
more focused, task forces with expertise to develop,
implement, and evaluate projects of the working group.

The working group has created task forces to assist
local, state, and national public health departments,
water utilities, and regulatory agencies in preparing for
and managing outbreaks. The task forces have the
following responsibilities:

* Develop and evaluate informational materials about
cryptosporidiosis.
* Develop guidelines on when to initiate or end boil
water advisories.
* Help formulate the language for EPA's Information
Collection Rule.
* Identify officials with authority to issue boil water
advisories. Examine legal issues associated with boil
water advisories and the environmental testing,
surveillance, and diagnostic requirements for waterborne
Cryptosporidium.
 
In addition, technical task forces will collect data to
develop guidelines for persons who may want to use
bottled water and personal-use water filters and provide
updates on the status of environmental sampling, water
testing, and surrogate indicators of Cryptosporidium
oocysts. These task forces will also report on the status
of clinical diagnostic and serologic tools and provide
local cryptosporidiosis infection rates to use in
assessing the risk for waterborne transmission.

C. parvum oocysts are present in most surface water
supplies; better technological tools and epidemiologic
assessments are needed to determine the public health
risks from these oocysts. Until the risks are fully
known, efforts should be made to inform the public about
cryptosporidiosis. Information on opportunistic
infections, including cryptosporidiosis, for physicians
who treat diseases in immunocompromised patients will be
published this fall in a supplement to Clinical
Infectious Diseases by authors from CDC and the
Infectious Diseases Society of America.

Daniel G. Colley
National Center for Infectious Diseases
Centers for Disease Control and Prevention
Atlanta, Georgia, USA