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Impact of Annual Praziquantel Treatment on Urogenital Schistosomiasis in a Seasonal Transmission Focus in Central Senegal
- Source :
- PLoS Neglected Tropical Diseases, Vol 10, Iss 3, p e0004557 (2016), PLoS Neglected Tropical Diseases, PLoS Neglected Tropical Diseases, 2016, 10 (3), pp.e0004557. ⟨10.1371/journal.pntd.0004557⟩
- Publication Year :
- 2016
- Publisher :
- Public Library of Science (PLoS), 2016.
-
Abstract
- In Sub-Saharan Africa, urogenital schistosomiasis remains a significant public health problem, causing 150.000 deaths/year with approximately 112 million cases diagnosed. The Niakhar district is a disease hotspot in central Senegal where transmission occurs seasonally with high prevalences. The aim of this study was to determine the effect of annual treatment over 3 years on the seasonal transmission dynamics of S. haematobium in 9 villages in the Niakhar district. Adults and children aged between 5 and 60 years were surveyed from 2011 to 2014. Urine samples were collected door-to-door and examined for S. haematobium eggs at baseline in June 2011, and all participants were treated in August 2011 with PZQ (40 mg/kg). After this initial examination, evaluations were conducted at 3 successive time points from September 2011 to March 2014, to measure the efficacy of the annual treatments and the rates of reinfection. Each year, during the transmission period, from July to November-December, malacological surveys were also carried out in the fresh water bodies of each village to evaluate the infestation of the snail intermediate hosts. At baseline, the overall prevalence of S. haematobium infection was 57.7%, and the proportion of heavy infection was 45.3%, but one month after the first treatment high cure rates (92.9%) were obtained. The overall infection prevalence and proportion of heavy infection intensities were drastically reduced to 4.2% and 2.3%, respectively. The level of the first reinfection in February-March 2012 was 9.5%. At follow-up time points, prevalence levels varied slightly between reinfection and treatment from 9.5% in June 2012 to 0.3% in March 2013, 11.2 in June 2013, and 10.1% April 2014. At the end of the study, overall prevalence was significantly reduced from 57.7% to 10.1%. The overall rate of infested Bulinid snails was reduced after repeated treatment from 0.8% in 2012 to 0.5% in 2013. Repeated annual treatments are suggested to have a considerable impact on the transmission dynamics of S. haematobium in Niakhar, due to the nature of the epidemiological system with seasonal transmission. Thus, to maintain this benefit and continue to reduce the morbidity of urogenital schistosomiasis, other approaches should be integrated into the strategy plans of the National program to achieve the goal of urogenital schistosomiasis elimination in seasonal foci in Senegal.<br />Author Summary Urogenital schistosomiasis represents a serious cause of morbidity and mortality in S. haematobium endemic countries. Treatment with praziquantel (PZQ) is effective at reducing or eliminating active infection, but does not prevent reinfection that remains a continuing problem in high-risk communities, especially in areas where contacts with infested water are inevitable. The efficacy of PZQ treatment is challenged by regular re-infection in high risk communities due to frequent contact with water infested with snails carrying the larvae of S. haematobium. A large number of countries have initiated schistosomiasis control and elimination programs based on repeated PZQ mass drug administration (MDA). However, little information is available on the impact of repeated treatment on S. haematobium transmission dynamics in areas where transmission occurs seasonally in temporary water bodies. This observational study assessed the effect of annual repeated cohort treatment with PZQ over 3 years on the seasonal transmission dynamics of S. haematobium in nine villages in Niakhar district, District. Repeated annual treatments have a considerable impact on the transmission dynamics of S. haematobium in Niakhar. The prevalence of S. haematobium was dramatically reduced from 57.7% in 2011 to 10.1% in 2014. The reinfection rate did not exceed 10% from 2012 to 2014. Also, the rate of infested Bulinid snails decreased from 0.8% in 2012 to 0.5% in 2013. These results suggest that it may be possible to implement urogenital schistosomiasis elimination strategies in the Niakhar district and other seasonal transmission areas in Senegal if praziquantel MDAs are carried out in combination with other measures such as health education, improvement of access to clean water and snail control.
- Subjects :
- Male
Time Factors
Physiology
Snails
Marine and Aquatic Sciences
Fresh Water
Urine
medicine.disease_cause
Praziquantel
Geographical Locations
Schistosomiasis haematobia
0302 clinical medicine
Seasonal transmission
Epidemiology
Medicine and Health Sciences
Schistosomiasis
030212 general & internal medicine
Child
Schistosoma haematobium
biology
lcsh:Public aspects of medicine
Malacology
Middle Aged
Senegal
Body Fluids
Infectious Diseases
Helminth Infections
Child, Preschool
[SDE]Environmental Sciences
Schistosoma
Female
Seasons
Anatomy
medicine.drug
Research Article
Neglected Tropical Diseases
Adult
medicine.medical_specialty
lcsh:Arctic medicine. Tropical medicine
Adolescent
lcsh:RC955-962
030231 tropical medicine
Drug Administration Schedule
Host-Parasite Interactions
03 medical and health sciences
Schistosomicides
Young Adult
Helminths
Infestation
parasitic diseases
medicine
Parasitic Diseases
Urogenital Schistosomiasis
Animals
Humans
Ponds
business.industry
Public health
Public Health, Environmental and Occupational Health
Organisms
Biology and Life Sciences
lcsh:RA1-1270
Molluscs
Bodies of Water
biology.organism_classification
Tropical Diseases
Invertebrates
Surgery
Fresh water
Gastropods
People and Places
Africa
Earth Sciences
Hydrology
business
Zoology
Demography
Subjects
Details
- Language :
- English
- ISSN :
- 19352735 and 19352727
- Volume :
- 10
- Issue :
- 3
- Database :
- OpenAIRE
- Journal :
- PLoS Neglected Tropical Diseases
- Accession number :
- edsair.doi.dedup.....36ae20173f24e5363994a8b4c6494270