First evidence of lymphatic filariasis transmission interruption in Cameroon: Progress towards elimination

Nana-Djeunga, Hugues C.; Tchouakui, Magellan; Njitchouang, Guy R.; Tchatchueng-Mbougua, Jules Brice; Nwane, Philippe; Domche, André; Bopda, Jean; Mbickmen-Tchana, Stève; Akame, Julie; Tarini, Ann; Epée, Emilienne; Biholong, Benjamin; Zhang, Yaobi; Tougoue, Jean Jacques; Kaboré, Achille; Njiokou, Flobert; Kamgno, Joseph

doi:10.1371/journal.pntd.0005633

Cited by 12 publications

(14 citation statements)

References 26 publications

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“…This represents the first evidence for Madagascar that transmission is being halted in traditionally high endemic districts, and that MDA may be partially stopped in the country. These results are consistent with those reported in other endemic countries of Africa and Asia, where scale-up of TAS has allowed confirmation in multiple regions of a reduction in LF transmission below sustainable levels [ 15 – 18 ]. Despite progress, Madagascar still faces considerable challenges for LF elimination and its evaluation.…”

Section: Discussionsupporting

confidence: 90%

Towards elimination of lymphatic filariasis in southeastern Madagascar: Successes and challenges for interrupting transmission

Garchitorena

Raza-Fanomezanjanahary²,

Mioramalala

et al. 2018

PLoS Negl Trop Dis

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IntroductionA global strategy of mass drug administration (MDA) has greatly reduced the burden of lymphatic filariasis (LF) in endemic countries. In Madagascar, the National Programme to eliminate LF has scaled-up annual MDA of albendazole and diethylcarbamazine across the country in the last decade, but its impact on LF transmission has never been reported. The objective of this study was to evaluate progress towards LF elimination in southeastern Madagascar.MethodsThree different surveys were carried out in parallel in four health districts of the Vatovavy Fitovinany region in 2016: i) a school-based transmission assessment survey (TAS) in the districts of Manakara Atsimo, Mananjary, and Vohipeno (following a successful pre-TAS in 2013); ii) a district-representative community prevalence survey in Ifanadiana district; and iii) a community prevalence survey in sentinel and spot-check sites of these four districts. LF infection was assessed using the Alere Filariasis Test Strips, which detect circulating filarial antigens (CFA) of adult worms. A brief knowledge, attitudes and practices questionnaire was included in the community surveys.Principal findingsNone of the 1,825 children sampled in the TAS, and only one in 1,306 children from sentinel and spot-check sites, tested positive to CFA. However, CFA prevalence rate in individuals older than 15 years was still high in two of these three districts, at 3.5 and 9.7% in Mananjary and Vohipeno, respectively. Overall CFA prevalence in sentinel and spot-check sites of these three districts was 2.80% (N = 2,707), but only two individuals had detectable levels of microfilaraemia (0.06%). Prevalence rate estimates for Ifanadiana were substantially higher in the district-representative survey (15.8%; N = 545) than in sentinel and spot-check sites (0.8%; N = 618). Only 51.2% of individuals surveyed in these four districts reported taking MDA in the last year, and 42.2% reported knowing about LF.ConclusionsAlthough TAS results suggest that MDA can be stopped in three districts of southeastern Madagascar, the adult population still presents high CFA prevalence levels. This discordance raises important questions about the TAS procedures and the interpretation of their results.

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Section: Discussionsupporting

confidence: 90%

Towards elimination of lymphatic filariasis in southeastern Madagascar: Successes and challenges for interrupting transmission

Garchitorena

Raza-Fanomezanjanahary²,

Mioramalala

et al. 2018

PLoS Negl Trop Dis

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“…8 RTI International, Washington, DC, USA. 9 Helen Keller International, Regional Office for Africa, Dakar, Senegal.…”

Section: Resultsmentioning

confidence: 99%

“…The implementation of MDA against LF in Cameroon started in 2008 in the North and Far North regions [9]. However, the implementation of MDA in the southern parts of Cameroon is facing serious drawbacks due to the co-endemicity of Loa loa and the risk of severe adverse events (SAE) in individuals with high microfilaria (Mf) loads, if treated with ivermectin [10,11].…”

Section: Introductionmentioning

confidence: 99%

Mapping lymphatic filariasis in Loa loa endemic health districts naïve for ivermectin mass administration and situated in the forested zone of Cameroon

et al. 2020

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Background: The control of lymphatic filariasis (LF) caused by Wuchereria bancrofti in the Central African Region has been hampered by the presence of Loa loa due to severe adverse events that arise in the treatment with ivermectin. The immunochromatographic test (ICT) cards used for mapping LF demonstrated cross-reactivity with L. loa and posed the problem of delineating the LF map. To verify LF endemicity in forest areas of Cameroon where mass drug administration (MDA) has not been ongoing, we used the recently developed strategy that combined serology, microscopy and molecular techniques. Methods: This study was carried out in 124 communities in 31 health districts (HDs) where L. loa is present. At least 125 persons per site were screened. Diurnal blood samples were investigated for circulating filarial antigen (CFA) by FTS and for L. loa microfilariae (mf) using TBF. FTS positive individuals were further subjected to night blood collection for detecting W. bancrofti. qPCR was used to detect DNA of the parasites. Results: Overall, 14,446 individuals took part in this study, 233 participants tested positive with FTS in 29 HDs, with positivity rates ranging from 0.0 to 8.2%. No W. bancrofti mf was found in the night blood of any individuals but L. loa mf were found in both day and night blood of participants who were FTS positive. Also, qPCR revealed that no W. bancrofti but L.loa DNA was found with dry bloodspot. Positive FTS results were strongly associated with high L. loa mf load. Similarly, a strong positive association was observed between FTS positivity and L loa prevalence. Conclusions: Using a combination of parasitological and molecular tools, we were unable to find evidence of W. bancrofti presence in the 31 HDs, but L. loa instead. Therefore, LF is not endemic and LF MDA is not required in these districts.

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“…GPELF uses a two-pronged approach, combining mass drug administration (MDA) for all those eligible in at risk populations [ 5 ] with assistance for those with lymphedema and elephantiasis to reduce LF morbidity and suffering [ 1 ]. It is thought that MDA given for long enough, at high enough coverage and adherence (compliance) will be sufficient to interrupt transmission and eliminate the parasite [ 1 , 6 , 7 ]. Districts are deemed eligible for MDA if they have greater than 1% microfilaria prevalence (mf) in the total population [ 1 ].…”

Section: Introductionmentioning

confidence: 99%

Assessing knowledge about lymphatic filariasis and the implementation of mass drug administration amongst drug deliverers in three districts/cities of Indonesia

et al. 2018

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BackgroundThis research assesses knowledge amongst drug deliverers about the implementation of mass drug administration (MDA) for lymphatic filariasis (LF) in Agam District (West Sumatera Province), the City of Depok (West Java Province) and the City of Batam (Kepulauan Riau Province), Indonesia.MethodsA cross-sectional survey was conducted from January to March 2015 at these three sites. Respondents were identified using purposive sampling (i.e. cadre, health worker or community representatives). A total of 318 questionnaires were accepted for analysis. Three outcomes were assessed: knowledge about LF; knowledge about MDA implementation; and was informed about MDA coverage. Logistic regression analyses were employed to examine factors associated with these three outcomes.ResultsLess than half of respondents were charactersised as having a high level of LF knowledge and less than half a high level of knowledge about MDA. The odds of having a high level of knowledge of LF was significantly lower in Batam City than Agam District, yet higher amongst health workers than cadres. Deliverers living in urban areas reported more feedback on MDA outcomes than in the rural district. Health workers received more feedback than cadres (P < 0.001). Deliverers perceived the difference between coverage (drug receipt) and compliance (drug ingestion) in the community.ConclusionsThere are variations in knowledge about LF and MDA as well as feedback across drug deliverers in MDA across geographical areas. Adaptation of the MDA guidelines, supportive supervision, increasing the availability of supporting materials and directly-observed therapy might be beneficial to improve coverage and compliance in all areas.

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First evidence of lymphatic filariasis transmission interruption in Cameroon: Progress towards elimination

Cited by 12 publications

References 26 publications

Towards elimination of lymphatic filariasis in southeastern Madagascar: Successes and challenges for interrupting transmission

Towards elimination of lymphatic filariasis in southeastern Madagascar: Successes and challenges for interrupting transmission

Mapping lymphatic filariasis in Loa loa endemic health districts naïve for ivermectin mass administration and situated in the forested zone of Cameroon

Assessing knowledge about lymphatic filariasis and the implementation of mass drug administration amongst drug deliverers in three districts/cities of Indonesia

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