Would you like your malaria by infected blood injection or directly from the mosquito?
14 August, 2025

By Dr Claire Hilton, Honorary Archivist at the RCPsych.
If this sounds like a horror story, fantasy or sci-fi, it is not. A century ago, transmitting malaria to a patient suffering from ‘general paralysis of the insane’ (GPI), a late manifestation of the sexually transmitted disease syphilis, was an established method of treatment. Symptoms of GPI included grandiose delusions, hallucinations, lack of judgment, depression, memory loss and epileptic seizures. Without treatment, death usually followed in months or a couple of years. Malaria inoculation was the best available treatment. Patients requested it. Learning from it also helped break down barriers between physical and mental health services, influencing service development.
Back in the 1920s…
In the 1920s, mental hospitals across 萝莉视频 and Wales had about 100,000 inpatients in total. Of that number, about 8,000 died each year. Among them, GPI caused the deaths of around 900 men and 200 women.
Many people admitted had symptoms which we would recognise as mental disorders today, but others were primarily physically ill. Some had delirium associated with severe infections or terminal disease. Some had depression associated with tuberculosis. Others had vitamin deficiencies, hormonal abnormalities, brain pathologies only fully revealed at post-mortem, or other conditions. Physical causes of disturbed behaviour might be overlooked before or during mental hospital admission, sometimes because of an individual doctor’s laziness, lack of skill or interest. David K Henderson and Robert Gillespie in their Textbook of Psychiatry (1927, p.66-7) reminded doctors that if they wrote in the clinical notes that a patient was ‘so disordered mentally as to be quite unco-operative, and on that account a complete examination is impossible’, they were fooling themselves: ‘How seldom is that really the case!’
GPI: diagnosis and treatment
Developments in Victorian and Edwardian science were the key to understanding the pathology of syphilis. At the beginning of the twentieth century, August Paul von Wassermann (1866-1925) and his team in Germany developed a blood test, eponymized with his name, which could detect treponema pallidum, the spiral shaped bacterium causing the disease. In 1913, treponema pallidum was finally identified in the brains of patients who died from GPI.
Untreated, syphilis can affect many organs of the body. Highly toxic medications derived from mercury and arsenic were used to treat it in most organs, but these substances did not cross into the brain so were ineffective for GPI. Something different was needed.
Over the centuries, physicians had observed that fevers could alleviate symptoms of mental illness. Dr Julius Wagner-Jauregg, working in Vienna, observed this and it aroused his interest. He theorized that malaria produced high fevers which might kill treponema pallidum, but unlike other fevers, those caused by malaria could be controlled with quinine. That would allow an induced fever to be terminated should the patient react adversely to it. It was a desperate remedy for an incurable, desperate disease.
In the middle of the First World War, Wagner-Jauregg inoculated blood from a soldier repatriated from the Eastern Front who was suffering from malaria, into . Three of them were cured. The mid-war timing of Wagner-Jauregg’s discovery, the need to translate reports from German, wider incredulity at his findings, challenges of post-war reconstruction and of finding suitable sources of malaria in more northerly climates, contributed to delaying treatment by malaria inoculation in other countries. Its first recorded use in the UK was in 1922.
There were two ways of inoculating malarial parasites: either blood from one malaria-infected person (likely also being treated for syphilis) could be injected into another with a syringe, or malaria-infected mosquitoes could be allowed to bite the patient directly. Patients may not have been asked about their preference, but their families disliked the idea of blood from a patient with syphilis being injected into their relative, preferring the direct bite method. Fortunately, some evidence indicated that a direct bite was more effective. To achieve this, malaria-infected mosquitoes were transferred into a glass jar and the mouth of the jar covered with netting. The netting was placed against the patient's thigh, allowing the mosquitoes to bite through. The bites were painted with iodine to allay irritation and bandaged to prevent the patient from scratching them.
To use malaria-carrying mosquitoes to provide treatment necessitated collaboration between psychiatrists and tropical medicine experts. In 1922, specialists at the Liverpool School of Tropical Medicine and at Whittingham Mental Hospital, Lancashire, joined forces. They inoculated three patients suffering from GPI, with malaria-infected blood from another patient. Two did well, and one failed to develop a fever, but the overall outcome inspired further activity. By the end of 1923, across 萝莉视频 and Wales offered the treatment, and a (Annual Reports of the Board of Control for 1923 and 1924).
Treatment by malaria inoculation required close monitoring, so doctors needed to take a more medical approach than that which was customary in a mental hospital. Physical examinations and blood and urine tests underpinned decisions as to whether it was safe to continue treatment or to terminate the fevers with quinine. With physical and mental debility due to GPI plus the malarial treatment, some succumbed, and the rest were left exhausted and profoundly anaemic. Great effort was invested to improve their general health including through good diet, fresh air and ‘ [beer]’, wrote Dr Nicol of Horton Hospital, Epsom.
Not all institutions in the UK achieved the high cure rate reported from Vienna, but optimistic reports of the treatment appeared in national newspapers. Patients began to request the treatment, despite the risks.

Dr Nicol and the malaria ward nurses at Horton Hospital. Credit: League of Nations, Principles and Methods of Antimalarial Measures in Europe. 1927. p.38. (CC BY-NC 4.0)
Why we should know about this
From the 1940s, antibiotics were used to treat GPI, and gradually malaria inoculation was abandoned. However, it left legacies concerning psychiatric research, practice, legislation and stigma.
Firstly, it demonstrated a biological treatment for a biologically caused mental disorder, which helped shape future research and pointed to the need for clinicians and scientists to collaborate.
It also fed into arguments for mental hospital staff to have sufficient skills to treat physically unwell patients, and for having on-site, potentially life-saving diagnostic and laboratory facilities to assist them.
The Lunacy Act 1890 (萝莉视频 and Wales) forbade public funding of psychiatric wards and outpatient clinics in general hospitals. However, knowledge from GPI supported arguments for Lunacy Act reform: since mental and physical illnesses and their treatments overlapped, some mental illness beds should be available in general hospitals; and with evidence that prompt treatment produced better outcomes than delayed, patients should have access via clinics to seek help early on.
Caring for people with mental disorders in the same hospital as those with physical disorders also had the potential to reduce stigma.
Have a look in the Cabinet of Curiosities at our replica net-covered jar to allow mosquitoes to bite the patient.


Original image credit: League of Nations, Principles and Methods of Antimalarial Measures in Europe. (1927) p.43. (CC BY-NC 4.0). Reproduction constructed and photographed by author.