AND FUTUNA HEALTH AGENCY

EPINET EPIDEMIOLOGICAL UNIT Dr Laurent Morisse, Dr Gwénaël Roualen, Dr Jean-François Yvon

ACUTE HEPATITIS A / BULLETIN No. 2

Situation as at 20 August 2006

Since the last bulletin on 06 June 2006, the Hepatitis A outbreak on the island of Futuna has been confirmed with the diagnosis of 17 new cases. On the island of Wallis, 1 new case was reported following the patient’s stay on Futuna, something which raises concerns that the outbreak will spread to Wallis. This situation justifies strengthened surveillance and awareness campaigns for both health professionals and the community.

• Recorded cases

- total number of confirmed cases (1) since 01/01/2006 : 26 including : ¾ 24 on the island of Futuna ¾ 2 on the island of Wallis

- number of cases reported since 06/06/2006 : 20, including: ¾ 18 on the island of Futuna ¾ 1 on the island of Wallis (patient returning from Futuna)

Comments: due to the high percentageof asymptomatic forms (up to 90 % in young children), the number of reported cases is probably less than the real number of cases.

(1) : classification of cases : ¾ suspect case : FEVER, fatigue and nausea ; abdominal pain followed by jaundice ¾ confirmed case: anti-HAV IgMs in the blood or a case compatible with the clinical description in a patient who, in the 15 to 50 days preceding his or her initial symptoms, had an epidemiological link with a patient who had laboratory- confirmed Hepatitis A.

• Chronological distribution

Graph 1: Weekly number of reported cases of acute Hepatitis A on 10 Futuna 9 Wallis 8 7 s 6

5 4 nombre de ca de nombre 3

2 1 0 13579111315171921232527293133 semaines

Comments: Systematic hospitalisation of patients during the contagious phase for surveillance and isolation purposes does not appear to halt inter-patient transmission.

• Geographic distribution

Page 1 sur 3 WALLIS AND FUTUNA HEALTH AGENCY

EPINET EPIDEMIOLOGICAL UNIT Dr Laurent Morisse, Dr Gwénaël Roualen, Dr Jean-François Yvon

Table 1: Distribution of the cases of acute Hepatitis A by village on Wallis and Futuna

Reported ISLAND / Villages affected cases

FUTUNA − 18 − 3 − Nuku 1 − Kolia 2

WALLIS − Ahoa 1 − Haafuasia 1

Map no. 1: Distribution of cases of Hepatitis A by village on Wallis and Futuna in 2006

Comments : - On Futuna, the outbreak began in March in the village of Fiua, which, to date, covers 18 of the 26 reported cases (69 %). The bordering villages of Vaisei (3 cases) and Nuku (1 case) have been affected by the outbreak since then, in July and August, respectively. - On Wallis, to date, there has just been one isolated case in Ahoa. The case in the village of Haafuasia appeared when the patient came back from Fiua, Futuna.

• Population at risk

Page 2 sur 3 WALLIS AND FUTUNA HEALTH AGENCY

EPINET EPIDEMIOLOGICAL UNIT Dr Laurent Morisse, Dr Gwénaël Roualen, Dr Jean-François Yvon

Graph 2 : Distribution of Hepatitis A cases by age on Wallis and Futuna in 2006 12 Wallis

10 Futuna

8

6 nombre de cas nombre 4

2

0 0 - 4 5 - 9 10 - 14 15 - 19 > 20 groupes d'âges

Comments: It has mainly been children under the age of 15 who have been at risk, i.e. 92 % of cases. As asymptomatic forms of Hepatitis A are frequent (90 % in children under the age of 6, 50 to 60 % in children aged 6 to 14), the number of reported cases is probably less than the real number of cases.

• Virological analysis

Virological analysis of the first 5 strains isolated (1 on Wallis and 4 on Futuna) showed: - that the same virus is involved on both islands ; - that this virus is identical to the one that has been circulating in New Caledonia since early 2005. The first case on Futuna (Week 11) was in a patient who had returned from a stay in New Caledonia.

• Prevention measures

As Hepatitis A is a disease with faecal-oral transmission, the main prevention measure is strictly following the basic rules of hygiene (washing hands +++). Community education via the media is vital. The heads of educational institutions should have soap so as to encourage the pupils to wash their hands and limit the risk of intra-community transmission. Another possible source of contamination is drinking contaminated water or eating contaminated seafood. The community should be reminded to boil their water and properly cook all food.

• Conclusion

The outbreak is growing on the island of Futuna and it can be expected that the disease will spread throughout the island over the coming weeks. As there are many exchanges between Wallis and Futuna, the outbreak will probably take a foothold on Wallis, too. For all these reasons, the community education campaign based on the basic rules of hygiene must be strengthened. As the population at risk is children under the age of 15, pre-schools and junior secondary schools must also be targeted by these prevention activities. The situation justifies sustained health surveillance.

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