1. Why histoplasma antigen detection should be included on the EDL ?

2. Queiroz Telles et al, Lancet Inf Dis 2017
Lortholary et al, Clin Infect Dis 2013
Queiroz Telles et al, Lancet Inf Dis 2017
Colombo et al, Medical Mycology 2011

4. The story of Histoplasmosis in French Guiana

5. The story of Histoplasmosis in French Guiana
culture

6. The story of Histoplasmosis in French Guiana
culture

7. Histoplasmosis overall incidence rate among HIV-infected patients 1
Histoplasmosis overall incidence rate among HIV-infected patients 1.5 per 100 person-years

8. Incidence rate in an endemic area (30% positive histoplasmin skin test)

9. What is AIDS in the Americas?
Panama: 7.65% of patients with HIV infection had culture-positive H. capsulatum 
Guatemala: Histoplamosis is #1/2 with TB
Venezuela: In patients with AIDS, histoplasmosis was documented in 29 of 66 (44%) autopsies performed in one study 
Colombia: histoplasmosis ranks very high
378 HIV patients consecutively admitted in Fortaleza 164 (43%) Histoplasmosis
French Guiana : 42% of CD4<200; 85% of CD4<50
Suriname 25% of hospitalised HIV patients ag+
Not so many studies because mycologists compile histo cases but don’t have the other aids diagnoses
Some Clinicians may do retrospective studies
HIV aids programmes don’’t have the incentive because not part of standard indicators because no reliable diagnosis and because not seen as a problem vicious circle

11. The Anesthetic of familiarity

12. Connecting the dots

15. (a) HIV-associated histoplasmosis
Histoplasmosis incidence estimates among HIV infected patients (per 100 PLWHIV at country scale)
HIV-associated tuberculosis cases Observed:
[  996]
(a) HIV-associated histoplasmosis
#Histo cases > or = #TB cases
30% to 62% countries
Global: [  225]
Symptomatic: [N30] – [N50] – [N70]

16. Many patients still diagnosed for HIV at the advanced HIV stage
Confusion with TB+++
Lack of Diagnostic test=>no diagnosis/no data/no awareness/not a problem/why get a diagnostic test?

17. Histoplasmosis & HIV: Diagnostic methods
Microscopy (special stains)
74% sensitivity
Culture
76% sensitivity
Antibody detection
75% sensitivity
Antigen detection
92-96% sensitivity
Molecular biology
60-100% sensitivity
Hage et al. Seminars in Respiratory and Critical Care Medicine Vol. 36 No. 5/2015

18. Histoplasmosis & HIV: Diagnostic methods
Microscopy (special stains)
74% sensitivity
Culture
76% sensitivity
Antibody detection
75% sensitivity
Antigen detection
92-96% sensitivity
Molecular biology
60-100% sensitivity
Hage et al. Seminars in Respiratory and Critical Care Medicine Vol. 36 No. 5/2015

19. ↑ analytical performance
Time in days
Mean days
(SD)
↑ analytical performance
Novel technologies
All are lab tests…
But, have different analytical performance and turnaround time results.
Conventional
performance
↓ analytical
Data from: Y. Valencia et al, manuscript in preparation. Medical and Experimental Mycology Group, CIB, Medellín, Colombia. (P-013)

20. Antigen Detection to diagnose PDH
2006: Quantitative ELISA
Wheat et al Indianapolis, USA
: Validation of CDC PoAb ELISA in Latin-America
1986: RIA
J Wheat et al Indianapolis, USA
Future
1997: ELISA
Gómez Et al Medellin, Col
J Wheat et al Indianapolis, USA
2007: PoAb ELISAs: *Commercial IMMY, USA
*CDC in house ELISA
: MoAb Commercial IMMY ELISA, US and Latin-America

21. Systematic reviews One systematic review and metaanalysis

22. Potential sources of variation of results
Heterogeneity of designs
Often no gold standard =>extrapolation of results as if the test was vs gold standard
Specificity often calculated using non fungal controls which may not reflect real life in some settings
Mostly non consecutive patients
Often mixed bag of AIDS and non AIDS cases (i.e. for subacute Histo mv EIA se 30%/PDH 94.6%)
Small sample sizes
No confidence intervals given except 2 studies
Potential bias : many recommendations originate from authors with potential financial conflicts of interest (i.e. recommended test, number of tests per patient item 18 PRISMA-DTA 2018)

23. positive likelyhood ratio
Computations using the paper by Scheel et al.: Results of a positive test
proportion of histoplamosis among advanced HIV
pretest odds
post test odds
positive likelyhood ratio
post test probability
0.01
0.0101
13.5
0.12
0.1
0.1111
1.5
0.6
0.25
0.3333
4.5
0.81
0.4
0.6666 9
0.9

24. Histoplasma antigen detection CDC polyclonal EIA

25. negative likelyhood ratio
Computations using the paper by Scheel et al.: Results of a negative test
proportion of histoplamosis among advanced HIV
pretest odds
post test odds
negative likelyhood ratio
post test probability
0.01
0.0101
0.002
0.2021
0.1
0.1111
0.0224
0.021
0.25
0.3333
0.0673
0.063
0.4
0.6666
0.1347
0.118

26. positive likelyhood ratio (Se/1-Spe)
Computations using the paper by Caceres et al.: Results of a positive test
proportion of histoplamosis among advanced HIV
pretest odds
post test odds
positive likelyhood ratio (Se/1-Spe)
post test probability
0.01
0.0101
0.3299
32.66
0.248
0.1
0.1111
3.629
0.784
0.25
0.3333
10.888
0.915
0.4
0.6666
21.777
0.956

27. Histoplasma antigen detection Immy monocclonal EIA

28. negative likelyhood ratio
Computations using the paper by Caceres et al.: Results of a negative test
proportion of histoplamosis among advanced HIV
pretest odds
post test odds
negative likelyhood ratio
post test probability
0.01
0.0101
0.0002
0.0206
0.1
0.1111
0.0022
0.25
0.3333
0.0068
0.4
0.6666
0.0137
0.0135

29. Urine or/and serum?

30. Of 601 paired specimens, 542 were concurrent negatives and 48 were concurrent positives (98% agreement).

31. Why histoplasma antigen detection should be included on the EDL ?
Diagnosis of histoplasmosis by Antigen detection by ELISA is sensitive and specific
It has made a difference where it has been used (whatever the test)
It has saved lives, it saves lives, it will save many more if made available at least in reference hospitals: be histo-aware
It will allow to measure the burden of disease among patients with advanced HIV
It will allow to understand the natural history of histoplasmosis and perhaps screen patients to identify those who are not yet symptomatic
PICO question : Are histoplasma antigen detection tests better than the standard of care to increase the diagnosis of histoplasmosis and reduce mortality among patients with advanced HIV-disease?

32. Caceres et al. 2015
Adenis et al.2014
Expected outcomes

34. comparator if no gold standard Regulatory approval cost number histo
Study
year
consecutive patients
territory
Gold standard
comparator if no gold standard
Regulatory approval
cost
number histo
number of controls
pretreated
HIV
Wheat et al
1989 no
usa
culture 61 27
partly 35/26
yes
zimmerman
RIA MV  19 24 ?
Gomez
1997
colombia
35 serum 16 urine
48 serum 20 urine
mix
Conolly
2007
culture? 65
100
FDA
2008
culture/pathology 47
231
mix?
Cloud
other test
Le Monte
immy alpha/MV
no/yes
Gutierrez
usa/panama
clinical suspicion aids patient
21 panama/65 usa
0 no controls
Scheel
2009
guatemala 41
197
Hage
2011
yes?
usa multicentric
culture/pathology/serology/ag
158 disseminated
229
seems not
mixed
Theel
2013
mv/immy ASR galactomannan
Caceres
2014 28
174
follow up
2015
2018
colombia/guatemala
no/research use only (pending?) 63
526
Studies on epidemics non hiv (williams, zhang) not included

35. AP-ELISA HRP-Elisa/RIA
Study
number histo
number of controls
HIV
Se urine
Sp urine
test
confidence intervals
split
samples
Wheat et al 61 27
yes
96.7
not in paper
RIA no
zimmerman 19 24
89.5/94.7
AP-ELISA HRP-Elisa/RIA
Gomez
35 serum 16 urine
48 serum 20 urine
mix
71.4 (global)
98/84 (patients with other fungal infections)
Conolly 65
100 99
MV2nd gen ELISA
FDA 47
231
mix?
80.9
98.7
IMMY alpha
Cloud ?
not possible
alpha/mv
Le Monte
44% but not possible
84% but not possible No
serious issues with paper (methodological/conflict of interest/bias)
Gutierrez
21 panama/65 usa
0 no controls mv
Scheel 41
197 81 95
CDC EIA
Hage
158 disseminated
229
mixed
91.8
99% non-fungal controls MV
Theel
no sens vs mv 64.5
no spe vs mv 99.8
MV/IMMY ASR galactomannan
Caceres 28
174 86 94 63
526
98%(95%CI=95-99)
97%

36. culture/pathology/serology/ag 158 disseminated (60 pulmonary)
Study
year
consecutive patients
territory
Gold standard
Regulatory approval
cost
number histo
number of controls
pretreated
HIV
Wheat et al
1989 no
usa
culture 61 27
partly 35/26
yes
Gomez
1997
colombia
35 serum 16 urine
48 serum 20 urine ?
mix
Conolly
2007
culture? 65
100
FDA
2008
culture/pathology 47
231
mix?
Cloud
Scheel
2009
guatemala 41
197
Hage
2011
yes?
usa multicentric
culture/pathology/serology/ag
158 disseminated (60 pulmonary)
229
seems not
mixed
Caceres
2014 28
174
follow up
2018
colombia/guatemala
no/research use only (pending?) 63
526

37. 98/84 (patients with other fungal infections)
Study
number histo
number of controls
HIV
Se urine
Sp urine
test
confidence intervals
Wheat et al 61 27
yes
96.7
not in paper
RIA no
Gomez
35 serum 16 urine
48 serum 20 urine
mix
71.4 (global)
98/84 (patients with other fungal infections)
Conolly 65
100 99
MV2nd gen ELISA
FDA 47
231
mix?
80.9
98.7
IMMY alpha
Yes
(large 62-98)
Scheel 41
197 81 95
CDC EIA
Hage
158 disseminated
229
mixed
91.8
99% non-fungal controls MV
Caceres 28
174 86 94 63
526
98%
(95%CI=95-99)
97%
 Immy monoclonal EIA
Yes (narrow)