Research

Current projects:

• Malaria eradiction modelling: The main focus of my current research is to extend existing deterministic and individual-based mathematical models that can inform malaria eradication strategies - how, where and when should resources be invested to most effectively reduce the global case burden and eventually eradicate Plasmodium parasites?
• R21/Matrix-M and RTS,S/AS01 malaria vaccines: Two malaria vaccines have been recently recommended by the World Health Organization for implementation among young children in sub-Saharan Africa. With my colleagues, I model the cost-effectiveness of these vaccines relative to the scale-up of existing interventions such as insecticide-treated bed nets and seasonal malaria chemoprevention.
• Metapopulation models in sub-Saharan Africa: Our group primarily models one specific country or administrative unit setting at a time. However, malaria is geographically heterogenous, and malaria transmission in one area affects the transmission levels in other areas due to mosquito and human movement. I am developing a metapopulation model to be able to capture interaction between settings. The goal is to be able to look at areas of high transmission which border areas of near-elimination (e.g. Mozambique and South Africa) to better inform border strategies.
• Gender inequality in publications: Women and ethnic minorities are underrepresented among authors of scientific publications. In both the UK and the US, there are also fewer women appointed to full-time faculty than men, despite more women obtaining bachelor's, master's, and doctoral degrees than men, a trend which also follows for ethnic minority groups. I am working with a team to characterize the representation of women and ethnic minorities at Imperial College London's School of Public Health. We are hoping that this work will inform strategies to increase representation and remove barriers to publication and career advancement in our field.
• Community engagement: Innovation in malaria tools and increased funding can save more than 13.2 million lives over the next 15 years. I am one of the malaria modellers contributing to the "Zero Malaria Experience", a film collaboration and public interactive installation with Malaria No More UK, the Mill (a creative community), David Beckham, and global public health leaders. Check it out!

Select publications:

The public health impact and cost-effectiveness of the R21/Matrix-M malaria vaccine: a mathematical modelling study.
Schmit N*, Topazian HM*, Natama MH, Bellamy D, Traoré O, Some AN, Rouamba T, Tahita MC, Bonko MA, Sourabié A, Sorgho H, Stockdale L, Provstgaard-Morys S, Aboagye J, Woods D, Rapi K, Datoo MS, Ramos Lopez F, Charles G, McCain K, Ouédraogo J, Hamaluba M, Ologu A, Dicko A, Tinto H, Hill AVS, Ewer K, Ghani A, Winskill P (2023) The Lancet Infectious Diseases PREPRINT.

Resource allocation strategies for insecticide-treated bed nets to achieve malaria eradication.
Schmit N*, Topazian HM*, Pianella M*, Charles GD, Winskill P, White MT, Hauck K, Ghani AC (2023) elife 12:RP88283.

Modelling the relative cost-effectiveness of the RTS,S/AS01 malaria vaccine compared to investment in vector control or chemoprophylaxis.
Topazian HM, Schmit N, Gerard-Ursin I, Charles GD, Thompson H, Ghani AC, Winskill P (2023) Vaccine 41(20):3215-3223.

No evidence of sustained nonzoonotic Plasmodium knowlesi transmission in Malaysia from modelling malaria case data.
Fornace KM, Topazian HM, Routledge I, Asyraf S, Kelip J, Lindblade KA, Jaeffree MS, Cuenca PR, Bhatt S, Ahmed K, Ghani AC, Drakeley C (2023) Nature Communications 41(20):3215-3223.

Low complexity of infection is associated with molecular persistence of Plasmodium falciparum in Kenya and Tanzania.
Topazian HM, Moser KA, Ngasala B, Oluoch PO, Forconi CS, Mhamilawa LE, Aydemir O, Kharabora O, Deutsch-Feldman M, Read AF, Denton M, Lorenzo A, Mideo N, Ogutu B, Moormann AM, Mårtensson A, Odwar B, Bailey JA, Akala H, Ong’echa JM, Juliano JJ (2022) Frontiers in Epidemiology 2:852237.

Effectiveness of a national mass distribution campaign of long-lasting insecticide-treated nets and indoor residual spraying on clinical malaria in Malawi, 2018–2020.
Topazian HM*, Gumbo A*, Edwards JK, Brandt K, Goel V, Kayange M, Mvalo T, Emch M, Pettifor A, Smith J, Juliano JJ, Hoffman I (2021) BMJ Global Health 6:e005447.

Asymptomatic Plasmodium falciparum malaria prevalence among adolescents and adults in Malawi, 2015-2016.
Topazian HM, Gumbo A, Puerto-Meredith S, Njiko R, Mwanza A, Kayange M, Mwalilino D, Mvula B, Tegha G, Mvalo T, Edwards JK, Emch M, Pettifor A, Smith JS, Hoffman I, Meshnick SR, Juliano JJ (2020) Scientific Reports 10:18740.

Household prevalence of P. falciparum, P. vivax, and P. ovale in the Democratic Republic of the Congo, 2013-2014.
Mitchell CL*, Topazian HM*, Brazeau NF, Deutsch-Feldman M, Muwonga J, Sompwe E, Tshefu AK, Mwandagalirwa MK, Parr JB, Juliano JJ (2021) Clinical Infectious Diseases 73(11):e3966-3969.

* Equal contribution