436

to estimate the degree of protection from malarial infectionwhich the presence of domestic animals has given to thehuman community.1V orld War IIThe application during World War II of this knowledge

of the A. maculipennis atroparvus enabled precautionsto be taken to avoid a repetition of the 1917-19 epidemic.A map was prepared by the Ministry of Health showingthe areas where malaria was most likely to be contractedand where the disease was most likely to spread (fig. 5).This map contained three areas, and the percentageof cases of indigenous malaria from each area after the1914-18 war was : area A, 69 ; area B, 23 ; area C, 5 ;and outside these areas, 3; From these figures it wasdeduced that, should a malaria problem arise, it wouldmost probably be in area A, and to a lesser extent inarea B. Copies of this map were sent in 1942 to thedirectors of hygiene of each of the three fighting Services,and the request was made that, as far as possible,potentially relapsing cases of malaria should not becongregated in areas A or B.

Prompt action was taken over every notified indigenouscase of malaria during and since World War II : the patient’shouse was visited and a mosquito survey made. Patientswere usually treated with mepacrine, and the rooms andstaircase of the house were sprayed with dicophane (D.D.T.),as were any animal houses which were found to be harbouringlarge numbers of adult mosquitoes.

These precautions were particularly vigorous in Kentor Essex, and the striking absence of a major outbreakof malaria after the late war seems to have justified themeasures taken (table ill and fig. 6).

Recent Industrial DevelopmentsThe construction of the Kent Oil Refinery was started

in 1950 at Grain, on the very site of the last malaria

epidemic in this country. The peak construction forceof 8000 was the largest ever assembled in this countryon any one site, and 2000 of this force were accommo-dated in a labour camp adjacent to the site. A certainproportion of this force were ex-Servicemen or colouredimmigrants who had recently been in parts of the worldwhere malaria is endemic, and who might thereforeexhibit a relapse parasitaemia. This produced a nightlyconcentration of man-power, contrary to the Ministry’swar-time recommendations.

A meeting of representatives of the Ministry of Health andlocal authorities was held in the summer of 1952 on the Isleof Grain to examine the potential risk of an outbreak ofmalaria which this concentration of men might have created.Mr. P. G. Shute (representing,the Ministry) demonstrated alarge number of A. naaculipennis atroparvus in the campsleeping quarters, and the meeting recommended thatimmediate steps should be taken to eliminate the high con-centration of mosquitoes in the area of the camp. These stepswere taken, and although we took blood slides from all personson the site who reported sick with a fever of unknown origin,to my knowledge no malarial parasitaemia was ever found.

Floods considerably damaged the sea wall aroundGrain in 1953, and reconstruction work resulted in manyburrow-pits and other small collections of brackish waterbeing left inside the wall. Larvae of A. maculipen7zisatroparvus were still being found in gravel pits nearGrain village early in the summer of that year, andsome anxiety was felt because these potential mosquitobreeding-grounds were close to the jetties at which

many tankers from the Middle East arrived. Frequentcomplaints by refinery personnel of being bitten at nightwarned us that mosquitoes were about in no smallnumbers.

This uncertain presence of a malarial hazard made merequest a second meeting in September, 1954, attended byrepresentatives of local authorities, Service medical repre-sentatives, and other specialists, including Prof. G. Macdonaldof the London School of Hygiene and Tropical Medicine.

The following recommendation received unanimous approval:" The meeting, after having considered the history of theincidence of anopheline and culicine mosquito infestationlocally, and elsewhere in the United Kingdom, is satisfiedthat there still exists a heavy incidence of mosquitoes in theIsle of Grain. This infestation, in addition to creating a seriousnuisance, makes possible the transmission of malaria inchanged circumstances now existing. The meeting, therefore,-strongly recommends that adequate measures should beundertaken to control the breeding of mosquitoes in theIsle of Grain, and is satisfied that this could be achievedat a reasonable cost." And while we attempt to implementthese recommendations, we are a little relieved by the factthat no case of indigenous malaria has been reported.

Conclusion r

Perhaps the ghost of malaria in the Thames area hasbeen finally laid. Malaria has fought a losing battle,first with the social and economic advances of the late19th century, and later with scientific attacks against itslines of communication. It is unlikely that importedmalaria will ever again succeed in reproducing the 1917epidemic, and all that remains is the nuisance of mosquitobites.

I wish to thank Mr. R. J. Marsh and Mr. E. N. Moore, thelibrarians of Rochester and Gravesend, for their assistance,and also Mr. P. G. Shute, assistant director of the MalariaReference Laboratory, Epsom, for his technical advice. Iwould like to acknowledge the ready assistance given me bymany medical officers of health and general practitioners inKent and Essex. I also thank Dr. J. Greenwood Wilson,medical officer of health for the Port of London, and Dr.S. D. McClean, chief medical officer of the British PetroleumCompany Ltd., for reading this paper, and Mr. C. S.Cleverly, general manager of Kent Oil Refinery Ltd., forpermitting me to publish it.

REFERENCES

Arnold, R. (1947) The Hundred of Hoo. London.Burnett, C. B. (1906) History of the Isle of Grain. London.Creighton, C. (1894) A History of Epidemics in Britain, ii, 306.

Cambridge.James, S. P. (1929) Proc. R. Soc. Med. 23, 1.McArthur, W. (1951) Brit. med. Bull. 8, 78.Ministry of Health (1917-53) Annual reports of the Chief Medical

Officer. H.M. Stationery Office.Registrar-General (1918) Annual report. H.M. Stationery Office.’Shute, P. G. (1945) Publ. Hlth, Lond. 57, 62.

— (1949) Mon. Bull. Minist. Hlth Lab. Serv. 8, 2.— (1954) Ibid, 13, 48.

Whitley, G. (1863) Sixth report of the Medical Officer of the PrivyCouncil. 430.

Willoughby, W. (1910-23) Annual reports of the Medical Officerof Health for the Port of London.

Statistics for England and WalesProvisional death-rates from cancer, tuberculosis, and

maternal mortality in England and Wales in 1955 havebeen announced by the Registrar-General.l

Cancer.-The death-rate for all forms of cancer was 2252per million population for men, and 1873 for women ; the1954 figures were 2223 and 1861. The rate for cancer of thelung and bronchus increased in men from 657 per million in1954 to 693 in 1955, and in women from 102 per million in1954 to 106 in 1955. Of the deaths from cancer in males,31 % were certified as due to cancer of the lung and bronchus ;of the deaths from cancer in women only 6 % were so certified.

Tuberculosis.-The provisional death-rate from respiratorytuberculosis in 1955 was 131 per million-a decrease of 18%compared with the previous year. The death-rate from otherforms of tuberculosis was 15 per million, compared with19 in 1954.Maternal causes.-The provisional rate for maternal mort-

ality (including abortion) was 0-64 per 1000 live and still births-the lowest ever recorded.

The Registrar-General estimates,2 on certain statedassumptions, that the total population of England andWales will increase from 44,623,000 as at mid-1955 to45,580,000 in 1965, 46,364,000 in 1975, and 46,690,000in 1985, declining to 46,328,000 in 1995.

1. Registrar-General’s weekly return no. 13, 1956. H.M. StationeryOffice. Pp. 20. 1s. 3d.

2. Registrar-General’s return for the quarter ended Dec. 31, 1955.H.M. Stationery Office. Pp. 23. 1s. 6d.