Impact of the Lymphatic Filariasis Control Program towards elimination of filariasis in Vanuatu, 1997-2006 (original) (raw)

Surveillance efforts after mass drug administration to validate elimination of lymphatic filariasis as a public health problem in Vanuatu

Tropical medicine and health, 2017

Vanuatu was formerly highly endemic for lymphatic filariasis (LF), caused by Wuchereria bancrofti and transmitted by Anopheles mosquitoes. After a baseline survey showing 4.8% antigen prevalence in 1998, the country conducted nationwide (in one implementation unit) annual mass drug administration (MDA) with albendazole and diethylcarbamazine citrate from 2000 to 2004 and achieved prevalence of 0.2% by 2006 in a representative nationwide cluster survey among all age groups. Post MDA surveillance was conducted from 2006 to 2012. After MDA, the country was divided for surveillance into three evaluation units (EUs) formed by grouping provinces according to baseline prevalence: EU1: Torba, Sanma and Malampa; EU2: Penama; EU3: Shefa and Tafea. The study compiled all past data and information on surveys in Vanuatu from the country programme. This paper reviews the surveillance activities done after stopping MDA to validate the interruption of transmission and elimination of LF as a public ...

Reduction in Acute Filariasis Morbidity during a Mass Drug Administration Trial to Eliminate Lymphatic Filariasis in Papua New Guinea

PLoS Neglected Tropical Diseases, 2011

Background: Acute painful swelling of the extremities and scrotum are debilitating clinical manifestations of Wuchereria bancrofti infection. The ongoing global program to eliminate filariasis using mass drug administration is expected to decrease this and other forms of filarial morbidity in the future by preventing establishment of new infections as a consequence of eliminating transmission by the mosquito vector. We examined whether mass treatment with anti-filarial drugs has a more immediate health benefit by monitoring acute filariasis morbidity in Papua New Guinean communities that participated in a 5-year mass drug administration trial.

Lymphatic filariasis in Fiji: progress towards elimination, 1997–2007

Tropical Medicine and Health

Background Lymphatic filariasis (LF) is a major public health problem in the Pacific Region, including in Fiji. Through transmission by the mosquito vector Aedes, Fiji has suffered the burden of remaining endemic with LF despite efforts at elimination prior to 1999. In the year 1999, Fiji agreed to take part in the Pacific Programme for Elimination of LF (PacELF) and the Global Programme to Eliminate LF. Methods This study reviewed and collated past data on LF in Fiji between 1997 and 2007. Sources included published papers as well as unpublished PacELF and WHO program meeting and survey reports. Records were held at Fiji’s Department of Health and Medical Services, James Cook University and the WHO office in Suva, Fiji. Results Baseline surveys between 1997 and 2002 showed that Fiji was highly endemic for LF with an estimated 16.6% of the population antigen positive and 6.3% microfilaria positive at that time. Five rounds of annual mass drug administration (MDA) using albendazole a...

Assessing Transmission of Lymphatic Filariasis Using Parasitologic, Serologic, and Entomologic Tools after Mass Drug Administration in American Samoa

The American Journal of Tropical Medicine and Hygiene, 2009

Assessing the interruption of lymphatic filariasis transmission after annual mass drug administration (MDA) requires a better understanding of how to interpret results obtained with the available diagnostic tools. We conducted parasitologic, serologic, and entomologic surveys in three villages in American Samoa after sentinel site surveys suggested filarial antigen prevalence was < 1% after five annual MDAs with diethylcarbamazine and albendazole. Antigen and antifilarial antibody prevalence ranged from 3.7% to 4.6% and from 12.5% to 14.9%, respectively, by village. Only one person was microfilaria positive. Although no children less than 10 years of age were antigen positive, antifilarial antibody prevalence in this age group was 5.1% and antibody-positive children were detected in all three villages. Wuchereria bancrofti-infected mosquitoes were also detected in all three villages. Thus, monitoring of infections in mosquitoes and antifilarial antibody levels in children may serve as indicators of local transmission and be useful for making decisions about program endpoints.

Progress towards, and challenges for, the elimination of filariasis from Pacific-island communities

Annals of Tropical Medicine and Parasitology, 2002

The Pacific Programme for the Elimination of Lymphatic Filariasis (PacELF) the first regional campaign to attempt to eliminate filariasis as a public-health problem is using five, annual, mass drug administrations (MDA) ofdiethylcarbamazine (DEC) plus albendazole to stop transmission. In 2001, nine countries and territories covered by the programme had begun annual MDA campaigns, with population treatment coverages ranging from 52% to 95%. By the end of 2002, it is anticipated that countries/territories will have begun such MDA campaigns. Even with high MDA coverage, the efficiency of Aedes polynesiensis as a vector of Wuchereria bancrofti may limit the effectiveness of the elimination campaigns in some countries. In areas of limited MDA coverage, additional strategies, such as vector control (as a adjunct to the MDA), or alternative approaches, such as the use of DEC-fortified salt, may be necessary to stop transmission. THE PACELF CAMPAIGN In the South Pacific sub-region, 22 countries and territories are participating in the Pacific Programme for the Elimination of Lymphatic Filariasis (PacELF; Burkot and Ichimori, 2002). The goal of PacELF is the elimination of lymphatic filariasis as a public-health problem in its member countries and territories. The programme hopes to achieve this goal by using five, annual rounds of mass drug administration (MDA) to stop transmission, together with clinical management of the existing infections, to minimize pathology.

Determinants of success in national programs to eliminate lymphatic filariasis: a perspective identifying essential elements and research needs

The American journal of tropical medicine and hygiene, 2008

The Global Programme to Eliminate Lymphatic Filariasis (GPELF) was launched in 2000. To understand why some national programs have been more successful than others, a panel of individuals with expertise in LF elimination efforts met to assess available data from programs in 8 countries. The goal was to identify: 1) the factors determining success for national LF elimination programs (defined as the rapid, sustained reduction in microfilaremia/antigenemia after repeated mass drug administration [MDA]); 2) the priorities for operational research to enhance LF elimination efforts. Of more than 40 factors identified, the most prominent were 1) initial level of LF endemicity; 2) effectiveness of vector mosquitoes; 3) MDA drug regimen; 4) population compliance. Research important for facilitating program success was identified as either biologic (i.e., [1] quantifying differences in vectorial capacity; [2] identifying seasonal variations affecting LF transmission) or programmatic (i.e., [...

Investigation of risk factors for better control and surveillance of lymphatic filariasis in Papua New Guinea

2018

First and foremost, it gives me great pleasure to acknowledge my supervisors, Dr Louise Kelly-Hope (Primary), Prof. Moses J. Bockarie and Dr Lisa Reimer. Prof Bockarie for the initial planning stages of my PhD project and the entomology section planning, Dr Reimer for entomological planning stages while she was still in PNGIMR and then in LSTM where she assisted so greatly in securing bench space for me to complete laboratory analyses of my mosquito samples. However, I really think all this would never have been possible without Dr Louise Kelly-Hope. You have been that light in the darkest tunnel for me, I am forever indebted to you and your family, for stealing your family time and most of all giving you white hairs ☺ 1. To review LF research in PNG, with specific focus on entomology in Madang Province 2. To map W. bancrofti antigen (Ag) prevalence and risk factors associated with LF in Madang Province 3. To micro-map and spatially analysis MF prevalence in a highly endemic village in Madang Province 4. To examine the distribution and incrimination of Anopheles species in LF transmission in a highly endemic village in Madang Province

Sustained reduction in prevalence of lymphatic filariasis infection in spite of missed rounds of mass drug administration in an area under mosquito nets for malaria control

Parasites & Vectors, 2011

Background: The Global Programme to Eliminate Lymphatic Filariasis (GPELF) was established by the World Health Organisation (WHO) in 2000 with the goal of eliminating lymphatic filariasis (LF) as a public health problem globally by 2020. Mass drug administration (MDA) of antifilarial drugs is the principal strategy recommended for global elimination. Kenya launched a National Programme for Elimination of Lymphatic Filariasis (NPELF) in Coast Region in 2002. During the same year a longitudinal research project to monitor trends of LF infection during MDA started in a highly endemic area in Malindi District. High coverage of insecticide treated nets (ITNs) in the coastal region has been associated with dramatic decline in hospital admissions due to malaria; high usage of ITNs is also expected to have an impact on LF infection, also transmitted by mosquitoes. Results: Four rounds of MDA with diethylcarbamazine citrate (DEC) and albendazole were given to 8 study villages over an 8-year period. Although annual MDA was not administered for several years the overall prevalence of microfilariae declined significantly from 20.9% in 2002 to 0.9% in 2009. Similarly, the prevalence of filarial antigenaemia declined from 34.6% in 2002 to 10.8% in 2009. All the examined children born since the start of the programme were negative for filarial antigen in 2009. Conclusions: Despite the fact that the study villages missed MDA in some of the years, significant reductions in infection prevalence and intensity were observed at each survey. More importantly, there were no rebounds in infection prevalence between treatment rounds. However, because of confounding variables such as insecticidetreated bed nets (ITNs), it is difficult to attribute the reduction to MDA alone as ITNs can lead to a significant reduction in exposure to filariasis vectors. The results indicate that national LF elimination programmes should be encouraged to continue provision of MDA albeit constraints that may lead to missing of MDA in some years.