Australia and yellow fever.

Date:
[1915?]
Catalogue details

Licence: Public Domain Mark

Credit: Australia and yellow fever. Source: Wellcome Collection.

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    Vig Assuming that it then bites another person on the vessel and infects that person, there will be an incubation period of several days before that person becomes infective, and at the lapse of that period he will remain infective to mosquitoes for three days only. If there be no mosquitoes on board, or if this patient be not bitten during those three days, then all further danger might appear to have ceased. . In these facts Finckh finds the safety of Australia. But there are several cogent objections to this presumption of safety. In the first place, there is no reliable information as to the duration of infectivity in the mosquito. The United States Army Commission established the fact that infected mosquitoes may remain infective for as long as 57 days, and also showed that infected Stegomyia have survived for 71 days. There is, however, no maximum limit of infectivity yet established. Van Loghem states (44) that “ Stegomyia fascoata can remain infective very long after having bitten a yellow fever patient.” It is certain that the Stegomyia mosquito can remain alive for prolonged periods. Breil has kept Stegomyra alive in Townsville (Queensland) for a period of five months (45). It must, therefore, be concluded that the Stegomyza can remain alive throughout the whole journey from the most remote yellow fever centre to Australia, and that, in the absence of any knowledge to the contrary, it may remain infective for the whole of that period, even without producing any case of yellow fever on board. Finckh assumes that this production of a case on the vessel would be sufficient danger signal to protect Australia, but this is clearly not so. Instances of transmission of yellow fever by vessels will presently be considered, but it may be opportune to repeat here a remark from a leading article in the Yellow Fever Bureau Bulletin (46) :— It disproves again, as other examples have done before, the assertion which has been made by various authors, that a ship is not dangerous, and should not be considered infected, unless yellow fever cases have occurred on board. Quite apart from this direct danger, it is not inconceivable, and any quarantine officer will readily believe it possible, that the case on board may not be accurately diagnosed by the ship’s surgeon or master, and the presence of another infectible mosquito will start the twelve-day cycle afresh, making a total of 12 + 6 + 12 days from the port of departure. A series of cases will aggravate the danger, and it appears to be definitely acceptable that any vessel coming from a yellow fever focus, and keeping within 37° N. and 37° S. all the way, offers a potential danger to Australia. Can this conclusion, which has been arrived at on theoretical grounds, be supported by the experience of vessels in the past. The following are instances of transmission of yellow fever :— 8.8. Hong-Kong Maru.—On 23rd October, 1910, the Japanese steamer Hong-Kong Maru, on her way from South American and Mexican ports to Japan, arrived at Honolulu, and on examination by the quarantine staff a sick Chinese passenger was declared to have yellow fever. The steamer ultimately proceeded to Japan, having had no communication with the shore, other than to receive supplies, during which time a guard was on board. The guard was itself segregated on shore for safety, but, on 27th October,