METHODS: We performed a systematic literature review of articles published until May 2022 that reported HZ epidemiology, clinical management, and health economic data in six Southeast Asian countries: Indonesia, Malaysia, the Philippines, Singapore, Thailand, and Vietnam. Literature searches were conducted in Medline, Scopus, Embase, and gray literature. Articles written in English or local languages were considered for inclusion.
RESULTS: In total, 72 publications were included in the study; 22 were case studies and over 60% originated in Singapore and Thailand. Only two studies (data from Thailand) reported incidence of HZ. The proportion of patients reported with HZ was 0.68-0.7% among dermatology clinics, 0.14% at one emergency department (5.3% of dermatology cases) in Singapore, and 3% of admissions at another hospital in Singapore. Pain was the most common symptom associated with HZ, reported in 74.21-100% of patients. HZ complications were reported in 10.2-21.2% of patients, and the proportions with postherpetic neuralgia and HZ ophthalmicus were 6.3-50% and 4.98-28.57%, respectively. Additionally, there is a lack of comprehensive, up-to-date HZ economic data, with only six studies identified for the Philippines, Singapore, and Thailand.
CONCLUSIONS: Overall, there are limited data reporting incidence and prevalence of HZ in Southeast Asia at a national level. High rates of complications, symptoms, and abundance of case reports suggest substantial healthcare resource utilization for patients with HZ and highlight the need for further research in Southeast Asia assessing the societal impact.
METHODS: For each country, we adapted a static multicohort Markov model developed with a 1-year cycle length and lifetime horizon. Demographics were obtained from the World Health Organization, HZ incidence from a worldwide meta-regression reporting Asian-specific values, proportions of postherpetic neuralgia (PHN) and non-PHN complications from local/regional studies, and vaccine efficacy from a long-term follow-up trial. First-dose coverage and second-dose compliance were assumed to be 30% and 70%, respectively. A one-way deterministic sensitivity analysis (OWSA) and probabilistic sensitivity analysis (PSA) were performed to assess the robustness and uncertainty of inputs for each country.
RESULTS: Without RZV, it was estimated that there would be a total of approximately 10 million HZ cases, 2.1 million PHN cases, and 1.4 million non-PHN complications in individuals aged ≥ 50 years included in the model. Introducing RZV under 30% coverage could avoid approximately 2.2 million (22%) HZ cases, almost 500,000 (21%) PHN cases, and around 300,000 (22%) non-PHN complications. OWSA showed that first-dose coverage and initial HZ incidence had the largest impact on the estimated number of HZ cases avoided. The number needed to vaccinate ranged from 15 to 21 to prevent one case of HZ and from 68 to 104 to prevent one case of PHN across each country.
CONCLUSIONS: This study demonstrated that there is substantial HZ disease burden in older adults for the five selected countries in Southeast Asia, negatively impacting national healthcare systems. Introducing RZV could potentially reduce this burden. A graphical abstract is available with this article.