Public Health and Prevention
Vaccines
Currently, there are no approved vaccines for Leishmaniasis. Although individuals may acquire partial immunity to the disease, they continue to be susceptible to re-infection. Vaccination attempts using killed promastigotes have proved ineffective. Attempts that have yielded some promise have not resulted in beneficial outcomes for other forms of the disease. For example, immunization with live promastigotes in Russia and Israel may yield some benefits; however, the vaccine's efficacy against visceral leishmaniasis has not been proven. Greater funding should be allocated to fund this complex research in Leishmaniasis to lessen the risk of infection for over 300 million people at risk for the disease.
Public Health
According to Dr. Blackburn, an infectious disease expert at Stanford University , combating Leishmaniasis is a complex endeavor that involves multi-level support for public health initiatives. Similar to many infectious diseases, there is no single solution that would successfully eliminate Leishmaniasis worldwide.
Despite this obstacle, there are steps that may be taken to reduce the burden of disease in many countries. For example:
• Vector control Ex: insecticides, reduce breeding sites
• Control of animal reservoirs
• Personal protective measures against sandflies- Ex: long clothing that covers the body
• Early diagnosis and treatment, particularly for Leishmania /HIV co-infections (Although this approach may not be as effective in areas where there are animal reservoirs who maintain the possibility of transmission.)
• Better housing and working conditions- Ex: insecticide spraying of houses and insecticide-impregnated bednets
• Focus intense treatment and efforts in endemic areas
• Increase surveillance Ex: WHO created 6 new institutions in Brazil , China , India , Kenya , Nepal and Sudan . There, they have improved mapping techniques and databases, in addition to implementing workshops for visceral leishmaniasis/HIV co-infection
• Donor support- Ex: increasing access to anti-Leishmaniasis drugs
• Improving public health infrastructure/organization- Ex: access to transportation to treatment facilities
• Education- Ex: disseminating materials and health education about Leishmaniasis
Public Health Case Study
2002 Epidemic in Afghanistan
Case:
• 22 known cases of Leishmania infections among troops returning from military service in Afghanistan , Iraq , and Kuwait 2002-2003
• banned exposed military personnel from donating blood
• 200,000 Afghani's in Kabul alone are affected
• disease is known as, “little sister” due to widespread prevalence
Treatment:
• intravenous administration of sodium stibogluconate
• therapy was successful, with minimal side-effects
Public Health Initiatives in the Middle East :
• WHO appeals for 1.2 million from the US to aid in ameliorating the largest single epidemic in Afghanistan for a 2-year program to reduce the incidence of disease
• Drugs for mass treatment
• 55,000 long-lasting, insecticide-treated bednets
• Social mobilization and health education
• Insecticide-treated sheeting which also protects from other insect-born diseases
• Rehabilitated a central laboratory
• Established a task force and national coordinator
• Initiated further research
Obstacles in controlling the epidemic:
• Concentrated population of people facilitates rapid transmission of this form of the parasite which is transferred from person to person by of the bite of the sandfly
• Unsanitary conditions in impoverished settings allow sandflies to breed at a rapid rate
• Long incubation period of the disease masks new cases that may emerge several months after inoculation (typically from May to October)
Epidemic in Eritrea, Ethiopa and eastern Sudan
• WHO carried out assessment surveys
• provided first-line drugs and dipsticks K39 for serological diagnosis
• bednets
Further WHO initiatives:
• Syria : distributed 10,000 insecticide-impregnated bednets to cover 10,000 people
• Result: 50% reduction in number of cutaneous leishmaniasis cases
Why is it so difficult to control Leishmaniasis?
One important obstacle in controlling Leishmaniasis is that the disease is mostly endemic in resource-poor countries. From Africa to India , where the highest rates of Leishmaniasis occur, impoverished conditions foster the spread of Leishmaniasis with unsanitary conditions allowing sandflies to breed and a lack of funding for public health prevention strategies. Other factors that pose difficulties in controlling Leishmaniasis include:
• Need for field diagnosis tests which are less expensive and requires shorter lengths of courses and administration
• Disease resistance Ex: pentavalent antimony is ineffective in India
• Limited access to drugs including pentamidine and amphotericin B which are also expensive and slightly toxic
• Slow research and development
• Lack of funds and inadequate public health infrastructure in resource-poor settings
Sources:
http://www.who.int/leishmaniasis/research/en/
http://www.medicinenet.com/script/main/art.asp?articlekey=24919
http://www.who.int/leishmaniasis/resources/documents/en/wer7729.pdf
http://www.who.int/leishmaniasis/epidemic/en/
http://www.utdol.com/utd/content/topic.do?topicKey=parasite/15570
http://www.who.int/leishmaniasis/surveillance/en/