what are zoonoeses
diseases that can be transmitted to from animals to humans
what are arboviruses
Group of viruses which are transmitted by mosquitomticks or other arthrpods
Describe the epidemiology of dengue Fever
how many reproted cases ? is this the reality
- 3.2 reported cases per annum
- reality is much higher up 284-548 million cases
- with around 56-136 with clinical symptoms
- many get infected but lack the diagsnositc fonrimation techniques
- with good access to medical care - fatalituy is 1%
- total death tole is approx - 24K- likely to. be much higher
dengue risk around the equator- sub tropical- brazil, africa, indiam, south eastern asia
what vector is responsible for the spread of Dengue fever
aedes aegyptii mosquito,
dengue virus lives in epithelium of mosuqito gut (mosquiot inaffected passed to person
what are the distinct serotupes of dengue virus
do we gain immunity?
DEN-1
DEn-2
den-3
den 4
recovery from infeciton provides life long immunity from serotype buyt subsequent infection s y other serotypes increase the risk of developing severe dengue
Describe the jungle (sylvatic) urban dengue fever transmisison
- jungle- dnegue fever reservoir in primates
- mosquitos bite sprimates then bites perosm
- perosn moves back to urban environment
- infected perosn bitten by aother Aedes aegyptii mosquio
- bites other person
- Major epidemics in urban
Describe the stages of Dengue fever
- Febrile (days 1-3)
- fever, high temper, dehydration
- fall in plateltes
- viraemai will fall off after first 3 days
- Igm —> igG
- may go onto ciritcal
- Critical ( 4-5
- fall in temperatutre
- chock /bleeding due to low plateletes
- organb impairment high haemocrat
- recovry
- risk of rebasoption/ fluid overload
what is dengue without warning signs?
fever with two of
- nausea and vomiting/rash/aches and paines/leukopenia/ positive toruniquet test ( rahs after toruniquet applies may be in ciritcial phase)
Dengue with warning signs
more severe then dengue without warning signs
abdominal pain/tenderness
persistent vomiting
clinical fluid accumulation (acicites/pleual effusion)
mucosal bleeding
lethargy
restlessnes
liver enrlargement > 2cm
increase in HCT with rapdi decrease in platelelt (bleeding risk
Describe severe Dengue shock
msot seveere category fo dengue (worse than dengue with warning/without)
fluid accumulation with repsiraoty distress
sevre bleeding as evaluation by clinicna (high HCt and low platelet)
sever ogran impairment due to drop in blood pressure)
How can we prveent dengue
- Prevemnt mosquitoes layign egegs
- dispose of soldi waste proeper
- cover and clean water sotrage container
- ionsectides
- perosnal houseolf protetion
- sapce spaying (fogging) during outbreaks
- active montioring and surveillance of msoquitos
is there a denge vaccine in development?
- limited use (dengavaxis)- reduces severity of deases
- contrainidcted in those without evidenc o previosu dengue infection (need one for all setoypes
- WHO recommends in areas with high burden of disaes
- 5 addtional candidates coming
Describe the treatment of each category of dengue fever
without warnign signs—-> supportive
dengue with warning signs—-> supporitve close montioring
severe dngue shock (DSS)—-> medical emergency, fluid replcement, good care taltity rate <1%
Why are we seeing emerging virsues and zoonoeses
often invvolces dynamic interactions among populations of wildlife , livestock and people within rapdily changing environments
commerical ari travel
global trade
iurbanisiaiton
living in close proximity to animasl
uncheck population gorwht
climate change
