Terapia antimicotica: come e quando

Matteo Bassetti, MD, PhDInfectious Diseases Division

Santa Maria Misericordia University Hospital

Udine, Italy

hCandidahAspergillus

IncidenceIncidence ((episodesepisodes/1000 /1000 personperson daysdays))

0

0,2

0,4

0,6

0,8

1

1,2

1,4

1,6

2008 2009 2010

albicans

parapsilosis

glabrata

tropicalis

krusei

Bassetti M et al. PLoS ONE 2011; 6(9): e24198

Epidemiology of candidemia

45,6

54,4

26

15,68,1

2,5

0

10

20

30

40

50

60

Total glabrata parapsilosis tropicalis krusei

albicans Non albicans glabrata parapsilosis tropicalis krusei

North America; 2019 cases of candidemia

Horn DL et al. Clin Infect Dis 2009; 48:1695–703

Epidemiology of candidaemia

Italy; 348 cases of candidaemia (2008-2010)

28,4

9,5 6,62,6

48,9

0

10

20

30

40

50

60

C.albicans

C.parapsilosis

C.glabrata

C.tropicalis

C.krusei

Bassetti M et al. PLoS ONE 2011; 6: e24198

Candida distribution in hospital

Mortality for Candidaemia

North America; 2019 cases of candidaemia

Horn DL, et al. Clin Infect Dis 2009;48:1695–703

Mortality for Candidaemia

44,350

36,2

47,8

57,1

43,5

0

10

20

30

40

50

60

All C.albicans

C.glabrata

C.parapsilosis

C.tropicalis

C.krusei

Italy; 324 cases of candidaemia

Mortality Associated With CandidaInfections in hospital

Variable Mortality rate (%)*WardsInternal medicineSurgical

51,129,3

Hemato-oncologyTransplantICU

47,634,447,6

Overall 43,5

*30 days Crude mortality

Relationship Between Hospital Mortality and the Timing of Antifungal Treatment

35

Hos

pita

l mor

talit

y (%

)

30

25

20

15

10

5

0< 12

Delay in start of antifungal treatment (hours)

12–24 24–48 > 48

Morrell M, et al. Antimicrob Agents Chemother 2005;49:3640–5

Time to Identification of Candida in Blood Cultures

P < 0.001

Meyer MH, et al. J Clin Microbiol 2004;42:773–7

So, what about prophylaxis?

Fluconazole in High-Risk SICU Patients

p < 0.01 by log-rank test

0 7 14 21 28Days

260 surgical ICU patients (stay > 3 days) randomised to double-blind oral antifungal prophylaxis

Pelz RZ, et al. Ann Surg 2001;233:542–8

0.6Placebo

Pro

porti

on in

fect

ed 0.5

0.4

0.3

Fluconazole0.2

0.1

Prophylaxis in the (S)ICU

h Pelz et al., Ann Surg 2001; 233:542–8 - Fluco vs. placebo in extremely high risk ICU- Placebo: 16% rate of invasive candidiasis

hThis rate equals that in BMT- Fluco 400/d: 8% rate- P < 0.01

h A very unusual population- Median APACHE III = 60, lots of liver transplant- Applicability in most ICUs is unclear

Fluconazole in Low-Risk Surgical Patients

Double-blind single-dose 400 mg fluconazole prophylaxis in 109 patients with intra-abdominal perforation

60

Sandven P, et al. Crit Care Med 2002;30:541–7

10%

43%

7.5%10%

34%

14%

Emergence ofcolonisation

Death

NS Fluco

Placebo50

40%

NSNS30

20

10

0Complications

Candida Prophylaxis in ICU Patients

Successof

prophylaxis

Emergence ofcolonisationby Candida

Death fromany cause

Invasivecandidiasis

Candidaemia

P<0.001

P<0.01

NS

NS P=0.014

Fluco 100 mg/d

Placebo

Garbino J, et al. Intensive Care Med 2002;28:1708–17

Antifungals in Critically Ill and SurgicalPatients: Meta-Analysis

Impact on Candidal infections Impact on mortality

h NNT = 94h NNT in high-risk = 9h NNT in low risk = 188

Playford EG, et al. J Antimicrob Chemother 2006;57:628–38

Prophylactic Fluconazole……

• HAS ELIMINATED CANDIDA COLONISATION!

More patient comfort

……BUT……

• HAS ELIMINATED CANDIDA COLONISATION!

More patient comfort

• DID NOT REDUCE MORTALITY

• HAS SELECTED RESISTANT CANDIDA SPECIES

Restriction of Prophylactic Fluconazole Use

00,5

11,5

22,5

33,5

19992000

20012002

20032004

20052006

2007

years observed

inci

denc

e of

can

dide

mia

0

2000

4000

6000

8000

10000

12000

Fluc

onaz

ole

DD

Ds

x 10

0 pt

s/da

ys

Incidence of Candidemia/ 10000pts-days/yearIncidence of Candidemia due to C. albicans/10000 pts-days/yearDDD of fluconazole/100 pts/day

Bassetti M et al. J Antimicrob Chemother 2009: 64:625-9.

So, what about empiricaltherapy?

15 July 2008

4 days of fever (>38.3°C)ICU stay > 96hAPACHE II ≥ 16Broad-spectrum antibioticsCentral line ≥ 24h

Double-blind, placebo-controlled trial with fluconazole800 mg (x14 d) in 270 adult IC-patients

Fluconazole Placebo 95% CI / P-value

n (ITT) 133 137

Success 44 (36%) 48 (38%) 0.69–1.32; P = 0.78

Invasive mycosis 6 (5%) 11 (9%) RR 0.57; 0.22–1.49

30-day mortality 29 (24%) 22 (17%) RR 1.36; 0.82–2.24

Schuster MG, et al. Ann Intern Med 2008;149;83–90

…Empirical Therapy...

Wrong drug or strategy?

Distribution of Candida spp. In Vitro Susceptibility to Fluconazole

h 342 isolates testedh 16,4 % fluconazole-R or S-DD (using EUCAST breakpoint)

Species In vitro susceptibility to fluconazole n tested S S-DD or R

Candida albicans 167 96,4% 3,6% Candida glabrata 33 6,1% 93,9% Candida parapsilosis 98 98% 2% Candida tropicalis 23 74% 26% Total 342 83,6% 16,4%

Fluconazole

hPro- Well known- Cheap- Tolerability- C. parapsilosis

hCons- No activity on C. krusei

and glabrata- Resistance- No activity on biofilm- Fungistatic- Interactions- Inferior in 1 RCT to

anidulafungin (C. albicans)

So, what about pre-emptive therapy with predictive

rules?

Candida Score

León C, et al. Crit Care Med 2006;34:730–7

Candida Score Validation

León C, et al. Crit Care Med 2009;37:1624–33

Other Predictive Rules

The best performing predictive rule was:

Patients in the ICU >4 daysAND

Any systemic antibiotic (days 1–3)OR

Central venous catheter (days 1–3)AND at least two:h Total parenteral nutrition (days 1–3)h Any dialysis (days 1–3)h Major surgery (days -7–0)h Pancreatitis (days -7–0)h Any use of steroids (days -7–3)h Immunosuppressive agents (days -7–0)

Ostrosky-Zeichner L, et al. Eur J Clin Microbiol Infect Dis 2007;26:271–6

Role of (1-3)-β-D-Glucan Concentrations

Karageorgopoulos DE, et al. Clin Infect Dis 2011;52:750–70

Criteria to Start Pre-EmptiveAntifungal Therapy

Patient in ICU ≥ 4 days

2 of the following:•Total parenteral nutrition (days 1–3)•Any dialysis (days 1–3)•Major surgery (days -7–0)•Pancreatitis (days -7–0)•Any use of steroids (days -7–3)•Immunosuppressive agents (days -7–0)

Abx in the last 7 daysor

CVC from 7 days

Candida colonisation or (1-3)-β-D-glucan/mannan-anti-

mannam

Start an antifungal

Bassetti M, et al. Crit Care 2010;14:244

Anti-Candida activity of different antifungals

Bassetti M, et al. Crit Care 2010;14:244

ESCMID Diagnostic & Management Guideline for Candida Diseases 2011

Authors: Murat Akova, Maiken Arendrup, Sevtap Arikan-Akdagli, MatteoBassetti, Jacque Bille, Thierry Calandra, Elio Castagnola, Oliver A. Cornely, Manuel Cuenca-Estrella, Peter Donnelly, Jorge Garbino , Andreas Groll, Raoul Herbrecht, William Hope, Henrik Elvang Jensen, Bart-Jan Kullberg, Cornelia Lass-Flörl, Olivier Lortholary, Wouter Meersseman, GeorgiosPetrikkos, Malcolm Richardson, Emmanuel Roilides, Andrew J. Ullmann, Paul Verweij, Claudio Viscoli

Main Coordinator: Andrew J. Ullmann

Strength of the EFISG Recommendation by Quality of Evidence

Two Parts: Strength of recommendationQuality of Evidence

Strength of recommendationGrade A ESCMID (fungal infection study group) strongly supports a

recommendation for useGrade B ESCMID (fungal infection study group) moderately supports a

recommendation for useGrade C ESCMID (fungal infection study group) marginally supports a

recommendation for useGrade D ESCMID (fungal infection study group) supports a

recommendation against use

Strength of the EFISG Recommendation by Quality of Evidence

Quality of evidenceLevel I Evidence from at least 1 properly designed randomized, controlled trialLevel II* Evidence from at least 1 well-designed clinical trial, without randomization;

from cohort or case-controlled analytic studies (preferably from >1 center); from multiple time series; or from dramatic results of uncontrolled experiments

Level III Evidence from opinions of respected authorities, based on clinical experience, descriptive case studies, or reports of expert committees

*: added index: r: meta-analysis (or systematic review of RCT); t: transferred evidence i.e. results from different patients‘ cohorts, or similar

immune-status situation; h: comparator group: historical control;u: uncontrolled trialsa: for published abstract (presented at an international symposium or meeting)

Empiric Therapy:When is it Indicated?

Population Intention Intervention SoR QoE Reference

At risk + persistent FUO

Reduce overall mortality

Antifungal treatment (unspecified)

C III Garey CID 2004Morrell AAC 2005Parkins JAC 2007Kumar Chest 2009

Adult ICU patients with fever despite broad-spectrum antibiotics, APACHE II >16

Resolution of fever

Fluconazole400mg/d

D I SchusterAnn Int Med 2008

Definitions:•Empiric = persistent FUO / Fever driven approach•Pre-emptive = treatment based on a validated marker / Diagnosis driven approach

Targeted Treatment of CandidaemiaPolyenes

Compound SoR

QoE

Reference Comment

Amphotericin B, deoxycholate, any dose

D I Ullmann CID 2006Bates CID 2001Anaissie CID 1996Rex NEJM 1994Philips EJCMID 1995Mora-Duarte NEJM 2002

Amphotericin B, liposomal

B I Kuse Lancet 2007Dupont Crit Care 2009

•Similar efficacy as micafungin•Higher toxicity than micafungin

Amphotericin B, lipid complex

C IIa Anaissie ICAAC 1995Ito CID 2005

Amphotericin B, colloidal dispersion

D IIu Noskin CID 1998 •Mostly immunocompromisedpatients (HCT, haem/onc or SOT) rather than ICU patients

HCT, haematopoietic stem cell transplantation; SOT, solid organ transplantation.

Targeted Treatment of CandidaemiaEchinocandins

Compound SoR

QoE

Reference Comment

Anidulafungin200/100

A I Reboli NEJM 2007 • Broad spectrum• Resistance rare• Fungicidal• Local epidemiology• C. parapsilosis, C. krusei• Safety profile• Less drug-drug interactions

than caspofungin

Caspofungin70/50

A I Mora-Duarte NEJM 2002Pappas CID 2007

• Largely as above

Micafungin100

A I Kuse Lancet 2007Pappas CID 2007

• Largely as above• Consider EMA warning label

Targeted Treatment of CandidaemiaAzoles

Compound SoR

QoE

Reference Comment

Fluconazole C I Anaissie CID 1996Rex NEJM 1994Rex CID 2003Philips EJCMID 1995Reboli NEJM 2007Tuil CCM 2003Abele-Horn Infect 1996Leroy CCM 2009Gafter-Gvili Mayo Clin Proc 2008

• Limited spectrum• Inferiority to anidulafungin

(especially in the subgroup with high APACHE scores),

• C. parapsilosis

Itraconazole D IIa Tuil CCM 2003 (abstract)Posaconazole D III No reference found • PO onlyVoriconazole B I Kullberg Lancet 2005

Ostrosky EJCMID 2003Perfect CID 2003

• Limited spectrum compared to echinocandins

• Drug-drug interactions• IV in renal impairment• Need for TDM

TDM, Therapeutic drug monitoring.

Targeted Treatment of Candidaemia:Duration & Diagnostics

Population Intention Intervention SoR QoE ReferenceAvoid organ involvement

Treat for 14 days after the end of candidaemia

B II Oude-Lashof CID 2011

Take 1 blood culture per day until negative

B III No reference found

Transoesophagealechocardiography

B IIa Fernández-Cruz ICAAC 2010

Fundoscopy B II Oude-Lashof CID 2011Rodriguez Med 2003Brooks Arch Int Med 1989Parke Ophthalmol 1982

No organ involvement

Detect organ involvement

If CVC, PICC, or intravascular devices, search for thrombus

B III No reference found

Any To simplify treatment

Step down to flucona-zoleafter 10 days of IV, if•Species is susceptible•Patient tolerates PO•Patient is stable

B II Reboli NEJM 2007Mora-Duarte NEJM 2002Pappas CID 2007

CVC, Central venous catheter; PICC, Peripherally inserted central catheter.

Treatment of candida in non-neutropenicpatients (ESCMID guidelines 2011)

Blood culture positive for

yeast or empirictherapy (CIII)

BloodBlood culture culture positive positive forfor

yeastyeast or or empiricempirictherapytherapy (CIII)(CIII)

Start antifungal

therapy(AII)

Start Start antifungalantifungal

therapytherapy(AII)

Stronglyrecommended:

echinocandin (AI)

StronglyStronglyrecommendedrecommended:

echinocandin (AI)

Moderatelyrecommended:

L-AMB or voriconazole (BI)

ModeratelyModeratelyrecommendedrecommended: :

L-AMB or voriconazole (BI)

Marginallyrecommended:fluconazole or

ABLC (CI)

MarginallyMarginallyrecommendedrecommended::fluconazole or

ABLC (CI)

Not recommeded (D):Conventional Amphotericin

BItraconazole

PosaconazoleCombination

Not recommeded (D):Not recommeded (D):Conventional Amphotericin

BItraconazole

PosaconazoleCombination

Cornely OA et al. 21st ECCMID, Milano 20011http://www.escmid.org/escmid_library/online_lecture_library/eccmid/21st_eccmid27th_icc_2011_milan/educational_workshops_2011/

Treatment of candida in non-neutropenicpatients (ESCMID guidelines 2011)

Treatment withechinocandins

(AI)

Treatment withechinocandins

(AI)

Treatment forat least 14 days after

candidemiaresolution (BII)

Treatment forat least 14 days after

candidemiaresolution (BII)

After 10 days:-Stable-Isolate susceptible tofluco- PO suitable

After 10 days:-Stable-Isolate susceptible tofluco- PO suitable

YesStep-down to

fluco (BII) Step-down to

fluco (BII)

nono

Remains in echinocandinRemains in

echinocandin

Diagnostic proceduresrecommended:

- 1 daily blood culture till negativization ( BIII)

-Fundoscopic examination ( BII)- TEE (BII)

Diagnostic proceduresrecommended:

- 1 daily blood culture till negativization ( BIII)

-Fundoscopic examination ( BII)- TEE (BII)

Cornely OA et al. 21st ECCMID, Milano 20011http://www.escmid.org/escmid_library/online_lecture_library/eccmid/21st_eccmid27th_icc_2011_milan/educational_workshops_2011/

Candidemia in non-neutropenic: ESCMID vs IDSA

ESCMID 2011 IDSA 2009

Fluconazole CI AI

Voriconazole BI AI ( alternative agent)

Lip-AMB B-D I-II AI ( alternative agents)

D-AMB DI AI ( alternative agent)

Echinocandins AI AI (for moderatelysevere to severe illness and for

patients with recent azoleexposure)

Empiric treatment (asfor candidemia)

CIII BIII

Criteria to Start Pre-EmptiveAntifungal Therapy

Patient in ICU ≥ 4 days

2 of the following:•Total parenteral nutrition (days 1–3)•Any dialysis (days 1–3)•Major surgery (days -7–0)•Pancreatitis (days -7–0)•Any use of steroids (days -7–3)•Immunosuppressive agents (days -7–0)

Abx in the last 7 daysor

CVC from 7 days

Candida colonisation or (1-3)-β-D-glucan

Start an echinocandin

Chioces of antifungals for treatment of candidemia in critically ill patients

Bassetti M, et al. Crit Care 2010;14:244

hWoman, 58 years oldh2003: myelodysplastic syndrome (MDS)hOctober 2009: AMLhTherapy with:

- fludarabin, ara-C, idarubicin, gemtuzumab(Mylotarg®)

hDecember 2009 admitted to haematologyward

h 8 days after consolidation cycle ( high-dose ara-C and idarubicin) and on levofloxacin prophylaxis

h 11 days of neutropenia (< 100/ mm3) h Fever ( 38.5 ° C) h Submammarian painh Basal crackles

hSerum GM: 1.542 (positive if > 0.5)hBAL after 3 days of antifungal treatment:

GM negative and bacterial culturesnegative

How do you define this case?

a) Proven aspergillosisb) Probable aspergillosisc) Possible aspergillosisd) None of the above

EORTC/MSG Consensus Definitions

h Proven IPA- Histopathology + culture

h Probable IPA- 1 host + 1 clinical + 1 microbiological - Host: neutropenia, HSCT, prolonged use of steroids, treatment with T cell

immunosuppressive therapy, severe immunodeficiency- Clinical:

h CT: Dense, well-circumscribed lesions(s) with or without a halo sign, air-crescent sign or Cavity

- Microbiological: - positive culture sputum, BAL, bronchial brush,- Non-invasive test:

– Galactomannan antigen detected in plasma, serum, bronchoalveolar lavage fluid– 1-3 beta D-glucan

h Possible IPA- 1 host + 1 clinical

- CT: CT: Dense, well-circumscribed lesions(s) with or without a halo sign, Air-crescent sign or Cavity

De Paw B et al. Clin Infect Dis 2008; 46:1813–21

Diagnostic accuracy of the GM test for prediction of probable or proven IA

(according to the old EORTC–MSG criteria)

Penack O et al. Ann Oncol 2008; 19: 984–989

Pulmonary aspergillosis: Early Treatment is Critical

hMortality when treatment started after diagnosis:

≤10 days 41%> 10 days 90%

Von Eiff M et al. Respiration 1995;62:241-7.

Factors Associated with Overall and AttributableMortality in Invasive Aspergillosis

Nivoix N et al. Clin Infect Dis 2008; 47:1176–84

Serum Aspergillus Galactomannan AntigenValues Strongly Correlate With Outcome

of Invasive Aspergillosis

Woods G et al. Cancer 2007;110:830–4.

Antifungals in aspegillosis

hEchinocandins- Caspofungin- Micafungin

hPolyenes- Lipid- amphotericin B

hAzoles- Voriconazole- Posaconazole

Linee guida IDSA: 2008

Walsh et al. CID 2008; 46:327–60

Voriconazole in Invasive Aspergillosis: Global Comparative Study

h Satisfactory (Complete/Partial Responses) at week 12- Difference: 21.2%

h Improved survival with voriconazole

h Importance of early therapy h Limited role for rescue therapyh Lower success in high risk

patients- Disseminated infection- Allogeneic Bone Marrow

TransplantationhVoriconazole:

32.4%hAmphotericin B:

13.3%

Responses at week 12

31,6

52,8

0

20

40

60

80

100

Voriconazole ±OLAT (n=144)

Amphotericin B ±OLAT (n=133)

Com

plet

e/Par

tial R

espo

nses

(%)

%

%

Herbrecht R et al NEJM 2002;347:408-15;Patterson TF et al, Clin Infect Dis 2005;41:1448-52

Note: OLAT=other licensed antifungal therapy

Difference in proportions (%) and 95% CI

Vori Ampho B53 32 55 34 43 13 32 13 63 38 50 32 51 32 54 32 45 20 60 37

50 28

Overall (MITT)

Pulmonary onlyExtra pulmonary

Allogeneic HSCTOther hemat. dis.

Other

Non-neutropenic

Definite IA

Neutropenic

Probable IA

Overall (ITT)-20 0 20 40 60

Week 12 successful response rate (%)

Voriconazole versus Amphotericin B forInvasive Aspergillosis: SURVIVAL

1.0

0.0

0.2

0.4

0.6

0.8

Amphotericin B -> OLATVoriconazole -> OLAT

HR = 0.60 (95% CI 0.40 to 0.89), p=0.012

Prob

abili

ty o

f Sur

viva

l

0 10 20 30 40 50 60 70 80 90Time (Days)

Therapeutic Drug Monitoring:Voriconazole Serum Concentration and Response

• Random voriconazolelevels in patients with progression (n=17) or toxicity (n=11)

• Better responses in patients with higher levels

• Improved outcomes with dose escalation in patients with levels < 2 mcg/ml

Reponse to Voriconazole

0

20

40

60

80

100

<2.05 (n=18) > 2.05 (n=10)Serum concentration (mcg/ml)

Succ

ess

(%)

44%

100%

Smith J et al. Antimicrob Agents Chemother 2006;50:1570-2

AmBIload

N (%)AmBi-3mg

N=107AmBi-10mg

N=94Favorable Overall Response at EOT

53 (50) 43 (46)

CR 1 (1) 2 (2)

PR 52 (49) 41 (44)

Unfavorable Response

Stable 8 (7) 5 (5)

Failure 36 (34) 36 (38)

Not evaluable 10 (9) 10 (11)

p= 0.65

Cornely et al. Clin Infect Dis. 2007;44:1289-97

AmBiLoad Trial: Laboratory Abnormalities

N (%)AmBi-3mg

N=115 AmBi-10mg

N=111 P-valueNephrotoxicity1 16/111 (14) 31/100 (31) p<.01Hypokalemia

K+ < 3.0 (grade 3)

18/113 (16) 32/106 (30) p=.015

K+ < 2.5 (grade 4)

3/113 (3) 4/106 (4) NS

LFT abnormalities2 18 (16) 16 (14) NS

1. Serum creatinine > 2x baseline2. Treatment emergent grade 3 or 4 values of ALT, AST, alkaline phosphatase, or

bilirubinCornely et al. Clin Infect Dis. 2007;44:1289-97

Initial Therapy for Invasive Aspergillosis

Voriconazole vs. AmB-d AmBiLoad Responses at EOT

50%

46%

72%

0 20 40 60 80 100

L-AmB 3mg/kg/day

L-AmB 3mg/kg/day

L-AmB 10mg/kg/day

Responses at week 12

71%

53%

32%

0 20 40 60 80 100

Voriconazole

Voriconazole

Ampho B-d

Survival at week 12 Survival at week 12

Cornely et al. Clin Infect Dis. 2007Herbrecht R et al NEJM 2002

Antifungal Therapy in NeutropenicPatients with Aspergillus Infections

0%

10%

20%

30%

40%

50%

60%

70%

80%

Caspofungin Voriconazole L-AmBSecond line First line

Herbrecht et al. 2002Betts et al., Cancer 2006Glasmacher, JAC 2005 Cornely et al. 2007

N=65 N=65 N=107Resp

onse

rate

(95%

CI)

Rationale for Combination Therapy for IA

h Clinical rationale

- Success with monotherapy still suboptimal

h45-55% for primary therapy

h35-40% for salvage therapy

- Significant mortality (30-50%) with the current regimens

h Scientific rationale

- Encouraging in vitro data

- Promising animal model data

- Preliminary clinical evidence

Combination therapy in guidelines

h In the absence of a well-controlled, prospective clinical trial, routine administrationof combination therapy for primary therapy isnot routinely recommended (B-II).

h The committee recognizes, however, that in the context of salvage therapy, an additionalantifungal agent might be added to currenttherapy, or combination antifungal drugs fromdifferent classes other than those in the initialregimen may be used (B-II).

Walsh T et al. CLin Infect Dis 2008; 46:327–60

IDSA GuidelinesDuration of antifungal therapy for invasive pulmonary

aspergillosis is not well defined. We generally recommend that treatment of invasive

pulmonary aspergillosis be continued for a minimum of 6–12 weeks; in immunosuppressed patients therapy should be continued throughout the period of immunosuppression and until lesions have resolved.

Long-term therapy of invasive aspergillosis is facilitated by the availability of oral voriconazole in stable patients.

For patients with successfully treated invasive aspergillosis who will require subsequent immunosuppression, resumption of antifungal therapy can prevent recurrent infection (A-III)

Walsh T et al. CLin Infect Dis 2008; 46:327–60