Jung, 1904.)
EXTERMINATION OF MOSQUITOES,
207
Major Ross, 1.M.8., for the abolition of breeding places and destruction of larve, Pools were drained or filled in, discarded vessels and tins removed, the Maka Masjid tank was filled in, and, at the prison, a regular weekly inspection is now made, for the purpose of applying kerosine oil where necessary, and sweeping away small collec- tions of water. In the town two men, paid out of a small municipal grant, were tentatively employed in the same way, but this arrangement has been interrupted owing to the recent severe epidemic of plague and consequent evacuation of the houses ; they were, of course, only capable of dealing with anopheles resorts, as these became known. A vernacular leaflet was. also circulated, explaining the object of the measures employed, and some of the educated inhabitants began to take an inter- est in the work.
Results.—The records of the civil hospital are useless in this connection, owing to the outbreak of plague and the diminished attendance which resulted.
The prison records are not affected by these conditions, and the admissions for malarial fevers for the last two years are quoted below. It may be noted that the rainfall in 1903 was heavier than that of the previous year, and there is no apparent reason why malarial fevers should not, other things being equal, have been as prevalent in the former.
During the year 1902 the average daily strength was 408'3 ; 88 prisoners were admitted to hos- pital for ague and remittent fever, showing a proportion of 21°5 per cent.
During the year 1903 the average daily strength was 301'1 ; 41 prisoners were admitted for these diseases, showing a proportion of 13°6 per cent.
These figures do not represent the total com- parative prevalence of malarial fevers during the two years; in the autumn of 1902 many men were treated in the convalescent gang for more or leas pronounced symptoms of malaria, while during the past year no such measures were called for. The health of the prison, in this respect, was undoubtedly better in 1903 than in 1902,
No statistics are available with regard to the number of cases of malarial fevers in the three houses in the citadel, and they would in any case be misleading, owing to the fact that several quarters have been vacant for long periods; but there have certainly been fewer actual cases, and it would probably be safe to say that here also there has been a marked relative diminution.
As regards mosquitoes, the closing of the Maka Masjid tank has caused an almost total disappearance in one of the citadel houses, and a great diminution in all, and the measures taken at the prison have resulted in a very marked reduction of mosquitoes in the quarters of the staff, the warders’ lines and the cells.
Further operations.—It is proposed to prevent the accumulation of water in the citadel moat
by a combination of filling in and drainage, and to continue work on the lines previously indi- cated. Under the conditions prevailing here the question early arises whether an attempt should be made to deal with both culex and anopheles mosquitoes, or only the latter. On the one hand it may be said that anopheles no doubt occa- sionally breed in situations where only culex larvee may have been found, that culex give rise to filariasis, and that they are also a con- stant nuisance ; but it has also to be remembered that the regular resorts of anopheles are usually very much less numerous, and that if these are treated, the vast majority of the genus will be included; while in Bijapur, as in many other places, noticeable disease due to filariasis is so rare that it can be disregarded in this connection, The argument, to my mind, most in favour of & sweeping crusade against all mosquitoes, is the marked improvement in general sanitation which necessarily accompanies, and one would certainly prefer to work on these lines. This is the course which appears to have been almost exclusively advocated by well-known authorities, but I notice that Sir P. Manson, in the last edition of his ‘Tropical Diseases, takes up a different standpoint: ‘War need not be waged against all mosquitoes; our present knowledge seems to indicate that only anopheles has to be considered.’ Economy is usually an object in these matters, and in some cases, where the extra expenditure necessary to institute compre- hensive measures against all varieties may mean the abandonment of the whole scheme, it is well to remember the alternative. Considerable sums have recently been expended here on plague operations, and it is not likely that much money will be at present available for anti-malarial measures, but there seems every probability that a great diminution of anopheles mosquitoes may be effected at a comparatively small cost.
LEMNA MINOR AS A PREVENTIVE AGAINST MOSQUITOES.
By J. R. ADIE,
MAJOR, I.M.S.,
Civil Surgeon, Ferozepore.
Dourina last autumn J searched a tank in the Deputy Commissioner’s Office compound. It wasa sort of hollow, out of which mud was obtained to build outhouses, &c., originally, and one which is usually described as a dirty green slimy pestilential tank—“a disgrace to a com- pound,” ete. Such tanks are common all over India. It was about 20 yards square, and a buffalo was enjoying himself in the middle.
I could not obtain a single larva of any mos- quito in this tank. The green scum was thick and covered the entire surface of the water. In one or two spots on the windward side the water was free from green; but here even there were no larve. At that time of year, larve were quite plentiful in other naked waters:
