Control of malaria and other vector-borne protozoan diseases in the tropics: enduring challenges despite considerable progress and achievements

A comparative analysis of the profile and treatment outcomes of tuberculosis patients managed at the community and primary health care facilities in Botswana

Background

Successful treatment of Tuberculosis (TB) is necessary for mitigating and averting millions of deaths annually. This study compared the profiles and measured the association between patients, health system-related factors, and TB treatment outcomes of patients managed through the community tuberculosis care model with those managed in primary health care settings.

Methods

A retrospective multicenter cross-sectional study was conducted in six districts in Botswana. Patient's records were reviewed using a data extraction sheet, and data not captured on registers were obtained using a structured questionnaire.

Results

Three hundred and twenty-four TB patients were sampled. Most participants (84 %; n = 273) were receiving community-based DOT. Patients with moderate TB knowledge (OR 5.3,955 CI 1.01-27.7), good perception of TB care (OR 11, 95 % CI 1.29-94.0), were more likely to enroll for community DOT and achieve treatment cure. Those in businesses (OR 3.85 95 %CI 1.10-22.6), always had treatment available (OR 3.66, 95 % CI 1.12-11.4), never drank alcohol (OR 2.11, 95 %CI 1.06-4.19), used their vehicle (OR 2.11.95 %CI 0.99-4.48) were likely to enroll for community DOT.

Conclusion

A patient-specific education program and continuous improvement practices to increase patient TB knowledge and satisfaction should be implemented at all levels to improve treatment outcomes.

Naturally occurring phenylethanoids and phenylpropanoids: antimalarial potential

Malaria as an infectious disease is one of the world's most dangerous parasitic diseases. There is an urgent need for the development of new antimalarial drugs. Natural products are a very rich source of new bioactive compounds. Our research aims to shed light on the recent studies which demonstrated the antimalarial potential of phenylpropanoids as a major natural-products class. This study involves an in silico analysis of naturally-occurring phenylpropanoids and phenylethanoids which showed 25 compounds with moderate to strong binding affinity to various amino acid residues lining the active site; P. falciparum kinase (PfPK5), P. falciparum cytochrome bc1 complex (cyt bc1), and P. falciparum lysyl-tRNA synthetase (PfKRS1); of Plasmodium falciparum parasite, a unicellular protozoan which causes the most severe and life-threatening malaria. Furthermore, the study was augmented by the assessment of antiplasmodial activity of glandularin, a naturally occurring dibenzylbutyrolactolic lignan, against chloroquine-sensitive 3D7 strain of P. falciparum using SYBR green I-based fluorescence assay, which showed high antimalarial activity with IC50 value of 11.2 μM after 24 hours of incubation. Our results highlight phenylpropanoids and glandularin in particular as a promising chemical lead for development of antimalarial drugs.

Parasitological and histopathological studies to the effect of aqueous extract of Moringa oleifera Lam. leaves combined with praziquantel therapy in modulating the liver and spleen damage induced by Schistosoma mansoni to male mice

This study assessed the effectiveness of an aqueous extract of Moringa Oleifera Lam. leaves (MOL) alone or in combination with praziquantel (PZQ) drug targeting-infected mice with Schistosoma mansoni-induced liver and spleen damage. Mice were divided into eight groups control mice group treated orally with saline. PZQ group: non-infected mice treated orally with 300 mg/kg bwt PZQ three consecutive days. MOL group: non-infected mice treated orally with 150 mg/kg bwt MOL extract for 15 days. PZQ/ MOL group: non-infected mice treated orally with 300 mg/kg bwt PZQ for three consecutive days and 150 mg/kg bwt MOL extract for 15 days. IF group: infected mice with 100 cercariae/mouse of the Egyptian strain of S. mansoni. IF/PZQ group infected mice with S. mansoni cercariae and treated orally with 300 mg/kg bwt PZQ for three consecutive days. IF/MOL group: infected mice with S. mansoni cercariae treated orally with 150 mg/kg bwt MOL extract for 15 days. IF/PZQ +MOL group: infected mice with S. mansoni cercariae treated orally with 300 mg/kg bwt PZQ for three consecutive days and 150 mg/kg bwt MOL extract for 15 days. Blood, liver, spleen, worm, and eggs were collected at the end of the experimental period. Treatment of infected mice with MOL and PZQ together significantly reduced the number of ova/g tissue and eliminated the parasites. In addition, the liver and spleen of infected mice showed less histopathological alteration and immunohistochemical expression of nuclear factor kappa β (NF-Kβ). We can conclude that MOL extract combined with PZ has a curative effect on S. mansoni infection and helped to lessen its pathological effects.

Analysis of epidemiological changes and elimination effects for malaria in Handan city, the north China

The elimination of malaria requires high-quality surveillance data to quickly detect and respond to individual cases. This study aims to analyze the epidemiological characteristics of malaria and ascertain the long-term epidemic trends of malaria by 2020 in Handan China. Case-level data for the period 2011 to 2020 were extracted from Chinese Information System for Disease Control and Prevention. The lamp trap method was used to capture mosquitoes so that the characteristics of mosquitoes can be analyzed. The incidence, accuracy, and timeliness of malaria case diagnosis, reporting and investigation were evaluated at the elimination stage (2011-2020) in Handan City, China. Between 2011 and 2020, 94 malaria cases were reported in Handan City, of which 93 malaria cases were male and all of which were imported from abroad. The annual average incidence decreased from 622.33/100,000 to 0.11/100,000 in the elimination stage. Since the initiation of the National Malaria Elimination Program in 2010, malaria cases have been consistent with the increase in overseas export channels and labor personnel service. There is a need to strengthen malaria surveillance of returning workers from Africa and to conduct timely blood tests to diagnose and treat imported infections. Local authorities ensure that imported malaria cases can be timely diagnosed, reported, treated and investigated at local level.

The arrival of highly pathogenic avian influenza viruses H5N8 in Iran through two windows, 2016

The highly pathogenic avian influenza (HPAI) H5N1 virus has received considerable attention during the past 2 decades due to its zoonotic and mutative features. This Virus is of special importance due to to the possibility of causing infection in human populations. According to it's geographical location, Iran hosts a large number of aquatic migratory birds every year, and since these birds can be considered as the host of the H5 HPAI, the country is significantly at risk of this virus. the In this study, the molecular characteristics of hemagglutinin (HA) and neuraminidase (NA) genes of the H5N8 strain were identified in Malard county of Tehran province and Meighan wetland of Arak city, Markazi province were investigated. Based on the analysis of the amino acid sequence of the HA genes, the cleavage site of the gene includes the PLREKRRKR/GLF polybasic amino acid motif, which is a characteristic of highly pathogenic influenza viruses. The HA gene of two viruses had T156A, S123P, S133A mutations associated with the increased mammalian sialic acid-binding, and the NA gene of two viruses had H253Y mutations associated with the resistance to antiviral drugs. Phylogenetic analysis of the HA genes indicated the classification of these viruses in the 2.3.4.4 b subclade. Although the A/Goose/Iran/180/2016 virus was also an H5N8 2.3.4.4 b virus, its cluster was separated from the A/Chicken/Iran/162/2016 virus. This means that the entry of these viruses in to the country happened through more than one window. Furthermore, it seems that the introduction of these H5N8 HPAI strains in Iran probably occurred through the West Asia-East African flyway by wild migratory aquatic birds.

Family APGAR and treatment outcomes among HIV patients at two ART Centres in Kumasi, Ghana

OBJECTIVES

This study aimed to examine the association between Family Adaptability, Partnership, Growth, Affection and Resolve (Family APGAR) and HIV treatment outcomes.

DESIGN

A cross-sectional study using the Family APGAR questionnaire.

SETTING

The study was conducted in Kumasi, Ghana, at the Komfo Anokye Teaching Hospital and the Kwame Nkrumah University of Science and Technology Hospital.

PARTICIPANTS

Consenting HIV-positive patients who had been on treatment for at least 12 months were recruited.

MAIN OUTCOME MEASURES

The Family APGAR questionnaire was administered, and relevant data were extracted from hospital records and analysed using STATA® software. The relationship between Family APGAR and treatment outcomes was determined using Chi-squared tests or Fisher's exact test.

RESULTS

Approximately 70.1% of 304 participants were females with a mean age of 41.8 years (±9.9). At treatment initiation, 47.4% of the patients presented at World Health Organisation (WHO) clinical stages I and II and had a CD4 count ≥ 200 cells/mm3. Females were less likely (Odds Ratio= 0.52; 95% CI=0.31 - 0.90, p = 0.018) to report late for treatment compared with the males. After 12 months of treatment, approximately 70% recorded undetectable viral load. Patients with functional families constituted 70.4%, which had a statistically significant relationship with viral load (p = 0.041).

CONCLUSION

HIV care providers should incorporate family functionality evaluation into clinical practice and provide early essential support to enhance treatment outcomes.

FUNDING

None declared.

Determining suitable machine learning classifier technique for prediction of malaria incidents attributed to climate of Odisha

This study investigated the influence of climate factors on malaria incidence in the Sundargarh district, Odisha, India. The WEKA machine learning tool was used with two classifier techniques, Multi-Layer Perceptron (MLP) and J48, with three test options, 10-fold cross-validation, percentile split, and supplied test. A comparative analysis was carried out to ascertain the superior model among malaria prediction accuracy techniques in varying climate contexts. The results suggested that J48 had exhibited better skill than MLP with the 10-fold cross-validation method over the percentile split and supplied test options. J48 demonstrated less error (RMSE = 0.6), better kappa = 0.63, and higher accuracy = 0.71), suggesting it as most suitable model. Seasonal variation of temperature and humidity had a better association with malaria incidents than rainfall, and the performance was better during the monsoon and post-monsoon when the incidents are at the peak.

Role of health extension workers in the relationship between vector control interventions and malaria in Ethiopia

BACKGROUND

Despite a tremendous decline in the burden of malaria through public health interventions, it is yet remains a critical parasitic health problem in Ethiopia. Insecticide-treated nets and indoor residual spray are considered as the most effective preventive interventions against malaria. This study intended to determine the role of health extension workers in influencing the relationship between vector control strategies and malaria prevalence in Ethiopia.

METHODS

The study adopted a descriptive study based on panel data collected from 10 regions of Ethiopia from 2010 to 2018. The data collected were analyzed using STATA version 13.0. Structural equation modelling was used to assess the mediating effect of health extension workers in the relationship. Further, the random effect model was employed to investigate the direct relationship among the study variables.

RESULTS

We observed a strong mediating role of health extension workers to the relationship between strategic interventions and malaria prevalence, where the direct path is (β = 0.64, p < 0.05), and the indirect path (β = 0.72, p < 0.001) and (β = 0.98, p < 0.001) confirming the mediation condition to appear. Our analysis revealed that, insecticide-treated nets and indoor residual spray significantly impacts the malaria prevalence (β = 0.20, p < 0.05) and (β = 0.70, p < 0.001) respectively. Further, our analysis suggests that the cumulative effect of indoor residual spray and insecticide-treated mosquito nets have helped better avert malaria prevalence (β = 81.3%, P < 0.05). Moreover, the finding demonstrates the incremental rate of 30.2%, which is the indirect effect of the research [(β = 0.813) - (β1 = 0.511)].

CONCLUSION

The findings are potentially useful for the health sector in charge of infectious disease prevention and control, particularly in developing countries explaining how these group provided support to reduce malaria ensuring the provision of proper health message about the program.

Addressing tuberculosis through complex community-based socioeconomic interventions in low- and middle-income countries: A systematic realist review

The established relationship between poverty and tuberculosis has led to the implementation of complex socioeconomic interventions to address poverty as both a risk factor for and consequence of tuberculosis. However, limited research to date has examined the conditions that facilitate the successful implementation of these interventions. We conducted a systematic realist review to examine how complex socioeconomic interventions for tuberculosis treatment and care were defined, implemented, and evaluated in low- and middle-income countries. We used a systematic search to identify published work that implemented complex socioeconomic interventions for tuberculosis, followed by a realist analysis informed by existing programme theories. From a total of 2825 collected records, 36 peer-reviewed articles and 17 grey literature reports were included in this review. The realist analysis identified three main contexts (sociopolitical and cultural; relational and interpersonal; operational and administrative) and ten mechanisms that facilitated successful implementation of interventions. Overall, this review highlights the importance of political commitment in shaping sustainable programme delivery, the role of healthcare and community-based provider training in creating patient-centred treatment environments, and the opportunity to leverage operational research for evidence-based decision making to address the socioeconomic needs of tuberculosis patients experiencing poverty.

Synthesis of 2-(N-cyclicamino)quinoline combined with methyl (E)-3-(2/3/4-aminophenyl)acrylates as potential antiparasitic agents

A rationally designed series of 2-(N-cyclicamino)quinolines coupled with methyl (E)-3-(2/3/4-aminophenyl)acrylates was synthesized and subjected to in vitro screening bioassays for potential antiplasmodial and antitrypanosomal activities against a chloroquine-sensitive (3D7) strain of Plasmodium falciparum and nagana Trypanosoma brucei brucei 427, respectively. Substituent effects on activity were evaluated; meta-acrylate 24 and the ortho-acrylate 29 exhibited the highest antiplasmodial (IC₅₀  = 1.4 µM) and antitrypanosomal (IC₅₀  = 10.4 µM) activities, respectively. The activity against HeLa cells showed that the synthesized analogs are not cytotoxic at the maximum tested concentration. The ADME (absorption, distribution, metabolism, and excretion) drug-like properties of the synthesized compounds were predicted through the SwissADME software.

Taking a re-look at cap-binding signatures of the mRNA cap-binding protein eIF4E orthologues in trypanosomatids

Protein translation leading to polypeptide synthesis involves three distinct events, namely, initiation, elongation, and termination. Translation initiation is a multi-step process that is carried out by ribosomes on the mRNA with the assistance of a large number of proteins called translation initiation factors. Trypanosomatids are kinetoplastidas (flagellated protozoans), some of which cause acute disease syndromes in humans. Vector-borne transmission of protozoan parasites like Leishmania and Trypanosoma causes diseases that affect a large section of the world population and lead to significant morbidity and mortality. The mechanisms of translation initiation in higher eukaryotes are relatively well understood. However, structural and functional conservation of initiation factors in trypanosomatids are only beginning to be understood. Studies carried out so far suggests that at least in Leishmania and Trypanosoma eIF4E function may not be restricted to canonical translation initiation and some of the homologues may have alternate/non-canonical functions. Nonetheless, all of them bind the cap analogs, albeit with different efficiencies, indicating that this property may play an important role in the functionality of eIF4Es. Here, I give a brief background of trypanosomatid eIF4Es and revisit the cap-binding signatures of eIF4E orthologues in trypanosomatids, whose genome sequences are available, in detail, in comparison to human eIF4E1 and Trypanosoma cruzi eIF4E5, with an expanded list of members of this group in light of newer findings. The group 1 and 2 eIF4Es may use either a variation of heIF4E1 or T. cruzi eIF4E5 cap-4-binding signatures, while eIF4E5 and eIF4E6 use distinct amino acid contacts.

Alsinol, an arylamino alcohol derivative active against Plasmodium, Babesia, Trypanosoma, and Leishmania: past and new outcomes

Malaria, babesiosis, trypanosomosis, and leishmaniasis are some of the most life-threatening parasites, but the range of drugs to treat them is limited. An effective, safe, and low-cost drug with a large activity spectrum is urgently needed. For this purpose, an aryl amino alcohol derivative called Alsinol was resynthesized, screened in silico, and tested against Plasmodium, Babesia, Trypanosoma, and Leishmania. In silico Alsinol follows the Lipinski and Ghose rules. In vitro it had schizontocidal activity against Plasmodium falciparum and was able to inhibit gametocytogenesis; it was particularly active against late gametocytes. In malaria-infected mice, it showed a dose-dependent activity similar to chloroquine. It demonstrated a similar level of activity to reference compounds against Babesia divergens, and against promastigotes, and amastigotes stages of Leishmania in vitro. It inhibited the in vitro growth of two African animal strains of Trypanosoma but was ineffective in vivo in our experimental conditions. It showed moderate toxicity in J774A1 and Vero cell models. The study demonstrated that Alsinol has a large spectrum of activity and is potentially affordable to produce. Nevertheless, challenges remain in the process of scaling up synthesis, creating a suitable clinical formulation, and determining the safety margin in preclinical models.

Preparedness for Chagas disease spreading worldwide

Chagas disease remains a serious problem for public health due to the high disease burden together with its global spreading patterns. However, current treatment and vector control are highly challenged by drug and insecticide resistance. Chemotherapy and vector control have been proved to be effective attempts to minimize the disease burden. Continued efforts are necessary to keep adapting the surveillance-response systems to the dynamic health systems. More attention and investments are needed to improve appropriate strategy and technology in different settings. This may be accomplished by creating effective risk early warning, addressing vulnerability and building resilience systems, implementing a vector surveillance system, as well as innovating research and technology.

Humanized Mice Are Instrumental to the Study of Plasmodium falciparum Infection

Research using humanized mice has advanced our knowledge and understanding of human haematopoiesis, non-adaptive and adaptive immunity, autoimmunity, infectious disease, cancer biology, and regenerative medicine. Challenges posed by the human-malaria parasite Plasmodium falciparum include its complex life cycle, the evolution of drug resistance against anti-malarials, poor diagnosis, and a lack of effective vaccines. Advancements in genetically engineered and immunodeficient mouse strains, have allowed for studies of the asexual blood stage, exoerythrocytic stage and the transition from liver-to-blood stage infection, in a single vertebrate host. This review discusses the process of "humanization" of various immunodeficient/transgenic strains and their contribution to translational biomedical research. Our work reviews the strategies employed to overcome the remaining-limitations of the developed human-mouse chimera(s).

Everybody needs sphingolipids, right! Mining for new drug targets in protozoan sphingolipid biosynthesis

Sphingolipids (SLs) are an integral part of all eukaryotic cellular membranes. In addition, they have indispensable functions as signalling molecules controlling a myriad of cellular events. Disruption of either the de novo synthesis or the degradation pathways has been shown to have detrimental effects. The earlier identification of selective inhibitors of fungal SL biosynthesis promised potent broad-spectrum anti-fungal agents, which later encouraged testing some of those agents against protozoan parasites. In this review we focus on the key enzymes of the SL de novo biosynthetic pathway in protozoan parasites of the Apicomplexa and Kinetoplastidae, outlining the divergence and interconnection between host and pathogen metabolism. The druggability of the SL biosynthesis is considered, alongside recent technology advances that will enable the dissection and analyses of this pathway in the parasitic protozoa. The future impact of these advances for the development of new therapeutics for both globally threatening and neglected infectious diseases is potentially profound.

Protocol and baseline data for a multi-year cohort study of the effects of different mass drug treatment approaches on functional morbidities from schistosomiasis in four African countries

BACKGROUND

The Schistosomiasis Consortium for Operational Research and Evaluation (SCORE) focus is on randomized trials of different approaches to mass drug administration (MDA) in endemic countries in Africa. Because their studies provided an opportunity to evaluate the effects of mass treatment on Schistosoma-associated morbidity, nested cohort studies were developed within SCORE's intervention trials to monitor changes in a suite of schistosomiasis disease outcomes. This paper describes the process SCORE used to select markers for prospective monitoring and the baseline prevalence of these morbidities in four parallel cohort studies.

METHODS

In July 2009, SCORE hosted a discussion of the potential impact of MDA on morbidities due to Schistosoma infection that might be measured in the context of multi-year control. Candidate markers were reviewed and selected for study implementation. Baseline data were then collected from cohorts of children in four country studies: two in high endemic S. mansoni sites (Kenya and Tanzania), and two in high endemic S. haematobium sites (Niger and Mozambique), these cohorts to be followed prospectively over 5 years.

RESULTS

At baseline, 62% of children in the S. mansoni sites had detectable eggs in their stool, and 10% had heavy infections (≥ 400 eggs/g feces). Heavy S. mansoni infections were found to be associated with increased baseline risk of anemia, although children with moderate or heavy intensity infections had lower risk of physical wasting. Prevalence of egg-positive infection in the combined S. haematobium cohorts was 27%, with 5% of individuals having heavy infection (≥50 eggs/10 mL urine). At baseline, light intensity S. haematobium infection was associated with anemia and with lower scores in the social domain of health-related quality-of-life (HRQoL) assessed by Pediatric Quality of Life Inventory.

CONCLUSIONS

Our consensus on practical markers of Schistosoma-associated morbidity indicated that height, weight, hemoglobin, exercise tolerance, HRQoL, and ultrasound abnormalities could be used as reference points for gauging treatment impact. Data collected over five years of program implementation will provide guidance for future evaluation of morbidity control in areas endemic for schistosomiasis.

TRIAL REGISTRATION

These cohort studies are registered and performed in conjunction with the International Standard Randomised Controlled Trial Registry trials ISRCTN16755535 , ISRCTN14117624 , ISRCTN95819193 , and ISRCTN32045736 .

Ethical, legal and societal considerations on Zika virus epidemics complications in scaling-up prevention and control strategies

Much of the fear and uncertainty around Zika epidemics stem from potential association between Zika virus (ZIKV) complications on infected pregnant women and risk of their babies being born with microcephaly and other neurological abnormalities. However, much remains unknown about its mode of transmission, diagnosis and long-term pathogenesis. Worries of these unknowns necessitate the need for effective and efficient psychosocial programs and medical-legal strategies to alleviate and mitigate ZIKV related burdens. In this light, local and global efforts in maintaining fundamental health principles of moral, medical and legal decision-making policies, and interventions to preserve and promote individual and collectiveHuman Rights, autonomy, protection of the most vulnerable, equity, dignity, integrity and beneficence that should not be confused and relegated by compassionate humanitarian assistance and support. This paper explores the potential medical and ethical-legal implications of ZIKV epidemics emergency response packages and strategies alongside optimizing reproductive and mental health policies, programs and best practice measures. Further long-term cross-borders operational research is required in elucidating Zika-related population-based epidemiology, ethical-medical and societal implications in guiding evidence-based local and global ZIKV maternal-child health complications related approaches and interventions. Core programs and interventions including future Zika safe and effective vaccines for global Zika immunization program in most vulnerable and affected countries and worldwide should be prioritized.

Risk assessment of malaria transmission at the border area of China and Myanmar

Background

In order to achieve the goal of malaria elimination, the Chinese government launched the National Malaria Elimination Programme in 2010. However, as a result of increasing cross-border population movements, the risk of imported malaria cases still exists at the border areas of China, resulting in a potential threat of local transmission. The focus of this paper is to assess the Plasmodium vivax incidences in Tengchong, Yunnan Province, at the border areas of China and Myanmar.

Methods

Time series of P. vivax incidences in Tengchong from 2006 to 2010 are collected from the web-based China Information System for Disease Control and Prevention, which are further separated into time series of imported and local cases. First, the seasonal and trend decomposition are performed on time series of imported cases using Loess method. Then, the impact of climatic factors on the local transmission of P. vivax is assessed using both linear regression models (LRM) and generalized additive models (GAM). Specifically, the notion of vectorial capacity (VCAP) is used to estimate the transmission potential of P. vivax at different locations, which is calculated based on temperature and rainfall collected from China Meteorological Administration.

Results

Comparing with Ruili County, the seasonal pattern of imported cases in Tengchong is different: Tengchong has only one peak, while Ruili has two peaks during each year. This may be due to the different cross-border behaviors of peoples in two locations. The vectorial capacity together with the imported cases and the average humidity, can well explain the local incidences of P. vivax through both LRM and GAM methods. Moreover, the maximum daily temperature is verified to be more suitable to calculate VCAP than the minimal and average temperature in Tengchong County.

Conclusion

To achieve malaria elimination in China, the assessment results in this paper will provide further guidance in active surveillance and control of malaria at the border areas of China and Myanmar.

Electronic supplementary material

The online version of this article (doi:10.1186/s40249-017-0322-2) contains supplementary material, which is available to authorized users.

Infectious Diseases of Poverty, the first five years

Although the focus in the area of health research may be shifting from infectious to non-communicable diseases, the infectious diseases of poverty remain a major burden of disease of global health concern. A global platform to communicate and share the research on these diseases is needed to facilitate the translation of knowledge into effective approaches and tools for their elimination. Based on the “One health, One world” mission, a new, open-access journal, Infectious Diseases of Poverty (IDP), was launched by BioMed Central in partnership with the National Institute of Parasitic Diseases (NIPD), Chinese Center for Disease Control and Prevention (China CDC) on October 25, 2012. Its aim is to identify and assess research and information gaps that hinder progress towards new interventions for a particular public health problem in the developing world. From the inaugural IDP issue of October 25, 2012, a total of 256 manuscripts have been published over the following five years. Apart from a small number of editorials, opinions, commentaries and letters to the editor, the predominant types of publications are research articles (69.5%) and scoping reviews (21.5%). A total of 1 081 contributing authors divided between 323 affiliations across 68 countries, territories and regions produced these 256 publications. The journal is indexed in major international biomedical databases, including Web of Science, PubMed, Scopus and Embase. In 2015, it was assigned its first impact factor (4.11), which is now 2.13. During the past five years, IDP has received manuscripts from 90 countries, territories and regions across six continents with an annual acceptance rate of all contributions maintained at less than 40%. Content analysis shows that neglected tropical diseases (NTDs), followed by the “Big Three” (HIV/AIDS, malaria and tuberculosis) and infectious diseases in general comprise 88% of all publications. In addition, a series of 10 thematic issues, covering 118 publications in all, was published as separate parts of the first five volumes. These publications were cited 975 times, which equals an average of 8.3 times per publication. The current challenge is to identify cutting-edge research topics and attract and to publish first-rate publications leading to increasing importance and impact of the journal in its field.

Efficacy of praziquantel on Schistosoma haematobium and re-infection rates among school-going children in the Ndumo area of uMkhanyakude district, KwaZulu-Natal, South Africa

BACKGROUND

Despite its low cure rates and possible resistance, praziquantel (PZQ) is the only drug available for schistosomiasis treatment. Hence, monitoring its efficacy is crucial. This study assessed the efficacy of PZQ, determined re-infection and incidence rates of Schistosoma haematobium infection among school-going children in the Ndumo area, KwaZulu-Natal.

METHODS

A cohort of 320 school-going children (10 - 15 years) in 10 primary schools was screened for S. haematobium infection using the filtration technique. Infected children were treated at different times and hence were divided into two sub-cohorts; A1 and A2. Non-infected children constituted the sub-cohort B. Children who continued excreting viable eggs 4 weeks post-treatment received a second dose of PZQ. Re-infection rates were determined in sub-cohort A1 and A2 at 28 and 20 weeks post-treatment, respectively. Cure rates (CR) and egg reduction rates (ERR) were calculated. Incidence rate was assessed 28 weeks post baseline survey using children that were negative for schistosome eggs at that survey. Analysis of data was done using the Chi square and the Wilcoxon rank test. A 95% confidence interval with a P-value < 0.05 determined significance.

RESULTS

At baseline, 120 (37.5%) of the 320 study participants were found infected with Schistosoma haematobium. Heavy infections accounted for 36.7%. The calculated cure rates were 88.07% and 82.92% for females and males, respectively. Egg Reduction Rates of 80% and 64% for females and males were observed 4 weeks after the initial treatment. After the second treatment, CR was 100% in females and 50% in males with an ERR of 100% in females and 70% in males. At 20 and 28 weeks post treatment, reinfection rates of 8.03% and 8.00% were observed, respectively, giving an overall rate of 8.1%. An incidence rate of 4.1% was observed 28 weeks after the baseline screening.

CONCLUSIONS

The study indicated high CR while the ERR was low suggesting a reduced PZQ efficacy. The efficacy improved among females after the second dose. Re-infection rates at 20 and 28 weeks post-treatment were low. The study also indicated a low incidence rate for the 28 weeks period.

Hidden reservoir of resistant parasites: the missing link in the elimination of falciparum malaria

Background

To successfully eliminate malaria, an integrated system that includes a number of approaches and interventions—aimed at overcoming the threat of antimalarial drug resistance—is required. Significant progress has been made in reducing malaria incidence through large-scale use of artemisinin-based combination therapies and insecticide-treated nets. To consolidate these gains, attention should be paid to the missing links in the elimination of malaria. One of these gaps is the residual reservoir of submicroscopic resistant parasites, which remains after case management or other control measures have been carried out. Therefore, the present opinion piece highlights the importance of exploring the role that submicroscopic resistant parasites could play in hindering malaria elimination by allowing the persistence of transmission, particularly in areas of low transmission or in the pre-elimination and/or elimination phase.

Discussion

If malaria elimination interventions are to be effective, the relative role of the hidden reservoir of resistant parasites needs to be assessed, particularly in regions that are low-transmission settings and/or in pre-elimination and/or elimination phases. Various ongoing studies are focusing on the role of submicroscopic malaria infections in malaria transmission but overlook the possible build-up of resistance to antimalarial drugs among submicroscopic parasite populations. This is an important factor as it may eventually limit the effectiveness of malaria elimination strategies.

Conclusions

An evidence-based estimation of the “true” reservoir of resistant parasites can help target the existing and emerging foci of resistant parasites before they spread. Emergence and spread of artemisinin-resistant Plasmodium falciparum malaria in Southeast Asia underline the need to contain drug resistance.

Electronic supplementary material

The online version of this article (doi:10.1186/s40249-016-0227-5) contains supplementary material, which is available to authorized users.

Tuberculosis patients' pre-hospital delay and non-compliance with a longstanding DOT programme: a mixed methods study in urban Zambia

Background

Tuberculosis (TB) remains a major health problem in Zambia, despite considerable efforts to control and prevent it. With this study, we aim to understand how perceptions and cultural, social, economic, and organisational factors influence TB patients’ pre-hospital delay and non-compliance with care provided by the National Tuberculosis Programme (NTP).

Methods

A mixed methods study was conducted with 300 TB patients recruited at Kanyama clinic for structured interviews. Thirty were followed-up for multiple in-depth interviews. Six focus group discussions were organised and participant observation was conducted. Ten biomedical care providers, 10 traditional healers, and 10 faith healers were interviewed. Factors associated with non-compliance (disruption of treatment > one week) were assessed by applying logistic regression analyses; qualitative analysis was used to additionally assess factors influencing pre-hospital delay and for triangulation of study findings.

Results

TB treatment non-compliance was low (10 %), no association of outcome with cultural or socio-economic factors was found. Only patients’ time constraints and long distance to the clinic indicated a possible association with a higher risk of non-compliance (OR 0.52; 95 % CI 0.25, 1.10, p = 0.086). Qualitative data showed that most TB patients combined understandings of biomedical and traditional TB knowledge, used herbal, traditional and/or faith healing, suffered from stigmatizing attitudes, experienced poverty and food shortages, and faced several organisational obstacles while being on treatment. This led in some cases to pre-hospital delay or treatment non-compliance.

Conclusions

Mixed methods analysis demonstrated the importance of in-depth information ascertained by qualitative approaches to understand how cultural, socio-economic and organisational factors are influencing patients’ pre-hospital delay and treatment compliance. To strengthen the Zambian NTP, combating stigma is of utmost priority coupled with programmes addressing poverty. Organisational barriers and co-operation between (private) clinics and traditional/faith healers should be considered.

Electronic supplementary material

The online version of this article (doi:10.1186/s12889-016-3771-9) contains supplementary material, which is available to authorized users.

Dynamic denominators: the impact of seasonally varying population numbers on disease incidence estimates

BACKGROUND

Reliable health metrics are crucial for accurately assessing disease burden and planning interventions. Many health indicators are measured through passive surveillance systems and are reliant on accurate estimates of denominators to transform case counts into incidence measures. These denominator estimates generally come from national censuses and use large area growth rates to estimate annual changes. Typically, they do not account for any seasonal fluctuations and thus assume a static denominator population. Many recent studies have highlighted the dynamic nature of human populations through quantitative analyses of mobile phone call data records and a range of other sources, emphasizing seasonal changes. In this study, we use mobile phone data to capture patterns of short-term human population movement and to map dynamism in population densities.

METHODS

We show how mobile phone data can be used to measure seasonal changes in health district population numbers, which are used as denominators for calculating district-level disease incidence. Using the example of malaria case reporting in Namibia we use 3.5 years of phone data to investigate the spatial and temporal effects of fluctuations in denominators caused by seasonal mobility on malaria incidence estimates.

RESULTS

We show that even in a sparsely populated country with large distances between population centers, such as Namibia, populations are highly dynamic throughout the year. We highlight how seasonal mobility affects malaria incidence estimates, leading to differences of up to 30 % compared to estimates created using static population maps. These differences exhibit clear spatial patterns, with likely overestimation of incidence in the high-prevalence zones in the north of Namibia and underestimation in lower-risk areas when compared to using static populations.

CONCLUSION

The results here highlight how health metrics that rely on static estimates of denominators from censuses may differ substantially once mobility and seasonal variations are taken into account. With respect to the setting of malaria in Namibia, the results indicate that Namibia may actually be closer to malaria elimination than previously thought. More broadly, the results highlight how dynamic populations are. In addition to affecting incidence estimates, these changes in population density will also have an impact on allocation of medical resources. Awareness of seasonal movements has the potential to improve the impact of interventions, such as vaccination campaigns or distributions of commodities like bed nets.

Natural Mosquito-Pathogen Hybrid IgG4 Antibodies in Vector-Borne Diseases: A Hypothesis

Chronic exposure to antigens may favor the production of IgG4 antibodies over other antibody types. Recent studies have shown that up to a 30% of normal human IgG4 is bi-specific and is able to recognize two antigens of different nature. A requirement for this specificity is the presence of both eliciting antigens in the same time and at the same place where the immune response is induced. During transmission of most vector-borne diseases, the pathogen is delivered to the vertebrate host along with the arthropod saliva during blood feeding and previous studies have shown the existence of IgG4 antibodies against mosquito salivary allergens. However, there is very little ongoing research or information available regarding IgG4 bi-specificity with regard to infectious disease, particularly during immune responses to vector-borne diseases, such as malaria, filariasis, or dengue virus infection. Here, we provide background information and present our hypothesis that IgG4 may not only be a useful tool to measure exposure to infected mosquito bites, but that these bi-specific antibodies may also play an important role in modulation of the immune response against malaria and other vector-borne diseases in endemic settings.

Major parasitic diseases of poverty in mainland China: perspectives for better control

Significant progress has been made in the prevention, control, and elimination of human parasitic diseases in China in the past 60 years. However, parasitic diseases of poverty remain major causes of morbidity and mortality, and inflict enormous economic costs on societies.In this article, we review the prevalence rates, geographical distributions, epidemic characteristics, risk factors, and clinical manifestations of parasitic diseases of poverty listed in the first issue of the journal Infectious Diseases of Poverty on 25 October 2012. We also address the challenges facing control of parasitic diseases of poverty and provide suggestions for better control.

Comparative evaluation of the diagnosis, reporting and investigation of malaria cases in China, 2005-2014: transition from control to elimination for the national malaria programme

Background

The elimination of malaria requires high-quality surveillance data to enable rapid detection and response to individual cases. Evaluation of the performance of a national malaria surveillance system could identify shortcomings which, if addressed, will improve the surveillance program for malaria elimination.

Methods

Case-level data for the period 2005–2014 were extracted from the China National Notifiable Infectious Disease Reporting Information System and Malaria Enhanced Surveillance Information System. The occurrence of cases, accuracy and timeliness of case diagnosis, reporting and investigation, were assessed and compared between the malaria control stage (2005–2010) and elimination stage (2011–2014) in mainland China.

Results

A total of 210 730 malaria cases were reported in mainland China in 2005–2014. The average annual incidence declined dramatically from 2.5 per 100 000 people at the control stage to 0.2 per 100 000 at the elimination stage, but the proportion of migrant cases increased from 9.8 % to 41.0 %. Since the initiation of the National Malaria Elimination Programme in 2010, the overall proportion of cases diagnosed by laboratory testing consistently improved, with the highest of 99.0 % in 2014. However, this proportion was significantly lower in non-endemic provinces (79.0 %) than that in endemic provinces (91.4 %) during 2011–2014. The median interval from illness onset to diagnosis was 3 days at the elimination stage, with one day earlier than that at the control stage. Since 2011, more than 99 % cases were reported within 1 day after being diagnosed, while the proportion of cases that were reported within one day after diagnosis was lowest in Tibet (37.5 %). The predominant source of cases reporting shifted from town-level hospitals at the control stage (67.9 % cases) to city-level hospitals and public health institutes at the eliminate stage (69.4 % cases). The proportion of investigation within 3 days after case reporting has improved, from 74.6 % in 2010 to 98.5 % in 2014.

Conclusions

The individual case-based malaria surveillance system in China operated well during the malaria elimination stage. This ensured that malaria cases could be diagnosed, reported and timely investigated at local level. However, domestic migrants and overseas populations, as well as cases in the historically malarial non-endemic areas and hard-to-reach area are new challenges in the surveillance for malaria elimination.

Electronic supplementary material

The online version of this article (doi:10.1186/s40249-016-0163-4) contains supplementary material, which is available to authorized users.

Occupational Hazards in the Thai Healthcare Sector

Healthcare personnel work in vulnerable conditions that can adversely impact physical and/or mental health. This paper aims to synthesize the state of knowledge on work-related illnesses, injuries, and risks experienced by Thai healthcare workers. We found that Thai healthcare personnel, like others worldwide, are at risk for injury related to needle sticks and sharp instruments; infectious diseases due to biological hazards exposure such as airborne pathogens and patient secretions; muscle pain due to workload and long duration of work; and psychological disorders related to stressful working conditions. Because detailed surveillance data are limited for the Thai healthcare workforce, we recommend that additional surveillance data on Thai healthcare workers' health outcomes be collected. Future research efforts should also focus on evidence-based interventions in order to develop methods to prevent and treat occupational health injuries and illnesses acquired in the workplace for Thai healthcare sector workers.

Prevalence and hematological indicators of G6PD deficiency in malaria-infected patients

BACKGROUND

This study aimed to evaluate the prevalence and alteration of hematological parameters in malaria patients with a glucose-6-phosphate dehydrogenase (G6PD) deficiency, in the western region of Thailand, an endemic region for malaria.

METHODS

Data about patients with malaria hospitalized between 2013 and 2015 were collected. Clinical and sociodemographic characteristics such as age and gender, diagnosis on admission, and parasitological results were mined from medical records of the laboratory unit of the Phop Phra Hospital in Tak Province, Thailand. Venous blood samples were collected at the time of admission to hospital to determine G6PD deficiency by fluorescence spot test and detect malaria parasites by thick and thin film examination. Other data such as complete blood count and parasite density were also collected and analyzed.

RESULTS

Among the 245 malaria cases, 28 (11.4 %) were diagnosed as Plasmodium falciparum infections and 217 cases (88.6 %) were diagnosed as P. vivax infections. Seventeen (6.9 %) patients had a G6PD deficiency and 228 (93.1 %) patients did not have a G6PD deficiency. Prevalence of male patients with G6PD deficiency was higher than that of female patients (P < 0.05, OR = 5.167). Among the patients with a G6PD deficiency, two (11.8 %) were infected with P. falciparum, while the remaining were infected with P. vivax. Malaria patients with a G6PD deficiency have higher monocyte counts (0.6 × 10(3)/μL) than those without a G6PD deficiency (0.33 × 10(3)/μL) (P < 0.05, OR = 5.167). Univariate and multivariate analyses also confirmed that malaria patients with a G6PD deficiency have high monocyte counts. The association between G6PD status and monocyte counts was independent of age, gender, nationality, Plasmodium species, and parasite density (P < 0.005).

CONCLUSION

This study showed a prevalence of G6PD deficiency in a malaria-endemic area. This study also supported the assertion that patients with G6PD-deficient red blood cells had no protection against the P. falciparum infection. In addition, malaria patients with a G6PD deficiency had higher monocyte counts than those without a G6PD deficiency. These findings will help to recognize and diagnose malaria patients with a G6PD deficiency, as well as to identify the risks and protective factors against malaria in endemic areas.

China's 1-3-7 surveillance and response strategy for malaria elimination: Is case reporting, investigation and foci response happening according to plan?

Background

The China’s 1-3-7 strategy was initiated and extensively adopted in different types of counties (geographic regions) for reporting of malaria cases within 1 day, their confirmation and investigation within 3 days, and the appropriate public health response to prevent further transmission within 7 days. Assessing the level of compliance to the 1-3-7 strategy at the county level is a first step towards determining whether the surveillance and response strategy is happening according to plan. This study assessed if the time-bound targets of the 1-3-7 strategy were being sustained over time. Such information would be useful to improve implementation of the 1-3-7 strategy in China.

Methods

This cross-sectional study involved country-wide programmatic data for the period January 1st 2013 to June 30th 2014. Data variables were extracted from the national malaria information system and included socio-demographic information, type of county, date of diagnosis, date of reporting, date of case investigation, case classification (indigenous, or imported, or unknown), focus investigation, date of reactive case detection (RACD), and date of indoor residual spraying (IRS). Summary statistics and proportions were used and comparisons between groups were assessed using the chi-square test. Level of significance was set at a P-value ≤ 0.05.

Results

Of a total of 5,688 malaria cases from 731 counties, there were 55 (1 %) indigenous cases (only in Type 1 and Type 2 counties) and 5,633 (99 %) imported cases from all types of counties. There was no delay in reporting malaria cases by type of county. In terms of case investigation, 97.5 % cases were investigated within 3 days with the proportion of delays (1.5 %) in type 2 counties, being significantly lower than type 1 counties (4.1 %). Regarding active foci, 96.4 % were treated by RACD and/or IRS.

Conclusions

The performance of 1-3-7 strategy was encouraging but identified some challenges that if addressed can further improve implementation.

Electronic supplementary material

The online version of this article (doi:10.1186/s40249-015-0089-2) contains supplementary material, which is available to authorized users.

Mining geographic variations of Plasmodium vivax for active surveillance: a case study in China

BACKGROUND

Geographic variations of an infectious disease characterize the spatial differentiation of disease incidences caused by various impact factors, such as environmental, demographic, and socioeconomic factors. Some factors may directly determine the force of infection of the disease (namely, explicit factors), while many other factors may indirectly affect the number of disease incidences via certain unmeasurable processes (namely, implicit factors). In this study, the impact of heterogeneous factors on geographic variations of Plasmodium vivax incidences is systematically investigate in Tengchong, Yunnan province, China.

METHODS

A space-time model that resembles a P. vivax transmission model and a hidden time-dependent process, is presented by taking into consideration both explicit and implicit factors. Specifically, the transmission model is built upon relevant demographic, environmental, and biophysical factors to describe the local infections of P. vivax. While the hidden time-dependent process is assessed by several socioeconomic factors to account for the imported cases of P. vivax. To quantitatively assess the impact of heterogeneous factors on geographic variations of P. vivax infections, a Markov chain Monte Carlo (MCMC) simulation method is developed to estimate the model parameters by fitting the space-time model to the reported spatial-temporal disease incidences.

RESULTS

Since there is no ground-truth information available, the performance of the MCMC method is first evaluated against a synthetic dataset. The results show that the model parameters can be well estimated using the proposed MCMC method. Then, the proposed model is applied to investigate the geographic variations of P. vivax incidences among all 18 towns in Tengchong, Yunnan province, China. Based on the geographic variations, the 18 towns can be further classify into five groups with similar socioeconomic causality for P. vivax incidences.

CONCLUSIONS

Although this study focuses mainly on the transmission of P. vivax, the proposed space-time model is general and can readily be extended to investigate geographic variations of other diseases. Practically, such a computational model will offer new insights into active surveillance and strategic planning for disease surveillance and control.

The future of genomic medicine education in Africa

There are many challenges and opportunities for Africans in the emerging area of genome medicine. In particular, there is a need for investment in local education using real-world African genetic data sets. Cloud-based computing platforms offer one solution for engaging the next generation of biomedical scientists in tackling disease in Africa, and by extension, the world.

Immunity to visceral leishmaniasis: implications for immunotherapy

Visceral leishmaniasis, caused by Leishmania donovani, L. infantum (syn. Leishmania chagasi), is a globally widespread disease with a burden of about 400,000 new infections reported annually. It is the most dangerous form of human leishmaniasis in terms of mortality and morbidity and is spreading to several nonendemic areas because of migration, global traveling and military conflicts. The emergence of Leishmania-HIV co-infection and increased prevalence of drug-resistant strains have worsened the impact of the disease. The traditional low-cost drugs are often toxic with several adverse effects, highlighting the need for development of new therapeutic and prophylactic strategies. Therefore, a detailed understanding of mechanisms of protective immunity is extremely important in order to develop new therapeutics in the form of vaccines or immunotherapies. This review gives an overview of visceral leishmaniasis, with particular emphasis on the innate and adaptive immune responses, vaccine and vaccination strategies and their potentials for immunotherapy against the disease.

Preparedness for malaria resurgence in China: case study on imported cases in 2000-2012

Malaria is the most important parasitic protozoan infection that has caused serious threats to human health globally. China has had success in reducing the morbidity and mortality of malaria to the lowest level through sustained and large-scale interventions. Although the total number of malaria cases declined gradually, the burden of the imported malaria cases mainly from Southeast Asian and African countries has increased substantially since 2000, posing a severe threat to public health in China. This review explores and analyses the epidemiological characteristics of the imported malaria based on data from 2000 to 2012, in order to provide theoretical bases and insights into effective prevention, avoid the resurgence of malaria in malaria-susceptible areas and develop appropriate strategies to protect people's health in China. This review also intends to offer the useful information of innovative approaches and tools that are required for malaria elimination in various settings.

Approaches to the evaluation of malaria elimination at county level: case study in the Yangtze River Delta region

As the progress on transition from malaria control to malaria elimination in the People's Republic of China (P.R. China), four counties/districts, namely Zhabei District and Songjiang District of Shanghai municipality, and Anji County and Haiyan County of Zhejiang Province, representatives of the Yangtze River Delta region, were included in the pilot project of the national malaria elimination programme in P.R. China. A baseline survey was conducted first. The main measures performed were blood examination of febrile cases, improving the information management system of malaria cases, providing standard diagnosis and treatment, standardized disposal of epidemic focus, and health education and health promotion, strengthening the management of mobile population, etc. All the measures were assessed and evaluated through data examination and on-site investigation. In the whole process of the pilot project, quality control was especially emphasized. During the implementation of pilot project, the three-level control system was improved, professional staff was enriched and the working fund was ensured (a total fund of RMB 2,923,600). Thirty-nine training courses were conducted. Among 102,451 febrile cases receiving blood examination, all of the 23 malaria cases were confirmed as imported from other provinces or foreign countries. All the epidemic foci were surveyed and some control measures were carried out. Various health education and promotion activities were carried out including publicizing malaria control knowledge through news media, newspapers and periodicals and networks. Assessment and evaluation of the project was done by the Zhejiang and Shanghai Government, comprehensive score was >95 points under the evaluation system which indicated all four pilot counties/districts had first achieved the goal of elimination of malaria in P.R. China. Experiences and lessons about the measures carried out in the project were discussed.

Feasibility and roadmap analysis for malaria elimination in China

To understand the current status of the malaria control programme at the county level in accordance with the criteria of the World Health Organisation, the gaps and feasibility of malaria elimination at the county and national levels were analysed based on three kinds of indicators: transmission capacity, capacity of the professional team, and the intensity of intervention. Finally, a roadmap for national malaria elimination in the People's Republic of China is proposed based on the results of a feasibility assessment at the national level.

China-Africa cooperation initiatives in malaria control and elimination

Malaria has affected human health globally with a significant burden of disease, and also has impeded social and economic development in the areas where it is present. In Africa, many countries have faced serious challenges in controlling malaria, in part due to major limitations in public health systems and primary health care infrastructure. Although China is a developing country, a set of control strategies and measures in different local settings have been implemented successfully by the National Malaria Control Programme over the last 60 years, with a low cost of investment. It is expected that Chinese experience may benefit malaria control in Africa. This review will address the importance and possibility of China–Africa collaboration in control of malaria in targeted African countries, as well as how to proceed toward the goal of elimination where this is technically feasible.

Surveillance and response strategy in the malaria post-elimination stage: case study of Fujian province

Malaria used to be a serious health problem in Fujian province in the past, but no local malaria transmission has been found since 2000. In order to eliminate the potential residual cases and prevent re-introduction of malaria so as to achieve the final goal of malaria elimination in Fujian province, various strategy and intervention approaches were tailored to the local settings. For instance, the monitoring of febrile patients by blood smear examinations and vector surveillance and control were strengthened in addition to the routine intervention in the mountainous area of Fujian province, where malaria was highly endemic and the mosquito Anopheles anthropophagus distributed with a high vectorial capacity. There were two local cases who got infected due to imported cases found in the building site of an expressway in 2004 and 2005, respective. All other imported malaria cases were detected during post-elimination stage through surveillance system. Based on results from post-transmission surveillance, malaria transmission has been interrupted in Fujian province for 13 years. Therefore, post-transmission surveillance and response is an important intervention to maintain the malaria elimination achievements in Fujian province.

Lessons from malaria control to elimination: case study in Hainan and Yunnan provinces

Reduction patterns of Plasmodium falciparum and P. vivax malaria transmission and the role of an integrated strategy of case management and vector control are compared between different ecological zones. The epidemiology of malaria in Hainan and Yunnan provinces was disparate, even though distinct malaria control strategies have been adapted to different situations based on risk group, vector behaviours, local health infrastructure, and environmental conditions. The island Hainan appears to be victorious in eliminating malaria. However, there is still a long way to go to prevent the reintroduction of malaria in Hainan province and eliminating malaria in the border areas of Yunnan province. This review of the experiences and challenges from malaria control to elimination in Hainan and Yunnan provinces of southern China will provide a basis for the future elimination of malaria in the whole country.

Emerging and reemerging neglected tropical diseases: a review of key characteristics, risk factors, and the policy and innovation environment

In global health, critical challenges have arisen from infectious diseases, including the emergence and reemergence of old and new infectious diseases. Emergence and reemergence are accelerated by rapid human development, including numerous changes in demographics, populations, and the environment. This has also led to zoonoses in the changing human-animal ecosystem, which are impacted by a growing globalized society where pathogens do not recognize geopolitical borders. Within this context, neglected tropical infectious diseases have historically lacked adequate attention in international public health efforts, leading to insufficient prevention and treatment options. This subset of 17 infectious tropical diseases disproportionately impacts the world's poorest, represents a significant and underappreciated global disease burden, and is a major barrier to development efforts to alleviate poverty and improve human health. Neglected tropical diseases that are also categorized as emerging or reemerging infectious diseases are an even more serious threat and have not been adequately examined or discussed in terms of their unique risk characteristics. This review sets out to identify emerging and reemerging neglected tropical diseases and explore the policy and innovation environment that could hamper or enable control efforts. Through this examination, we hope to raise awareness and guide potential approaches to addressing this global health concern.

Vaccination strategies for SIR vector-transmitted diseases

Vector-borne diseases are one of the major public health problems in the world with the fastest spreading rate. Control measures have been focused on vector control, with poor results in most cases. Vaccines should help to reduce the diseases incidence, but vaccination strategies should also be defined. In this work, we propose a vector-transmitted SIR disease model with age-structured population subject to a vaccination program. We find an expression for the age-dependent basic reproductive number R(0), and we show that the disease-free equilibrium is locally stable for R(0) ≤ 1, and a unique endemic equilibrium exists for R(0) > 1. We apply the theoretical results to public data to evaluate vaccination strategies, immunization levels, and optimal age of vaccination for dengue disease.

Surveillance-response systems: the key to elimination of tropical diseases

Tropical diseases remain a major cause of morbidity and mortality in developing countries. Although combined health efforts brought about significant improvements over the past 20 years, communities in resource-constrained settings lack the means of strengthening their environment in directions that would provide less favourable conditions for pathogens. Still, the impact of infectious diseases is declining worldwide along with progress made regarding responses to basic health problems and improving health services delivery to the most vulnerable populations. The London Declaration on Neglected Tropical Diseases (NTDs), initiated by the World Health Organization's NTD roadmap, set out the path towards control and eventual elimination of several tropical diseases by 2020, providing an impetus for local and regional disease elimination programmes. Tropical diseases are often patchy and erratic, and there are differing priorities in resources-limited and endemic countries at various levels of their public health systems. In order to identify and prioritize strategic research on elimination of tropical diseases, the 'First Forum on Surveillance-Response System Leading to Tropical Diseases Elimination' was convened in Shanghai in June 2012. Current strategies and the NTD roadmap were reviewed, followed by discussions on how to identify and critically examine prevailing challenges and opportunities, including inter-sectoral collaboration and approaches for elimination of several infectious, tropical diseases. A priority research agenda within a 'One Health-One World' frame of global health was developed, including (i) the establishment of a platform for resource-sharing and effective surveillance-response systems for Asia Pacific and Africa with an initial focus on elimination of lymphatic filariasis, malaria and schistosomiasis; (ii) development of new strategies, tools and approaches, such as improved diagnostics and antimalarial therapies; (iii) rigorous validation of surveillance-response systems; and (iv) designing pilot studies to transfer Chinese experiences of successful surveillance-response systems to endemic countries with limited resources.

Preparation for malaria resurgence in China: approach in risk assessment and rapid response

With the shrinking of indigenous malaria cases and endemic areas in the People's Republic of China (P.R. China), imported malaria predominates over all reported cases accounting for more than 90% of the total. On the way to eliminate malaria, prompt detection and rapid response to the imported cases are crucial for the prevention of secondary transmission in previous endemic areas. Through a comprehensive literature review, this chapter aims to identify risk determinants of potential local transmission caused by the imported malaria cases and discusses gaps to be addressed to reach the elimination goal by 2020. Current main gaps with respect to dealing with potential malaria resurgence in P.R. China include lack of cross-sectoral cooperation, lack of rapid response and risk assessment, poor public awareness, and inadequate research and development in the national malaria elimination programme.