Establishment of Outbreak Thresholds for Hepatitis A in South Africa Using Laboratory Surveillance, 2017–2020

As South Africa transitions from endemic to intermediate endemicity, hepatitis A surveillance needs strengthening to monitor trends in disease incidence and to identify outbreaks. We used passive laboratory-based surveillance data from the National Health Laboratory Services to calculate national hepatitis A incidence and to establish thresholds for outbreaks. Incidence was calculated by age and geographic location. The static threshold used two or three standard deviations (SDs) above the mean hepatitis A incidence in 2017–2019, and a cumulative summation (CuSum2) threshold used three SDs above the mean of the preceding seven months. These thresholds were applied to hepatitis A data for 2020. From 2017 to 2020, the mean incidence of hepatitis A IgM was 4.06/100,000 and ranged from 4.23 to 4.85/100,000 per year. Hepatitis A incidence was highest in the Western Cape province (WCP) (7.00–10.92/100,000 per year). The highest incidence was in the 1–9-year-olds. The incidence of hepatitis A in 2020 exceeded the static threshold in two districts of the WCP: Cape Winelands in January and Overberg district in August. The provincial incidence did not exceed the static and CuSum2 thresholds. District-level analysis using either threshold was sensitive enough to monitor trends and to alert district health authorities, allowing early outbreak responses.

PP167 Cost Effectiveness Of Universal Childhood Vaccination Against Hepatitis A

IntroductionHepatitis A (HA) is a liver disease with a low mortality rate, but it can cause debilitating symptoms and fulminant hepatitis in some cases. Its incidence is greater in geographical areas with poor sanitation and hygiene. Spain is considered a low-endemicity country, so universal childhood immunization against HA is currently not financed by the National Health System. The aim of this study was to synthesize the scientific evidence on the cost effectiveness of universal childhood vaccination against HA.MethodsFull economic evaluations, published in the English or Spanish languages, were included if they reported outcome measures related to the prevention of HA, adverse effects, or incremental cost-effectiveness ratios (ICERs). The Medline, Embase and Cochrane Library databases were searched for articles published from the beginning of the databases to April 2018.ResultsA total of 23 economic evaluations were included: one in a country of high endemicity, nine in countries of intermediate endemicity, and 13 in countries with low endemicity. Only one Spanish study, published in 1997, was found. Studies conducted in high- and intermediate- endemicity countries concluded that a universal childhood vaccination program against HA was a cost-effective option. However, in the case of countries with low endemicity the results were heterogeneous, although most agreed that a systematic vaccination strategy would not be a cost-effective option and that the adoption of such a strategy would not be justified given the limited benefits it would offer. The results of the economic evaluations depended on parameters such as the price and duration of the vaccine effect and the program coverage.ConclusionsIn countries with low endemicity the results were heterogeneous, although most studies concluded that the implementation of a universal vaccination strategy is not justified from the point of view of cost effectiveness.

Seasonality of tuberculosis in intermediate endemicity setting dominated by reactivation diseases in Hong Kong

Summer-spring predominance of tuberculosis (TB) has been widely reported. The relative contributions of exogenous recent infection versus endogenous reactivation to such seasonality remains poorly understood. Monthly TB notifications data between 2005 and 2017 in Hong Kong involving 64,386 cases (41% aged ≥ 65; male-to-female ratio 1.74:1) were examined for the timing, amplitude, and predictability of variation of seasonality. The observed seasonal variabilities were correlated with demographics and clinical presentations, using wavelet analysis coupled with dynamic generalised linear regression models. Overall, TB notifications peaked annually in June and July. No significant annual seasonality was demonstrated for children aged ≤ 14 irrespective of gender. The strongest seasonality was detected in the elderly (≥ 65) among males, while seasonal pattern was more prominent in the middle-aged (45–64) and adults (30–44) among females. The stronger TB seasonality among older adults in Hong Kong suggested that the pattern has been contributed largely by reactivation diseases precipitated by defective immunity whereas seasonal variation of recent infection was uncommon.

Evidence of Circulation of Several HAV Genetic Variants and Emergence of Potential Antigenic Variants in an Endemo-Epidemic Country before Vaccine Introduction

Similar to several other countries in the world, the epidemiology of hepatitis A virus changed from high to intermediate endemicity level in Tunisia, which led to the occurrence of outbreaks. This study aimed to determine the genetic and antigenic variability of HAV strains circulating in Tunisia during the last few years. Genotyping using complete VP1 gene and VP1-2A junction confirmed the predominance of genotype IA, with co-circulation of several genetic and antigenic variants. Phylogenetic analysis including Tunisian and strains from other regions of the world showed the presence of at least two IA-variants within IA subgenotype. Amino-acid analysis showed several mutations in or close to epitope regions in the VP1-region. This study provides a baseline on the genetic and antigenic variability of HAV circulating strains before the introduction of vaccination into the national immunization schedule.

Prevalence of hepatitis B virus genotypes among patients with liver disease in Eritrea

Eritrea is an East African multiethnic country with an intermediate endemicity for hepatitis B. Our aim was to establish the most prevalent genotypes of hepatitis B virus (HBV) among patients with liver disease. A total of 293 Eritrean patients with liver disease who were hepatitis B surface antigen (HBsAg) positive were enrolled. All sera were tested for liver transaminases, HBV DNA viral load, and hepatitis B seromarkers including HBsAg, anti-HBcAb (total), HBeAg, and anti-HBeAb. Those reactive for HBsAg and anti-HBc (total) were further tested for HBV genotyping. The median (interquartile range) of HBV DNA viral load and ALT levels were 3.47 (1.66) log IU/mL and 28 (15.3) IU/L, respectively. Using type-specific primer-based genotyping method, 122/293 (41.6%) could be genotyped. Irrespective of mode of occurrence, HBV genotype D (21.3%) was the predominant circulating genotype, followed by genotypes C (17.2%), E (15.6%), C/D (13.1%), and C/E (10.7%). Genotypes C/D/E (7.4%), A/D (4.9%), D/E (4.1%), A (2.5%), and B, A/E, B/E, and A/D/C (0.8%) were also present. HBV in Eritrea is comprised of a mixture of HBV genotypes. This is the first study of HBV genotyping among patients with liver disease in Eritrea.

Seroprevalence of hepatitis a virus antibody in 11-15 years old children in Vijayawada and age-related incidence of hepatitis a virus in GGH, Vijayawada

Background: To estimate seropositivity of hepatitis A virus Ig G antibody (HAV Ig G antibody) in 11 to 15 years aged children in Vijayawada.Methods: The study group includes 265 consecutive children aged 11 to 15 years attending GGH, Vijayawada and had a blood sample taken for any reason. The serum samples collected were screened for Anti HAV IgG antibody using commercially available Elisa kit (WANTAI). Information related to various socio demographic factors also were elicited by interview method. All the Anti-Hepatitis A virus IgM antibody positive individuals list are collected from 1stJuly 2015 to 1st august 2017 and were categorized based on age and analysed.Results: The total seropositivity against Hepatitis A virus is 71%. The number of children in the urban population showing IgG antibodies is lower compared to that of rural population (p value-0.028). The highest number of Hepatitis A virus infected population (positive IgM) is between 10-14 years (50), followed by 15-19 years (45) and 5-9 years (43). This shows that there is increased risk of infection in the older age group and there is a shift to 2nd and 3rd decade (p value – 0.045).Conclusions: The seropositivity of HAV IgG antibody in children aged 11-15 years is 71% in Vijayawada. Seroprevalence in the nearby area, Chennai, ten years back was found to be 95% by 12 years of age. This indicates there is a shift from high to intermediate endemicity in Vijayawada. There is need for vaccination in the susceptible individuals.

Seroprevalence of hepatitis B virus and hepatitis C virus infection among Malaysian population

Malaysia is a country with an intermediate endemicity for hepatitis B. As the country moves toward hepatitis B and C elimination, population-based estimates are necessary to understand the burden of hepatitis B and C for evidence-based policy-making. Hence, this study aims to estimate the prevalence of hepatitis B and C in Malaysia. A total of 1458 participants were randomly selected from The Malaysian Cohort (TMC) aged 35 to 70 years between 2006 and 2012. All blood samples were tested for hepatitis B and C markers including hepatitis B surface antigen (HBsAg), anti-hepatitis B core antibody (anti-HBc), antibodies against hepatitis C virus (anti-HCV). Those reactive for hepatitis C were further tested for HCV RNA genotyping. The sociodemographic characteristics and comorbidities were used to evaluate their associated risk factors. Descriptive analysis and multivariable analysis were done using Stata 14. From the samples tested, 4% were positive for HBsAg (95% CI 2.7–4.7), 20% were positive for anti-HBc (95% CI 17.6–21.9) and 0.3% were positive for anti-HCV (95% CI 0.1–0.7). Two of the five participants who were reactive for anti-HCV had the HCV genotype 1a and 3a. The seroprevalence of HBV and HCV infection in Malaysia is low and intermediate, respectively. This population-based study could facilitate the planning and evaluation of the hepatitis B and C control program in Malaysia.

Familial transmission of hepatitis B: an interesting case report

Hepatitis-B is a health problem of global importance. India falls in the low intermediate endemicity zone (prevalence rate 2-4%) for hepatitis-B virus infection. Intrafamilial transmission of HBV has an important role in maintaining endemicity in our country. Here we report an interesting case of intrafamilial clustering of HBV infection from western India. Out of 14 family members, 12 members (85.7%) were hepatitis-B infected (overt or occult). This report highlights that vertical transmission of hepatitis-B is also an important route of hepatitis-B transmission. Screening of family members and contacts of HBsAg positive individuals with both HBsAg and Anti-HBc is required for timely active immunization and adaptation of hygienic precautions to prevent the chain of transmission of hepatitis B.

AB0937 COMPARATIVE STUDY OF PYOGENIC SPONDYLODISCITIS VERSUS TUBERCULOUS SPONDYLODISCITIS

Background:Infectious spondylodiscitis is a life-threatening infection of the intervertebral disc and adjacent vertebrae that can be caused by a variety of microorganisms. Our country is at intermediate endemicity for Tuberculosis.Objectives:To compare the clinical, biological, radiological characteristics, management and prognosis of pyogenic versus tuberculous spondylodiscitis.Methods:Retrospective study of 89 patients admitted to our department over a period of 20 years [1998-2018]. The diagnosis of spondylodiscitis was made based on clinical, biological, radiological and bacteriological data.Results:The average age of the patients was 56.1 years. There were 46 men (51.6%) and 43 women (48.4%) with a female predominance during tuberculous spondylodiscitis (57.1%) versus 26.9% during pyogenic spondylodiscitis (p = 0.009).Diabetes was more frequent during pyogenic spondylodiscitis but with no statistically significant difference (p = 0.4). The evolution time was statistically greater during tuberculous spondylodiscitis (p <0.001). Patients with tuberculous spondylodiscitis had more frequently an impaired general condition (p = 0.02).Hyperleukocytosis was noted more frequently in the pyogenic group than in the tuberculosis group (p=0.03), while the increase in sedimentation rate was not significantly different between the two groups (90 mm/h and 76 mm/h, respectively, p=0.1). We found no statistically significant difference regarding the site of spondylodiscitis.Radiologically, the frequency of para-vertebral and psoas abscesses, epiduritis and the presence of spinal cord compression were similar in the two groups (p=0.2; p=0.1 and p=0.1, respectively), whereas mirrored geodes were more frequent during tuberculosis (p = 0.04).Surgical and interventional treatments (percutaneous sampling, abscess drainage) were more frequently noted during pyogenic spondylodiscitis, but without significant difference (p=0.2). The occurrence of immediate complications was more frequent during tuberculosis but without a statistically significant difference (p=0.2).Conclusion:In our series, patients with tuberculous spondylodiscitis tend to have a chronic pattern of progression and more often an impaired general condition. However, there was no significant difference in the presence of abscess, epiduritis and the occurrence of complications between tuberculous spondylodiscitis and pyogenic spondylodiscitis.Disclosure of Interests:None declared