[3][4][5] As of 2019[update] she serves as a professor of Immunology and Infectious Diseases at the University of Cambridge, where she is also a Wellcome Trust Principal Research Fellow and a practicing physician.

[2][8][4] In 2018 and 2019 Ramakrishnan coauthored two influential papers[9] in the British Medical Journal (BMJ) arguing that the widely accepted estimates of the prevalence of latent tuberculosis—estimates used as a basis for allocation of research funds—are far too high.

Zebrafish larvae are optically transparent and lend themselves to genetic manipulation; by infecting them with their natural pathogen, Mycobacterium marinum, a bacterium that causes tuberculosis in fish and is a close genetic relative of the bacteria that cause tuberculosis in humans, she could carefully track the infection while manipulating the genes of both the larvae and the bacteria.

[20] In 2014, Ramakrishnan joined the faculty of the University of Cambridge as a principal research fellow for the Wellcome Trust and Professor of Immunology and Infectious Diseases.

Work in Seattle, and subsequently in Cambridge, led to the discovery of the molecular and cellular details of mycobacterial and host interactions at each step of infection.

[28] In addition to basic science investigations, Ramakrishnan, along with Marcel Behr and Paul Edelstein, reviewed studies concerning the concept of latent tuberculosis in order to determine whether tuberculosis-infected persons have life-long infection capable of causing disease at any future time.

Ramakrishnan told the New York Times that researchers "have spent hundreds of millions of dollars chasing after latency, but the whole idea that a quarter of the world is infected with TB is based on a fundamental misunderstanding.

"[9] The first BMJ article about latency was accompanied by an editorial written by Soumya Swaminathan, Deputy Director-General of the World Health Organization, who endorsed the findings and called for more funding of TB research directed at the most heavily afflicted parts of the world, rather than disproportionate attention to a relatively minor problem that affects just the wealthy countries.

Writing in The Atlantic, science journalist Katherine J. Wu commented that "even the world's biggest authorities on TB are dispensing with what was once conventional wisdom.