Prevalence and Correlates of Lymphatic Filariasis Infection and Its Morbidity Following Mass Ivermectin and Albendazole Administration in Mkinga District, North-Eastern Tanzania

Abstract

Lymphatic filariasis (LF) is a neglected tropical disease targeted for elimination as public health problem through morbidity management and preventive annual mass drug administration (MDA). This cross-sectional community-based surveillance assessed the prevalence and correlates of LF infection in Mkinga district, Tanga-region, Tanzania. A total of 4115 individuals (49.7% males, 35.2% children) were screened for circulating filarial antigens (CFA), microfilaremia (mf) and disease manifestations in 15 villages between November 2018 and January 2019. MDA uptake in the previous year was assessed. Overall prevalence of CFA-positivity was 5.8% (239/4115; 95% CI: 5.1–6.6), with significant heterogeneity between villages (range 1.2% to 13.5%). CFA-positivity was higher in males (8.8%) than females (3.3%), and correlated with increasing age (p < 0.001). Prevalence of mf among CFA-positives was 5.2%. Only 60% of eligible inhabitants in the study area took MDA in the previous year, and CFA-positivity was 2-fold higher in those who missed MDA (p < 0.0001). Prevalence of scrotal enlargement, hydrocele, arms or legs swelling, lymphoedema and lymphadenopathy was 6.4%, 3.7%, 1.35%, 1.2% and 0.32%, respectively. Compared to baseline data, 16 years of MDA intervention significantly reduced LF transmission and morbidity, although the intended elimination target of <1% mf and <2% antigenemia to level where recrudescence is unlikely to occur by the year 2020 may not be attained. The finding of hotspots with ongoing transmission calls for intensified control measures.

Lymphatic filariasis elimination status: Wuchereria bancrofti infections in human populations and factors contributing to continued transmission after seven rounds of mass drug administration in Masasi District, Tanzania

“…The prevalence of Mf was below the WHO-recommended elimination threshold of 1%; however, the prevalence of antigenemia remains above the recommended threshold of 2% [ 6 ], indicating that the district is yet to interrupt LF transmission. The prevalence of CFA and Mf reported in the current study are corroborated by the findings from a recent study in Mkinga District, North-eastern Tanzania [ 26 ] reporting a CFA and Mf prevalence of 5.8% and 0.3% respectively. Similarly, a significant drop in microfilaraemia was reported in Zanzibar after five rounds of MDA with ivermectin and albendazole complemented with intensive community mobilization and high treatment coverage [ 27 ].…”

Safety and Tolerability of Mass Diethylcarbamazine and Albendazole Administration for the Elimination of Lymphatic Filariasis in Kenya: An Active Surveillance Study

“…However, the high incidence of AEs in the 16–20 years of age category may not be explained by variation in metabolic drug capacity. A recent study reported a high prevalence of LF infection in young adults and the elderly (65+ years) [ 31 ]. Previous studies reported significant side-effects often associated with the treatment of LF in infected patients due to treatment-induced immunologic reaction [ 14 , 15 ].…”

Prevalence, Intensity, and Correlates of Soil-Transmitted Helminth Infections among School Children after a Decade of Preventive Chemotherapy in Western Rwanda

“…It is well recognized that the WHO intervention strategy and implementation of the global NTD program have contributed to reducing the disease burden. However, the long-term intervention measures taken so far by many endemic countries in sub-Saharan Africa, including Rwanda, have not managed to control and eliminate STH and other NTDs as a public health problem by 2020 [ 16 , 20 , 30 , 31 ]. Several factors may have contributed to this shortcoming [ 32 ].…”