Hayley Joseph

Lymphatic filariasis (LF) due to Wuchereria bancrofti is being eliminated from Oceania under the Pacific Elimination of Lymphatic Filariasis Programme. LF was endemic in Solomon Islands but in the 2010-2020 Strategic Plan of the Global Programme to Eliminate LF, Solomon Islands was listed as non-endemic for LF. In countries now declared free of LF an important question is what monitoring strategy should be used to detect any residual foci of LF?

Ongoing transmission of lymphatic filariasis (LF) was assessed in five Samoan villages by measuring microfilaraemia (Mf), circulating filarial antigen (CFA) and antibody prevalence. Compared to the other villages, Fasitoo-Tai had a significantly higher Mf prevalence (3·2%), CFA prevalence (14·6%) and antibody prevalence in children (62·0%) (P1% CFA prevalence and a high antibody prevalence in children (46·6%). Overall, antibody prevalence in children appeared to reflect the transmission dynamics in the villages and, in Siufaga, identified an area of ongoing transmission. The Filariasis Cellabs Enzyme-Linked Immunosorbent Assay (CELISA), based on recombinant antigen Bm14, to detect antibodies, could potentially be a promising diagnostic tool for inclusion in future surveillance in the South Pacific.

Elimination of lymphatic filariasis (LF) in the Pacific Island Countries and Territories (PICT) has been defined as <0.1% circulating filarial antigen (CFA) prevalence in children born after the implementation of successful mass drug administrations (MDAs). This research assessed the feasibility of CFA and antibody testing in three countries; Tonga, Vanuatu, and Samoa. Transmission is interrupted in Vanuatu and Tonga as evidenced by no CFA positive children and a low antibody prevalence and titre. Transmission is ongoing in Samoa with microfilaraemic (Mf) and CFA positive children and a high antibody prevalence and titre. Furthermore, areas of transmission were identified with Mf positive adults, but no CFA positive children. These areas had a high antibody prevalence in children. In conclusion, CFA testing in children alone was not useful for identifying areas of residual endemicity in Samoa. Thus, it would be beneficial to include antibody serology in the PICT surveillance strategy.

Background: Skin infections are a common public health problem in developing countries; however, they are rarely managed using a population based approach. Recent data on the burden of skin infections in Timor-Leste are limited. Our survey appears to be the only widespread survey conducted in more than 30 years and was designed to determine the baseline prevalence of some common skin infections in Timor-Leste. Methods: We conducted a cross sectional survey in 14 sites including community health clinics, schools and hospitals within four different geographical regions. Participants were examined for five conditions (scabies, pyoderma, fungal infections, leprosy and yaws) by a multidisciplinary team. Analyses were conducted using EpiInfo version 6.04d. Results: We examined the skin of 1535 participants aged between four months and 97 years. The majority of participants were male, aged between 11 and 20 years and had at least one condition of interest (56.0%, 56.0%, and 63.1%, respectively). Fungal infections were the most common presentation (39.0%) and males were more commonly affected than females (42.3% vs 34.0%, respectively, pvalue < 0.0001). Among those people with more than one condition the two most common co-infections were scabies with either pyoderma or a fungal infection (38.0% and 32.0%, respectively). The survey identified 29 previously undiagnosed cases of leprosy and six cases of yaws. Conclusions: Our findings indicate the need for a comprehensive programme to address these conditions. There are successful disease control programmes in place within the country and it is hoped a healthy skin programme could be integrated into an established disease control programme in order to maximise health benefits and resources.

Demonstration of successful elimination of lymphatic filariasis (LF) in endemic countries requires sensitive diagnostics for accurate definitions of endpoints and future surveillance. There has been interest in complementing available diagnostics with antibody serology testing in children, since negative serology would correspond with cessation of LF transmission. The Filariasis CELISA detects antifilarial and has favourable results with serum samples but field application requires an easier sampling method. Ninety-four paired plasma and filter paper samples were assayed with promising results. The filter paper method resulted in a sensitivity of 92% and a specificity of 77% when compared to the paired plasma. One hundred and one filter paper samples were assessed for storage effects. Following 10-month storage at there was a significant reduction in reactivity (). Overall the results indicated that filter paper sampling would be a favourable sensitive and specific alternative for blood collection in surveys.