Epidemiologic Notes and Reports Outbreak of a Distinct Strain of
Penicillinase-Producing Neisseria gonorrhoeae -- King County,
Washington
In 1986, penicillinase-producing Neisseria gonorrhoeae (PPNG)
infections accounted for approximately 2% of gonorrhea reported in
the
United States, a 90% increase over the 1985 percentage (1). The
majority of PPNG cases were reported in Florida, New York, and
California. Except for a brief outbreak in 1980 (2), King County
(Seattle), Washington, had reported sporadically occurring cases of
PPNG until the incidence began to increase in the second half of
1986.
The incidence of PPNG increased substantially in King County in
1987. Eighty-four (5%) of the 1,784 cases of gonorrhea reported in
King County from January 1 through June 30, 1987, were PPNG,
whereas
30 (0.8%) of the 3,990 gonorrhea cases reported in 1986 were PPNG.
The
PPNG cases reported during the first half of 1987 included two
cases
of disseminated gonococcal infection (DGI) and one case of adult
gonococcal ophthalmia. Eight (5%) of 164 reported cases of
gonococcal
pelvic inflammatory disease were PPNG. Thirty-one (37%) of the PPNG
infections occurred in women; 52 (62%), in heterosexual men; and
one,
in a bisexual man. The increase appears to be limited to King
County
since immediately adjacent counties reported only 13 PPNG cases
during
the same time period. The evidence in this outbreak does not
indicate
that PPNG was imported from other areas of the United States or
from
other countries.
Seventy-five (89%) of the PPNG isolates found during the first
half of 1987 belong to a single auxotype/serovar (A/S) class of N.
gonorrhoeae (Figure 1). The epidemic strain is a proline-requiring
auxotype, Protein IA-4 serovar. The proportion of PPNG cases caused
by
other A/S classes remained stable in the community. All PPNG
isolates
of the epidemic strain have had characteristic antimicrobial
susceptibilities, with minimum inhibitory concentration ranges:
penicillin G greater than 8 ug/mL, tetracycline 0.125-0.5 ug/mL,
spectinomycin 16 ug/mL, cefoxitin 0.5-1.0 ug/mL, and ceftriaxone
0.001-0.004 ug/mL.
To control this outbreak, the Seattle-King County Department of
Public Health has intensified its case finding, interviewing, and
partner-tracing efforts and has advised all clinical facilities to
increase their screening efforts. The health department, in
cooperation with the King County Medical Society and local media,
has
advised all health providers to use only ceftriaxone or
spectinomycin
as initial therapy for all persons suspected or proven to have
gonorrhea (3). In accordance with CDC treatment guidelines (3,4), a
7-day course of tetracycline or doxycycline for possible coexistent
chlamydial infection continues to be recommended for all patients
with
gonorrhea. Providers have also been advised to confirm all
suspected
cases by culture to allow screening for beta-lactamase production
and
to immediately report all confirmed PPNG infections by telephone to
the health department.
Reported by: RJ Rice, MD, HH Handsfield, MD, R Tulloch,
Seattle-King
County Dept of Public Health and University of Washington, Seattle;
L
Klopfenstein, M Donnelly, JM Kobayashi, MD, State Epidemiologist,
Washington Dept of Social and Health Svcs. Sexually Transmitted
Diseases Laboratory Program, Center for Infectious Diseases; Div of
Sexually Transmitted Diseases, Center for Prevention Svcs, CDC.
Editorial Note
Editorial Note: PPNG outbreaks caused by organisms belonging to a
single A/S class are uncommon. Recent reported outbreaks from
Denver
(5), Miami (6), and Amsterdam (7) have all implicated multiple
strains
in endemic transmission. It is unclear whether multiple-strain
outbreaks arise because of importation of different PPNG strains
into
a community or through the conjugal transfer of plasmids that code
for
beta-lactamase from native PPNG strains to non-PPNG gonococci.*
Single-strain PPNG epidemics in the United States were
suspected
in 1980 (2) in Seattle and in Shreveport, Louisiana. At that time,
complete A/S classification was not possible. In single-strain
epidemics, eradication of PPNG from a community may be feasible. In
the United States (2) and in Sweden (8), eradication efforts have
been
more successful in areas where single-strain PPNG has been
suspected.
A/S classification may be useful as an adjunct to the management
guidelines for the control of antibiotic-resistant strains of N.
gonorrhoeae recently published by CDC (3).
Handsfield HH, Sandstrom EG, Knapp JS, et al. Epidemiology of
penicillinase-producing Neisseria gonorrhoeae infections:
analysis
by auxotyping and serogrouping. N Engl J Med 1982;306:950-4.
Centers for Disease Control. Antibiotic-resistant strains of
Neisseria gonorrhoeae: policy guidelines for detection,
management, and control. MMWR 1987;36(suppl 5S).
Centers for Disease Control. Multiple strain outbreak of
penicillinase-producing Neisseria gonorrhoeae--Denver,
Colorado,
1986. MMWR 1987;36:534-6,542-3.
Zenilman JM, Knapp JS, Whittington WL, et al. Characterization
of
penicillinase-producing Neisseria gonorrhoeae (PPNG) strains
from
Miami, Florida (Abstract). In: Hartman PA, ed. Abstracts of the
American Society for Microbiology. Washington, DC: American
Society for Microbiology, 1987:369.
Ansink-Schipper MC, Bygdeman SM, van Klingeren B, Sandstrom EG.
Serovars, auxotypes, and plasmid contents of PPNG strains from
outbreak in Amsterdam. Genitourin Med 1987;63:157-9.
Ramstedt KM, Hallhagen GJ, Bygdeman SM, et al. Serologic
classification and contact-tracing in the control of
microepidemics of beta-lactamase-producing Neisseria
gonorrhoeae.
Sex Transm Dis 1985;12:209-14.
*Scientists hypothesize that conjugal transfer of beta-lactamase
plasmids may occur when an infection consists of PPNG and non-PPNG
strains (a mixed infection).
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