Yellow Fever

What is Yellow Fever?

• A tropical disease that is caused by _

Disease Agent

• Genus: _

• The yellow fever virus is 35-40 nm in size. It consists of a _

• Vectors

• _

  • A. aegypti

  • A. africanus

  • A. simpsoni

  • A. furcifer

  • A. luteocephalus

  • A. albopictus

Yellow Fever in Asia

There are no reported cases of yellow fever in Asia. It is suspected that the high incidence of __ confer protection against yellow fever, and that the Asian mosquito strains are not as __

Transmission of Yellow Fever

• Reservoir: __

• Incubation period:

  • Intrinsic Incubation period

    • __

  • Extrinsic Incubation Period

    • _

• Period of communicability: First 4 days of illness

• Mode of transmission

  • Sylvan

  • Urban

Transmission Cycle of Yellow Fever

• The natural yellow-fever cycle __

• The shift from jungle yellow fever to urban yellow fever is thought to be the result of humans entering the sylvan setting and __

• Initially, wood cutters and other forest workers were bitten by forest-canopy mosquitoes carrying the yellow-fever virus. The humans then __

Symptoms

• A toxic phase can follow the period of remission and presents with:

• __

• Dark urine

• Reduced amounts of urine production

• Bleeding from the gums, nose or in the stool

• __

• Hiccups

• Diarrhea

• Slow pulse in relation to fever

Treatment

• No specific treatments have been found to benefit patients with yellow fever. ___

• Treatment is symptomatic. Rest, fluids, and use of pain relievers and medication to reduce fever may relieve symptoms of aching and fever.

• Care should be taken to avoid certain medications. ____ which may increase the risk of bleeding.

• Yellow fever patients should be protected from further mosquito exposure (staying indoors and/or under a mosquito net) during the first few days of illness. _____ mosquitoes, thus breaking the transmission cycle and reducing risk to the persons around them.

Outcome

• The majority of infected persons will be asymptomatic or have mild disease with complete recovery.

• In persons who become symptomatic but recover, __

• Among those who develop severe disease, __

• Those who recover from yellow fever generally have lasting immunity against ___

Yellow Fever Vaccine

• ____ by inoculating rhesus monkeys with the blood of an African patient

• Edward Hindle developed inactivated vaccine _

• Theilar and Smith developed vaccine from the Asibi strain in cell cultures from embryonated chicken eggs

• It is a safe and effective vaccine

Persons Exempt from Vaccine

• Infants below __

• Crew and passengers of an aircraft transitioning through an airport located in yellow fever infected area provided the Health Officer is satisfies that such persons remained within the airport premises during the period of stay.

Yellow Fever and the Panama Canal

• Defeated French efforts to construct a ___

• Incapacitated many workers and caused atleast 20,000 to die, led the French to abandon their goal in 1889

Panama Canal Perfect for Mosquitoes

• The Isthmus of Panama was an ___

• The high temperature varies little during the year

• The rainy season ___ and the interior of the Isthmus is tropical jungle, ideal for mosquito breeding

• The Panama Canal extends diagonally across the Isthmus of Panama from south-east to north-west, a distance of ___

• At Panama, the antimalarial work was principally rural, located for 47 miles along the line of the railroad between Panama and Colon

• The population was about 80,000 living within half a mile of the railroad and occupying some ___

• Walter Reed

• US Army doctor discovered the cause of Yellow Fever ____

Yellow Fever Research

• Walter Reed, M.D., (1851-1902) was an American Army surgeon who led the team

which proved the theory first set forth in 1881 by the Cuban doctor and scientist Dr.

Carlos Finlay that yellow fever is transmitted by mosquitoes rather than direct contact.

• The risky but fruitful research work was __,

including some of the medical personnel such as Clara Maass and surgeon Jesse W.

Lazear Walter Reed Medal winner who allowed themselves to be deliberately infected

and died of the virus.

• All this lead to the elimination of Yellow Fever from Cuba and allowed the final

construction of the Panama Canal.

• On August 14, 1901, Maass allowed herself to be bitten by infected mosquitoes for the

seventh time. ___ Her

death roused public sentiment and put an end to yellow fever experiments on humans.

• In 1904, the Isthmian Canal Commission, prepared a plan for the sanitation of the Canal

Zone and the __

• On June 30, 1904, the Sanitary Department was formed ___

Gorga’s Success

• ___

• fumigated areas infested with adult mosquitoes; isolated disease-stricken patients

with screening and netting; and constructed quarantine facilities.

• In major urban centers, new domestic water systems provided running water to

residents, thereby eliminating the need for collecting rain water in barrels, which

had provided perfect breeding sites for __

• The US government’s $___

• Gorgas’s sanitation department dispensed approximately one ton of prophylactic quinine

each year at 21 dispensaries along the Panama Canal route

• __