Satellite mapping of Loa loa prevalence in relation to ivermectin use in west and central Africa

  title={Satellite mapping of Loa loa prevalence in relation to ivermectin use in west and central Africa},
  author={MC Thomson and Val{\'e}rie Obsomer and M Dunne and SJ Connor and D. H. Molyneux},
  journal={The Lancet},
For many years, ivermectin has been widely distributed throughout west Africa for the safe and effective control of onchocerclasis. However, recent events in Loa-loa-endemic areas of Cameroon, where severe adverse reactions have occurred, now constrain the public-health use of this drug in the forest habitat of the L. loa vector. We have created a model of L. loa prevalence to identify areas where high endemicity may be associated with the occurrence of such reactions. The model results have… 
Mapping the distribution of Loa loa in Cameroon in support of the African Programme for Onchocerciasis Control
The model developed has proven very useful in defining the areas at risk of post-ivermectin Loa-related severe adverse events, and is now routinely used by APOC when projects of community-directed treatment with ivermECTin are examined.
Environmental Factors Associated With Loa loa Microfilaria Prevalence and Intensity in Diverse Bioecological Zones of Cameroon
Loiasis (African Eye Worm) is a filarial infection caused by Loa loa and transmitted by Chrysops vectors, which are confined to the tropical rainforests of Central and West Africa. Loiasis is a major
Relationships between the prevalence and intensity of Loa loa infection in the Central province of Cameroon
The monitoring procedure during large-scale ivermectin treatments for the control of onchocerciasis only needs to be strengthened in those communities where the prevalence of Loa microfilaraemia in adults exceeds 20%.
Hypo-endemic onchocerciasis hotspots: defining areas of high risk through micro-mapping and environmental delineation
It is demonstrated that micro-stratification overlap mapping of available onchocerciasis and loiasis prevalence maps can be used to identify 12 key high risk areas, where low O. volvulusand high L. loa transmission overlap is defined as “hypo-endemic hotspots”.
ntegrated rapid mapping of onchocerciasis and loiasis in the Democratic epublic of Congo : Impact on control strategies fework
Background: Onchocerciasis can be effectively controlled by annual mass treatment with ivermectin in endemic communities. However, in communities that are endemic for loiasis there may be significant
Integrated rapid mapping of onchocerciasis and loiasis in the Democratic Republic of Congo: impact on control strategies.
Integrated rapid mapping of onchocerciasis and loiasis reduces both time and cost of surveys and greatly facilitates operational decision-making on ivermectin treatment in areas where loiasis might be co-endemic.
Research for control: the onchocerciasis experience *
  • J. Remmé
  • Medicine
    Tropical medicine & international health : TM & IH
  • 2004
The research included the development of epidemiological modelling and its application in programme evaluation and operational planning, research on disease patterns and disease burden in different bioclimatic zones to justify and guide control operations, and community trials of ivermectin.
Potential vectors of loiasis and other tabanids on the island of Bioko, Equatorial Guinea
The possibility of loiasis being endemic on Bioko contra‐indicates ivermectin treatment of onchocerciasis cases, due to risks of adverse side‐effects.
Human Onchocerciasis: Modelling the Potential Long-term Consequences of a Vaccination Programme
Investigation of the impact of vaccination in areas where loiasis and onchocerciasis are co-endemic and ivermectin is contraindicated indicates that the deployment of an onChocerCIasis vaccine would have a beneficial impact in onchopocalypse–loiasis co- endemic areas, markedly reducing microfilarial load in the young (under 20 yr) age groups.
Structure of the microfilarial reservoir of Loa loa in the human host and its implications for monitoring the programmes of Community-Directed Treatment with Ivermectin carried out in Africa
Logistic analysis showed that the prevalence of microfilaraemia increased significantly with age, reaching 60% in the oldest males, suggesting that the figure commonly reported, according to which only one third of the infected individuals were microfileraemic, should be reconsidered.


Prevalences of Loa loa microfilaraemia throughout the area endemic for the infection.
In the present review, the available data on Loa endemicity are detailed and maps showing the prevalence of Loa microfilaraemia throughout the area endemic for the infection are presented and it is possible to identify several areas, in south-eastern Nigeria, southern and central Cameroon, the south of the Central African Republic, Equatorial Guinea, Gabon, and the north and west of the Democratic Republic of the Congo (ex-Zaire).
Country-wide rapid epidemiological mapping of onchocerciasis (REMO) in Cameroon.
The prevalence of infection in local communities has been used as the basis for the country-wide repartition of onchocerciasis in Cameroon, following the principles for rapid epidemiological mapping
Serious reactions after mass treatment of onchocerciasis with ivermectin in an area endemic for Loa loa infection
Empirical surveys aimed at assessing the intensity of infection with L loa microfilariae should be done before ivermectin is distributed for onchocerciasis control in areas where loiasis is endemic.
Electrophoretic enzyme typing revealed that a single group A Neisseria meningitidis clonal complex, designated III-1, was responsible for recent epidemics in Nepal, Saudi Arabia, and Chad, suggesting that clonal virulence is an important factor in the development of epidemics of meningococcal disease.
Elimination of lymphatic filariasis as a public health problem.
  • F. Cox
  • Medicine
    Parasitology today
  • 2000
A Meeting on the ‘Elimination of Filariasis as a Public Health Problem’ took place in London, UK, 20 January 2000, under the auspices of the Royal Society of Tropical Medicine and Hygiene. Summaries
Meningitis caused by a serogroup W135 clone of the ET‐37 complex of Neisseria meningitidis in West Africa
The findings of this study indicate that outbreaks of meningococcal meningitis in Africa can be associated with serogroup W135 infections and that serogroupsing is essential before vaccination campaigns are started.
Environmental information systems for the control of arthropod vectors of disease
This review explains remote sensing approaches and spatial information technologies used for investigations of arthropod pests and vectors of diseases affecting humans and livestock.