An Expanded Transmission Assessment Survey to Confirm the Interruption of Lymphatic Filariasis Transmission in Wallis and Futuna.

Historically, the human prevalence of Wuchereria bancrofti infection in Wallis and Futuna (WAF) was among the highest in the Pacific and mass drug administration (MDA) against lymphatic filariasis (LF) either with diethylcarbamazine citrate (DEC) or the combination of DEC and albendazole had been implemented for decades. To determine whether LF antigen prevalence in WAF was lower than 1%, the infection threshold for elimination in an area where Aedes spp. are the principal vectors, we conducted the WHO-recommended transmission assessment survey in 2012. We present the results of a school-based survey, which targeted 1,014 students in all 13 elementary schools in WAF. From a fingerprick, the circulating filarial antigen (CFA) positivity was checked for grade 2-5 students using BinaxNOW filariasis test (immunochromatographic test). Of 935 children tested, three were positive for CFA in two schools. At the territory level, this was below the critical cutoff of nine cases, if the whole territory was considered as a single evaluation unit. The prevalence of CFA in WAF is less than 1%, reaching the goal for LF elimination set by the WHO. We were able to recommend stopping LF MDA and move to post-MDA surveillance to detect any recrudescence. This survey successfully paved the way for WAF to be validated as achieving LF elimination as a public health problem by 2020.

Improving hepatitis B birth dose coverage through village health volunteer training and pregnant women education.

Hepatitis B is highly endemic in the Republic of Kiribati, while the coverage of timely birth dose vaccination, the primary method shown to prevent mother-to-child transmission of hepatitis B virus, was only 66% in 2014. Children born at home are especially at high risk, as they have limited access to timely birth dose (i.e. within 24 h) vaccination. To improve birth dose coverage, a project to improve linkages between village health volunteers and health workers and educate pregnant women on hepatitis B vaccination was carried out in 16 communities with low birth dose coverage in Kiribati from November 2014 to May 2015. After project completion, the coverage of timely birth dose administration increased significantly both in the densely populated capital region of South Tarawa (from 89% to 95%, p=0.001) and the Outer Islands (from 57% to 83%, p<0.001). The coverage of timely birth dose administration among infants born at home increased significantly from 70% to 84% in South Tarawa (p=0.001) and from 49% to 75% in the Outer Islands (p<0.001). Timely birth dose was associated with being born in a hospital, being born during the study period and caregivers having developed an antenatal birth dose plan. The project demonstrates a successful model for improving hepatitis B vaccine birth dose coverage that could be adopted in other areas in Kiribati as well as other similar settings.

Low Level of Hepatitis B Virus Infection in Children 20 Years After Initiation of Infant Vaccination Program in Wallis and Futuna.

The prevalence of hepatitis B virus (HBV) in Wallis and Futuna (WAF) was one of the highest in the Pacific and was the driving factor for introducing hepatitis B (HepB) vaccination in 1992 and HepB birth dose (HepB-BD) in 2006. Using lymphatic filariasis (LF) transmission assessment survey (TAS) as a survey platform for eliminating LF, we assessed HBV surface antigen (HBsAg) seroprevalence, HepB vaccination coverage, and its timeliness among schoolchildren in WAF. From one finger prick of all registered fourth and fifth grade students, we tested HBsAg and filariasis antigen simultaneously, and estimated HepB vaccination coverage and timeliness by reviewing students' immunization cards. Since the children targeted were born when the three-dose HepB schedule was 2, 3, and 8 months, we defined timely vaccination if each dose was given by 3, 4, and 12 months. Of 476 targeted, 427 were enrolled. HBsAg prevalence was 0.9%. Estimated HepB vaccination coverage was 97%, 97%, and 96% for the first, second, and third doses, respectively, yielding coverage for all three doses of 96%. Proportion of timely vaccination was lower: 80%, 56%, and 65%, respectively, and less than 50% for all three doses combined. The seroprevalence of HBsAg among schoolchildren in WAF is less than 1%, close to the control goal. HepB vaccination coverage was high, but many children were vaccinated late. We recommend increasing the efforts for timely HepB vaccination. By combining an HBV seroprevalence survey and coverage assessment, we demonstrated the benefit of using TAS as a public health platform to access schoolchildren.