scholarly journals Onchocerciasis control in Ghana (1974–2016)

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Nana-Kwadwo Biritwum ◽  
Dziedzom K. de Souza ◽  
Odame Asiedu ◽  
Benjamin Marfo ◽  
Uche Veronica Amazigo ◽  
...  
Keyword(s):  
Confidence Interval ◽  
Vector Control ◽  
Control Strategy ◽  
Financial Support ◽  
Control Programme ◽  
Ivermectin Treatment ◽  
Mobile Community ◽  
The Mean ◽  
The Impact ◽  
Onchocerciasis Control

Abstract Background The control of onchocerciasis in Ghana started in 1974 under the auspices of the Onchocerciasis Control Programme (OCP). Between 1974 and 2002, a combination of approaches including vector control, mobile community ivermectin treatment, and community-directed treatment with ivermectin (CDTI) were employed. From 1997, CDTI became the main control strategy employed by the Ghana OCP (GOCP). This review was undertaken to assess the impact of the control interventions on onchocerciasis in Ghana between 1974 and 2016, since which time the focus has changed from control to elimination. Methods In this paper, we review programme data from 1974 to 2016 to assess the impact of control activities on prevalence indicators of onchocerciasis. This review includes an evaluation of CDTI implementation, microfilaria (Mf) prevalence assessments and rapid epidemiological mapping of onchocerciasis results. Results This review indicates that the control of onchocerciasis in Ghana has been very successful, with a significant decrease in the prevalence of infection from 69.13% [95% confidence interval) CI 60.24–78.01] in 1975 to 0.72% (95% CI 0.19–1.26) in 2015. Similarly, the mean community Mf load decreased from 14.48 MF/skin snip in 1975 to 0.07 MF/skin snip (95% CI 0.00–0.19) in 2015. Between 1997 and 2016, the therapeutic coverage increased from 58.50 to 83.80%, with nearly 100 million ivermectin tablets distributed. Conclusions Despite the significant reduction in the prevalence of onchocerciasis in Ghana, there are still communities with MF prevalence above 1%. As the focus of the GOCP has changed from the control of onchocerciasis to its elimination, both guidance and financial support are required to ensure that the latter goal is met.

scholarly journals Patterns of epidemiology and control of onchocerciasis in West Africa

1997 ◽  
Vol 71 (2) ◽  
pp. 91-101 ◽  
Author(s):  
B. Boatin ◽  
D.H. Molyneux ◽  
J.M. Hougard ◽  
O.W. Christensen ◽  
E.S. Alley ◽  
...  
Keyword(s):  
West Africa ◽  
Vector Control ◽  
Control Strategies ◽  
Control Programme ◽  
Transmission Potential ◽  
The Public ◽  
And Control ◽  
Combined Impact ◽  
The Impact ◽  
Onchocerciasis Control

AbstractThis paper summarizes the work of the Onchocerciasis Control Programme (OCP) in West Africa, a programme which over a 22 year history has reduced the public health problems of blinding onchocerciasis in eleven countries of West Africa through vector control and, more recently, ivermectin distribution. The paper emphasizes the different approaches to control the programme has developed in the different parts of the programme area which have been determined by the epidemiology of the disease (savanna/forest form), the migratory characteristics of the vectors, intensity of the disease before commencement of treatment, the combined impact of vector control and ivermectin and the likelihood of infiltration of infective blackflies from outside the programme area. The programme has constantly monitored the impact of operations on the trends in prevalence, incidence, annual transmission potential, ocular morbidity and species of fly populations, and as a result, has identified areas where special interventions are required until the programme comes to an end in 2002. The paper illustrates the changes in intensity of infection as measured by community microfilarial load and annual transmission potential over the duration of the programme control activities. The paper also defines and justifies the control strategies in different areas and identifies areas for special interventions.

Impact of parental onchocerciasis and intensity of transmission on development and persistence ofOnchocerca volvulusinfection in offspring: an 18 year follow-up study

Parasitology ◽  
2003 ◽  
Vol 127 (4) ◽  
pp. 327-335 ◽  
Author(s):  
A. K. KIRCH ◽  
H. P. DUERR ◽  
B. BOATIN ◽  
W. S. ALLEY ◽  
W. H. HOFFMANN ◽  
...  
Keyword(s):  
Associated Factors ◽  
Multiple Logistic Regression Analysis ◽  
Infection Intensity ◽  
Control Programme ◽  
Multiple Logistic Regression ◽  
Transmission Potential ◽  
Follow Up Study ◽  
The Impact ◽  
Onchocerciasis Control

This study analysed the impact and the extent by which parentalOnchocerca volvulusinfection, intensity of transmission ofO. volvulusinfective 3rd-stage larvae (L3) and anthropometric factors may influence the acquisition, development and persistence ofO. volvulusinfection in offspring. A total of 15 290 individuals in 3939 families with 9640 children were surveyed for microfilariae ofO. volvulus, and prevalence and level ofO. volvulusinfection in children aged 0 to 20 years from infected and non-infected parents were followed longitudinally for 18 years. Children fromO. volvulus-infected mothers had not only a substantially higher risk to become infected; they also acquired infection earlier in life and developed higher infection levels. Multiple logistic regression analysis showed that maternalO. volvulusinfection and children's age are the predominant predictors for patentO. volvulusinfection, while the intensity of transmission, measured by the annual transmission potential (ATP) ofO. volvulusL3, was less decisive. Longitudinal follow up of children showed that during vector control activities by the Onchocerciasis Control Programme (OCP) and in low-level transmission areas, infection persisted at higher levels in children fromO. volvulus-positive mothers. In summary, the dominant risk factor for children to become infected is maternal onchocerciasis, and also age-associated factors will strongly impact on the development of patentO. volvulusinfection in offspring.

scholarly journals Monitoring of Insecticide Resistance in Anopheles culicifacies in Twelve Districts of Madhya Pradesh, Central India (2017–2019)

2022 ◽  
Vol 2022 ◽  
pp. 1-8
Author(s):  
Ashok K. Mishra ◽  
Praveen K Bharti ◽  
Gyan Chand ◽  
Aparup Das ◽  
Himanshu Jayswar ◽  
...  
Keyword(s):  
Insecticide Resistance ◽  
Vector Control ◽  
Indoor Residual Spraying ◽  
Central India ◽  
Control Programme ◽  
Madhya Pradesh ◽  
Control Measures ◽  
Malaria Vectors ◽  
Malaria Vector Control ◽  
The Impact

Background. Indoor residual spraying (IRS) and long-lasting insecticidal nets (LLINs) are malaria vector control measures used in India, but the development of insecticide resistance poses major impediments for effective vector control strategies. As per the guidelines of the National Vector Borne Disease Control Programme (NVBDCP), the study was conducted in 12 districts of Madhya Pradesh to generate data on insecticide resistance in malaria vectors. Methods. The susceptibility tests were conducted on adult An. culicifacies as per the WHO standard technique with wild-caught mosquitoes. The blood-fed female mosquitoes were exposed in 3 to 4 replicates on each occasion to the impregnated papers with specified discriminating dosages of the insecticides (DDT: 4%, malathion: 5%, deltamethrin: 0.05%, and alphacypermethrin: 0.05%), for one hour, and mortality was recorded after 24-hour holding. Results. An. culicifacies was found resistant to DDT 4% in all the 12 districts and malathion in 11 districts. The resistance to alphacypermethrin was also observed in two districts, and possible resistance was found to alphacypermethrin in seven districts and to deltamethrin in eight districts, while the vector was found susceptible to both deltamethrin and alphacypermethrin in only 3 districts. Conclusion. An. culicifacies is resistant to DDT and malathion and has emerging resistance to pyrethroids, alphacypermethrin, and deltamethrin. Therefore, regular monitoring of insecticide susceptibility in malaria vectors is needed for implementing effective vector management strategies. However, studies to verify the impact of IRS with good coverage on the transmission of disease are required before deciding on the change of insecticide in conjunction with epidemiological data.

Progress in controlling the reinvasion of windborne vectors into the western area of the Onchocerciasis Control Programme in West Africa

1990 ◽  
Vol 328 (1251) ◽  
pp. 731-750 ◽  
Keyword(s):  
West Africa ◽  
Vector Control ◽  
Sierra Leone ◽  
Control Programme ◽  
West African ◽  
Breeding Sites ◽  
Western Area ◽  
Monsoon Winds ◽  
First Time ◽  
Onchocerciasis Control

Since vector control began in 1975, waves of Simulium sirbanum and S. damnosum s.str ., the principal vectors of severe blinding onchocerciasis in the West African savannas, have reinvaded treated rivers inside the original boundaries of the Onchocerciasis Control Programme in West Africa. Larviciding of potential source breeding sites has shown that these ‘savanna’ species are capable of travelling and carrying Onchocerca infection for at least 500 km northeastwards with the monsoon winds in the early rainy season. Vector control has, therefore, been extended progressively westwards. In 1984 the Programme embarked on a major western extension into Guinea, Sierra Leone, western Mali, Senegal and Guinea-Bissau. The transmission resulting from the reinvasion of northern Cote d’Ivoire and Burkina Faso has been reduced by over 95%, but eastern Mali has proved more difficult to protect because of sources in both Guinea and Sierra Leone. Rivers in Sierra Leone were treated for the first time in 1989 and biting and transmission rates in Sierra Leone and Guinea fell by over 90%. Because of treatment problems in some complex rapids and mountainous areas, flies still reinvaded Mali, though biting rates were approximately 70% lower than those recorded before anti-reinvasion treatments started. It was concluded that transmission in eastern Mali has now been reduced to the levels required to control onchocerciasis.

scholarly journals Effect of population inflow and outflow between rural and urban areas on regional antimicrobial use surveillance

PLoS ONE ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. e0248338
Author(s):  
Ryuji Koizumi ◽  
Yoshiki Kusama ◽  
Yuichi Muraki ◽  
Masahiro Ishikane ◽  
Daisuke Yamasaki ◽  
...  
Keyword(s):  
Confidence Interval ◽  
Antimicrobial Stewardship ◽  
Urban Areas ◽  
Regional Level ◽  
National Database ◽  
Antimicrobial Use ◽  
Population Mobility ◽  
Defined Daily Doses ◽  
The Mean ◽  
The Impact

Purpose Regional-level measures can complement national antimicrobial stewardship programs. In Japan, sub-prefectural regions called secondary medical areas (SMAs) provide general inpatient care within their borders, and regional antimicrobial stewardship measures are frequently implemented at this level. There is therefore a need to conduct antimicrobial use (AMU) surveillance at this level to ascertain antimicrobial consumption. However, AMU estimates are generally standardized to residence-based nighttime populations, which do not account for population mobility across regional borders. We examined the impact of population in/outflow on SMA-level AMU estimates by comparing the differences between standardization using daytime and nighttime populations. Methods We obtained AMU information from the National Database of Health Insurance Claims and Specific Health Checkups of Japan. AMU was quantified at the prefectural and SMA levels using the number of defined daily doses (DDDs) divided by (a) 1,000 nighttime population per day or (b) 1,000 daytime population per day. We identified and characterized the discrepancies between the two types of estimates at the prefectural and SMA levels. Results The national AMU was 17.21 DDDs per 1,000 population per day. The mean (95% confidence interval) prefectural-level DDDs per 1,000 nighttime and daytime population per day were 17.27 (14.10, 20.44) and 17.41 (14.30, 20.53), respectively. The mean (95% confidence interval) SMA-level DDDs per 1,000 nighttime and daytime population per day were 16.12 (9.84, 22.41) and 16.41 (10.57, 22.26), respectively. The nighttime population-standardized estimates were generally higher than the daytime population-standardized estimates in urban areas, but lower in the adjacent suburbs. Large differences were observed in the main metropolitan hubs in eastern and western Japan. Conclusion Regional-level AMU estimates, especially of smaller regions such as SMAs, are susceptible to the use of different populations for standardization. This finding indicates that AMU standardization based on population values is not suitable for AMU estimates in small regions.

scholarly journals How Can Onchocerciasis Elimination in Africa Be Accelerated? Modeling the Impact of Increased Ivermectin Treatment Frequency and Complementary Vector Control

2018 ◽  
Vol 66 (suppl_4) ◽  
pp. S267-S274 ◽  
Author(s):  
Suzanne Verver ◽  
Martin Walker ◽  
Young Eun Kim ◽  
Grace Fobi ◽  
Afework H Tekle ◽  
...  
Keyword(s):  
Vector Control ◽  
Ivermectin Treatment ◽  
Treatment Frequency ◽  
The Impact

scholarly journals Dog and cat population dynamics in an urban area: evaluation of a birth control strategy

2018 ◽  
Vol 38 (3) ◽  
pp. 511-518 ◽  
Author(s):  
Rita C.M. Garcia ◽  
Marcos Amaku ◽  
Alexander W. Biondo ◽  
Fernando Ferreira
Keyword(s):  
Urban Area ◽  
Birth Control ◽  
Control Strategy ◽  
Control Program ◽  
Population Management ◽  
Life Expectancy At Birth ◽  
Canine Population ◽  
The Mean ◽  
The Impact ◽  
Birth Control Program

ABSTRACT: For canine and feline population management in an urban area, a set of well-developed strategies is required to prevent overpopulation, the abandonment of animals, and zoonosis. An understanding of the dynamics of these populations and a characterization of these populations are necessary for action planning. The proposed strategies should be monitored and evaluated so that canine and feline population management programs are properly implemented. Population management programs can be improved through evidence based adaptive management. The objective of this study was to characterize the canine and feline populations and their dynamics in an urban area and to evaluate the impact of a birth control program. Three cross-sectional census surveys and a birth control program were conducted in a neighborhood of São Paulo area with 4,275 households. The two first surveys were performed in 2005 and 2006, prior to implementation of the birth control program, and were used to characterize the canine and feline populations. The third survey was performed in 2008, eighteen months after the birth control strategy had been established. The canine population decreased from 2006 to 2008, after birth control. The mean age for the canine population was 3.36 years; 65% of the dogs were younger than 3 years of age. The mean life expectancy at birth was 3.9 years for male dogs and 5.9 years for female dogs. The mean age for the feline population was 1.66 years; 74% of the cats were 1 year of age or less. The canine and feline populations had a high mortality rate for juveniles younger than 1 year of age. There was an 8% and an 18% decrease in canine and feline birth rates, respectively, after spay or neuter intervention. There was a high animal population turnover, which was more pronounced in the feline population.

The Position Servo Control Strategy of High Dynamic Response Based on Electric Steering Gear

2013 ◽  
Vol 310 ◽  
pp. 524-531
Author(s):  
Guo Ping Zhao ◽  
Hong Xing Wu ◽  
Min Xiu Kong ◽  
Li Yi Li
Keyword(s):  
Vector Control ◽  
Control Strategy ◽  
Servo System ◽  
Current Loop ◽  
Feed Forward ◽  
Loop Control ◽  
Feed Forward Control ◽  
High Dynamic ◽  
Position Servo ◽  
The Impact

This paper studies the current loop, velocity loop and position loop controller of PMSM position servo system for Electric steering gear servo system. It makes research around the principle of PMSM vector control and three control loop control strategy. The control strategy bases on the principle of vector control of PMSM when id=0 and uses the classic PI control theory. A new method of decouple control for the current of direct axis and cross axis direct is presented. It will overcome the impact of EMF when the motor is working in high dynamic. The system uses the feed-forward control to compensate the position deviation of permanent magnet synchronous motor using in the steering gear. The paper also researches transfer function of feed-forward control of the location, and establishes the feed-forward controller model of the position loop. Simulation results demonstrate the effectiveness of our proposed scheme.

The WHO Onchocerciasis Control Programme: Retrospect and prospects

1990 ◽  
Vol 328 (1251) ◽  
pp. 721-729 ◽  
Keyword(s):  
West Africa ◽  
Insecticide Resistance ◽  
Vector Control ◽  
Species Complex ◽  
Control Programme ◽  
Related Research ◽  
Simulium Damnosum ◽  
The Future ◽  
History Of ◽  
Onchocerciasis Control

The history of onchocerciasis control in Africa and the genesis of the WHO Onchocerciasis Control Programme in West Africa (OCP) are briefly reviewed. The importance of experience gained in anti-locust campaigns in helping to plan the OCP is stressed. Members of the Simulium damnosum species complex are the vectors of onchocerciasis, which OCP is controlling with insecticide treatments on the stretches of rivers where the Simulium breed. Migrations of flies have been responsible for reinfestations of controlled areas and the spread of insecticide resistance. The management of these problems and related research are described, but it is emphasized that despite setbacks OCP is achieving its aims. A strategy for the future is outlined: vector control supplemented by chemotherapy is expected to continue until the year 2004.

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