Bridging the data gaps in the epidemiology of hepatitis C virus infection in Malaysia using multi-parameter evidence synthesis

BACKGROUND: Collecting adequate information on key epidemiological indicators is a prerequisite to informing a public health response to reduce the impact of hepatitis C virus (HCV) infection in Malaysia. Our goal was to overcome the acute data shortage typical of low/middle income countries using statistical modelling to estimate the national HCV prevalence and the distribution over transmission pathways as of the end of 2009. METHODS: Multi-parameter evidence synthesis methods were applied to combine all available relevant data sources - both direct and indirect - that inform the epidemiological parameters of interest. RESULTS: An estimated 454,000 (95% credible interval [CrI]: 392,000 to 535,000) HCV antibody-positive individuals were living in Malaysia in 2009; this represents 2.5% (95% CrI: 2.2-3.0%) of the population aged 15-64 years. Among males of Malay ethnicity, for 77% (95% CrI: 69-85%) the route of probable transmission was active or a previous history of injecting drugs. The corresponding proportions were smaller for male Chinese and Indian/other ethnic groups (40% and 71%, respectively). The estimated prevalence in females of all ethnicities was 1% (95% CrI: 0.6 to 1.4%); 92% (95% CrI: 88 to 95%) of infections were attributable to non-drug injecting routes of transmission. CONCLUSIONS: The prevalent number of persons living with HCV infection in Malaysia is estimated to be very high. Low/middle income countries often lack a comprehensive evidence base; however, evidence synthesis methods can assist in filling the data gaps required for the development of effective policy to address the future public health and economic burden due to HCV. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12879-014-0564-6) contains supplementary material, which is available to authorized users

Projections of the current and future disease burden of hepatitis C virus infection in Malaysia

The prevalence of hepatitis C virus (HCV) infection in Malaysia has been estimated at 2.5% of the adult population. Our objective, satisfying one of the directives of the WHO Framework for Global Action on Viral Hepatitis, was to forecast the HCV disease burden in Malaysia using modelling methods.An age-structured multi-state Markov model was developed to simulate the natural history of HCV infection. We tested three historical incidence scenarios that would give rise to the estimated prevalence in 2009, and calculated the incidence of cirrhosis, end-stage liver disease, and death, and disability-adjusted life-years (DALYs) under each scenario, to the year 2039. In the baseline scenario, current antiviral treatment levels were extended from 2014 to the end of the simulation period. To estimate the disease burden averted under current sustained virological response rates and treatment levels, the baseline scenario was compared to a counterfactual scenario in which no past or future treatment is assumed.In the baseline scenario, the projected disease burden for the year 2039 is 94,900 DALYs/year (95% credible interval (CrI): 77,100 to 124,500), with 2,002 (95% CrI: 1340 to 3040) and 540 (95% CrI: 251 to 1,030) individuals predicted to develop decompensated cirrhosis and hepatocellular carcinoma, respectively, in that year. Although current treatment practice is estimated to avert a cumulative total of 2,200 deaths from DC or HCC, a cumulative total of 63,900 HCV-related deaths is projected by 2039.The HCV-related disease burden is already high and is forecast to rise steeply over the coming decades under current levels of antiviral treatment. Increased governmental resources to improve HCV screening and treatment rates and to reduce transmission are essential to address the high projected HCV disease burden in Malaysia

Modeling the impact of tuberculosis control measures in a highly endemic and an overcrowded prison / Herlianna Naning

Globally, the prevalence of tuberculosis (TB) is up to 100 times higher in closed settings such as prisons compared to the general population. Despite this, effecive TB interventions are rarely deployed in prisons in low and middle-income countries where the burden of TB is highest. Our aim was to explore the impact of introducing interventions to reduce the transmission of TB in an overcrowded prison in Malaysia. We used a deterministic transmission model to simulate the effects of three TB control strategies and evaluate their impact on the predicted prevalence of active TB over a tenyear period. In the first set of simulations, in which the current environmental situation (degree of cell crowding and ventilation rate) of the prison was held constant, we investigated the effects of isoniazid preventive therapy (IPT) and anti-tuberculosis treatment (ATBT), independently or as a combined strategy. We susbsequently repeated the simulations assuming improved environmental conditions. We also simulated the effect of prolonging IPT beyond the normal 6-months regimen, to 12 and 36 months. Our model showed that implementing either the ATBT or the combined IPT and ATBT strategy reduced the current 8% prevalence of active TB to below 2.5%, whereas implementing IPT alone increased the projected prevalance to 15%. After successful IPT treatment, reinfection compromises the effectiveness of IPT, irrespective of the treatment regime duration. Reducing overcrowding from six to four inmates per cell and increasing the ventilation rate from 2 to 12 air changes per hour improved IPT effectiveness by reducing the prevalence of active TB to 8% after ten years. To achieve control in such a high TB burden setting, there is an urgent need to implement effective TB interventions, like intensified TB case finding, IPT and environmental changes in the Malaysian prison

Modelling the Impact of Different Tuberculosis Control Interventions on the Prevalence of Tuberculosis in an Overcrowded Prison.

The aim of this study was to simulate the effects of tuberculosis (TB) treatment strategies interventions in an overcrowded and poorly ventilated prison with both high (5 months) and low (3 years) turnover of inmates against improved environmental conditions. We used a deterministic transmission model to simulate the effects of treatment of latent TB infection and active TB, or the combination of both treatment strategies. Without any intervention, the TB prevalence is estimated to increase to 8.8% for a prison with low turnover of inmates but modestly stabilize at 5.8% for high-turnover prisons in a 10-year period. Reducing overcrowding from 6 to 4 inmates per housing cell and increasing the ventilation rate from 2 to 12 air changes per hour combined with any treatment strategy would further reduce the TB prevalence to as low as 0.98% for a prison with low inmate turnover

Automaattisen hitsauskoneen modernisointi

Tämä insinöörityö tehtiin Insinööritoimisto Ketema Oy:lle (Ketema). Ketema on pieni suomalainen yritys jonka päätoimiala on teollisuuden sähkökäyttöjen suunnittelu ja toteutus asiakkaan yksilöllisten tarpeiden mukaisesti. Tämän insinöörityön tavoitteena oli suunnitella ja toteuttaa automaattisen hitsauskoneen liikkeenohjauslaitteistojen modernisointi. Modernisoinnissa käytettäviksi laitteistoiksi oli valittu jo ennen tämän työn aloitusta Siemensin uudemmat version aiemmin käytetyistä laitteista. Modernisoinnin yhteydessä ohjaus- ja käyttölaitteistojen välinen kommunikaatio muutettiin Profinet -väyläpohjaiseksi ratkaisuksi, joka osaltaan vähentää työmäärää sekä sähkösuunnittelun että -asennusten osalta. Työn tuloksena saatiin laadittua suunnitelmat ja ohjelmistototeutus hitsauskoneen modernisoimiseksi. Suunnittelun lähestymistavaksi otettiin tarpeettomien muutosten minimointi alkuperäisen ja uuden koneen välillä. Tämä lähestymistapa mahdollisti kaksi käytännöllistä asiaa: 1) saavutettiin aikaisemmin tehdyn ohjelmistototeutuksen mahdollisimman suuri uudelleenkäyttöaste ja 2) pidettiin koneen käytettävyys operaattorin kannalta ennallaan. Työn suunnitteluosuuden aikana kävi ilmeiseksi, että modernisoinnin kohteeksi ajateltua konetta ei voida vapauttaa päivittäisestä tuotantokäytöstä johtuen asiakasyrityksen tuotantotilanteesta. Asiakasyrityksellä oli muutenkin tarve lisätä automaattista hitsauskapasiteettia, joten ratkaisuksi tilanteeseen tuli uuden koneen rakentaminen. Mekaniikka kopioidaan vanhasta koneesta minimaalisin muutoksin ja ohjaus- ja käyttölaitteistot toteutetaan tämän työn suunnitelmien mukaisesti. Insinöörityön tekemisen ja alkuperäisen tavoitteen kannalta asiassa ei kuitenkaan ole eroa. Tämän työn valmistumisen aikaan uusi kone on kokoonpanossa, joten koneen käyttöönotosta ei tämän työn tekemisen aikana saatu kokemusta. Perustavanlaatuisia ongelmia aikaisempien koneiden kohdalla saadun kokemuksen perusteella ei ole odotettavissa, mutta joitain pieniä yllätyksiä lähes varmasti.This thesis work was done for Insinööritoimisto Ketema Oy (Ketema). Ketema is small Finnish company that has specialized in planning and implementing industrial automation systems according to customers’ needs. The goal of this thesis work was to design and implement modernization of motion control devices in an automatic welding machine. The new devices are manufactured by Siemens. As part of the project, the communication between control unit and drive units was changed to Profinet. This change helps in reducing the work load both in electric design as well as in wiring the equipment during the device installation work. The thesis work resulted in appropriate design plans and software implementation fulfilling the set goal. All unnecessary changes were minimized. This approach gave two practical benefits: 1) maximal re-use of existing SW implementation and 2) daily operation of the machine is as close to original machine as possible. During the design phase it became obvious that the target machine could not be released from daily production for the modernization work. Since the client had clear need for in-creasing welding capacity, the solution was to build a new welding machine where the me-chanics was were copied from old machine and the motion control systems were as de-signed in this project. However, this makes no significant change considering the original goal of the thesis work. At the time of completing the thesis work, the new machine is under construction. Because of this, the introduction of the machine into production use remains to be done. No major challenges are expected but naturally there will be some minor surprises to cope with

Projected HCV-related disease burden in DALYs/year, over the period 1960–2039.

<p>Three historical incidence scenarios are compared (1-B, 2-B, and 3-B), with current treatment uptake and SVR rates assumed to apply to the year 2014 onwards.</p

Distributions of age at acute infection, for PWID and non-PWID.

<p>Distributions of age at acute infection, for PWID and non-PWID.</p

Projections of HCV-related disease outcomes for Scenario 1-B, over the period 1960–2039.

<p>Projected incidence and prevalence are shown in the upper and lower panels, respectively.</p

Patterns of acute incidence underlying Scenarios 1 to 3.

<p>The assumed historical HCV incidence time series for Scenarios 1 to 3 are shown separately for PWID and non-PWID risk groups (upper, centre, and lower panels, respectively).</p

Progression probabilities for transitions between disease progression model states, and corresponding prior distributions.

<p>Background mortality probabilities were derived from the national age-specific mortality rates for Malaysia, adjusted for the degree of excess non-liver-related mortality calculated from persons diagnosed HCV Ab+ in Scotland (1991–2005), in which the window of 6 months subsequent to HCV diagnosis date is excluded from follow-up time to reduce bias associated with testing individuals presenting with disease.</p><p>Progression probabilities for transitions between disease progression model states, and corresponding prior distributions.</p