The epidemiological impact of an HIV vaccine on the HIV/AIDS epidemic in Southern India

The potential epidemiological impact of preventive HIV vaccines on the HIV epidemic in Southern India is examined using a mathematical deterministic dynamic compartmental model. Various assumptions about the degree of protection offered by such a vaccine, the extent of immunological response of those vaccinated, and the duration of protection afforded are explored. Alternative targeting strategies for HIV vaccination are simulated and compared with the impact of conventional prevention interventions in high-risk groups and the general population. The impact of disinhibition (increased risk behavior due to the presence of a vaccine) is also considered. Vaccines that convey a high degree of protection in a share of or all of those immunized and that convey life-long immunity are the most effective in curbing the HIV epidemic. Vaccines that convey less than complete protection may also have substantial public health impact, but disinhibition can easily undo their effects and they should be used combined with conventional prevention efforts. Conventional interventions that target commercial sex workers and their clients to increase condom use can also be highly effective and can be implemented immediately, before the arrival of vaccines.Poverty and Health,Disease Control&Prevention,Health Monitoring&Evaluation,Public Health Promotion,HIV AIDS,HIV AIDS,Health Monitoring&Evaluation,Adolescent Health,HIV AIDS and Business,Health Service Management and Delivery

Forecasting malaria incidence from historical morbidity patterns in epidemic-prone areas of Ethiopia: a simple seasonal adjustment method performs best.

The aim of this study was to assess the accuracy of different methods of forecasting malaria incidence from historical morbidity patterns in areas with unstable transmission. We tested five methods using incidence data reported from health facilities in 20 areas in central and north-western Ethiopia. The accuracy of each method was determined by calculating errors resulting from the difference between observed incidence and corresponding forecasts obtained for prediction intervals of up to 12 months. Simple seasonal adjustment methods outperformed a statistically more advanced autoregressive integrated moving average method. In particular, a seasonal adjustment method that uses mean deviation of the last three observations from expected seasonal values consistently produced the best forecasts. Using 3 years' observation to generate forecasts with this method gave lower errors than shorter or longer periods. Incidence during the rainy months of June-August was the most predictable with this method. Forecasts for the normally dry months, particularly December-February, were less accurate. The study shows the limitations of forecasting incidence from historical morbidity patterns alone, and indicates the need for improved epidemic early warning by incorporating external predictors such as meteorological factors

How to optimize tuberculosis case finding: explorations for Indonesia with a health system model

BACKGROUND: A mathematical model was designed to explore the impact of three strategies for better tuberculosis case finding. Strategies included: (1) reducing the number of tuberculosis patients who do not seek care; (2) reducing diagnostic delay; and (3) engaging non-DOTS providers in the referral of tuberculosis suspects to DOTS services in the Indonesian health system context. The impact of these strategies on tuberculosis mortality and treatment outcome was estimated using a mathematical model of the Indonesian health system. METHODS: The model consists of multiple compartments representing logical movement of a respiratory symptomatic (tuberculosis suspect) through the health system, including patient- and health system delays. Main outputs of the model are tuberculosis death rate and treatment outcome (i.e. full or partial cure). We quantified the model parameters for the Jogjakarta province context, using a two round Delphi survey with five Indonesian tuberculosis experts. RESULTS: The model validation shows that four critical model outputs (average duration of symptom onset to treatment, detection rate, cure rate, and death rate) were reasonably close to existing available data, erring towards more optimistic outcomes than are actually reported. The model predicted that an intervention to reduce the proportion of tuberculosis patients who never seek care would have the biggest impact on tuberculosis death prevention, while an intervention resulting in more referrals of tuberculosis suspects to DOTS facilities would yield higher cure rates. This finding is similar for situations where the alternative sector is a more important health resource, such as in most other parts of Indonesia. CONCLUSION: We used mathematical modeling to explore the impact of Indonesian health system interventions on tuberculosis treatment outcome and deaths. Because detailed data were not available regarding the current Indonesian population, we relied on expert opinion to quantify the parameters. The fact that the model output showed similar results to epidemiological data suggests that the experts had an accurate understanding of this subject, thereby reassuring the quality of our predictions. The model highlighted the potential effectiveness of active case finding of tuberculosis patients with limited access to DOTS facilities in the developing country setting

Modelling the impact of COVID-19-related programme interruptions on visceral leishmaniasis in India

BACKGROUND: In March 2020, India declared a nationwide lockdown to control the spread of coronavirus disease 2019. As a result, control efforts against visceral leishmaniasis (VL) were interrupted. METHODS: Using an established age-structured deterministic VL transmission model, we predicted the impact of a 6- to 24-month programme interruption on the timeline towards achieving the VL elimination target as well as on the increase of VL cases. We also explored the potential impact of a mitigation strategy after the interruption. RESULTS: Delays towards the elimination target are estimated to range between 0 and 9 y. Highly endemic settings where control efforts have been ongoing for 5-8 y are most affected by an interruption, for which we identified a mitigation strategy to be most relevant. However, more importantly, all settings can expect an increase in the number of VL cases. This increase is substantial even for settings with a limited expected delay in achieving the elimination target. CONCLUSIONS: Besides implementing mitigation strategies, it is of great importance to try and keep the duration of the interruption as short as possible to prevent new individuals from becoming infected with VL and continue the efforts towards VL elimination as a public health problem in India

The Long Term Effect of Current and New Interventions on the New Case Detection of Leprosy: A Modeling Study

Leprosy is a contagious disease that will remain prevalent, despite the declining number of patients worldwide over the last century. With approximately 250,000 new cases detected annually, leprosy is far from being eradicated. Leprosy can be treated with drugs after disease detection

Draadslachtoffers in de Westerbroekstermadepolder, Schatting van het aantal dode vogels als gevolg van een hoogspanningslijn in een natuurgebied.

Met behulp van gegevens van onderzoek uit literatuur is van een groot aantal in Nederland voorkomende vogelsoorten een verband gelegd tussen het aantal draadslachtoffers per kilo-meter hoogspanningslijn en de vogeldichtheid. Met behulp van deze gegevens is het aantal draadslachtoffers in de Westerbroek- stermadepolder (WBM-polder) geschat. Jaarlijks zouden er 395 draadslachtoffers vallen. De WBM-polder wordt steeds aantrekkelijker voor broedvogels. Naar verwachting neemt het aantal draadslachtoffers evenredig toe tot 433.5 draadslachtoffers per jaar. Bij de schatting is er van uit gegaan, dat de WBM-polder de gemiddelde eigenschappen had van de gebieden uit de liitera-tuur. In de literatuur waren te weinig gegevens bekend om een preciezere schatting door middel van een formule te maken. Daarom zijn gegevens over vogeldichtheden gebruikt uit de vogelatlas van SOVON (1987). Omdat de vogeldichtheden in Nederland over het algemeen zijn toegenomen sinds de jaren zeventig, is het aantal draad-slachtoffers vrijwel zeker onderschat. Uitgaande van een schatting door Braaksma op grond van ringgegevens zouden er jaarlijks meer dan 1000 draadslachtoffers in de WBM-polder vallen. Om de uitkomsten te testen en bij te stellen, moet vervolg- onderzoek worden gedaan. Omdat in de literatuur vooral te weinig aandacht is besteed aan het aantal potentiële draad-slachtoffers, moet daar bij vervolgonderzoek veel aandacht aan besteed worden. Vervolgonderzoek is nodig, want het aantal draadslachtoffers in Nederland wordt op één miljoen per jaar geschat. Er is een grote keus aan preventieve maatregelen die het dodental kan beperken

The effects of shellfish fishery on the ecosystems of the Dutch Wadden Sea and Oosterschelde : final report on the second phase of the scientific evaluation of the Dutch shellfish fishery policy (EVA II)

This publication summarises the findings of the scientific research projects carried out as part of EVA II, the second phase in the evaluation of shellfish fisheries policy in the Zeeland Delta and the Wadden Sea, and relates these findings to other studies on the ecological effects of shellfish fisheries in the Wadden Sea and elsewhere. Four policy qustions were at the heart of the project: (1) what are the ecological impacts of shellfish fishery?, (2) did the policies implemented in 1993 achieve their objectives, (3) is current shellfish fishery in line with international obligations, (4) what possiblities for improvement do exist? These policy questions were translated into research questions. Numbers of large shellfish-eating birds declined. Some restoration of seagrass beds occurred, but restoration was not maximal. The area of littoral mussel beds in the Wadden Sea increased to more than 2000 ha, after having disappeared completely in 199