Charles H. King

Helminth infections: the great neglected tropical diseases

Helminths are parasitic worms. They are the most common infectious agents of humans in developing countries and produce a global burden of disease that exceeds better-known conditions, including malaria and tuberculosis. As we discuss here, new insights into fundamental helminth biology are accumulating through newly completed genome projects and the nascent application of transgenesis and RNA interference technologies. At the same time, our understanding of the dynamics of the transmission of helminths and the mechanisms of the Th2-type immune responses that are induced by infection with these parasitic worms has increased markedly. Ultimately, these advances in molecular and medical helminth biology should one day translate into a new and robust pipeline of drugs, diagnostics, and vaccines for targeting parasitic worms that infect humans.

2012 American College of Rheumatology Guidelines for Management of Gout. Part 1: Systematic Nonpharmacologic and Pharmacologic Therapeutic Approaches to Hyperuricemia

DINESH KHANNA, JOHN D. FITZGERALD, PUJA P. KHANNA, SANGMEE BAE, MANJIT K. SINGH, TUHINA NEOGI, MICHAEL H. PILLINGER, JOAN MERILL, SUSAN LEE, SHRADDHA PRAKASH, MARIAN KALDAS, MANEESH GOGIA, FERNANDO PEREZ-RUIZ, WILL TAYLOR, FREDERIC LIOTE, HYON CHOI, JASVINDER A. SINGH, NICOLA DALBETH, SANFORD KAPLAN, VANDANA NIYYAR, DANIELLE JONES, STEVEN A. YAROWS, BLAKE ROESSLER, GAIL KERR, CHARLES KING, GERALD LEVY, DANIEL E. FURST, N. LAWRENCE EDWARDS, BRIAN MANDELL, H. RALPH SCHUMACHER, MARK ROBBINS, NEIL WENGER, AND ROBERT TERKELTAUB

Reassessment of the cost of chronic helmintic infection: a meta-analysis of disability-related outcomes in endemic schistosomiasis

BACKGROUND Schistosomiasis is one of the worlds most prevalent infections, yet its effect on the global burden of disease is controversial. Published disability-adjusted life-year (DALY) estimates suggest that the average effect of schistosome infection is quite small, although this is disputed. To develop an evidenced-based reassessment of schistosomiasis-related disability, we did a systematic review of data on disability-associated outcomes for all forms of schistosomiasis. METHODS We did structured searches using EMBASE, PUBMED, and Cochrane electronic databases. Published bibliographies were manually searched, and unpublished studies were obtained by contacting research groups. Reports were reviewed and abstracted independently by two trained readers. All randomised and observational studies of schistosomiasis morbidity were eligible for inclusion. We calculated pooled estimates of reported disability-related effects using weighted odds ratios for categorical outcomes and standardised mean differences for continuous data. FINDINGS 482 published or unpublished reports (March, 1921, to July, 2002) were screened. Of 135 selected for inclusion, 51 provided data for performance-related symptoms, whereas 109 reported observed measures of disability-linked morbidities. Schistosomiasis was significantly associated with anaemia, chronic pain, diarrhoea, exercise intolerance, and undernutrition. INTERPRETATION By contrast with WHO estimates of 0.5% disability weight assigned to schistosomiasis, 2-15% disability seems evident in different functional domains of a person with schistosomiasis. This raised estimate, if confirmed in formal patient-preference studies, indicates a need to reassess our priorities for treating this silent pandemic of schistosomiasis.

2015 American College of Rheumatology Guideline for the Treatment of Rheumatoid Arthritis.

To develop a new evidence‐based, pharmacologic treatment guideline for rheumatoid arthritis (RA).

The Global Burden of Disease Study 2010: Interpretation and Implications for the Neglected Tropical Diseases

The publication of the Global Burden of Disease Study 2010 (GBD 2010) and the accompanying collection of Lancet articles in December 2012 provided the most comprehensive attempt to quantify the burden of almost 300 diseases, injuries, and risk factors, including neglected tropical diseases (NTDs) [1]–[3]. The disability-adjusted life year (DALY), the metric used in the GBD 2010, is a tool which may be used to assess and compare the relative impact of a number of diseases locally and globally [4]–[6]. Table 1 lists the major NTDs as defined by the World Health Organization (WHO) [7] and their estimated DALYs [1]. With a few exceptions, most of the NTDs currently listed by the WHO [7] or those on the expanded list from PLOS Neglected Tropical Diseases [8] are disablers rather than killers, so the DALY estimates represent one of the few metrics available that could fully embrace the chronic effects of these infections. Table 1 Estimated DALYs (in millions) of the NTDs from the Global Burden of Disease Study 2010. Disease DALYs from GBD 2010 (numbers in parentheses indicate 95% confidence intervals) [1] NTDs 26.06 (20.30–35.12) Intestinal nematode infections 5.19 (2.98–8.81) Hookworm disease 3.23 (1.70–5.73) Ascariasis 1.32 (0.71–2.35) Trichuriasis 0.64 (0.35–1.06) Leishmaniasis 3.32 (2.18–4.90) Schistosomiasis 3.31 (1.70–6.26) Lymphatic filariasis 2.78 (1.8–4.00) Food-borne trematodiases 1.88 (0.70–4.84) Rabies 1.46 ((0.85–2.66) Dengue 0.83 (0.34–1.41) African trypanosomiasis 0.56 (0.08–1.77) Chagas disease 0.55 (0.27–1.05) Cysticercosis 0.50 (0.38–0.66) Onchocerciasis 0.49 (0.36–0.66) Trachoma 0.33 (0.24–0.44) Echinococcosis 0.14 (0.07–0.29) Yellow fever <0.001 Other NTDs * 4.72 (3.53–6.35) Open in a separate window * Relapsing fevers, typhus fever, spotted fever, Q fever, other rickettsioses, other mosquito-borne viral fevers, unspecified arthropod-borne viral fever, arenaviral haemorrhagic fever, toxoplasmosis, unspecified protozoal disease, taeniasis, diphyllobothriasis and sparganosis, other cestode infections, dracunculiasis, trichinellosis, strongyloidiasis, enterobiasis, and other helminthiases. Even DALYs, however, do not tell the complete story of the harmful effects from NTDs. Some of the specific and potential shortcomings of GBD 2010 have been highlighted elsewhere [9]. Furthermore, DALYs measure only direct health loss and, for example, do not consider the economic impact of the NTDs that results from detrimental effects on school attendance and child development, agriculture (especially from zoonotic NTDs), and overall economic productivity [10], [11]. Nor do DALYs account for direct costs of treatment, surveillance, and prevention measures. Yet, economic impact has emerged as an essential feature of the NTDs, which may trap people in a cycle of poverty and disease [10]–[12]. Additional aspects not considered by the DALY metrics are the important elements of social stigma for many of the NTDs and the spillover effects to family and community members [13], [14], loss of tourism [15], and health system overload (e.g., during dengue outbreaks). Ultimately NTD control and elimination efforts could produce social and economic benefits not necessarily reflected in the DALY metrics, especially among the most affected poor communities [11].

2012 American College of Rheumatology guidelines for management of gout. Part 2: Therapy and antiinflammatory prophylaxis of acute gouty arthritis

In response to a request for proposal from the American College of Rheumatology (ACR), our group was charged with developing non-pharmacologic and pharmacologic guidelines for treatments in gout that are safe and effective, i.e., with acceptable risk-benefit ratio. These guidelines for the management and anti-inflammatory prophylaxis of acute attacks of gouty arthritis complements our manuscript on guidelines to treat hyperuricemia in patients with evidence of gout (or gouty arthritis) (1). Gout is the most common cause of inflammatory arthritis in adults in the USA. Clinical manifestations in joints and bursa are superimposed on top of local deposition of monosodium urate crystals. Acute gout characteristically presents as self-limited, attack of synovitis (also called “gout flares”). Acute gout attacks account for a major component of the reported decreased health-related quality of life in patients with gout (2, 3). Acute gout attacks can be debilitating and are associated with decreased work productivity (4, 5). Urate lowering therapy (ULT) is a cornerstone in the management of gout, and, when effective in lowering serum urate (SUA), is associated with decreased risk of acute gouty attacks (6). However, during the initial phase of ULT, there is an early increase in acute gout attacks, which has been hypothesized due to remodeling of articular urate crystal deposits as a result of rapid and substantial lowering of ambient urate concentrations (7). Acute gout attacks attributable to the initiation of ULT may contribute to non-adherence in long-term gout treatment, as reported in recent studies (8). In order to systematically evaluate a broad spectrum of acute gouty arthritis, we generated multifaceted case scenarios to elucidate decision making based primarily on clinical and laboratory test-based data that can be obtained in a gout patient by both non-specialist and specialist health care providers in an office practice setting. This effort was not intended to create a novel classification system of gout, or new gout diagnostic criteria, as such endeavors are beyond the scope of this work. Prior gout recommendations and guidelines, at the independent (i.e, non pharmaceutical industry-sponsored) national or multinational rheumatology society level, have been published by EULAR (9, 10), the Dutch College of General Practitioners (11), and the British Society for Rheumatology (BSR)(12). The ACR requested new guidelines, in view of the increasing prevalence of gout (13), the clinical complexity of management of gouty arthritis imposed by co-morbidities common in gout patients (14), and increasing numbers of treatment options via clinical development of agents(15–17). The ACR charged us to develop these guidelines to be useful for both rheumatologists and other health care providers on an international level. As such, this process and resultant recommendations, involved a diverse and international panel of experts. In this manuscript, we concentrate on 2 of the 4 gout domains that the ACR requested for evaluation of pharmacologic and non-pharmacologic management approaches: (i) analgesic and anti-inflammatory management of acute attacks of gouty arthritis, and (ii) pharmacologic anti-inflammatory prophylaxis of acute attacks of gouty arthritis. Part I of the guidelines focused on systematic non-pharmacologic measures (patient education, diet and lifestyle choices, identification and management of co-morbidities) that impact on hyperuricemia, and made recommendations on pharmacologic ULT in a broad range of case scenarios of patients with disease activity manifested by acute and chronic forms of gouty arthritis, including chronic tophaceous gouty arthropathy(1). Each individual and specific statement is designated as a “recommendation”, in order to reflect the non-prescriptive nature of decision making for the hypothetical clinical scenarios. So that the voting panel could focus on gout treatment decisions, a number of key assumptions were made, as described in Part I of the guidelines (1). Importantly, each proposed recommendation assumed that correct diagnoses of gout and acute gouty arthritis attacks had been made for the voting scenario in question. For treatment purposes, it was also assumed that treating clinicians were competent, and considered underlying medical comorbidities (including diabetes, gastrointestinal disease, hypertension, and hepatic, cardiac, and renal disease), and potential drug toxicities and drug-drug interactions, when making both treatment choicesand dosing decisions on chosen pharmacologic interventions. The RAND/UCLA methodology used here emphasizes level of evidence, safety, and quality of therapy, and excludes analyses of societal cost of health care. As such, the ACR gout guidelines are designed to reflect best practice, supported either by level of evidence or consensus-based decision-making. These guidelines cannot substitute for individualized, direct assessment of the patient, coupled with clinical decision making by a competent health care practitioner. The motivation, financial circumstances, and preferences of the gout patient also need to be considered in clinical practice, and it is incumbent on the treating clinician to weigh the issues not addressed by this methodology, such as treatment costs, when making management decisions. Last, the guidelines for gout management presented herein were not designed to determine eligibility for health care cost coverage by third party payers.

Parasites and poverty: the case of schistosomiasis.

Simultaneous and sequential transmission of multiple parasites, and their resultant overlapping chronic infections, are facts of life in many underdeveloped rural areas. These represent significant but often poorly measured health and economic burdens for affected populations. For example, the chronic inflammatory process associated with long-term schistosomiasis contributes to anaemia and undernutrition, which, in turn, can lead to growth stunting, poor school performance, poor work productivity, and continued poverty. To date, most national and international programs aimed at parasite control have not considered the varied economic and ecological factors underlying multi-parasite transmission, but some are beginning to provide a coordinated approach to control. In addition, interest is emerging in new studies for the re-evaluation and recalibration of the health burden of helminthic parasite infection. Their results should highlight the strong potential of integrated parasite control in efforts for poverty reduction.

2015 American College of Rheumatology Guideline for the Treatment of Rheumatoid Arthritis: ACR RA Treatment Recommendations

To develop a new evidence‐based, pharmacologic treatment guideline for rheumatoid arthritis (RA).

Soil-Transmitted Helminth Reinfection after Drug Treatment: A Systematic Review and Meta-Analysis

Background Soil-transmitted helminth (STH) infections (i.e., Ascaris lumbricoides, hookworm, and Trichuris trichiura) affect more than a billion people. Preventive chemotherapy (i.e., repeated administration of anthelmintic drugs to at-risk populations), is the mainstay of control. This strategy, however, does not prevent reinfection. We performed a systematic review and meta-analysis to assess patterns and dynamics of STH reinfection after drug treatment. Methodology We systematically searched PubMed, ISI Web of Science, EMBASE, Cochrane Database of Systematic Reviews, China National Knowledge Infrastructure, WanFang Database, Chinese Scientific Journal Database, and Google Scholar. Information on study year, country, sample size, age of participants, diagnostic method, drug administration strategy, prevalence and intensity of infection pre- and posttreatment, cure and egg reduction rate, evaluation period posttreatment, and adherence was extracted. Pooled risk ratios from random-effects models were used to assess the risk of STH reinfection after treatment. Our protocol is available on PROSPERO, registration number: CRD42011001678. Principal Findings From 154 studies identified, 51 were included and 24 provided STH infection rates pre- and posttreatment, whereas 42 reported determinants of predisposition to reinfection. At 3, 6, and 12 months posttreatment, A. lumbricoides prevalence reached 26% (95% confidence interval (CI): 16–43%), 68% (95% CI: 60–76%) and 94% (95% CI: 88–100%) of pretreatment levels, respectively. For T. trichiura, respective reinfection prevalence were 36% (95% CI: 28–47%), 67% (95% CI: 42–100%), and 82% (95% CI: 62–100%), and for hookworm, 30% (95% CI: 26–34%), 55% (95% CI: 34–87%), and 57% (95% CI: 49–67%). Prevalence and intensity of reinfection were positively correlated with pretreatment infection status. Conclusion STH reinfections occur rapidly after treatment, particularly for A. lumbricoides and T. trichiura. Hence, there is a need for frequent anthelmintic drug administrations to maximize the benefit of preventive chemotherapy. Integrated control approaches emphasizing health education and environmental sanitation are needed to interrupt transmission of STH.

Drugs Five Years Later: Praziquantel

PURPOSE To identify advances in knowledge of the pharmacokinetics, mechanism of action, clinical use, and side effects of the antihelminthic drug praziquantel in the 5 years since its introduction in the United States. DATA IDENTIFICATION Studies reported from 1983 to July 1988 were identified by computer searches of MEDLINE and TOXLINE, and review of textbooks and review articles. STUDY SELECTION Of 57 articles originally identified, 39 were selected by two readers. DATA EXTRACTION Study quality and significance were independently assessed by each reader. RESULTS OF DATA ANALYSIS The pharmacokinetics and clinical efficacy of praziquantel have been well documented. Yet, despite extensive in vivo and in vitro laboratory studies, the drugs mechanism of action in killing parasites is unknown. Although the efficacy of praziquantel was first established for treating schistosomiasis, in the last 5 years its clinical use has been expanded to the treatment of intestinal, tissue, and lung flukes, and intestinal and tissue cestode infections, including neurocysticercosis. The introduction of praziquantel was a significant advance in antihelminthic therapy, in that it was effective therapy for several parasites that had been previously considered untreatable. Availability of a safe, effective broad-spectrum oral antihelminthic agent consolidated the central role of chemotherapy in population-based control of many trematode and cestode parasites. Randomized trials have shown, however, that older, cheaper agents may be more cost-effective in controlling Schistosoma mansoni and Schistosoma haematobium in some endemic areas. CONCLUSIONS Although praziquantel is the treatment of choice for most human trematode and cestode infections, cost factors have limited its use in developing countries.