View report page

(b) require the disinsecting and, if necessary, disinfection of the baggage of any infected
person or suspect, and of any other article on board and any part of the ship which the
medical officer considers to be contaminated.
(2) If there is rodent plague on board, the medical officer shall require the ship to be deratted
in a manner to be determined by him, but without prejudice to the generality of this requirement
the following special provisions shall apply to any such deratting —
(a) the deratting shall be carried out as soon as the holds have been emptied;
(b) one or more preliminary derattings of the ship with the cargo in situ, or during its unloading,
may be carried out to prevent the escape of infected rodents;
(c) if the complete destruction of rodents cannot be secured because only part of the cargo
is due to be unloaded, a ship shall not be prevented from unloading that part, but the
medical officer may apply any measure which he considers necessary to prevent the
escape of infected rodents. "
Plague being primarily a disease of rats all vessels are inspected immediately on arrival at
their berths in the docks and river for the presence of any mortality among the rats on board
which is not attributable to any known cause, such as trapping, poisoning, etc.
Incidentally one of the "Health Questions" on page 1 of the "Maritime Declaration of
Health" requires the Master to answer "Yes or No" to the question "Has plague occurred or
been suspected amongst the rats or mice on board during the voyage, or has there been an abnormal
mortality among them?"
Any dead rats are immediately sent to the Central Public Health Laboratory at Colindale for
examination for bacillus pestis, each rat being accompanied by a label on which is given precise
information as to where the rat was found in order to arrive at a focus of infection should the
examination prove positive. The information is, of course, far more vital when the rat has been
found ashore than when found on board a ship.
In the event of a positive result the "additional measures" referred to above would be put
into operation — the discharge of the cargo would be promptly stopped and arrangements made for
the vessel to be fumigated throughout with hydrogen cyanide, with the cargo in situ, the vessel
being moved to an approved mooring.
Following the initial fumigation and collection of dead rats resulting therefrom, further
samples of such rats would be submitted for examination and the discharge of cargo would be
permitted under observation. The destination of the cargo would be forwarded to the Medical
Officer of Health of the district to which it was proceeding, together with an exaplanatory note.
If any of the cargo had already been discharged overside into lighters before the discovery
of plague infection, the lighters would be fumigated immediately.
On completion of the discharge of cargo frorr the vessel a second fumigation would be
carried out, again using hydrogen cyanide, to destroy the residual rat population, if any.
MOSQUITO CONTROL AT THE ISLE OF GRAIN
Operational control has been vigorously carried out within the perimeter of the B.P. Refinery
during the breeding period from March until October, actual spraying commencing in late March.
The area under control comprises 1,200 acres and includes marshy stretches with pools dispersed
around the perimeter particularly, providing ideal breeding grounds if not properly dealt with.
Once again Dieldrin has been applied for larvicidal treatment. The relatively dry conditions
enabled the operator to maintain a three week cycle of the whole area from the start. Weekly
meetings with the operator were conducted when difficulties and progress were discussed.
During the season, a representative of the Malaria Reference Laboratory visited the Refinery.
He inspected the control sites and expressed satisfaction with the operational progress, declaring
that he considered the anopheline species had been eliminated. Apparently this success is not
entirely due to the annual spraying, a significant contribution having been made by the absence of
the piggeries which, hitherto, provided sites for hibernation and a blood meal during the cold
weather. The commonest species discovered in order of their appearance were Aedes detritus,
Aedes caspius, Theobaldia annulate and Culex Pipiens.
No complaints were received from Marine personnel or site employees about mosquitos.
section xii
MEASURES AGAINST RODENTS IN SHIPS FROM FOREIGN PORTS
(1) Procedure for inspection of ships for rats
The Port Health Authority employs sixteen Rodent Operatives working in conjunction with
and under the supervision of the Port Health Inspectors.
18