Effects of daily trimethoprim-sulfamethoxazole prophylaxis on long term clinical impact of malaria infection among HIV infected adults on successful ART in Blantyre, Malawi Felix Mkandawire, Randy G. Mungwira, Titus H. Divala, Osward M. Nyirenda, Maxwell Kanjala, Lufina Tsirizani, Francis Muwalo, Nicaise Ndembi, Terrie E. Taylor, Jane Mallewa, Joep J. van Oosterhout, Matthew B. Laurens, Miriam K. Laufer

Malaria and HIV Combined 2 million deaths annually Highest burdens overlap in sub-Saharan Africa Proportion of global incidence 88% of malaria cases and 90% of malaria deaths HIV 70% Geographical overlap: high risk of coinfection 1. WHO Annual report - 2008, 2. UNAIDS report – 2010, 3. WHO- 2015

Malaria and HIV immunosuppression Risk of malaria disease increases slightly with immunosuppression Cotrimoxazole preventive therapy (CPT) prevents OI’s reduces the risk of malaria 4 Laufer et al. - 2006, 5 WHO guidelines – 2006, 6. Polyak et al. – 2016, 7. Kasirye et al. – 2016

Role of CPT after ART Antiretroviral therapy (ART) now widely available in sub-Saharan Africa Highly effective in leading to immune recovery After immune reconstitution, is CPT still beneficial? Why consider CPT discontinuation? Side effects, pill burden, cost, antimicrobial resistance

With ART success, can CPT be discontinued? What we know about CPT discontinuation Two clinical trials: Most significant morbidity was increased malaria infection Also increase in diarrhea No increased risk of other OIs What is unknown Mechanism of clinical malaria susceptibility Impact on asymptomatic malaria 1. Polyak et al 2016, 2. Kasirye et al. 2016

Goals of this study What is the impact of discontinuing CPT on Clinical susceptibility to malaria infection Asymptomatic malaria infection Using data from an on-going clinical trial

Study site and setting Ndirande Health Centre, Blantyre, Malawi Participants selected from: A randomized, open-label controlled trial of daily cotrimoxazole or weekly chloroquine among adults on ART Small subgroup selected for immunology sub-study

Cohort selection from TSCQ Participants from the CPT and No CPT arm Non-pregnant adults aged ≥18 years ≥6 months on ART and CPT Clinically stable: no acute illness Evidence of successful ART and immune recovery HIV viral load <400 copies/ml, CD4 count >250 cells/mm3

Study procedures Follow up: every 4 weeks for 6 months Also evaluated when sick Data collected History: Malaria symptoms or signs, bednet use Examination: malaria signs Diagnostic specimens Blood smear if symptoms of malaria were present Dried blood spots on filter paper for qPCR at every visit

Molecular detection of malaria Qiagen extraction of dried blood spots on Whatman 3M filter paper Real-time PCR detection of P. falciparum 18s rRNA gene Standard curves evaluated for each run

Outcome definitions Clinical malaria Malaria symptoms plus positive blood smear Asymptomatic malaria No malaria-like symptoms plus positive Real-time PCR

Baseline characteristics were similar between groups CPT No CPT Total enrolled 34 27 Proportion Male (%) 15 19 Mean age (Yrs) 41 40 Median CD4 (cells/mm3) 494 519 Mean Hemoglobin (g/dL) 13 Bed net use (%) 85

Study profile Enrolled: 61 CPT: No CPT: Exposure 34 27 22 completed f/up Accrued: 14 PYO 31 completed f/up Accrued: 17 PYO Follow up # F/paper analyzed 225 # F/paper analyzed 239 Clinical: 4 cases Asymptomatic: 0 Outcome Clinical: 1 case Asymptomatic: 0

Clinical and asymptomatic malaria Clinical malaria 6/100 PYO (CPT) vs 29/100 PYO (No CPT) Incidence rate ratio 5.0 [95%-CI 0.5 to 246.4] No episodes of asymptomatic malaria detected in either group

Discussion: Clinical malaria More episodes of clinical malaria in the “no CPT” group Difference not statistically significant Small sample size Results of clinical disease incidence confirm previous findings

Discussion: Asymptomatic malaria No episode of asymptomatic malaria detected All infections manifested clinically Unusual in Blantyre Recent adult population survey in Blantyre 5% (120/2613) parasitaemia prevalence by qPCR All most all were asymptomatic 5 Walldorf et al. - 2015

Does CPT impact malaria immunity? CPT successfully prevented most Malaria infections We expected to find some degree of asymptomatic malaria Demonstrated by surveillance studies in same area However, all malaria infection → symptomatic disease By preventing malaria, CPT may have impacted immunity to malaria disease. Rebound effect described in some but not all previous prophylaxis studies

Strengths and limitations Detailed clinical and laboratory data from RCT setting Good active and passive malaria surveillance Limitations Power Sample size Low transmission area Did not measure malaria immunity

Conclusion CPT discontinuation after long term use Associated with increased risk of clinical malaria No infections were asymptomatic Suggests loss of malaria immunity Final analysis Higher power with inclusion of more TSCQ study participants Explore impact on malaria immunity Plan to evaluate serological response

Acknowledgements Ndirande Health Center Laboratory led by R. Masonga Study participants Data team led E. Huwa Blantyre Malaria Project Funding Study nurses led by M. Funsani NIH U01AI089342 Study clinicians led L. Khonde