The strength of the garrison was 2234. This included 297 invalids and convalescents from the Ionian Islands. Of these, two returned to their Corps, 163 were sent to England for discharge, and 90 remained in the depôt at Malta pending availability of transport to return them to England. The 18th and 80th Regiments were quartered in Valletta and, Floriana, the 85th in the Cottonera.
By the end of the Winter Quarter (21 Dec 1822 to 20 Mar 1823), 424 sick were admitted into the hospitals with seven deaths. There were 492 admissions with three deaths at the end of the Spring Quarter (21 Mar to 20 June 1823). The end of the Summer Quarter, (21 June to 20 Sep 1823), saw 677 admissions with three deaths. The Autumn Quarter (21 Sep to 20 Dec 1823) saw the arrival of 205 invalids from the Ionian Islands. 588 sick soldiers had been admitted during this quarter with 12 deaths.
Overall there were 2256 admissions into the hospitals, including relapses, with 25 deaths. In 1822, there had been 39 deaths. The proportion of deaths to disease for 1823 was 1 to 91. In 1822 it had been 1 to 73. Continued fever, the result of exposure to the sun and intemperance, had been the most prevalent disease. It accounted for one seventh of all the admissions to hospital.
The garrison had 237 sick soldiers with venereal infections, representing about a ninth of all the hospital admissions. There were: syphilis primitiva 22, syphilis consecutiva 13, genital ulcers 91, bubo simplex 31 and gonorrhoea 80. In addition there were 44 cases of hernia humoralis, which was also considered to be venereal in its origins. The non mercurial practice had been adopted in the garrison, but the PMO accepted its limitations and mercury was resorted to when warranted.
Staff Medical Officers who were away from Malta were not replaced, increasing the work load on the remaining officers. Inspector of Hospitals John Hennen complained that:
from the diminished state of the medical staff, the labour during the summer months have been felt in a very sensible degree by those who were present and fit for duty, not so much from any serious or unusual increase of sickness in the hospitals, as from the frequent calls to duties of the barracks, and examination and attendance on officers, women, and children in the hottest months of the year.