LETTERS
intestinal, and respiratory tracts, as Address for correspondence: Michael Dan, chosen after observations of treatment
well as wounds; bloodstream infec- Infectious Diseases Unit, Edith Wolfson failures at levels when used at below
tion is associated with higher death Hospital, Holon 58100, Israel; email: midan@ the expected recommended serum
rates than infection at other sites (4). post.tau.ac.il concentrations (2,3). Since 2005, a
Hand carriage is probably the biggest proportion of isolates exhibiting de-
factor in transmission of extended- creased susceptibility and high-level
spectrum β-lactamase producers, and resistance to ciprofloxacin have been
there is little evidence to suggest that tested for resistance to azithromycin
carriers of carbapenemase-producing by Etest (AB Biodisk, Solna, Swe-
K. pneumoniae would be different. den), using drug-sensitive strains of S.
Environmental contamination plays
a limited role in transmission of the
Alternatives to Typhi and S. Paratyphi A as controls.
From January 2001 through De-
organism (3). Caregivers should be Ciprofloxacin Use cember 2006, LEP reported 1,215
aware that multidrug-resistant or- for Enteric Fever, cases of S. Typhi infection and 1,274
ganisms of nosocomial origin can
be transmitted in the community (5).
United Kingdom cases of S. Paratyphi A infection. Of
these, ≈60% (1,493) reported recent
Acquisition of such strains is prob- To the Editor: In cases of ty- travel abroad; India and Pakistan were
ably of negligible importance in an phoid and paratyphoid fever, it is of- the most frequently visited countries
otherwise healthy person. However, ten necessary to commence treatment (4). Other cases were associated with
consequences may be different if the before the results of laboratory sensi- persons who had a history of such trav-
recipient of the strain is a debilitated tivity tests are available. It is therefore el, but the numbers involved were dif-
patient. important to be aware of optional drug ficult to document accurately because
therapies available because some or- of underreporting of foreign travel and
Tamar Gottesman,* ganisms may be resistant to key anti- other communication problems.
Orly Agmon,* Orna Shwartz,* microbial drugs. For typhoid and para- For S. Typhi, the occurrence of
and Michael Dan* typhoid, ciprofloxacin has become isolates resistant to ciprofloxacin at
*Edith Wolfson Hospital, Holon, Israel
the first-line drug of choice since the 0.125 mg/L increased from 60 (35%)
widespread emergence and spread of of 170 in 2001 to 169 (70%) of 240
References
strains resistant to chloramphenicol, cases in 2006, with 4.8 (2%) of isolates
ampicillin, and trimethoprim (1). in 2006 resistant at 1.0 mg/L (Table).
1. Desphande LM, Jones RN, Fritsche TR,
Sader HS. Occurrence and characteriza- The Laboratory of Enteric Patho- The corresponding figures for S. Para-
tion of carbapenemase-producing Enter- gens (LEP) of the Health Protection typhi A were 58 (25%) of 232 cases
obacteriacea: report from the SENTRY in 2001, rising to 84% in 2004, with
Antimicrobial Surveillance Program
Agency of England and Wales is the
reference center for Salmonella enter- an incidence of 73% in 2006; 9% of
(2000–2004). Microb Drug Resist.
2006;12:223–30. ica serovars Typhi and Paratyphi A for these were resistant to ciprofloxacin at
2. Leavitt A, Navon-Venezia S, Chmelnitsky the United Kingdom; as such, this lab- 1.0 mg/L (Table). Moreover, in 2006,
I, Schwaber MJ, Carmeli Y. Emergence 56 isolates of S. Typhi (23% of total)
of KPC-2 and KPC-3 in carbapenem-
oratory receives isolates from all cases
of infection. Isolates are screened by exhibited resistance to chlorampheni-
resistant Klebsiella pneumoniae strains
in an Israeli hospital. Antimicrob Agents breakpoint for resistance to antimi- col, ampicillin, and trimethoprim, 54
Chemother. 2007;51:3026–9. crobial drugs at the following levels: (96%) were also resistant to cipro-
3. Patel JB, Srinivasan A. Carbapenem resis- floxacin at 0.125 mg/L. When tested
tance in Enterobacteriaceae. Presented at
chloramphenicol, 8 mg/L; ampicillin,
8 mg/L; trimethoprim, 2 mg/L; cipro- for resistance to ceftriaxone and cefo-
the 107th American Society for Microbi-
ology General Meeting; 2007 May 21–25; floxacin, 0.125 mg/L (decreased sus- taxime, none of the isolates (either S.
Toronto, Ontario, Canada. ceptibility); and 1.0 mg/L (high-level Typhi or S. Paratyphi A) were resistant
4. Agmon O. Shwartz O, Gotesman T, Dan at 1.0 mg/L.
M. A year with KPC at an urban hospital in
resistance), ceftriaxone, 1 mg/L, and
cefotaxime, 1 mg/L. The levels for Although the levels of resistance
Israel. Presented at the 8th Congress of the
International Federation of Infection Con- testing for resistance to chlorampheni- to ciprofloxacin were for the most
trol; 2007 Oct 18–21; Budapest, Hungary. col, ampicillin, trimethoprim, ceftri- part below that regarded as therapeu-
5. Calbo E, Romaní V, Xercavins M, Gómez tic (MIC 0.25–1.0 mg/L), at least 21
L, Vidal CG, Quintana S, et al. Risk fac-
axone, and cefotaxime correspond to
internationally accepted therapeutic treatment failures have been docu-
tors for community-onset urinary tract in-
fections due to Escherichia coli harbour- levels for these antimicrobial agents. mented since 2005. These findings
ing extended-spectrum beta-lactamases. J In contrast, the levels for ciprofloxa- demonstrate that the efficacy of cip-
Antimicrob Chemother. 2006;57:780–3. rofloxacin for first-line treatment of
cin (0.125 and 1.0 mg/L) have been
860 Emerging Infectious Diseases • www.cdc.gov/eid • Vol. 14, No. 5, May 2008
LETTERS
Table. Incidence of resistance/decreased susceptibility to key antimicrobial agents in isolates of Salmonella enterica serovars Typhi
and Paratyphi A, United Kingdom, 2001–2006*
% S. Typhi resistant to % S. Paratyphi A resistant to
Year No. studied C A Tm CpL CpH No. studied C A Tm CpL CpH
2001 170 24 23 23 35 0 232 28 27 27 23 2
2002 150 18 17 17 35 1 149 10 9 10 39 3
2003 218 20 20 21 43 1 177 17 18 17 65 12
2004 215 23 23 24 47 2 221 5 5 5 70 14
2005 222 29 29 29 62 2 217 7 7 7 60 12
2006 240 23 24 24 68 2 278 2 3 2 64 9
*C, chloramphenicol; A, ampicillin, Tm, trimethoprim, CpL, ciprofloxacin MIC 0.25–1.0 mg/L; CpH, ciprofloxacin MIC >1.0 mg/L. No isolates exhibited
resistance to ceftriaxone or cefotaxime; of 50 S. Typhi and 40 S. Paratyphi A isolated in 2005 and 2006, the MIC to azithromycin by E test (AB Biodisk,
Solna, Sweden) was not greater than 8 mg/L for S. Typhi and 12 mg/L for S. Paratyphi A, which corresponds to those of drug-sensitive controls of the
respective serotypes.
enteric fever in the United Kingdom currence of strains with decreased sus- Usutu Virus
has been seriously jeopardized. In ceptibility, ciprofloxacin still remains
cases of treatment failures, commonly the drug of choice for many physi- Sequences in
used alternative antimicrobial agents cians. It is reassuring that in cases of Culex pipiens
have included third-generation ce- treatment failure, third-generation ce- (Diptera: Culicidae),
phalosporins such as ceftriaxone. The phalosporins such as ceftriaxone and
macrolide antimicrobial azithromycin macrolide antimicrobial agents such Spain
is also being increasingly used, par- as azithromycin appear to be viable To the Editor: Usutu virus
ticularly for patients with hypersen- alternatives. (USUV) is an arbovirus and a member
sitivity to penicillins (5). With this in of the mosquito-borne cluster within
mind, 50 S. Typhi and 40 S. Paratyphi E. John Threlfall,*
the Flavivirus genus. USUV belongs
A strains isolated from January 2005 Elizabeth de Pinna,*
to the Japanese encephalitis virus an-
through December 2006, which ex- Martin Day,* Joanne Lawrence,*
tigenic group, which is closely related
hibited resistance to ciprofloxacin at and Jane Jones*
to pathogens such as West Nile virus
0.125 mg/L, were tested for resistance *Health Protection Agency, London, UK
(WNV) (1).
to azithromycin by Etest. Results in- USUV has been isolated from a
dicated that none of the isolates of S. References
human in the Central African Repub-
Typhi exhibited MICs >8 mg/L, which lic and from several mosquito species
1. Threlfall EJ, Ward LR. Decreased sus-
corresponded to the MIC to azithromy- ceptibility to ciprofloxacin in Salmonella from tropical and subtropical Africa
cin of a drug-sensitive control strain enterica serotype Typhi, United Kingdom. (2). In late summer 2001, USUV
of S. Typhi (range 4–8 mg/L, MIC90 Emerg Infect Dis. 2001;7:448–50.
2. Rowe B, Ward LR, Threlfall EJ. Cip- emerged in central Europe and caused
6 mg/L). For S. Paratyphi A, none deaths in several species of resident
rofloxacin and typhoid fever. Lancet.
of the isolates exhibited MICs >12 1992;339:740. birds in Austria (3). However, moni-
mg/L, corresponding to that of a drug- 3. Aarestrup FM, Wiuff C, Mølbak K, Threl- toring of USUV in dead birds from
sensitive control strain of this serovar fall EJ. Is it time to change the break
points for fluoroquinolones for Salmonel- 2003 through 2005 showed that the
(range 6–12 mg/L, MIC90 10 mg/L). absolute numbers of USUV–associ-
la spp.? Antimicrob Agents Chemother.
Although there are no definitive data 2003;47:827–9. ated bird deaths declined, although
on resistance levels for azithromycin 4. Health Protection Agency. Foreign travel- USUV detection persisted in bird tis-
in relation to treatment of typhoid and associated illness in England, Wales and
Northern Ireland–2007 report. London: sues (4). This decrease in USUV-as-
paratyphoid, these findings suggest sociated bird deaths was attributed to
Health Protection Agency; 2007.
that resistance to this antimicrobial 5. Threlfall EJ, Day M, De Pinna E, Lewis herd immunity in the bird population
agent in terms of treatment efficacy H, Lawrence J. Drug-resistant enteric fe- (5). In the summer of 2005, USUV
has not yet been jeopardized. ver in the UK. Lancet. 2006;367:1576.
was detected in a blackbird in Hunga-
These results indicate that the ry. The complete genomic sequence
Address for correspondence: E. John Threlfall,
availability of effective antimicrobial of the Hungarian USUV strain shared
Health Protection Agency Laboratory of Enteric
agents for the treatment of typhoid 99.9% identity with the strain circu-
Pathogens, Centre for Infections, 61 Colindale
and paratyphoid infection is becom- lating in Austria since 2001 (6). On
Ave, London NW9 5EQ, UK; email: john.
ing increasingly limited for patients the other hand, neutralizing antibod-
threlfall@hpa.org.uk
in the United Kingdom. Nevertheless, ies against USUV have been detected
despite the dramatic upsurge in the oc- in sera of resident and migrant birds
Emerging Infectious Diseases • www.cdc.gov/eid • Vol. 14, No. 5, May 2008 861
