Image Credit: Clockwise from top left: Centers for Disease Control, Centers for Disease Control, Dr. Banchob Sripa (Khon Kaen University, Thailand), Dr. Héctor H. García (Universidad Peruana Cayetano Heredia, Lima, Peru), WHO/TDR/OCP, Dr. Mark L. Eberhard (CDC/CGH/DPDM, Atlanta, USA)

More than half of the world’s population is at risk of helminthiases (parasitic worms), and hundreds of millions of people are currently infected with one or more helminth species. Consequences of chronic infection include suffering, stigmatization, subtle and gross morbidity, and premature death. These infections are associated with low work productivity, poor cognitive performance, and slow socioeconomic development, thereby contributing to accentuate poverty and inequality.

The April 2012 issue of PLoS Neglected Tropical Diseases features the launch of a new collection, “A research agenda for the control and elimination of human helminthiases.” The collection includes a series of eight reviews from the Disease Reference Group on Helminth Infections (DRG4) that, taken together, outline a research and development (R&D) agenda for the control and elimination of helminth diseases of humans. Emphasis is placed on six major helminth diseases: soil-transmitted helminthiasis; schistosomiasis; lymphatic filariasis; onchocerciasis; food-borne trematodiasis; and cysticercosis/taeniasis. Additionally, an Editorial from Jürg Utzinger provides an overview to all eight reviews and emphasizes the importance of continued research on these six diseases, which together have an enormous global health impact.

Controlling and eventually eradicating major human helminthiases will take commitment at all levels – from local communities to politicians, philanthropic organisations, and civil societies. Although some of the necessary policies outlined in the collection have been implemented by various bodies, additional implementation and coordination is necessary. The series aims to move beyond providing a reference for researchers on existing and known issues in the field and instead plots a course for policymakers, researchers, and funding bodies in key areas to target in the ongoing campaign to eliminate helminthiases.

DRG4, chaired by Sara Lustigman and co-chaired by Boakye A. Boatin, was given the mandate to undertake a comprehensive review of recent advances in helminthiases research, identify research gaps, and rank priorities for an R&D agenda for the control and elimination of these infections.  The 14 members of DRG4 are academic or public health leaders at world-class research institutions, international bodies, and public health and governmental organizations. This group of eight reviews on helminth infections was developed out of analyses and deliberations by the group members conducted during 2010 and 2011.

DRG4 is part of an independent “think tank” of international experts, established and funded by the Special Programme for Research and Training in Tropical Diseases (TDR), to identify key research priorities through the review of research evidence and input from stakeholder consultations. TDR is a programme based at and executed by the World Health Organization (WHO), and co-sponsored by the United Nations Children’s Fund, the United Nations Development Programme, the World Bank, and the WHO. For more information on the TDR Think Tank and the resulting reports, please visit: http://www.who.int/tdr/stewardship/research-think-tank/en/.

Image Credit: Original image Grassi, B. Studi di uno zoologo sulla malaria (1901), featured courtesy of the Biodiversity Heritage Library. Permission to use the CCAL license granted by the Smithsonian Institution Libraries.

Mosquitoes are responsible for the transmission of a multitude of pathogens including malaria, dengue and West Nile virus. Modeling the transmission patterns of mosquito-borne pathogens can inform public policy in the efforts to eradicate these diseases. I had a quick Q&A with David Smith, Professor of Epidemiology at the Johns Hopkins Malaria Research Institute, about his recent review, published in PLoS Pathogens, that pulls together the first 70 years of mathematical modeling of malaria transmission by exploring the work of Ronald Ross and George Macdonald.

What was your motivation to start studying malaria epidemiology?

It was a slippery slope.  My academic interest was first sparked as a graduate student in mathematics. Malaria is a large, important problem with an interesting history.  The epidemiology is very complex.  It presents a durable intellectual challenge. I wanted to study it, but I resisted the urge because the complexity seemed overwhelming. I got pulled into it over the years by lots of people, but the most important ones were probably Ellis McKenzie, Simon Levin, and Ramanan Laxminarayan.

Sir Ronald Ross. Image Credit: NIH

When did you become aware of the Ross-Macdonald model of mosquito-borne pathogen transmission?

It was one of the first things I learned about malaria. I’m not sure I can recall the first time I heard of it — probably in a class in population biology at Brigham Young University, or possibly when I first arrived at Princeton and started learning about mathematical epidemiology.

What prompted you and your co-authors to write a historical review of this model?

Earlier this year, PLoS Medicine published the malERA series, including a paper describing a research agenda for mathematical modeling for malaria eradication. As we wrote the historical review for the MalERA publication it became clear that there were limitations to previous commentaries and reviews describing the development of the Ross-Macdonald model.

We wanted to do a comprehensive review of mathematical models of mosquito-transmitted pathogens, so we compiled a comprehensive bibliography.  The “Ross-Macdonald model” and its progeny now include approximately 600 peer-reviewed manuscripts and we had a hard time organizing the analysis. We recognized informally that many papers had influenced the Ross-Macdonald model, so we decided to devise a metric that we could use to measure similarity. That decision precipitated a need to define the Ross-Macdonald model in very rigorous terms, and it was then that we realized the “Ross-Macdonald” model was not any one thing. It is a “scientific theory” in the classical sense: a deliberately simplified set of concepts, abstractions, and quantities that conform to available data to explain a certain class of phenomena.

Do you think there is room to further build upon these theories?

I think so, but not by doing more of the same.  Mathematical epidemiologists need to spend more time trying to break their models and see how they stand up to serious scrutiny.  One of the things I think current models do very poorly is to consider the properties of transmission — how is the pathogen dispersed in space and time by mosquitoes and their human (or other vertebrate animal) hosts?  We have some clues that this is one of the things that the models get wrong, but this is one of the most neglected areas for mosquito-transmitted pathogen models.

What do you see as next direction for this area of epidemiology?

I’d like to see the models integrated and applied in vector-borne disease control programs — and I mean really used to design and evaluate intervention protocols — but there are a lot of intellectual problems yet to be solved.  How do you integrate all the information streams about mosquito-borne pathogen transmission and use that information to improve the efficiency of a control program?  It’s a formidable intellectual problem, but it’s an even bigger human problem.  The people and institutions that work to control malaria and dengue are as complex as the epidemiological and ecological problems it poses.  But the main message is that it is an urgent problem, especially in light of the evolution of antimalarial drug resistance, insecticide resistance, and the volatile funding environment.

What impresses me most, despite all of the complexity and failures, is that malaria has been in retreat for a century.  I think we can continue to make it retreat — I think that’s the task for scientists in my lifetime — how can we eliminate malaria from half the countries where it now exists?  As long as it keeps shrinking, the end of malaria is inevitable.

Read the review: Ross, Macdonald, and a Theory for the Dynamics and Control of Mosquito-Transmitted Pathogens.

More information on malERA – a research agenda for malaria eradication.

Image Credit: James Gathany, Centers for Disease Control and Prevention

Author: Renata Santillan

The current issue of PLoS Neglected Tropical Diseases presents a new collection of articles on the use of genetically modified (GM) insects for controlling some of the most widespread infectious diseases. Articles from across the PLoS journals describe the technological advances these tools represent, the regulatory framework, and the societal dialogue that is necessary for their wide-scale application for disease control.

Diseases transmitted by insects form a huge burden on human and animal populations. Insect control has historically been one of many strategies for control of diseases such as dengue, malaria, and sleeping sickness. The debate on whether GM insects could be used for disease control began as soon as transgenic insects were first produced in the 1980’s. Since then several experimental releases of GM insects have taken place. These trials show promise for limiting the spread of many vector-borne diseases (most notably Dengue fever). Articles in this collection showcase different aspects of this new technology including development, environmental impact, and regulation. Public discussion of the science and application of GM insects is necessary as new developments bring potential wide releases closer to a reality.

In an Editorial, Drs. Michael J Lehane (Liverpool School of Tropical Medicine) and Serap Aksoy (Yale School of Public Health) state that GM insects “may provide great promise for new means of controlling diseases with a devastating impact on people’s lives. If so, then public acceptance is likely to be a key issue in their implementation.” With many countries considering open field trials of GM insects, a Viewpoint by Guy Reeves et al. examines the regulation process of the first 3 countries that have had field trials of GM insects. Commentary by John Mumford highlights that both national and international regulations are required due to factors regarding each country’s individual environmental risk to GM insects.  In a commentary from an industry perspective, Luke Alphey and Camilla Beech argue that “the agencies tasked to regulate GM insects have appropriately taken a cautious, thorough approach that allows progress towards realisation of the substantial benefits GM insect technology could potentially provide, while rigorously protecting the public and environment.”

The articles in this collection highlight many different points of view surrounding the research into GM insects. As the recent history of GM insect development demonstrates, public discussion is necessary as scientists continue to research GM insect technologies to control some of the world’s most devastating diseases.

Image Credit: PEPFAR Male Circumcision Technical Working Group

On November 29, 2011, PLoS Medicine announced the publication of a sponsored collection, in conjunction with the Joint United Nations Programme on HIV/AIDS (UNAIDS) and the United States President’s Emergency Plan for AIDS Relief (PEPFAR) -  Voluntary Medical Male Circumcision for HIV Prevention: The Cost, Impact, and Challenges of Accelerated Scale-Up in Southern and Eastern Africa.

Today, December 19, 2011, a question-and-answer Twitter expert session [#VMMC@USAIDGH] will be held, from 1pm-2pm EST, with Emmanuel Njeuhmeli, Senior Biomedical Prevention Advisor of the Office of HIV/AIDS/USAID Washington, Co-Chair PEPFAR, Male Circumcision Technical Working Group, and an author on several of the articles in the Collection.

We encourage readers to tweet questions (with #VMMC@USAIDGH) about the new push for #VMMC for #endofaids and other topics about this collection.­

Disclaimer: The views expressed in the VMMC collection are those of the authors and do not necessarily reflect the official policy or position of the U.S. Government and UNAIDS. The collection was produced with support from the Joint United Nations Programme on HIV/AIDS (UNAIDS) and the United States President’s Emergency Plan for AIDS Relief (PEPFAR). The PLoS Medicine editors have sole editorial responsibility for the content of this collection.

View the Call for Papers and the MHTF-PLoS Collection page for all the details.

The continued need for attention and action to improve maternal health is indisputable.

Each year still close to 300,000 women unnecessarily die trying to give birth—a staggering number that ensures the Millennium Development Goal on maternal mortality will regrettably not be met. However, important progress has been made in some areas, and with new global pledges and a more reliable scientific understanding of what it takes to prevent deaths and disability among women and children worldwide, the time to accelerate progress to achieve maternal health goals is now.

The MHTF-PLoS Collection on Maternal Health welcomes primary research (both quantitative and qualitative) and incisive commentary related to quality of maternal health services broadly. Research articles should not be merely descriptions of activities but should include evaluation of the impact of initiatives after their implementation. Commentary articles on quality of maternal health care, targeted to the PLoS Medicine Essay or Policy Forum sections, must be novel and well-argued.

Articles will stand the best chance of inclusion in the 2011-2012 Collection if they are submitted by 1 April 2012.  More information is available at the Collection page: www.ploscollections.org/maternalhealth

The Collection comprises four reviews and five research articles, and highlights how scaling up voluntary medical male circumcision (VMMC) for HIV prevention in eastern and southern Africa can help prevent HIV, not only at the individual level but also at the community and population level, as well as leading to substantial cost savings for countries due to averted treatment and care costs. Two of the research articles are published in PLoS ONE; the remaining seven articles are published in PLoS Medicine on 29^th November 2011. They can be accessed from the PLoS Medicine VMMC Collection page; the table of contents is also included below.

The first article by Catherine Hankins of UNAIDS, Steven Forsythe of The Futures Institute, and Emmanuel Njeuhmeli of PEPFAR/USAID, offers an introduction to the cost, impact and challenges of accelerated scaling up and lays out the rationale for the Collection. The remaining eight papers focus on the various factors that have important roles in effective program expansion of VMMC, including data for decision making, policy and programmatic frameworks, logistics, demand creation, human resources, and translating research into services.

The potential cost savings of scale-up are clear. An initial investment of US$1.5 billion between 2011 and 2015 to achieve 80% coverage of VMMC services in 14 priority countries in southern and eastern Africa, and thereafter US$0.5 billion between 2016 and 2025 to maintain coverage of 80%, could result in net savings of US$16.5 billion between 2011 and 2025. However, as the articles in the Collection show, strong political leadership, country ownership, and stakeholder engagement, along with effective demand creation, community mobilization and human resource deployment, are essential for effectively expanding and maintaining VMMC programs.

All 9 articles were peer-reviewed, revised and considered in depth by the editorial team, and subjected to all the usual PLoS Medicine or PLoS ONE editorial processes. We would like to thank the numerous peer reviewers for their detailed critiques, which helped to shape the articles, and we would also like to thank the authors for their patience in making appropriate revisions to these reviews. In particular we would like to Stephanie Sansom, guest academic editor, who read all the articles and provided critical feedback and reviewer advice to the editorial team. A special thank you goes to Emmanuel Njeuhmeli of PEPFAR/USAID who served as the main editorial contact for the articles in this Collection.

A question-and-answer Twitter expert session [#VMMC@USAIDGH] will be held on December 19 2011, from 1pm-2pm EST, with Emmanuel Njeuhmeli, Senior Biomedical Prevention Advisor of the Office of HIV/AIDS/USAID Washington, Co-Chair PEPFAR, Male Circumcision Technical Working Group, and an author on several of the articles in the Collection. In regard to this Collection Dr. Njeuhmeli comments:

“The collaboration that led to the findings in the PLoS Collection is a true testament to what international partners can accomplish when they work together and do so effectively to support country strategy for HIV Prevention. I can say with confidence this collaboration has played a major role in moving the needle on VMMC and HIV prevention. This Collection represents extensive collaboration between Ministries of Health, WHO, UNAIDS, PEPFAR and implementing partners to document and share with policy makers and program implementers the estimated cost and potential impact of scaling up voluntary medical male circumcision (VMMC) services in southern and eastern Africa. The papers included in this Collection document the enormous potential of VMMC to alter the course of the epidemic. They also describe the way that country programs have successfully navigated human resource, demand generation and other challenges in an effort to rapidly scale up comprehensive VMMC services.”

Collection Table of Contents :

1)       Voluntary Medical Male Circumcision: An Introduction to the Cost, Impact, and Challenges of Accelerated Scaling Up

2)       Voluntary Medical Male Circumcision: Modeling the Impact and Cost of Expanding Male Circumcision for HIV Prevention in Eastern and Southern Africa

3)       Voluntary Medical Male Circumcision: A Framework Analysis of Policy and Program Implementation in Eastern and Southern Africa

4)       Voluntary Medical Male Circumcision: A Cross-Sectional Study Comparing Circumcision Self-Report and Physical Examination Findings in Lesotho

5)       Voluntary Medical Male Circumcision: Logistics, Commodities, and Waste Management Requirements for Scale-Up of Services

6)       Voluntary Medical Male Circumcision: A Qualitative Study Exploring the Challenges of Costing Demand Creation in Eastern and Southern Africa

7)       Voluntary Medical Male Circumcision: Strategies for Meeting the Human Resource Needs of Scale-Up in Southern and Eastern Africa

8)       Voluntary Medical Male Circumcision: Translating Research into the Rapid Expansion of Services in Kenya, 2008–2011

9)      Voluntary Medical Male Circumcision: Matching Demand and Supply with Quality and Efficiency in a High-Volume Campaign in Iringa Region, Tanzania

Disclaimer: The views expressed in the VMMC collection are those of the authors and do not necessarily reflect the official policy or position of the U.S. Government and UNAIDS. The collection was produced with support from the Joint United Nations Programme on HIV/AIDS (UNAIDS) and the United States President’s Emergency Plan for AIDS Relief (PEPFAR). The PLoS Medicine editors have sole editorial responsibility for the content of this collection.



Image Credit: PEPFAR Male Circumcision Technical Working Group

Permission to use the CCAL license granted by the PEPFAR Male Circumcision Technical Working Group.

Image Credit: yo|ko

In the introductory article Nicole A. Szlezák of Harvard University and colleagues analyze the changing relationships between “old actors” in global health (such as the World Health Organization and national health ministries) and new actors, such as public-private partnerships for health and new civil society organizations.

In the second article in the series, Julio Frenk offers a framework to better understand national health systems and their role in global health. (A video of a lecture given by Julio Frenk on globalization and health is available on the National Institutes of Health website).

Gerald Keusch and colleagues examine institutional arrangements for malaria research in the third article in the series. And in the fourth and final article Suerie Moon and colleagues propose future actions to strengthen global health  institutions.

Szlezak NA, Bloom BR, Jamison DT, Keusch GT, Michaud CM, et al. (2010) The Global Health System: Actors, Norms, and Expectations in Transition. PLoS Med 7(1): e1000183. doi:10.1371/journal.pmed.1000183

Frenk J (2010) The Global Health System: Strengthening National Health Systems as the Next Step for Global Progress. PLoS Med 7(1): e1000089. doi:10.1371/journal.pmed.1000089

Keusch GT, Kilama WL, Moon S, Szlezák NA, Michaud CM (2010) The Global Health System: Linking Knowledge with Action—Learning from Malaria. PLoS Med 7(1): e1000179. doi:10.1371/journal.pmed.1000179

Moon S, Szlezák NA, Michaud CM, Jamison DT, Keusch GT, et al. (2010) The Global Health System: Lessons for a Stronger Institutional Framework. PLoS Med 7(1): e1000193. doi:10.1371/journal.pmed.1000193

Between October 2009 and February 2010 PLoS Medicine published a seven part series exploring how best to treat mental, neurological and substance use disorders in low- and middle-income countries.

The full set of articles in the series are listed below:

Patel V, Thornicroft G Packages of Care for Mental, Neurological, and Substance Use Disorders in Low- and Middle-Income Countries: PLoS Medicine Series. PLoS Med 6(10): e1000160.

Patel V, Simon G, Chowdhary N, Kaaya S, Araya R (2009) Packages of Care for Depression in Low- and Middle-Income Countries. PLoS Med 6(10): e1000159.

Mbuba CK, Newton CR (2009) Packages of Care for Epilepsy in Low- and Middle-Income Countries.  PLoS Med 6(10): e1000162.

Mari JdJ, Razzouk D, Thara R, Eaton J, Thornicroft G (2009) Packages of Care for Schizophrenia in Low- and Middle-Income Countries. PLoS Med 6(10): e1000165.

Benegal V, Chand PK, Obot IS (2009) Packages of Care for Alcohol Use Disorders in Low- And Middle-Income Countries. PLoS Med 6(10): e1000170.

Prince MJ, Acosta D, Castro-Costa E, Jackson J, Shaji KS (2009) Packages of Care for Dementia in Low- and Middle-Income Countries. PLoS Med 6(11): e1000176.

Flisher AJ, Sorsdahl K, Hatherill S, Chehil S (2010) Packages of Care for Attention-Deficit Hyperactivity Disorder in Low- and Middle-Income Countries. PLoS Med 7(2): e1000235.