Control and Prevention of•Dengue fever•Malaria and•Leishmania

Objectives: You students will be capable to•identify the epidemiology of above arthropods transmissible infectious diseases

• assist the community in the prevention and control programs of the above mentioned infectious diseases.

•Leishmania is a parasitic disease spread by the bite of infected a. aedes aegypti b. culex c. anopheles d. sand flies e. aedes albopictus

Dengue: The vectors Aedes aegypti and A. albopictus

AedesDengue fever in Saudi Arabia

The world distribution of Aedes aegypti

Dengue (1999): WW

Areas infested with Aedes aegyptiAreas with Aedes aegypti and recent epidemic dengue

Dengue WW, 2008• Dengue

Aedes Aegypti: most common breeding places

Aedes aegypti adult male

Aedes albopictus adult male

Life cycle of Aedes Aegypti

Feeding. Females feed on any vertebrate host, but prefer humans. They fly upwind following odors. The first step can be to enter a house. Blood feeding and oviposition occur mostly in the morning and in the late afternoon.

Dengue fever

•Clinical Picture, diagnosis, treatment

•Dengue virus infection•Dengue fever•Dengue hemorrhagic fever•Dengue shock syndrome (Read the attached file)

Malaria

•World Malaria Day: April 25th , 2009.

•Malaria: plasmodium falciparum, vivax, malariae and ovale.

(Read the attached file)

• Map

Malaria patient

Malaria• In 104 countries

• 300-500 million cases/year

• World 1.1 to 2.7 million deaths/year

• Africa deaths 961000

• SEAR countries 53000

• India 20000

•KSA???

Anopheles mosquito

Group 1: 10 countries interrupted transmission: Bah, Cyp, Jor, Kuw, Leb, Lib, Pal, Tun, UAE

Group 2: 4 countries targeting elimination: Egy, Mor, Oma, SyrGroup 3: 4 countries low- moderate endemicity: Ira, Iraq, Pak, KSAGroup 4: 5 countries high burden: Afghanistan, Dji, Som, Sud, Yem

Leishmaniasis•What is Leishmaniasis?•Life cycle.•Mode of infection.•Control and Prevention.•Read also the attached file.

•Leishmaniasis is a protozoal disease caused by Leishmania parasite, which is transmitted by the sand fly .•Leishmaniasis is of three types ; cutaneous leishmaniasis, muco-cutaneous and the visceral (Kala-azar )

1

5

4

3

2

6

7

8Sand fly takes a blood meal

)Injects promastigote stage into the tissue (

Promastigotes arePhagocytized bymacrophages

Promastigotes transfer into amastigotes insidemacrophages

Amastigotes multiply in cells)Including macrophages (of

Various tissuesSand fly takes a blood meal

)ingest macrophagesInfected with amastigotes (

Ingestion of Parasitized cell

Amastigotes transform Into promastigote

stage in midgut

Divide in midgut and migrate to proboscis

i

d

i

d

Infective stage

Diagnostic stage

Leishmaniasis Life Cycle

Leishmaniasis: Mode of infection

•Sand fly bite•Others (infected blood transfusion and Pregnancy in (VL), physical contact in CL)

Sand fly

Leishmaniasis•Sand Flies are vector of the

disease. More than 500 species and subspecies in the world. of which, only 35 types are known to transmit the disease, Phlebotomus in OCL, and Lutzomia in NCL.

•There are more than 21 Leishmanial species .

Leishman test: Intradermal injection of leishmanial antigen causes a delayed

tuberculin type of reaction .

Clinical features.

Smear from the base of the ulcer stained with Wright‘s stain detects round or ovoid parasite in the cytoplasm of macrophages.

Leishmaniasis

Diagnosis:

The dogs in the Mediterranean countries

The man in the Middle East

The wild rodents in Asia and Africa

Leishmaniasis Reservoirs

Reservoirs

Cutaneous Leishmaniasis Cutaneous Leishmaniasis Visceral Leishmaniasis Visceral Leishmaniasis

>12 Million people infected in 88 countries

>350 Million people are risk

Mucocutaneous LeishmaniasisMucocutaneous Leishmaniasis

Annually,0.5M (VL)80,000 Deaths,1.5M(CL)

Leishmaniasis WW• Leishmaniasis

•Death, 90% in •Bangladesh, Brazil, India,

Nepal,and in Sudan

*Fever *Hepatosplenomegaly *Weight loss

•Skin ulceration ,•90%Afghanistan•,Syria,Iran,Iraq,Brazil,Peru,•and Saudi Arabia

•Might be fatal. 90%•in Bolivia,• Brazil and Peru

*Skin and mucus membranes affection

Leishmaniasis•Types

It is known in the Kingdom back to 1950.Ministry of Health has established the leishmaniasis unit in the 1980 Under The precautionary medicine to follow-up the disease in the Saudi cities

Leishmaniasis in KSA

•Leishmaniasis:

There are VL and CL.VL caused by L.Donovani LON 42, and the Rattus rattus is the reservoir.2 types of CL(ZCL and ACL)In the Riyadh and Eastern province, ZCL transmitted by P.Papatasi and caused by L.Major LON4

Leishmaniasis in KSA

• Types

CL in Southern region is ACL transmitted by P.Sergenti and caused by L.Tropica LON 72

Leishmaniasis in KSA

• Cont.

There are 20 types of Sand Flies in the KSA. 7 are Phlebotomous and 13 are of Sergentomyia type.

Leishmaniasis in KSA

•Sand flies:

Riyadh

Northern

Al-joufTabouk

Medina

Makkah

Baha

Aseer

Jazan

EasternNajran

Affected area

Visceral Leishmaniasis

• A area

Reported Cases of VL• RCVL

Cutaneous leishmaniasis

has many local names

Cutaneous Leishmaniasis

The peak of cutaneous leishmaniasis is in August, October, December, January and February. The least number of cases are reported in May and June.

CL: Seasonal Variations

• CL:

Riyadh

Qaseem

Northern

Al-jouf

Hail

Tabouk

Medina

Makkah

Baha

Aseer

Jazan

EasternNajran

Alhsa only 41.2 %

7.6 %

8.4 %

18.2 %

9.6 %

CL: Geographical Dist.

• CLGD

Riyadh

Qaseem

Northern

Al-jouf

Hail

Tabouk

Medina

Makkah

Baha

Aseer

Jazan

EasternNajran

Alhsa 20.9%

18.5 %

9.1 %

26.6%

4.1 %

4.1 %

CL: cont.• GD

Reported Cases of Cutaneous L.

• CL

Reported Cases of CL• CL

Cutaneous Leishmaniasis in Infants

Leishmaniasis usually affects children more than other age groups .

Mucosal Hyperkeratotic

Nodules Lymphangitis after Pentostam treatment

Clinical Types of CL

• CL

ErysipeloidPlaqueRecidivans

Lupoid/Disseminated

Clinical Types of CL.• Types

VBD Prevention Programs

• Efforts should focus on sustainable environmental control rather than eradication

• Control programs should be community-based and -integrated. They cannot rely solely on insecticides nor require large budgets

• Need to promote VBD as a priority among health officials and the general public

Community Approaches

•Define communities geographically

•More likely to be sustainable•Advantages: built-in manpower,

help develop resources and empower community organizations

•Disadvantages: more difficult to organize, take longer to get off the ground

Community Participation

•First must educate the public in the basics of VBD, such as:–Where the mosquito lays her eggs

–The link between larvae and adult mosquitoes

–General information about VBD transmission, symptoms and TTT.

Skills Deficit

•Knowledge is not sufficient to produce behavior change

•People may lack the skills necessary to carry out the recommended behaviors

•Need to address this skills deficit

Barriers and Motivation (Part 1)

• Knowledge combined with skills still may not be sufficient to change behavior

• Need to understand what barriers may prevent the behavior, and what factors may motivate people to take the desired action

• Barriers and motivating factors vary in different regions

Barriers and Motivation (Part 2)

• Structural factors– laws regarding Aedes aegypti habitats

• Environmental factors– lack of potable water, need to store water– inadequate solid waste disposal

• Attitudinal factors– beliefs: causes, treatment, prevention of

febrile illnesses• Community factors

– community history and structure– other priority problems in the community

Cues for VBD like Dengue Preventive Behaviors

•People need reminders when they are learning a new behavior

•Behavioral cues are prompts or signals to remind the person to engage in the desired behavior

Cues: Feedback

• Use regular feedback of entomologic and epidemiologic data

• Every time someone receives the information, it can serve as a reminder to act

• If the data indicate control activities are successful, they serve as positive reinforcement

Cues: Presence ofAdult Mosquitoes

• Idea to promote:

– Person sees adult mosquito

– Asks him/herself, “Where did it come from?”

– Immediately searches for larval habitats

– Eliminates or controls all potential habitats found

Cues: Water Shortagesand Rationing

• For locations where there are seasonal or other temporary water shortages

• Provide information on how to properly store water

Cues: Rainfall

• Link rainfall to the creation of larval habitats

• This mental link can remind people to look for and eliminate larval habitats after it rains

• Eliminates larval habitats influenced by rainfall, and perhaps others as well

The Challenge

• Achieve active community involvement

• Solicit input from the earliest program planning stages

• Encourage community ownership• Programs that emphasize telling

communities what to do, without involving them or taking their views into account, are not likely to be effective

• True community participation is the key

VBD Prevention

• Role of Vaccines: Are they available or under trials?

• Regional collaboration (VBD framework, WHO-EMRO)

• Role of Insecticide treated net ???

VBD Surveillance and Control

Surveillance: Goals and Objectives

•Provide early and precise information

•disease severity•Predict VBD like dengue and

malaria transmission and guide implementation of control measures

•Link clinical and entomologic surveillance

Vector Control MethodsChemical Control

•Larvicides may be used to kill immature aquatic stages

•Ultra-low volume fumigation ineffective against adult mosquitoes

•Mosquitoes may have resistance to commercial aerosol sprays

Vector Control Methods•Biological control

–Largely experimental–Option: place fish in containers to eat larvae

•Environmental control–Elimination of larval habitats

–Most likely method to be effective in the long term

Purpose of Control• Reduce female vector density to a

level below which epidemic vector transmission will not occur

• Based on the assumption that eliminating or reducing the number of larval habitats in the domestic environment will control the vector

• The minimum vector density to prevent epidemic transmission is unknown

Programs to Minimizethe Impact of

Epidemics•Education of the medical community

•Implementation of emergency plan

•Education of the general population

INSECTICIDE USE FOR VECTOR CONTROL - EMRO -

COUNTRY1995 1996 1997 1998 1999 2000 2001 2002

AfghanistanBahrainIran (Islamic Republic of)JordanMoroccoOmanPakistanSaudi ArabiaSudanSyrian Arab RepublicYemen

PERIOD OF REPORTING

WHO SPECIFICATIONS FOR

PUBLIC HEALTH PESTICIDES

Only available on the Internet

at

WWW.WHO.INT/CTD/WHOPES

WHO Collaborating Centres for WHO Collaborating Centres for quality control of pesticidesquality control of pesticides

CDC, AtlantaCDC, AtlantaCDC, AtlantaCDC, Atlanta

CIPEIN, Buenos AiresCIPEIN, Buenos AiresCIPEIN, Buenos AiresCIPEIN, Buenos Aires

HEJIR Chemistry, KarachiHEJIR Chemistry, KarachiHEJIR Chemistry, KarachiHEJIR Chemistry, Karachi

Station de Station de Phytopharmacie, Phytopharmacie, GemblouxGembloux

Station de Station de Phytopharmacie, Phytopharmacie, GemblouxGembloux

More Readings;

• WHO-EMRO: Country Profile: Saudi Arabia. EMRO website

• CDC materials and publications

• CDC: VBD fact sheets.

• Read the attached files.

Objectives: You students will be capable to• identify the epidemiology of above arthropods transmissible infectious diseases

• assist the community in the prevention and control programs of the above mentioned infectious diseases.