Carlos Chagas

Sergio Sosa-Estani, MD, PhD. CeNDIE, IECS, CONICET, Buenos Aires, Argentina

International Symposium on the Centenary of Chagas disease Discovery

Therapy, diagnosis and prognosis of chronic Chagas disease: insight gained in Argentina

9,000 y BC

1909 discover

1920-2009 Dx

1960-1970 Tr

Salvador Mazza

Diagnosis of infectionSerological tests

• Complement fixation (Muniz & Freitas 1944)

• Indirect immunofluorescence assay (Alvarez et al. 1968)

• Indirect hemagglutination assay (Cerisola et al. 1962)

• Enzyme immune assay (Voller 1975)

QUALITY CONTROL PROGRAM

Transfusion 2009

Appropriate Technology for taking blood samples for screening T. cruzi infection.

• Filter paper 1966-1983

• Capillary blood w/glycerin (Serokit®) 1985

• Immunocromatography (x ej. Stat-Pak®) 2003

Foto: MSF Honduras

Foto: MS Honduras

Markers associated with Progression

Prescription of Specific Treatment against T. cruzi Infection

• All patients undergoing the acute phase

• Children and young patients undergoing the chronic phase

• Laboratory or surgical accident

• Organ transplant recipients or donors

• Chronic phase, indetermined or incipient cardiac form in adults may be

considered, although with limited evidence

Clinical Studies (Observational) to assess treatment of T. cruzi Infection

T. cruzi-specific T lymphocytes secreting IFN-g in response

to T. cruzi lysate in patients with chronic Chagas disease treated and not treated

Clinical Studies (RCT) to assess treatment of T. cruzi Infection

I – Incidence of ECG abnormalities / BZD- children Source BZD n/N Plac n/N Weight % OR (95% CI)

Andrade 1/59 4/58 71 0.28 (0..05, 1.69)

Sosa-Estani 1/40 1/41 29 1.03 (0.06, 16.99)

Pooled 2/99 5/99 100 0.41 (0.09, 1.85)

Heterogeneity test X2 =0.58 p=0.45 / Overall effect test Z=-1.16 p=0.2 II- Negative seroconversion (AT ELISA – children – BZD) Source BZD N/N Plac n/N Weight % OR (95% CI)

Andrade 37/58 3/54 57.8 12.35 (5.72, 26.68)

Sosa-Estani 24/44 3/44 42.2 9.19 (3.73, 22.64)

Pooled 61/102 6/98 100 10.91 (6.07, 19.58)

Heterogeneity test X2 =0.24 p=0.63 / Overall effect test Z=8.0 p=0<0.001

III- Negative xenodiagnosis Source All TT n/N Plac n/N Weight % OR (95% CI)

Apt 314/336 146/165 48.9 1.93 (0.98, 3.81)

Coura 43/53 1/24 24.1 22.24 (8.45, 58.56)

Gianella 1/13 0/17 1.4 10.05 (0.19, 524.8)

Sosa-Estani 40/42 21/43 25.6 9.61 (3.76, 24.58)

Pooled 398/404 168/249 100 5.37 (3.34, 8.64)

Heterogeneity test X2 =18.54, p<0.001 / Overall effect test Z= 6.94 p<0 .001 0.01 0.1 1 10 100

Benznidazole Meta-analysisVillar JC, et al Cochrane Database Syst Rev. 2002;(1)

Slow seronegativization without evidence of parasitimia after treatment:

a) related attribute of the host (humoral immune response against Tc I and Tc II)?;

b) related mixed mechanism to cure (1st drugs against Tc I and T cII ?; 2nd immune response as a complement to complete clearance)?

Antibodies kinetic with long term of follow-up of children undergoing chronic T. cruzi infection, and treated with

benznidazole. Salta, Argentina, 1991-2005

Sosa-Estani S et al. 1998, AJTMH, and unpublished data

Not Cured

Cured

Antibodies kinetic with long term of follow-up of children undergoing chronic T. cruzi infection treated with benznidazole,

and cured. Salta, Argentina, 1991-2005

Sosa-Estani S unpublished data

Yun O et al. PLoS Negl Trop Dis. 2009 Jul 7;3(7):e488.

How to assess a treatment during chronic phase?(Successful=do not find Ab; Failure= find parasite)

• Immunological tests– Serological tests - Commercially Available

• Need long follow up to demonstrate efficacy (Seronegativization)– Serological tests - Not commercially available, tested as useful

• Need shorter time of follow up, but > 3 years• Need validation

– Specific cellular immune response (?) (under research)

• Parasitological tests– Direct tests (low sensitivity, not practical)– Xenodiagnosis (Center of reference, only for research-isolates , low sensitivity)– Hemoculture (available but only in few centers, not practical, low sensitivity)– PCR (higher sensitivity, currently under standardization, new techniques for

quantitative PCR with rapid developments)

RT-PCR

Some strategies to getting new treatments• New schemes / New prescriptions (i.e. BENEFIT Project. Efficacy of Bz

in Patients with cardiac disease)

• Pediatric formulation (i.e. dispersable tables and suspention-LAFEPE-DNDi, Solution-UNR)

• Registered drugs with anti-T. cruzi activity (i.e Posaconazole, Itraconazole (antimicotic), Bisphosphonates (osteoporosis) , Miltefosine (antineoplastic, antiprotozoal), Clomipramine (tricyclic antidepressant), Liposomal amphotericin (antifungical, antiprotozoal)

• Evaluation of Combination (i.e. Combination of registered compounds (Benznidazole/Nifurtimox) with drugs with demonstrated activity in Chagas’ disease)

• Evaluation of library of existing compounds (i.e. Furazolidone, Clemastine)

• Develop an specific new drug (i.e. inhibitors of trans-sialidase, cysteine proteinase, trypanothione reductase, others)

Evaluation of Care Quality for Diagnosis and Treatment,Argentina, 2007

Variable Obs % Valuation

Appropriate confirmation of infection 178 98% Good

Treatments completed 130 97% Good

Records with completed data (essentials) 195 5% Bad

Records with data about dates of Treatment 195 36% Bad

Opportunity of tratment (<30 days) 43 52.3 Regular

Tolerance 123Good tolerance 99%

Regular tolerance 1%

Records with data about monitory 195 56% Regular

Rodriguez V, Rubinstein F, Sosa-Estani S, unpublished data

Control of Congenital Transmission of Trypanosoma cruzi

Screening of Pregnant WomenScreening of Pregnant Women

Mother REACTIVEMother REACTIVE Mother Non-ReactiveDischarge

Mother Non-ReactiveDischarge

Parasitological Test in Newborn Negative

Parasitological Test in Newborn Negative

Parasitological Test in NewbornPOSITIVE

Treatment and Monitoring

Parasitological Test in NewbornPOSITIVE

Treatment and Monitoring

Serological Test >= 10 m oldNon-Reactive

Discharge

Serological Test >= 10 m oldNon-Reactive

Discharge

Serological Test >= 10 m oldREACTIVE

Treatment and Monitoring

Serological Test >= 10 m oldREACTIVE

Treatment and Monitoring

Screening of Pregnant Women

Screening of Pregnant Women

Mother REACTIVEMother REACTIVE Mother Non-ReactiveDischarge

Mother Non-ReactiveDischarge

Parasitological Test in Newborn Negative

Parasitological Test in Newborn Negative

Parasitological Test in Newborn

POSITIVETreatment and Monitoring

Parasitological Test in Newborn

POSITIVETreatment and Monitoring

Serological Test >= 10 m old

Non-ReactiveDischarge

Serological Test >= 10 m old

Non-ReactiveDischarge

Serological Test >= 10 m oldREACTIVE

Treatment and Monitoring

Serological Test >= 10 m oldREACTIVE

Treatment and Monitoring

In the health system:-Low rate of detection by parasitological test.-Health workers do not know the procedures.- Health workers do not have adequate training.-Health workers do not have good working conditions.

Hypotheses of Lost Opportunities for the Adequate Diagnosis of Congenital Trypanosoma cruzi Infection

In the community:-Mothers do not know the procedure.- Mothers do not understand the instructions.-Mothers do not have financial resources to get to the health center.

Early diagnosis of congenital Trypanosoma cruzi infection using PCR, hemoculture, and capillary concentration, as

compared with delayed serology. Mora MC, et al. J Parasitol. 2005;91(6):1468-73.

Diagnosis of Congenital Trypanosoma cruzi Infection by ELISA SAPA (matched samples from mothers infected and their newborns [n=31]).

Index (Subtraction OD ELISA-SAPA Newborn; OD ELISA-SAPA Mother), Ushuaia, Tierra del Fuego,

Argentina.

Mallimaci C, Sosa-Estani S, Russomando G, et al, Submitted, 2009

Detection of Specific T. cruzi Antibodies by Commercial ELISA and Shed Acute Phase Antigen

(SAPA) on Non- Infected Infants (n=36 ) under Follow-up.

Ushuaia, Tierra del Fuego, Argentina.

Mallimaci C, Sosa-Estani S, Russomando G, et al, Submitted, 2009

Evaluation of technology – Implementation research• New tools must to be addressed to the PHC System• Main user National Programs, Public Health S• Wide range of beneficiaries

Photo: H Freilij. BsAs, ARG Photo: S Sosa-Estani, Las Lomitas, Formosa, ARG

They are waiting for:•the researcher to research,

•the politician to decide, •and the health worker to act