Mosquito and Zoonotic Diseases

8/16/2019 Mosquito and Zoonotic Diseases

1/29

Regional Epidemiology and Surveillance Unit –

osqu to- orne an oonot c

Diseases Acute Hemorrhagic Fever Syndrome Malaria Leptospirosis Rabies


2/29


Acute Hemorrhagic Fever Syndrome

Description:

A febrile syndrome associated with bleeding manifestations.

Acute hemorrhagic fever syndromes can be attributable to dengue

(dengue hemorrhagic fever), Ebola-Marburg viral diseases, Lassafever, yellow fever, Rift alley fever, !antavirus infections,

"rimean-"ongo hemorrhagic fever, and other viral, bacterial or

ric#ettsial diseases with a $otential to $roduce e$idemics.


3/29



Importance of Surveillance:

%he syndromic a$$roach of the revised &nternational !ealth

Regulations (&!R), all cases of acute hemorrhagic feversyndrome whether single or in clusters, should be notified early,

without waiting for the causal agent to be identified.

'urveillance of acute hemorrhagic fever syndrome is aimed at

early detection of cases in order to avoid e$idemics and the

$ossible international s$read of the disease.


4/29



Standard Case Definition:

Any hos$italied $erson with acute onset of fever of less than

wee#s duration and with any two of the following*

-

hemorrhagic or $ur$uric rash- e$ista+is (nose bleeding)

- hematemesis (vomiting of blood)

- hemo$tysis (coughing out blood)

- blood in stools

- other hemorrhagic sym$toms

AND the diagnosis is not Dengue


5/29



Laboratory Confirmation:

&solation of organism through blood culture

etection of genomic seuences by $olymerase chain reaction("R)


6/29


Malaria

Description:

A $arasitic disease caused by / $rotooan $arasites with ase+ual

and se+ual $hases: Plasmodium falciparum, Plasmodium vivax,

Plasmodium ovale and Plasmodium malariae. isease transmission is through the bite of an infective female

Ano$heles mosuito. Most s$ecies feed at night0 some im$ortant

vectors also bite at dus# or in the early morning.

%he incubation $eriod is a$$ro+imately 123/ days for P.

falciparum, 34235 days for P. vivax and P. ovale, and 352/6 daysfor P. malariae. 'ome strains of P. vivax, mostly from tem$erate

areas, may have incubation $eriod of 5236 months and longer.


7/29Regional Epidemiology and Surveillance Unit –

Malaria

&nfections with the / human ty$es of malaria can $resent

sym$toms sufficiently similar to ma#e s$ecies differentiation

im$ossible without laboratory studies. %he fever $attern of the first

few days of infection resembles that in early stages of many other

illnesses (bacterial, viral and $arasitic).

Mi+ed infections are not infreuent in endemic areas.



Malaria


Malaria is the most highly $revalent tro$ical disease, with high

morbidity and mortality and high economic and social im$act. %he

/ elements of the 7lobal 'trategy for Malaria "ontrol are*

-rovision of early diagnosis and treatment,

- lanning and im$lementing selective and sustainable $reventive

measures, including vector control,

- Early detection, containment and $revention of e$idemics,

- 'trengthening local ca$acities in basic and a$$lied research to

$ermit and $romote the regular assessment of a country8s malariasituation, in $articular the ecological, social and economic

determinants of the disease.



Malaria

Standard Case Definition/Classification:

Uncomplicated malaria: 'igns and sym$toms vary0 most $atients

e+$erience fever. '$lenomegaly and anemia are common associated

signs. "ommon but non-s$ecific sym$toms include otherwise

une+$lained headache, bac# $ain, chills, sweating, myalgia, nausea,

vomiting.

Severe malaria* "oma, generalied convulsions, hy$er$arasitemia,

normocytic anemia, disturbances in fluid, electrolyte, and acid-base

balance, renal failure, hy$oglycemia, hy$er$yre+ia, hemoglobinuria,

circulatory colla$se9shoc#, s$ontaneous bleeding (disseminated

intravascular coagulation) and $ulmonary edema.



Malaria

In areas WITHOUT access to laboratorybaseddia!nosis*

"robable uncomplicated malaria case: A $erson with signs

(fever, s$lenomegaly, anemia) and9or sym$toms

(une+$lained headache, bac# $ain, chills, sweating, myalgia,

nausea, vomiting) of malaria who receives anti-malarialtreatment.

"robable severe malaria case* A $erson who reuires

hos$italiation for sym$toms and signs of severe malaria

(coma, generalied convulsions, renal failure, hy$er$yre+ia,

circulatory colla$se9shoc#, s$ontaneous bleeding, and $ulmonary edema) and receives anti-malarial treatment.

"robable malaria deat#: death of a $atient diagnosed with

$robable severe malaria



Malaria


In areas WITH access to laboratorybased dia!nosis:

$symptomatic malaria: A $erson with no recent history of

sym$toms and9or signs of malaria who shows laboratoryconfirmation of $arasitemia.

Confirmed uncomplicated malaria case: A $erson with signs

(fever, s$lenomegaly, anemia) and9or sym$toms (une+$lained

headache, bac# $ain, chills, sweating, myalgia, nausea,

vomiting) of malaria who receives anti-malarial treatmentA: with laboratory confirmation of diagnosis.



Malaria

Confirmed severe malaria case: A $erson who reuires

hos$italiation for sym$toms and signs of severe malaria

(coma, generalied convulsions, hy$er$arasitemia, normocytic

anemia, disturbances in fluid, electrolyte, and acid-base

balance, renal failure, hy$oglycemia, hy$er$yre+ia,hemoglobinuria, circulatory colla$se9shoc#, s$ontaneous

bleeding, disseminated intravascular coagulation, and

$ulmonary edema) and receives anti-malarial treatment A:

with laboratory confirmation of diagnosis (microsco$y or

R%).



Malaria

Confirmed malaria deat#: death of a $atient classified as

confirmed severe malaria.

%alaria Treatment &ailure: A $atient with uncom$licated

malaria without any clear sym$toms suggesting another

concomitant disease who has ta#en a correct dosage of anti-

malarial treatment, and who $resents with clinicaldeterioration or recurrence of sym$toms within 3/ days of the

start of treatment, in combination with $arasitemia (ase+ual

forms).


emonstration of malaria $arasites in blood films (mainly

ase+ual forms)



Leptospirosis



Leptospirosis

Description:

Le$tos$irosis is a grou$ of oonotic bacterial diseases with

variable manifestations.

isease transmission is through contact of the s#in,

es$ecially if abraded, or of mucous membranes with moist

soil, vegetation;es$ecially sugarcane;contaminated withthe urine of infected animals, or contaminated water, as in

swimming, wading in floodwaters, accidental immersion or

occu$ational abrasion0 direct contact with urine or tissues of

infected animals0 occasionally through drin#ing of water

and ingestion of food contaminated with urine of infectedanimals, often rats0 also through inhalation of dro$let

aerosols of contaminated fluids.



Leptospirosis

%he incubation $eriod is usually 36 days with a range of 42 6 days.

%he disease is characteried by sudden onset of fever,

headache, chills, severe myalgia (calves and thighs) and

con



Leptospirosis

Etiologic agent: athogenic le$tos$ires belong to thegenus Leptospira (long cor#screw-sha$ed bacteria, too thin

to be visible under the ordinary microsco$e)0 dar#-field

microsco$y is reuired. %he more than 466 $athogenic

serovars clustered into 4> serogrou$s cannot be

differentiated on the basis of mor$hology.



Leptospirosis

&n endemic areas the ma


19/29


Leptospirosis


'urveillance $rovides the basis for intervention strategies in

human or veterinary $ublic health.

Le$tos$irosis is $robably underre$orted in many countries

because of difficult clinical diagnosis and lac# of diagnostic

laboratory services.


20/29


Leptospirosis Standard Case Definition/Classification:

Suspected case: A $erson who develo$ed acute febrile illness

with headache, myalgia and $rostration associated with any of

the following*

- con


21/29


Leptospirosis

AFTER e+$osure to infected animals or an environment

contaminated with animal urine (e.g. wading in flood waters, rice

fields, drainage).

"robable case: :ot a$$licable

Confirmed case: A sus$ect case that is laboratory confirmed


22/29


Leptospirosis


&solation (and ty$ing) from blood or other clinical materials

through culture of $athogenic Le$tos$ira. ositive serology, $referably Microsco$ic Agglutination %est

(MA%), using a range of Le$tos$ira strains for antigens that

should be re$resentative of local strains.


23/29


Rabies


24/29


Rabies Description:

Rabies is a fatal acute viral ence$halomyelitis caused by the rabies virus, a

rhabdovirus of the genus Lyssavirus.

&t is a oonotic disease transmitted to humans through contact (mainly bites and

scratches) with infected animals both domestic and wild. =ver /6 666 human

deaths are estimated to occur each year worldwide, most of them in the

develo$ing world (mainly in Asia), and an estimated 36 million $eo$le receive

$ost-e+$osure treatment after being e+$osed to animals sus$ected of rabies.

Mode of transmission* !osts are usually Canidae, including dogs (res$onsible

for more than 11? of all human deaths from rabies), fo+es, coyotes, wolves,

and


25/29


Rabies 'ym$toms start with a sense of a$$rehension, headache, fever, malaise,

e+citability and aero$hobia. %he disease $rogresses to $aresis or

$aralysis, s$asm of swallowing muscles leading to fear of water or

hydro$hobia, delirium, convulsions and death.

Period of communicability: &n dogs and cats, usually for 2@ days

before onset of clinical signs (rarely over / days) and throughout the

course of the disease. Longer $eriods of e+cretion before onset of

clinical signs (3/ days) have been observed with Ethio$ian dog rabies

strains. &n one study, bats shed virus for 34 days before evidence of

illness0 in another, s#un#s shed virus for at least 5 days before onset of

clinical signs. '#un#s may shed virus for u$ to 35 days before death.


26/29


Rabies

%he incubation $eriod is usually -5 wee#s but maybe as short as 1

days and as long as @ years. %he incubation $eriod de$ends on the

severity of the wound, site of the wound in relation to richness of

nerve su$$ly, distance from the brain, amount and strain of virus.

%he != $romotes human rabies $revention through well-targeted

$ost e+$osure treatment and increased availability of modern rabies

vaccine, and disease elimination through mass vaccination of dogs

and other animal reservoirs


27/29


Rabies


'urveillance of both human and animal rabies is essential to

uic#ly detect outbrea#s in endemic areas and new cases in

rabies-free area.

etermine high ris# areas for intervention $ur$oses

Monitor the use of vaccine and immunoglobulin.

Evaluate effectiveness of intervention at the level of the animal

reservoir and e+$osed human $o$ulation.


28/29


Rabies


Suspected Case: A $erson $resenting with an acute neurological

syndrome (ence$halitis) dominated by forms of hy$eractivity

(furious rabies) or $aralytic syndromes (dumb rabies) that

$rogresses towards coma and death, usually by res$iratory failure,within @ to 36 days after the first sym$tom if no intensive care is

instituted. "robable case: A sus$ected case $lus history of contact with

sus$ected rabid animal.

:ote* Bites or scratches from a sus$ected animal can usually betraced bac# in the $atient medical history. %he incubation $eriod may

vary from days to years but usually falls between 6 and 16 days. Confirmed case: A sus$ected case that is laboratory confirmed.

R bi


29/29

Regional Epidemiology and Surveillance Unit

Rabies Laboratory Confirmation:

etection of rabies viral antigens by direct fluorescent antibody (CA)

in clinical s$ecimens, $referably brain tissue (collected $ost

mortem)0 etection by CA on s#in or corneal smear (collected ante mortem)0

CA $ositive after inoculation of brain tissue, saliva or "'C in cellculture, in mice or in suc#ling mice0

etectable rabies-neutraliing antibody titer in the "'C of an

unvaccinated $erson0 &dentification of viral antigens by "R on fi+ed tissue collected $ost

mortem or in a clinical s$ecimen (brain tissue or s#in, cornea orsaliva)0

&solation of rabies virus from clinical s$ecimens and confirmation of

rabies viral antigens by direct fluorescent antibody testing.

Mosquito and Zoonotic Diseases

Documents

Transcript of Mosquito and Zoonotic Diseases