Mosquito part 2

How did William Gorgas facilitate the successful construction of the Panama canal?

by using mosquito control to make sure infection would be limited. he fumagated homes, installed screens, spread larvae killing oil etc.

key determinant in the geographic distribution and the seasonality of malaria

climate (rainfall, humidity(allows for completion of extrinisic cycle which takes from 9-21 days at around 77 degrees)

signs of severe falciparum malaria

coma, convulsions, renal impairment, noncardiogenic pulmonary edema, liver dysfunction, hypoglycemia, metabolic acidosis, jaundice, weakness, hypotension, shock

When a disease, such as malaria, is introduced in a "virgin" population, what is the likely result?

death

What does the "basic reproduction number" (BRN) of infectious diseases mean?

describes the number of additional infections that an originally infected person will generate under ideal conditions

anopheles life cycle and specificities

develop in clean, unpolluted water Larvae: rest parallel to water surface. rudimentary breathing tube Pupae (differ only slightly from other species) Adult: Proboscis and body in same straight line

Aedes life cycle and specificities

develop in cleanish, container water Larvae: Rest at angle to water surface. long, slender breathing/air tube with one pair of hair tufts Pupae Adult: proboscis and body at an angle to one another

Culex life cycle and specificities

develop in stagnant, polluted water. Larvae: Rest at angle to water surface. short, stout breathing/air tube with one pair of hair tufts Pupae Adult: proboscis and body at an angle to one another

When a disease, such as malaria, is endemic in a population, how can anyone survive?

disease like malaria can be contained because it is chronic and circulates in bloodstreams with high immunity (however will kill outsiders)

When was quinine developed as a treatment for the "fevers" associated with malaria?

early 1600s

In 1790's Philadelphia, how did people think you got yellow fever?

either resided in cities or ships containing negroes brought it

main protective features of sickle cell anemia against malaria

enzyme heme oxygenase 1; decrease parasite growth and maturation, adherence to endothelium, and increases uptake by macrophages

When Europeans begin to explore Asia and Africa, what effect did endemic malaria have?

explorers with no immunity died

Describe the clinical symptoms of yellow fever. What usually causes death?

fever, coma, chills, muscle pain, headache, eye pain, liver failure, jaundice -death: internal hemorrhage, black vomit

What was Dr. Ronald Ross's challenge when trying to link mosquitoes with malaria transmission?

finding a mosquito that contained a malarial parasite

What contribution did Dr. Charles Laveran make in our understanding of malaria?

first to see malaria parasites in blood of infected person

slang for mosquitos in civil war

gallinippers

plasmodium sporozoites are released from these. mosquitos either take these up from blood meal or inject sporozoites

gametocytes

How did Dr. Fred Soper help to eliminate the malaria epidemic in Brazil in the 1930's?

he attacked all infected areas with insectisides, established drainage projects, and taught people to cover their wells. he also fumagated all sources of travel

first symptoms of uncomplicated malaria

headache, fatigue abdominal discomfort, muscle and joint aches, diarrhea, fever, anorexia, nausea, vomiting, orthostatic hypotension

What insight does the BRN for malaria provide when trying to understand its disease transmission?

how many additional people will be infected

How did malaria affect invading armies over the millennia?

invaders were unexposed and vulnerable, changing human habits. ie: huns, visigoths

P. knowlesi naturally infects ____________ living in southeast asia

macaques

Why did the French's attempt to build a canal across Panama fail in the 1880's?

many industrial workers were killed by the mosquito before it was fully understood

What technological advance allowed scientists and physicians to identify mosquitoes as a vector for disease transmission?

microscope

How did the use of quinine develop before we even knew what malaria was?

missionaries were offered powder from tree bark to cool fevers

malaria vaccine challenges

moderate to extreme antigenic variability

How was endemic malaria eliminated from the southern United States?

mosquito control

What were some of the tenants of "mosquito control" established by John Smith in the early 1900's?

motorized ditchdigger sliced drainage channels through thousands of acres of marsh and poured oil in waters where larvae developed. Barges pulled sand in river bottoms and filled in breeding swarms

plasmodium species found worldwide in tropical and subtropical areas. It is estimated that every year approximately 1 million people are killed by this species, especially in Africa where this species predominates. it can cause severe malaria, multiples rapidly in the blood, can cause severe anemia, and can cause cerebral malaria.

p. falciparum

cycle of malaria parasite

parasites picked up by mosquitos in a blood meal; parasites in mosquito gut; parasites in mosquito salivary gland; parasites in human liver cells; parasites in RBC

Malaria is caused by __________________ parasites

plasmodium

When humans are infected, these release from the liver and infect blood cells

plasmodium merozoites

what in the saliva infects humans

plasmodium sporozoite

these people are at high risk of dying from complications of severe malaria

pregnant women

an effective treatment for malaria during the civil war

quinine

stages of malaria infection

sporogonic cycle; infective period; prepatent period; incubation period; clinical illness

What was the design of some of the first experiments by Drs. Finlay and Lazear to demonstrate that yellow fever was transmitted by mosquitoes?

they allowed skitos to transmit yellow fever from infected people to healthy people

Why did it take until the early to middle 1900's to identify the causative agent for mosquito-borne encephalopathies?

they believed it was spread person to person

What factors kept malaria as a prominent disease in the southern United States in the early 1900's?

warm climate, wet lands, and poverty

What environmental conditions allowed yellow fever to persist in the southern United States?

warm, humid weather

How did the "sanitation doctrine" limit malaria and yellow fever even though the theory was wrong?

water and sewage systems were created underground which did not allow skitos to breed

What was more problematic, mosquito-delivered yellow fever, or mosquito-delivered malaria?

yellow fever

Approximately ____________ cases of malaria are reported every year in the United States, almost all in recent travelers.

1,500-2,000

What are the three factors that influence the BRN for mosquito-borne diseases?

1. vector abundance, or population density of the mosquito that carries the disease 2. focused feeding or skitos tendency to bite people 3. vector longevity. will skitos live long enough to transmit pathogen

factors required for malaria

1.Anopheles mosquitoes must be present; 2.Humans must be present, who are in contact with Anopheles mosquitoes; 3.Malaria parasites (Plasmodium sp.) must be present in mosquitoes and/or humans.

What was Dr. Patrick Manson's discovery about filariasis? When did this discovery occur?

1875, worms in lymph nodes

Malaria was eliminated from the United States in the early

1950s

# of people who are at risk of malaria worldwide

3.2 billion

Between 1957 and 2014, in the United States, ___ outbreaks of locally transmitted mosquito-borne malaria have occurred; in such outbreaks, local mosquitoes become infected by biting persons carrying malaria parasites (acquired in endemic areas) and then transmit malaria to local residents.

63

# of countries and territories that had ongoing malaria transmission in 2014

97

During 1963-2012, ___ cases of transfusion-transmitted malaria were reported in the United States;

97

Of the species of Anopheles mosquitoes found in the United States, the three species that were responsible for malaria transmission prior to elimination (_____________________________________________________________________) are still prevalent;

Anopheles quadrimaculatus in the east, An. freeborni in the west, and An. pseudopunctipennis along the U.S./Mexico border

What were some social consequences for foreigners and African Americans in some communities?

Blacks still served as slaves even with yellow fever due to discrimination

A certain species of malaria called ___________________ has recently been recognized to be a cause of significant numbers of human infections.

P. knowlesi

plasmodium species found throughout Southeast Asia as a natural pathogen of long-tailed and pig-tailed macaques. It has recently been shown to be a significant cause of zoonotic malaria in that region, particularly in Malaysia. it has a 24-hour replication cycle and so can rapidly progress from an uncomplicated to a severe infection; fatal cases have been reported.

P. knowlesi

plasmodium species found worldwide, is the only human malaria parasite species that has a three-day cycle. The three other species have a tertian, two-day cycle. If untreated, it causes a long-lasting, chronic infection that in some cases can last a lifetime.

P. malariae

Plasmodium species found mostly in Africa and the islands of the western Pacific. It is biologically and morphologically very similar to P. vivax.

P. ovale

plasmodium species found mostly in Asia, Latin America, and in some parts of Africa. It is the most prevalent human malaria parasite. It has dormant liver stages that can invade the blood ("relapse") several months or years after the infecting mosquito bite.

P. vivax

What mosquito carried the yellow fever virus to the new world? How did it survive the voyage?

aedes aegypti, bred in drinking water casks

signs of uncomplicated malaria

anemia, splenomegaly, hepatomegaly -sweating, chills, fever

species of mosquitos that transmit malaria

anopheles

Malarial parasite must replicate in

anopheles sporozoites

How did the mosquito, Anopheles gambiae, arrive in Brazil? What were the consequences of this arrival?

arrived by french mail delivery system (Avisos); most efficient malaria vector on eart

How do microfilaria infected mosquitoes transmit the disease filariasis to humans?

by sucking the blood of infected organisms