Friday, 8th of May 2009 |
CHILD SURVIVAL UPDATE 28/2009: POLIO IMPORTATIONS/ ROSS ON MALARIA TRANSMISSION /
ROSS ON MOSQUITO BRIGADES / BRITISH ANTIMALARIAL ACTIVITY IN WORLD WARS I AND II
1) POLIO IMPORTATIONS AND RESPONSE
Even as India, the largest of the four polio endemic countries, makes
striking advances against Type 1 and Type 3 polio transmission, fifteen
African countries have seen polio importations in 2008-09. Details of the
importations and the outbreak response are at
http://www.cdc.gov/mmwr/preview/mmwrhtml/mm5814a1.htm
From the editorial note: 'The risk for importation is greatest for
countries adjacent to those countries where WPV transmission continues;
however, globalized transportation and international migration pose a risk
for WPV reintroduction for all countries. Recent findings of WPV in sewage
samples in Switzerland and Egypt, where no polio cases have been detected
since 1984 and 2004, respectively, confirm that long-distance importations
can occur and that high levels of vaccination coverage limit local
transmission.'
2) ROSS ON MALARIA TRANSMISSION
Working in India, Ronald Ross showed that malaria was a mosquito borne
disease.
From the CDC homepage, http://www.cdc.gov/malaria/history/ross.htm
Sir Ronald Ross was born in Almora, India in 1857 to Sir C.C.G. Ross, a
General in the Indian Army and his wife Matilda. At the age of eight he
was sent to England to be educated and spent much of his childhood with an
aunt and uncle on the Isle of Wight. During his early years he developed
interests in poetry, literature, music, and mathematics, all of which he
continued to engage in for the rest of his life.
Although he had no predisposition to medicine, at the age of 17 he
submitted to his father's wish to see him enter the Indian Medical Service.
He began his medical studies at St Bartholomew's Hospital Medical College,
London in 1874 and sat the examinations for the Royal College of Surgeons
of England in 1879. He took the post of ship surgeon on a transatlantic
steamship while studying for, and gaining the Licentiate of the Society of
Apothecaries, which allowed him to enter the Indian Medical Service in
1881, where he held temporary appointments in Madras, Burma, and the
Andaman Islands. During a year's leave, from June 1888 to May 1889, he
developed his scientific interests and studied for the Diploma in Public
Health from the Royal Colleges of Physicians and Surgeons in England and
took a course in bacteriology under Professor E. E. Klein. He also married
Miss Rosa Bloxam who accompanied him to Bangalore when he returned for duty
as a staff surgeon.
In 1892 he became interested in malaria and, having originally doubted
the parasites' existence, became an enthusiastic convert to the belief that
malaria parasites were in the blood stream when this was demonstrated to
him by Patrick Manson during a period of home leave in 1894. (Sir Patrick
Manson is considered by many to be the father of tropical medicine. He was
the first person to demonstrate, in 1878, that a parasite that causes human
disease could infect a mosquito—in this case, the filarial worm that causes
elephantiasis. He was also physician to the Seamen's Hospital Society, the
Medical Advisor to the Colonial Office and later the founder of the London
School of Tropical Medicine and the Hong Kong College of Medicine.)
On his return to India in 1895, Ross began his quest to prove the
hypothesis of Alphonse Laveran and Manson that mosquitoes were connected
with the propagation of malaria, and regularly corresponded with Manson on
his findings. However his progress was hampered by the Indian Medical
Service which ordered him from Madras to a malaria-free environment in
Rajputana. Ross threatened to resign but, following representations on his
behalf by Manson, the Indian Government put him on special duty for a year
to investigate malaria and kala azar (visceral leishmaniasis).
On 20 August 1897, in Secunderabad, Ross made his landmark discovery.
While dissecting the stomach tissue of an anopheline mosquito fed four days
previously on a malarious patient, he found the malaria parasite and went
on to prove the role of Anopheles mosquitoes in the transmission of malaria
parasites in humans.
He continued his research into malaria in India, using a more convenient
experimental model, malaria in birds. By July 1898, he had demonstrated
that mosquitoes could serve as intermediate hosts for bird malaria. After
feeding mosquitoes on infected birds, he found that the malaria parasites
could develop in the mosquitoes and migrate to the insects' salivary
glands, allowing the mosquitoes to infect other birds during subsequent
blood meals.
In 1899 Ross resigned from the Indian Medical Service and returned to
England. He worked for the newly established Liverpool School of Tropical
Medicine, taking a post as lecturer and later becoming Professor of
Tropical Medicine, and accepted a personal chair in Tropical Sanitation at
Liverpool University. One of his first roles at the School was to
investigate and devise anti-malaria schemes in West Africa. This was the
first of many expeditions that Ross undertook to investigate and develop
malaria control measures including visits to Ismailia in Egypt at the
request of the Suez Canal Company in 1902, Panama in 1904, Greece in
1906, and Mauritius in 1907-1908.
In 1901 Ross was elected a Fellow of the Royal College of Surgeons of
England and also a Fellow of the Royal Society, of which he became
Vice-President from 1911 to 1913. In 1902 he was awarded the Nobel Prize
for Medicine "for his work on malaria, by which he has shown how it
enters the organism and thereby has laid the foundation for successful
research on this disease and methods of combating it". In 1902 he was
appointed a Companion of the Most Honourable Order of Bath by His Majesty
the King of Great Britain, and in 1911 he was elevated to the rank of
Knight Commander of the same Order. He received an honorary M.D. degree
in Stockholm at the centenary celebration of the Karolinska Institute in
1910 and was awarded honorary membership of many learned societies around
the world throughout his career.
During the First World War (1914-1918), Ross was appointed a consultant
physician on tropical diseases to Indian troops and was sent to Alexandria
for four months to investigate an outbreak of dysentery that was hampering
troops in the Dardanelles.
In 1917 he was appointed a consultant physician to the War Office and in
1919 he received an honorary post as consultant to the Ministry of
Pensions.
In 1926 the Ross Institute and Hospital for Tropical Diseases was opened
on Putney Heath, London by the Prince of Wales as a memorial to and in
recognition of Ross' work. The main focus of the Institute was the study of
the nature and treatment, propagation and prevention of tropical diseases.
Ross assumed the post of Director in Chief, which he held until his death
in 1932. The Institute was incorporated into the London School of Hygiene
& Tropical Medicine in 1934. . . .
While Ross is remembered for his malaria work, this remarkable man was
also a mathematician, epidemiologist, sanitarian, editor, novelist,
dramatist, poet, amateur musician, composer, and artist. He died, after a
long illness, at the Ross Institute on 16 September 1932.
Text contributed by the Archivist, London School of Hygiene & Tropical
Medicine.
3) 'Mosquito Brigades and how to Organise them'
Ross's 1902 'how to' book, at http://pds.lib.harvard.edu/pds/view/5995849
is a practical guide to malaria vector control, based on what was then
known on the subject. Full text is at this site.
For those interested, this Harvard site also reproduces a century old
pamphlet on Ross's introduction of mosquito brigades for drainage and
vector control in Sierra Leone.
4) The heritage of Ross: British Army Antimalarial Activity in World Wars I
and II
Mark Harrison, writing in Medical History, reviews the internal debates
within the British military on the relative importance of different
approaches (both quinine chemoprophylaxis and vector contro had their
champions). Ross was an adviser to the military, but his preference for
vector control was not universally accepted. Mutatis mutandis, the
discussions of 100 years ago on choice of preferred technology are being
repeated today. Here is an excerpt:
[Ross stated that]"Experience shows that if mosquitoes are left to abound
as before, quinine, even in very considerable prophylactic doses, merely
has the effect of keeping down the fever, while allowing the men to become
infected". Although the committee decided that quinine prophylaxis should
continue in the most dangerous areas, it placed greater emphasis on the
need for drainage and mosquito destruction. This represented a major
professional victory for Ross, whose much vaunted "mosquito brigades" were
to form the basis of malaria control in the British Empire until the end of
the Second World War.
Yet there were some British MOs who insisted that quinine prophylaxis could
be valuable as a routine measure, provided that a standardized dose was
given regularly to troops. In S R Christophers' opinion, everything
depended on good discipline and expert supervision. Indeed, it may well
have been that the ineffectiveness of prophylaxis during the First World
War (and before) was due as much to lax discipline as to the limitations of
quinine itself. Commanding officers generally took a relaxed view of such
matters and were sometimes reluctant to enforce quinine consumption because
of its unpopularity with troops. Thus, although General Allenby provided
his force in Palestine with mosquito repellent ointments and nets, quinine
prophylaxis was not compulsory and was left to the discretion of unit
commanders. In Mesopotamia an order was given to compel the prophylactic
use of quinine but, as the Advisory Committee reported in 1916, it was
"more honoured in the breach than the observance". Indian troops there were
also exempted from the general order insisting on the use of mosquito nets,
on the grounds that they were unpopular with the sepoys, who had, in many
cases, acquired an immunity to the disease.
Full text is at
www.pubmedcentral.nih.gov/picrender.fcgi?artid=1037165&blobtype=pdf
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