Summary Cutaneous leishmaniasis is endemic in the tropics and neotropics. It is often referred to as a group of diseases because of the varied spectrum of clinical manifestations, which range from ...small cutaneous nodules to gross mucosal tissue destruction. Cutaneous leishmaniasis can be caused by several Leishmania spp and is transmitted to human beings and animals by sandflies. Despite its increasing worldwide incidence, but because it is rarely fatal, cutaneous leishmaniasis has become one of the so-called neglected diseases, with little interest by financial donors, public-health authorities, and professionals to implement activities to research, prevent, or control the disease. In endemic countries, diagnosis is often made clinically and, if possible, by microscopic examination of lesion biopsy smears to visually confirm leishmania parasites as the cause. The use of more sophisticated diagnostic techniques that allow for species identification is usually restricted to research or clinical settings in non-endemic countries. The mainstays of cutaneous leishmaniasis treatment are pentavalent antimonials, with new oral and topical treatment alternatives only becoming available within the past few years; a vaccine currently does not exist. Disease prevention and control are difficult because of the complexity of cutaneous leishmaniasis epizoology, and the few options available for effective vector control.
Strongyloidiasis is a common neglected tropical disease in tropical and sub-tropical climatic zones. At the worldwide level, there is high uncertainty about the strongyloidiasis burden. This ...uncertainty represents an important knowledge gap since it affects the planning of interventions to reduce the burden of strongyloidiasis in endemic countries. This study aimed to estimate the global strongyloidiasis prevalence. A literature review was performed to obtain prevalence data from endemic countries at a worldwide level from 1990 to 2016. For each study, the true population prevalence was calculated by accounting for the specificity and the sensitivity of testing and age of tested individuals. Prediction of strongyloidiasis prevalence for each country was performed using a spatiotemporal statistical modeling approach. The country prevalence obtained from the model was used to estimate the number of infected people per country. We estimate the global prevalence of strongyloidiasis in 2017 to be 8.1% (95% CI: 4.2–12.4%), corresponding to 613.9 (95% CI: 313.1–910.1) million people infected. The South-East Asia, African, and Western Pacific Regions accounted for 76.1% of the global infections. Our results could be used to identify those countries in which strongyloidiasis prevalence is highest and where mass drug administration (MDA) should be deployed for its prevention and control.
...a clear understanding should be obtained as to how current estimates of the leishmaniases' burden of disease were obtained, both in terms of case numbers as well as DALYs. ...clarification should ...be obtained about the nature and origin of input parameters (e.g., whether duration of disease for CL includes scars or only the duration of active CL lesions; specifying the values of each input parameter), and how the disability weight for the leishmaniases was computed. ...whilst a leishmaniases surveillance system 1 would be laudable, due to cost constraints it is probably not feasible in practice--instead, there should be advocacy to integrate the leishmaniases with other disease surveillance programs (e.g., malaria or Chagas disease), particularly if these have established sentinel surveillance sites.
Approximately 800,000 children die each year due to pneumococcal disease and >90% of these deaths occur in developing countries where few children have access to life-saving serotype-based vaccines. ...Understanding the serotype epidemiology of invasive pneumococcal disease (IPD) among children is necessary for vaccine development and introduction policies. The aim of this study was to systematically estimate the global and regional distributions of serotypes causing IPD in children <5 years of age.
We systematically reviewed studies with IPD serotype data among children <5 years of age from the published literature and unpublished data provided by researchers. Studies conducted prior to pneumococcal conjugate vaccine (PCV) introduction, from 1980 to 2007, with ≥12 months of surveillance, and reporting ≥20 serotyped isolates were included. Serotype-specific proportions were pooled in a random effects meta-analysis and combined with PD incidence and mortality estimates to infer global and regional serotype-specific PD burden. Of 1,292, studies reviewed, 169 were included comprising 60,090 isolates from 70 countries. Globally and regionally, six to 11 serotypes accounted for ≥70% of IPD. Seven serotypes (1, 5, 6A, 6B, 14, 19F, 23F) were the most common globally; and based on year 2000 incidence and mortality estimates these seven serotypes accounted for >300,000 deaths in Africa and 200,000 deaths in Asia. Serotypes included in both the 10- and 13-valent PCVs accounted for 10 million cases and 600,000 deaths worldwide.
A limited number of serotypes cause most IPD worldwide. The serotypes included in existing PCV formulations account for 49%-88% of deaths in Africa and Asia where PD morbidity and mortality are the highest, but few children have access to these life-saving vaccines. Please see later in the article for the Editors' Summary.
Mobile and migrant populations (MMPs) pose a unique challenge to disease elimination campaigns as they are often hard to survey and reach with treatment. While some elimination efforts have had ...success reaching MMPs, other campaigns are struggling to do so, which may be affecting progress towards disease control and elimination. Therefore, this paper reviews the literature on elimination campaigns targeting MMPs across a selection of elimination diseases-neglected tropical diseases, malaria, trypanosomiasis, polio, smallpox, and rinderpest.
Through a systematic review process following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, a three-person review team identified papers from databases, conference records, and citation searches using inclusion/exclusion criteria. Papers were divided into three key outcome domains during the synthetization process: (1) MMP movement patterns in East Africa including reasons for movement and consequences in terms of health outcomes and healthcare access; (2) MMP contribution to the transmission of disease across all geographies; (3) surveillance methods and treatment interventions used to implement programming in MMPs across all geographies. Experts in the field also provided supplemental information and gray literature to support this review.
The review identified 103 records which were descriptively analyzed using the outcome domains. The results indicate that in East Africa, there are various motivations for migration from economic opportunity to political unrest to natural disasters. Regardless of motivation, mobile lifestyles affect health service access such that MMPs in East Africa report barriers in accessing healthcare and have limited health knowledge. Often lower service delivery to these populations has resulted in higher disease prevalence. A minority of articles suggest MMPs do not pose challenges to reaching disease control and elimination thresholds. Finally, the literature highlighted surveillance methods (e.g., using satellite imagery or mobile phone data to track movement, participatory mapping, snowball sampling) and intervention strategies (e.g., integration with animal health campaigns, cross-border coordination, alternative mass drug administration MDA methods) to implement health interventions in MMPs.
Ultimately, the literature reviewed here can inform programmatic decisions as the community attempts to reach these never treated populations.
The protocol for this manuscript was registered with the International Prospective Registry of Systematic Reviews (PROSPERO) (No. CRD42021214743).
The Kingdom of Saudi Arabia (KSA) quickly controlled the spread of SARS-CoV-2 by implementing several non-pharmaceutical interventions (NPIs), including suspension of international and national ...travel, local curfews, closing public spaces (i.e., schools and universities, malls and shops), and limiting religious gatherings. The KSA also mandated all citizens to respect physical distancing and to wear face masks. However, after relaxing some restrictions during June 2020, the KSA is now planning a strategy that could allow resuming in-person education and international travel. The aim of our study was to evaluate the effect of NPIs on the spread of the COVID-19 and test strategies to open schools and resume international travel.
We built a spatial-explicit individual-based model to represent the whole KSA population (IBM-KSA). The IBM-KSA was parameterized using country demographic, remote sensing, and epidemiological data. A social network was created to represent contact heterogeneity and interaction among age groups of the population. The IBM-KSA also simulated the movement of people across the country based on a gravity model. We used the IBM-KSA to evaluate the effect of different NPIs adopted by the KSA (physical distancing, mask-wearing, and contact tracing) and to forecast the impact of strategies to open schools and resume international travels.
The IBM-KSA results scenarios showed the high effectiveness of mask-wearing, physical distancing, and contact tracing in controlling the spread of the disease. Without NPIs, the KSA could have reported 4,824,065 (95% CI: 3,673,775-6,335,423) cases by June 2021. The IBM-KSA showed that mandatory mask-wearing and physical distancing saved 39,452 lives (95% CI: 26,641-44,494). In-person education without personal protection during teaching would have resulted in a high surge of COVID-19 cases. Compared to scenarios with no personal protection, enforcing mask-wearing and physical distancing in schools reduced cases, hospitalizations, and deaths by 25% and 50%, when adherence to these NPIs was set to 50% and 70%, respectively. The IBM-KSA also showed that a quarantine imposed on international travelers reduced the probability of outbreaks in the country.
This study showed that the interventions adopted by the KSA were able to control the spread of SARS-CoV-2 in the absence of a vaccine. In-person education should be resumed only if NPIs could be applied in schools and universities. International travel can be resumed but with strict quarantine rules. The KSA needs to keep strict NPIs in place until a high fraction of the population is vaccinated in order to reduce hospitalizations and deaths.
Strongyloides stercoralis is a soil-transmitted helminth (STH) that affects approximately 600 million people worldwide. Interventions targeting S. stercoralis have not been implemented yet. Specific ...treatment (ivermectin) could be included in already ongoing preventive chemotherapy (PC) campaigns targeting other STHs. The aim of this study was to estimate the quantity of ivermectin needed for an integrated STH/S. stercoralis control program.
Our study estimates the number of school- age children (SAC) (the main focus of STH deworming campaigns) in need of PC with ivermectin. The normal approximation of the binomial distribution was adopted to calculate the hypothetical prevalence distribution in each endemic country. Considering prevalence thresholds for PC equal to 10%, 15%, and 20%, we estimated the number of SAC in need of treatment. We adjusted the estimates accounting for ivermectin distributed in lymphatic filariasis and onchocerciasis elimination programs and excluded from our calculation areas where Loa loa is endemic. The global number of SAC that should be targeted in PC campaigns was estimated at 283.9 M (95% CI: 163.4-368.8), 207.2 M (95% CI: 160.9-380.7), and 160.7 M (95% CI: 86.6-225.7) when the threshold for intervention was set to 10%, 15%, and 20%, respectively. India, China, Indonesia, Bangladesh, and Nigeria accounted for about 50% of the global SAC would have to be covered by PC intervention.
Our analysis may support endemic countries to evaluate the ivermectin quantity needed for integrating strongyloidiasis in the existing STH programs. These estimates might also show to generic drug manufacturers the size of the potential market for ivermectin and encourage its production.
Many countries across sub-Saharan Africa are rapidly increasing insecticide-treated net (ITN) coverage to combat malaria, but systematic data on the use of those ITNs and the factors affecting this ...use are scarce.
A household survey was conducted during malaria season in 23 communities of Amhara and Oromia Regional States, Ethiopia, stratified by degree of urbanization (rural, peri-urban, or urban), whether or not they received indoor residual spraying (IRS), and whether or not free nets had been distributed. Descriptive statistics as well as univariate and multivariate logistic regression analyses were used to describe household net ownership and identify factors associated with use or non-use of nets already in the household. A qualitative component consisting of observations of ITNs in households and several open-ended questions provided further understanding of the reasons for ITN use and non-use.
Of 857 surveyed households, 91% owned at least one ITN, but only 65% of ITNs owned had been used the prior night. The multivariate analysis found that the factors significantly associated with an ITN being used were regional state (Amhara) (Odds Ratio OR = 0.61; 95% Confidence Interval C.I. 0.43 - 0.86; p < 0.01), residing in a house sprayed with IRS (OR = 1.89; 95% C.I. 1.36 - 2.63; p < 0.001), age of ITN (<12 months) (OR = 0.55; 95% C.I. 0.37 - 0.82; p < 0.01), shape (conical) (OR = 2.27; 95% C.I. 1.10 - 4.68; p < 0.05), and paying for the ITN rather than receiving it free (OR = 2.16; 95% C.I. 1.32 - 3.53; p < 0.01). The most common reasons for ITN non-use identified through the qualitative component of the study were: there are few mosquitoes around or malaria is not a serious problem; the ITN is no longer effective; ITN is in poor condition; the ITN is being saved. Observations showed many ITNs hanging incorrectly, and some being used for purposes other than as a bed net.
The very high ITN ownership in the study areas suggests that a strategy targeting free nets to rural and poor households combined with support for the commercial sector is an effective means of achieving high coverage. The data suggests that use of ITNs owned could be increased by distribution of conical ITNs, continued development of the commercial sector, replacement schemes for worn-out ITNs, assistance with hanging of ITNs, and communication addressing misperceptions about ITNs.
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