Post on 15-Jan-2016
transcript
Cutaneous leishmaniasis in Syria
LeishmaniasisIntroduction
Infectious disease caused by intracellular protozoan parasites of the genus Leishmania
visceral, cutaneous, and mucocutaneous
Visceral Leishmaniasis
Known as kala azarCharacterized by
chronic recurrent fever splenomegaly pancytopenia weight loss high mortality
Cutaneous leishmaniasis (CL)
most abundant CL is caused by at least 12
different species of Leishmania, and each of them has its own characteristic, vectors, and reservoirs
(CL) Presentation
Single or multiple chronic skin ulcersDestructive mucocutaneous lesions,
or Disseminated infection
Mode of Transmission
At least 70 different species of sandflies, small insects of the genus Phlebotomus
The primary sandfly vectors of the Southwestern Asia region include Phlebotomus
papatasi Phlebotomus
sergenti
CL Occurrence
CL is found in most countries of the tropical and subtropical regions of the world
90% of all cases occur in only six countries: Afghanistan, Brazil, Iran, Peru, Saudi Arabia, and Syria
CL Incidence
Incidence fluctuates due to:new agricultural projectsweather variabilitychanges in reservoir densities, andannual sandfly patterns
CL Incidence
The annual incidence of CL throughout the world is 1 to 1.5 million cases with 350 million people at risk of getting the disease, only 300,000 cases are officially reported
Most Important Infectious Agents
Old World: Leishmania major Leishmania tropica Leishmania aethiopica
New World: Leishmania braziliensis Leishmania mexicana
Leishmania major
Also known as the rural typeCauses moist cutaneous lesionsOccurs in southern districts of
SyriaReservoir host is the rodent
Psammomys obesus (Fat Sand Rat)Spreads zoonotically from desert
rodents to man by sand fly Phlebotomus papatasi
Leishmania major
Incubation period is week to monthsUlcers appear on the extremitiesSpontaneous healing occurs within 3
to 6 months, leaving a depigmented pitted scar
Rodent Sandfly Human
Leishmania majorMode of Transmission
Leishmania major Occurrence
Semi-arid climates hot dry season lasting 6 or more months temperature exceeding 35-40oC Rainfalls vary from 100mm- 600mm
annually.Found in low-lying desert regionsSoils are deep and friable but
sufficiently cohesive for the construction of deep, durable, rodent burrows
Leishmania tropica
Known as urban CL, or “anthroponotic CL”
Causes dry lesion Transmitted from person-to-person Humans and the domestic dogs serve
as the reservoirs of infectionCausative parasite in northern districtsTransmitted by the sandfly Plebotomus
sergenti
Leishmania tropica Occurrence
Spreads in areas of
urban centershigher altitudes temperate climatearid, cold and warm weather
Leishmania tropica
Incubation period 2 months > a yearLesion is usually facial and begins as
a pruritic, purplish nodule (the Aleppo button) then slowly enlarges and finally breaks down after 3 or 4 months
Healing of the ulcers may require a year or more
Leishmania tropicaMode of Transmission
Sandfly Human
Climate in Syria
Two seasons: dry and hot summer (July hottest month) wet and cold winter (January coldest month) spring and fall mild with some rainfall
Temperature declines from south to north (average annual temperature is 19.7oC in the south,and 17.2o in the north)
The average annual precipitation is 100mm-1500mm
Purpose of the Study
To describe temporal and spatial patterns of disease and to characterize risk factors for exposure.
CL Case Data Used in the Study
Location All of Syria Damascus Suburbs, Aleppo
Type of data Summary Count Summary Count
Time Period 1990-1997 1994-1997
Frequency Monthly Monthly
Spatial Units 14 Districts 1,824 Villages
No. of Cases 112,484 32,076
Preliminary Results
0
2000
4000
6000
8000
10000
12000
14000
16000
18000
1990 1991 1992 1993 1994 1995 1996 1997
Year
No
. C
as
es
Incidence Rate per 1000 in each district between 1990-1997
0.00
0.50
1.00
1.50
2.00
2.50
3.00
3.50
4.00
1990 1991 1992 1993 1994 1995 1996 1997
Years
IR/1
00
0
Damas City IR
Damas Sub IR
Daraa IR
Suweida IR
Qunaitra IR
Homs IR
Hama IR
Aleppo IR
Idleb IR
Lattakia IR
Tartous IR
DeirAlZor IR
Rakka IR
Hasakeh IR
IR/1000 in Damascus Suburbs b/w 1994-1997 according to sex
0.00
0.50
1.00
1.50
2.00
2.50
3.00
3.50
1994 1995 1996 1997
Years
IR/1
000
Total IR
Male IR
Female IR
IR/1000 in Aleppo b/w 1994-1997 according to sex
0.00
0.50
1.00
1.50
2.00
2.50
3.00
3.50
1994 1995 1996 1997
Year
IR/1
000
Total IR
Male IR
Female IR
IR/100 in Damascus Suburbs b/w 1994-1997 according to age groups
0.00
1.00
2.00
3.00
4.00
5.00
6.00
1994 1995 1996 1997
Years
IR/1
000
IR<1 yr
IR1-4 yr
IR5-14 yr
IR15+ yr
IR/100 in Aleppo b/w 1994-1997 according to age groups
0.00
1.00
2.00
3.00
4.00
5.00
6.00
1994 1995 1996 1997
Year
IR/1
000
IR <1yr
IR 1-4yrs
IR 5-14yrs
IR 15+yrs
Damascus Suburbs Total Incidence Rates
0.00
0.05
0.10
0.15
0.20
0.25
0.30
0.35
0.40
0.45
Jan Feb Mar Apr May Jun Jul Aug Sept Oct Nov Dec
Months
IR/1
000
TInc94
TInc95
TInc96
TInc97
Damascus SuburbsMale Incidence Rates
0.00
0.05
0.10
0.15
0.20
0.25
0.30
0.35
0.40
0.45
Jan Feb Mar Apr May Jun Jul Aug Sept Oct Nov Dec
Months
IR/1
000
MInc94
MInc95
MInc96
MInc97
Damascus SuburbsFemale Incidence Rates
0.00
0.05
0.10
0.15
0.20
0.25
0.30
0.35
0.40
0.45
Jan Feb Mar Apr May Jun Jul Aug Sept Oct Nov Dec
Months
IR/1
000
FInc94
FInc95
FInc96
FInc97
AleppoTotal Incidence Rates
0.00
0.05
0.10
0.15
0.20
0.25
0.30
0.35
0.40
Jan Feb Mar Apr May Jun Jul Aug Sept Oct Nov Dec
Months
IR/1
00
0
TInc94
TInc95
TInc96
TInc97
AleppoMale Incidence Rates
0.00
0.05
0.10
0.15
0.20
0.25
0.30
0.35
0.40
0.45
Jan Feb Mar Apr May Jun Jul Aug Sept Oct Nov Dec
Months
IR /
10
00
MInc94
MInc95
MInc96
MInc97
AleppoFemale Incidence Rates
0.00
0.05
0.10
0.15
0.20
0.25
0.30
0.35
0.40
0.45
Jan Feb Mar Apr May Jun Jul Aug Sept Oct Nov Dec
Months
IR /
10
00
FInc94
FInc95
FInc96
FInc97
Conclusion
There are few studies of the CL status in Syria despite the high rates
More research is needed to identify the epidemiological relationship between vector, reservoir and host and to limit the spread of the disease.