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1.
Artículo en Inglés | MEDLINE | ID: mdl-33807616

RESUMEN

Mozambique is a country in Southern Africa with around 30 million inhabitants. Malaria is the leading cause of mortality in the country. According to the WHO, Mozambique has the third highest number of malaria cases in the world, representing approximately 5% of the world total cases. Sussundenga District has the highest incidence in the Manica province and environmental conditions are the major contributor to malaria transmission. There is a lack of malaria risk maps to inform transmission dynamics in Sussundenga village. This study develops a malaria risk map for Sussundenga Village in Mozambique and identifies high risk areas to inform on appropriate malaria control and eradication efforts. One hundred houses were randomly sampled and tested for malaria in Sussundenga Rural Municipality. To construct the map, a spatial conceptual model was used to estimate risk areas using ten environmental and anthropic factors. Data from Worldclim, 30 × 30 Landsat images were used, and layers were produced in a raster data set. Layers between class values were compared by assigning numerical values to the classes within each layer of the map with equal rank. Data set input was classified, using diverse weights depending on their appropriateness. The reclassified data outputs were combined after reclassification. The map indicated a high risk for malaria in the northeast and southeast, that is, the neighborhoods of Nhamazara, Nhamarenza, and Unidade. The central eastern areas, that is, 25 de Junho, 1 and 2, 7 de Abril, and Chicueu presented a moderate risk. In Sussundenga village there was 92% moderate and 8% high risk. High malaria risk areas are most often located in densely populated areas and areas close to water bodies. The relevant findings of this study can inform on effective malaria interventions.


Asunto(s)
Malaria , África Austral , Humanos , Incidencia , Malaria/epidemiología , Mozambique/epidemiología , Población Rural
2.
Biomolecules ; 11(3)2021 03 15.
Artículo en Inglés | MEDLINE | ID: mdl-33804076

RESUMEN

Galectin-9 (Gal-9) is a ß-galactoside-binding lectin capable of promoting or suppressing the progression of infectious diseases. This protein is susceptible to cleavage of its linker-peptides by several proteases, and the resulting cleaved forms, N-terminal carbohydrate recognition domain (CRD) and C-terminal CRD, bind to various glycans. It has been suggested that full-length (FL)-Gal-9 and the truncated (Tr)-Gal-9s could exert different functions from one another via their different glycan-binding activities. We propose that FL-Gal-9 regulates the pathogenesis of infectious diseases, including human immunodeficiency virus (HIV) infection, HIV co-infected with opportunistic infection (HIV/OI), dengue, malaria, leptospirosis, and tuberculosis (TB). We also suggest that the blood levels of FL-Gal-9 reflect the severity of dengue, malaria, and HIV/OI, and those of Tr-Gal-9 markedly reflect the severity of HIV/OI. Recently, matrix metallopeptidase-9 (MMP-9) was suggested to be an indicator of respiratory failure from coronavirus disease 2019 (COVID-19) as well as useful for differentiating pulmonary from extrapulmonary TB. The protease cleavage of FL-Gal-9 may lead to uncontrolled hyper-immune activation, including a cytokine storm. In summary, Gal-9 has potential to reflect the disease severity for the acute and chronic infectious diseases.


Asunto(s)
Enfermedades Transmisibles/sangre , Galectinas/sangre , Enfermedad Aguda , Secuencia de Aminoácidos , /fisiopatología , Enfermedad Crónica , Enfermedades Transmisibles/inmunología , Enfermedades Transmisibles/fisiopatología , Dengue/sangre , Dengue/fisiopatología , Galectinas/genética , Galectinas/metabolismo , Infecciones por VIH/sangre , Infecciones por VIH/fisiopatología , Humanos , Factores Inmunológicos/metabolismo , Leptospirosis/sangre , Leptospirosis/fisiopatología , Malaria/sangre , Malaria/fisiopatología , Tuberculosis/sangre , Tuberculosis/fisiopatología
3.
Niger J Clin Pract ; 24(4): 496-504, 2021 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-33851670

RESUMEN

Background: Malaria rapid diagnostic tests (mRDTs) are the preferred option for programmatic deployment. Aims: There are numerous mRDTs on the Nigerian market and there is a need to guide practitioners on the relative performance of the commonly used brands of mRDT in Nigeria. Subjects and Methods: The performance of three commonly used Histidine-Rich-Protein-2-based mRDTs (SD-Bioline™, Carestart™ and Paracheck-Pf™) against microscopy of Giemsa stained blood and polymerase chain reaction (PCR) was evaluated among 190 febrile under-5 children in Ibadan, Nigeria. We calculated the sensitivity, specificity, predictive values, accuracy, and agreements. Results: There were 53.2% males. The prevalence of malaria parasite by microscopy was 46.8% and 57.9% by PCR. Malaria parasite detection by SD-Bioline™ was 60.5%, Carestart™: 60.0% and Paracheck-Pf™ 60.0%. Using microscopy as the gold standard, the sensitivities of SD-Bioline™, Carestart™ and Paracheck-Pf™ mRDT were 97.8%, 96.7% and 97.8% respectively while the specificities were 73.0%, 72.0% and 74.0% respectively. Using PCR as the gold standard, the sensitivity for both SD-Bioline™ and Paracheck-Pf™ was 85.5% and for CareStart was 84.6% while the specificity of SD-Bioline™, Carestart™, and Paracheck-Pf™ was 73.8%, 72.4%, and 75.0% respectively. The test accuracy was 81.0% for both SD-Bioline™ and Paracheck-Pf™ and 80.0% for Caresatrt™. The kappa coefficient of agreement between PCR and each of SD-Bioline™, Carestart, ParaCheck™ and microscopy was 0.597, 0.578, 0.609 and 0.739 respectively. Conclusion: The performance of the three mRDTs is a proof that any of the three is suitable for use in the diagnosis of malaria in the southwest of Nigeria.


Asunto(s)
Malaria Falciparum , Malaria , Niño , Pruebas Diagnósticas de Rutina , Femenino , Histidina , Humanos , Malaria/diagnóstico , Malaria Falciparum/diagnóstico , Malaria Falciparum/epidemiología , Masculino , Microscopía , Nigeria , Plasmodium falciparum , Reacción en Cadena de la Polimerasa , Sensibilidad y Especificidad
4.
Pan Afr Med J ; 38: 119, 2021.
Artículo en Francés | MEDLINE | ID: mdl-33912289

RESUMEN

Long-lasting insecticidal mosquito nets (LLIMNs) are needed for malaria vector control. However, their distribution is not yet optimal in sub-Saharan regions. According to projections, COVID-19 pandemic will further delay the distribution of LLIMNs. In Niger, a distribution campaign of LLIMNs with a multi-sectoral approach (state-partner-civil society) was organized in compliance with barrier measures for preventing transmission of COVID-19. A door-to-door strategy was chosen to implement this campaign, in order to avoid entry into confined spaces and to engage community. A total of 13,994,681 people received LLIMNs (reflecting a success rate of 101%) in six targeted regions. A collective effort is needed to sustain the fight against malaria in the COVID-19 era.


Asunto(s)
/prevención & control , Mosquiteros Tratados con Insecticida/provisión & distribución , Malaria/prevención & control , /epidemiología , Humanos , Control de Mosquitos , Mosquitos Vectores , Niger
5.
Artículo en Inglés | MEDLINE | ID: mdl-33810537

RESUMEN

BACKGROUND: Malaria is still endemic in sub-Saharan Africa, with a high disease burden. Misconceptions about malaria contribute to poor attitudes and practices, further increasing the burden in endemic countries. Studies have examined the knowledge, attitudes, and practices (KAP) of malaria among different populations. However, there seems to be no available literature reporting on the perspectives of day and night market traders. To the best of our knowledge, this is the first report on malaria KAP with a focus on day and night market traders. METHODS: A descriptive cross-sectional study involving day and night market traders in 10 selected markets within the Greater Accra Region of Ghana was carried out. Data were collected from consenting respondents using a structured questionnaire. RESULTS: Of the 760 respondents (33.3% (n = 253) night and 66.7% (n = 507) day traders) interviewed, there was no significant difference between the day and night market traders in terms of malaria KAP. Although the market traders had an overall moderate knowledge (54.0% of the day traders and 56.5% of the night traders), misconceptions about malaria (especially that it could be caused by exposure to the sun) still existed among the traders. Moreover, the majority of the traders who demonstrated high knowledge (43.98%, n = 250) did not always take laboratory tests to confirm their suspicion, indicating poor attitude. Furthermore, the market traders' choice of drug for malaria treatment (p = 0.001) and preferred malaria treatment type (orthodox or herbal) (p = 0.005) were significantly associated with their knowledge level. CONCLUSIONS: Despite the observation that no significant difference in KAP exists between day and night market traders, appropriate health education programs and interventions still need to be directed at misconceptions, poor attitudes, and poor practices revealed by this study. This will ultimately help in the prevention and control of malaria in Ghana, and globally.


Asunto(s)
Conocimientos, Actitudes y Práctica en Salud , Malaria , Estudios Transversales , Ghana/epidemiología , Humanos , Malaria/epidemiología , Encuestas y Cuestionarios
6.
Elife ; 102021 04 06.
Artículo en Inglés | MEDLINE | ID: mdl-33821799

RESUMEN

Combining spatial and temporal data is helping researchers to understand how deforestation influences the risk of malaria.


Asunto(s)
Conservación de los Recursos Naturales , Malaria , Bosques , Humanos , Incidencia , Laos , Malaria/epidemiología
7.
Nat Commun ; 12(1): 1494, 2021 03 08.
Artículo en Inglés | MEDLINE | ID: mdl-33686061

RESUMEN

Transmission-blocking vaccines that interrupt malaria transmission from humans to mosquitoes are being tested in early clinical trials. The activity of such a vaccine is commonly evaluated using membrane-feeding assays. Understanding the field efficacy of such a vaccine requires knowledge of how heavily infected wild, naturally blood-fed mosquitoes are, as this indicates how difficult it will be to block transmission. Here we use data on naturally infected mosquitoes collected in Burkina Faso to translate the laboratory-estimated activity into an estimated activity in the field. A transmission dynamics model is then utilised to predict a transmission-blocking vaccine's public health impact alongside existing interventions. The model suggests that school-aged children are an attractive population to target for vaccination. Benefits of vaccination are distributed across the population, averting the greatest number of cases in younger children. Utilising a transmission-blocking vaccine alongside existing interventions could have a substantial impact against malaria.


Asunto(s)
Vacunas contra la Malaria/inmunología , Malaria/prevención & control , Malaria/transmisión , Salud Pública , Adolescente , Adulto , Burkina Faso/epidemiología , Niño , Preescolar , Humanos , Lactante , Malaria/epidemiología , Malaria Falciparum/prevención & control , Persona de Mediana Edad , Prevalencia , Vacunación , Adulto Joven
8.
West Afr J Med ; 38(3): 274-281, 2021 Mar 22.
Artículo en Inglés | MEDLINE | ID: mdl-33765761

RESUMEN

BACKGROUND: Severe malaria is a significant cause of morbidity and mortality in Nigeria and concomitant bacteraemia may potentially worsen clinical outcomes. (Duration of admission, Mortality, Fever clearance time and Coma recovery time). OBJECTIVES: This study aimed at identifying the proportion of children with severe malaria who had concomitant bacteraemia, the pathogens implicated and their drug sensitivity pattern, predictors of bacterial co-infection and its effect on treatment outcome. METHODS: This was a hospital-based cross-sectional study at the Emergency Paediatric Unit of the University of Ilorin Teaching Hospital, Nigeria. The subjects were children aged 6 months to 14 years with severe malaria and microscopy confirmed parasitemia at admission. All subjects had blood culture samples drawn at admission for identification of bacterial isolates. Relevant clinical and laboratory parameters were recorded on case proformas. RESULTS: A total of 944 children were admitted into the Emergency Paediatric Unit during the study period with 176 (18.6%) managed for severe malaria. Of the 176 children with severe malaria, 41 (23.3%) had concomitant bacteraemia. Gram positive bacteria were the most common (70.7%) isolates with Staphylococcus aureus being the most predominant (65.9%). The bacterial isolates were mostly sensitive to Ciprofloxacin. Children with concomitant bacteraemia had a longer duration of admission (p = 0.028) and longer fever clearance time (p=0.015). Increasing duration of coma before presentation was the single independent predictor of bacteraemia (p= 0.010). CONCLUSION: Severe malaria constituted a significant cause of admissions in UITH with approximately a fourth of the subjects having bacterial co-infection and this was associated with a worse prognosis (longer duration of admission and fever clearance time). Increased duration of coma prior to admission was the only predictor of the presence of bacteraemia in children with severe malaria. This highlights the importance of investigating for concomitant bacteraemia, especially in children presenting with coma.


Asunto(s)
Bacteriemia , Coinfección , Malaria , Bacteriemia/tratamiento farmacológico , Bacteriemia/epidemiología , Niño , Coinfección/epidemiología , Estudios Transversales , Humanos , Lactante , Malaria/complicaciones , Malaria/tratamiento farmacológico , Malaria/epidemiología , Nigeria/epidemiología
9.
Pestic Biochem Physiol ; 173: 104783, 2021 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-33771262

RESUMEN

In the central western Senegal, malaria transmission has been reduced low due to the combination of several effective control interventions. However, despite this encouraging achievement, residual malaria transmission still occurring in few areas, mainly ensured by An. arabiensis and An. melas. The resurgence or the persistence of the disease may have originated from the increase and the spread of insecticide resistance genes among natural malaria vectors populations. Therefore, assessing the status and mechanisms of insecticides resistance among targeted malaria vectors is of highest importance to better characterize factors underlying the residual transmission where it occurs. Malaria vectors were collected from three selected villages using nocturnal human landing catches (HLC) and pyrethrum spray collections (PSC) methods. An. gambiae s.l. specimens were identified at the species level then genotyped for the presence of kdr-west (L1014F), kdr-east (L1014S) and ace-1R mutations by qPCR. An. arabiensis (69.36%) and An. melas (27.99%) were the most common species of the Gambiae complex in the study area. Among An. arabiensis population, the allelic frequency of the kdr-east (22.66%) was relatively higher than for kdr-west mutation (9.96%). While for An. melas populations, the overall frequencies of both mutations were very low, being respectively 1.12% and 0.40% for the L1014S and L1014F mutations. With a global frequency of 2%, only the heterozygous form of the G119S mutation was found only in An. arabiensis and in all the study sites. The widespread occurrence of the kdr mutation in both An. arabiensis and An. melas natural populations, respectively the main and focal vectors in the central-western Senegal, may have contributed to maintaining malaria transmission in the area. Thus, compromising the effectiveness of pyrethroids-based vector control measures and the National Elimination Goal. Therefore, monitoring and managing properly insecticide resistance became a key programmatic intervention to achieve the elimination goal where feasible, as aimed by Senegal. Noteworthy, this is the first report of the ace-1 mutation in natural populations of An. arabiensis from Senegal, which need to be closely monitored to preserve one of the essential insecticide classes used in IRS to control the pyrethroids-resistant populations.


Asunto(s)
Anopheles , Insecticidas , Malaria , Piretrinas , Animales , Anopheles/genética , Resistencia a los Insecticidas/genética , Insecticidas/farmacología , Malaria/genética , Mosquitos Vectores/genética , Mutación , Piretrinas/farmacología , Senegal
10.
Rev Soc Bras Med Trop ; 54: e04412020, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33656148

RESUMEN

INTRODUCTION: Colombia has an endemo-epidemic for malaria, with a downward trend in mortality over the last few decades. This study describes the malaria mortality rates from 2009-2018. METHODS: We obtained data from the Colombian Mortality Information System and calculated the case fatality and crude and age-adjusted mortality rates. RESULTS: During the study, 148 malaria-related deaths were registered. The average annual mortality rate was 0.032 deaths/100,000. Two peaks were observed in 2010 and 2016. Choco contributed to the highest number of deaths (27.7%). CONCLUSIONS: The unstable downward trend of malaria mortality rates calls for greater emphasis on surveillance and interventions.


Asunto(s)
Epidemias , Malaria , Colombia/epidemiología , Humanos , Mortalidad
11.
Nat Commun ; 12(1): 1629, 2021 03 12.
Artículo en Inglés | MEDLINE | ID: mdl-33712609

RESUMEN

The structural integrity of the host red blood cell (RBC) is crucial for propagation of Plasmodium spp. during the disease-causing blood stage of malaria infection. To assess the stability of Plasmodium vivax-infected reticulocytes, we developed a flow cytometry-based assay to measure osmotic stability within characteristically heterogeneous reticulocyte and P. vivax-infected samples. We find that erythroid osmotic stability decreases during erythropoiesis and reticulocyte maturation. Of enucleated RBCs, young reticulocytes which are preferentially infected by P. vivax, are the most osmotically stable. P. vivax infection however decreases reticulocyte stability to levels close to those of RBC disorders that cause hemolytic anemia, and to a significantly greater degree than P. falciparum destabilizes normocytes. Finally, we find that P. vivax new permeability pathways contribute to the decreased osmotic stability of infected-reticulocytes. These results reveal a vulnerability of P. vivax-infected reticulocytes that could be manipulated to allow in vitro culture and develop novel therapeutics.


Asunto(s)
Malaria Vivax , Plasmodium vivax , Reticulocitos/metabolismo , Reticulocitos/parasitología , Anemia Hemolítica , Médula Ósea , Diferenciación Celular , Eritrocitos , Hemólisis , Humanos , Malaria
12.
Mem Inst Oswaldo Cruz ; 116: e200497, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33729397

RESUMEN

BACKGROUND: Flight tones play important roles in mosquito reproduction. Several mosquito species utilise flight tones for mate localisation and attraction. Typically, the female wingbeat frequency (WBF) is lower than males, and stereotypic acoustic behaviors are instrumental for successful copulation. Mosquito WBFs are usually an important species characteristic, with female flight tones used as male attractants in surveillance traps for species identification. Anopheles darlingi is an important Latin American malaria vector, but we know little about its mating behaviors. OBJECTIVES: We characterised An. darlingi WBFs and examined male acoustic responses to immobilised females. METHODS: Tethered and free flying male and female An. darlingi were recorded individually to determine their WBF distributions. Male-female acoustic interactions were analysed using tethered females and free flying males. FINDINGS: Contrary to most mosquito species, An. darlingi females are smaller than males. However, the male's WBF is ~1.5 times higher than the females, a common ratio in species with larger females. When in proximity to a female, males displayed rapid frequency modulations that decreased upon genitalia engagement. Tethered females also modulated their frequency upon male approach, being distinct if the interaction ended in copulation or only contact. MAIN CONCLUSIONS: This is the first report of An. darlingi flight acoustics, showing that its precopulatory acoustics are similar to other mosquitoes despite the uncommon male:female size ratio, suggesting that WBF ratios are common communication strategies rather than a physical constraint imposed by size.


Asunto(s)
Anopheles , Malaria , Mosquitos Vectores , Animales , Femenino , Malaria/transmisión , Masculino , Reproducción
13.
Artículo en Inglés | MEDLINE | ID: mdl-33671594

RESUMEN

BACKGROUND/PURPOSE: In recent times, Sub-Saharan Africa (SSA) had been rated by the World Health Organization (WHO) as the most malaria-endemic region in the world. Evidence synthesis of the factors associated with malaria among children aged under-five in SSA is urgently needed. This would help to inform decisions that policymakers and executors in the region need to make for the effective distribution of scarce palliative resources to curb the spread of the illness. This scoping review is aimed at identifying studies that have used multivariate classical regression analysis to determine the predictors associated with malaria among children under five years old in SSA. METHODS/DESIGN: The search terms followed population, intervention, comparator, outcome, timing, setting (PICOTS), and were used in searching through the following databases: PubMed, MEDLINE, Web of Science, Cumulative Index of Nursing and Allied Health Literature (CINAHL), Scopus, and Measure DHS. The databases were searched for published articles from January 1990 to December 2020. RESULTS: Among the 1154 studies identified, only thirteen (13) studies met the study's inclusion criteria. Narrative syntheses were performed on the selected papers to synchronize the various predictors identified. Factors ranging from child-related (age, birth order and use of a bed net), parental/household-related (maternal age and education status, household wealth index) and community-related variables (community wealth status, free bed net distribution) were some of the identified significant predictors. CONCLUSIONS: It is timely to have a synthesis of predictors that influence the malaria status of children under-five in SSA. The outcome of the review will increase the knowledge of the epidemiology of morbidity that will form the basis for designing efficient and cost-effective distribution of palliatives and control of malaria in SSA.


Asunto(s)
Malaria , África del Sur del Sahara/epidemiología , Anciano , Niño , Preescolar , Humanos , Malaria/epidemiología
14.
Artículo en Inglés | MEDLINE | ID: mdl-33673292

RESUMEN

Mosquitoes have been a nuisance and health threat to humans for centuries due to their ability to transmit different infectious diseases. Biological control methods have emerged as an alternative or complementary approach to contain vector populations in light of the current spread of insecticide resistance in mosquitoes. Thus, this study aimed to evaluate the predation efficacy of selected potential predators against Anopheles mosquito larvae. Potential invertebrate predators and Anopheles larvae were collected from natural habitats, mainly (temporary) wetlands and ponds in southwest Ethiopia and experiments were conducted under laboratory conditions. Optimal predation conditions with respect to larval instar, water volume and number of predators were determined for each of the seven studied predators. Data analyses were carried out using the Poisson regression model using one way ANOVA at the 5% significant level. The backswimmer (Notonectidae) was the most aggressive predator on Anopheles mosquito larvae with a daily mean predation of 71.5 larvae (95% CI: [65.04;78.59]). Our study shows that larval instar, water volume and number of predators have a significant effect on each predator, except for dragonflies (Libellulidae), with regard to the preference of the larval instar. A selection of mosquito predators has the potential to control Anopheles mosquito larvae, suggesting that they can be used as complementary approach in an integrated malaria vector control strategy.


Asunto(s)
Anopheles , Malaria , Odonata , Animales , Ecosistema , Etiopía , Humanos , Larva , Malaria/prevención & control , Control de Mosquitos , Mosquitos Vectores
15.
MMWR Surveill Summ ; 70(2): 1-35, 2021 03 19.
Artículo en Inglés | MEDLINE | ID: mdl-33735166

RESUMEN

PROBLEM/CONDITION: Malaria in humans is caused by intraerythrocytic protozoa of the genus Plasmodium. These parasites are transmitted by the bite of an infective female Anopheles species mosquito. The majority of malaria infections in the United States occur among persons who have traveled to regions with ongoing malaria transmission. However, malaria is occasionally acquired by persons who have not traveled out of the country through exposure to infected blood products, congenital transmission, nosocomial exposure, or local mosquitoborne transmission. Malaria surveillance in the United States is conducted to provide information on its occurrence (e.g., temporal, geographic, and demographic), guide prevention and treatment recommendations for travelers and patients, and facilitate rapid transmission control measures if locally acquired cases are identified. PERIOD COVERED: This report summarizes confirmed malaria cases in persons with onset of illness in 2017 and trends in previous years. DESCRIPTION OF SYSTEM: Malaria cases diagnosed by blood film microscopy, polymerase chain reaction, or rapid diagnostic tests are reported to local and state health departments through electronic laboratory reports or by health care providers or laboratory staff members. Case investigations are conducted by local and state health departments, and reports are transmitted to CDC through the National Malaria Surveillance System (NMSS), the National Notifiable Diseases Surveillance System (NNDSS), or direct CDC consultations. CDC reference laboratories provide diagnostic assistance and conduct antimalarial drug resistance marker testing on blood samples submitted by health care providers or local or state health departments. This report summarizes data from the integration of all cases from NMSS and NNDSS, CDC reference laboratory reports, and CDC clinical consultations. RESULTS: CDC received reports of 2,161 confirmed malaria cases with onset of symptoms in 2017, including two congenital cases, three cryptic cases, and two cases acquired through blood transfusion. The number of malaria cases diagnosed in the United States has been increasing since the mid-1970s; in 2017, the number of cases reported was the highest in 45 years, surpassing the previous peak of 2,078 confirmed cases reported in 2016. Of the cases in 2017, a total of 1,819 (86.1%) were imported cases that originated from Africa; 1,216 (66.9%) of these came from West Africa. The overall proportion of imported cases originating from West Africa was greater in 2017 (57.6%) than in 2016 (51.6%). Among all cases, P. falciparum accounted for the majority of infections (1,523 [70.5%]), followed by P. vivax (216 [10.0%]), P. ovale (119 [5.5%]), and P. malariae (55 [2.6%]). Infections by two or more species accounted for 22 cases (1.0%). The infecting species was not reported or was undetermined in 226 cases (10.5%). CDC provided diagnostic assistance for 9.5% of confirmed cases and tested 8.0% of specimens with P. falciparum infections for antimalarial resistance markers. Most patients (94.8%) had symptom onset <90 days after returning to the United States from a country with malaria transmission. Of the U.S. civilian patients who reported reason for travel, 73.1% were visiting friends and relatives. The proportion of U.S. residents with malaria who reported taking any chemoprophylaxis in 2017 (28.4%) was similar to that in 2016 (26.4%), and adherence was poor among those who took chemoprophylaxis. Among the 996 U.S. residents with malaria for whom information on chemoprophylaxis use and travel region were known, 93.3% did not adhere to or did not take a CDC-recommended chemoprophylaxis regimen. Among 805 women with malaria, 27 reported being pregnant. Of these, 10 pregnant women were U.S. residents, and none reported taking chemoprophylaxis to prevent malaria. A total of 26 (1.2%) malaria cases occurred among U.S. military personnel in 2017, fewer than in 2016 (41 [2.0%]). Among all reported cases in 2017, a total of 312 (14.4%) were classified as severe malaria illnesses, and seven persons died. In 2017, CDC analyzed 117 P. falciparum-positive and six P. falciparum mixed-species samples for antimalarial resistance markers (although certain loci were untestable in some samples); identification of genetic polymorphisms associated with resistance to pyrimethamine were found in 108 (97.3%), to sulfadoxine in 77 (69.4%), to chloroquine in 38 (33.3%), to mefloquine in three (2.7%), and to atovaquone in three (2.7%); no specimens tested contained a marker for artemisinin resistance. The data completeness of key variables (species, country of acquisition, and resident status) was lower in 2017 (74.4%) than in 2016 (79.4%). INTERPRETATION: The number of reported malaria cases in 2017 continued a decades-long increasing trend, and for the second year in a row the highest number of cases since 1971 have been reported. Despite progress in malaria control in recent years, the disease remains endemic in many areas globally. The importation of malaria reflects the overall increase in global travel to and from these areas. Fifty-six percent of all cases were among persons who had traveled from West Africa, and among U.S. civilians, visiting friends and relatives was the most common reason for travel (73.1%). Frequent international travel combined with the inadequate use of prevention measures by travelers resulted in the highest number of imported malaria cases detected in the United States in 4 decades. PUBLIC HEALTH ACTIONS: The best way to prevent malaria is to take chemoprophylaxis medication during travel to a country where malaria is endemic. Adherence to recommended malaria prevention strategies among U.S. travelers would reduce the numbers of imported cases; reasons for nonadherence include prematurely stopping after leaving the area where malaria was endemic, forgetting to take the medication, and experiencing a side effect. Travelers might not understand the risk that malaria poses to them; thus, health care providers should incorporate risk education to motivate travelers to be adherent to chemoprophylaxis. Malaria infections can be fatal if not diagnosed and treated promptly with antimalarial medications appropriate for the patient's age, medical history, the likely country of malaria acquisition, and previous use of antimalarial chemoprophylaxis. Antimalarial use for chemoprophylaxis and treatment should be informed by the most recent guidelines, which are frequently updated. In 2018, two formulations of tafenoquine (i.e., Arakoda and Krintafel) were approved by the Food and Drug Administration (FDA) for use in the United States. Arakoda was approved for use by adults for chemoprophylaxis; the regimen requires a predeparture loading dose, taking the medication weekly during travel, and a short course posttravel. The Arakoda chemoprophylaxis regimen is shorter than alternative regimens, which could possibly improve adherence. This medication also might prevent relapses. Krintafel was approved for radical cure of P. vivax infections in those aged >16 years and should be co-administered with chloroquine (https://www.cdc.gov/malaria/new_info/2020/tafenoquine_2020.html). In April 2019, intravenous artesunate became the first-line medication for treatment of severe malaria in the United States. Artesunate was recently FDA approved but is not yet commercially available. The drug can be obtained from CDC under an investigational new drug protocol. Detailed recommendations for preventing malaria are available to the general public at the CDC website (https://www.cdc.gov/malaria/travelers/drugs.html). Health care providers should consult the CDC Guidelines for Treatment of Malaria in the United States and contact the CDC's Malaria Hotline for case management advice when needed. Malaria treatment recommendations are available online (https://www.cdc.gov/malaria/diagnosis_treatment) and from the Malaria Hotline (770-488-7788 or toll-free 855-856-4713). Persons submitting malaria case reports (care providers, laboratories, and state and local public health officials) should provide complete information because incomplete reporting compromises case investigations and efforts to prevent infections and examine trends in malaria cases. Molecular surveillance of antimalarial drug resistance markers (https://www.cdc.gov/malaria/features/ars.html) enables CDC to track, guide treatment, and manage drug resistance in malaria parasites both domestically and internationally. More samples are needed to improve the completeness of antimalarial drug resistance analysis; therefore, CDC requests that blood specimens be submitted for any case of malaria diagnosed in the United States.


Asunto(s)
Malaria/epidemiología , Plasmodium/aislamiento & purificación , Vigilancia de la Población , Adolescente , Adulto , Anciano , Antimaláricos/farmacología , Antimaláricos/uso terapéutico , Centers for Disease Control and Prevention, U.S. , Niño , Preescolar , Resistencia a Medicamentos , Femenino , Humanos , Lactante , Malaria/diagnóstico , Malaria/tratamiento farmacológico , Malaria/transmisión , Masculino , Persona de Mediana Edad , Personal Militar/estadística & datos numéricos , Embarazo , Complicaciones Parasitarias del Embarazo/diagnóstico , Complicaciones Parasitarias del Embarazo/epidemiología , Factores de Riesgo , Estaciones del Año , Índice de Severidad de la Enfermedad , Enfermedad Relacionada con los Viajes , Estados Unidos/epidemiología , Adulto Joven
16.
Artículo en Inglés | MEDLINE | ID: mdl-33670471

RESUMEN

BACKGROUND: In Cambodia, malaria persists with changing epidemiology and resistance to antimalarials. This study aimed to describe how malaria has evolved spatially from 2006 to 2019 in Cambodia. METHODS: We undertook a secondary analysis of existing malaria data from all government healthcare facilities in Cambodia. The epidemiology of malaria was described by sex, age, seasonality, and species. Spatial clusters at the district level were identified with a Poisson model. RESULTS: Overall, incidence decreased from 7.4 cases/1000 population in 2006 to 1.9 in 2019. The decrease has been drastic for females, from 6.7 to 0.6/1000. Adults aged 15-49 years had the highest malaria incidence among all age groups. The proportion of Plasmodium (P.) falciparum + Mixed among confirmed cases declined from 87.9% (n = 67,489) in 2006 to 16.6% (n = 5290) in 2019. Clusters of P. falciparum + Mixed and P. vivax + Mixed were detected in forested provinces along all national borders. CONCLUSIONS: There has been a noted decrease in P. falciparum cases in 2019, suggesting that an intensification plan should be maintained. A decline in P. vivax cases was also noted, although less pronounced. Interventions aimed at preventing new infections of P. vivax and relapses should be prioritized. All detected malaria cases should be captured by the national surveillance system to avoid misleading trends.


Asunto(s)
Malaria Falciparum , Malaria Vivax , Malaria , Adolescente , Adulto , Cambodia/epidemiología , Femenino , Humanos , Malaria/epidemiología , Malaria Falciparum/epidemiología , Malaria Vivax/epidemiología , Persona de Mediana Edad , Recurrencia Local de Neoplasia , Estudios Retrospectivos , Adulto Joven
17.
J Infect Public Health ; 14(4): 527-532, 2021 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-33744740

RESUMEN

BACKGROUND: Due to a high burden imposed on public health from malaria disease in Sub-Saharan Africa, the vector control strategy is a significant concern. Despite the implementation of malaria control interventions in Ethiopia, it remains a major public health problem. Moreover, none of the prior researches was conducted in this title specifically. Therefore, this study investigates the impact of vector control interventions on malaria based on panel data of 10 malaria endemic-regions from 2000 to 2018. METHODS: A reflexive analysis study based on before-and-after assessment was used to evaluate the impact of vector control interventions on malaria with a difference-in-difference approach, representing Period I for before and Period II for after strategic intervention. The random-effect model was also employed to explore the direct relationship between the study variables. The data exported to Stata version 13.0 for analysis. RESULTS: The study results suggest that the negative relationship between intervention strategy and malaria cases reported in comparison with its counterfactual, showing the increase in malaria cases during Period II comparing to Period I. The study explores a remarkable achievement on the decline in mean malaria-related death in all regions after the implementation of the strategy. Furthermore, a significant relationship between indoor residual spraying, insecticide-treated mosquito nets, and malaria was demonstrated within the strategic periods. CONCLUSION: Better results achieved in Period I on mean malaria cases. The results of Period II showed a decline in mean malaria related-death, which was encouraging. The study calls for a supplementary strategy to align with the existing program. The study demonstrates the need for extra efforts on the implementation of the programme and progress about malaria.


Asunto(s)
Mosquiteros Tratados con Insecticida , Insecticidas , Malaria/prevención & control , Control de Mosquitos/métodos , Etiopía/epidemiología , Humanos , Malaria/epidemiología
18.
Pestic Biochem Physiol ; 173: 104772, 2021 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-33771251

RESUMEN

Metabolic resistance driven by multiple P450 genes is worsening insecticide resistance in malaria vectors. However, it remains unclear whether such multiple over-expression imposes an additive fitness cost in the vectors. Here, we showed that two highly over-expressed P450 genes (CYP6P9a and CYP6P9b) combine to impose additive fitness costs in pyrethroid-resistant Anopheles funestus. Genotyping of the CYP6P9b resistance allele in hybrid mosquitoes from a pyrethroid-resistant FUMOZ-R and the susceptible FANG strains revealed that this gene imposes a fitness cost in resistant mosquitoes similar to CYP6P9a. Homozygote susceptible CYP6P9b_S (SS) significantly lay more eggs than the resistant (OR = 2.2, P = 0.04) and with greater hatching rate (p < 0.04). Homozygote resistant larvae CYP6P9b_R (RR) developed significantly slower than homozygote susceptible from L1-L4 (χ2 = 7.2; P = 0.007) with a late pupation observed for RR compared to both heterozygotes and homozygotes susceptible (χ2 = 11.17; P = 0.0008). No difference was observed between genotypes for adult longevity with no change in allele frequency and gene expression across the lifespan. Furthermore, we established that CYP6P9b combines with CYP6P9a to additively exacerbate the fitness cost of pyrethroid resistance with a greater reduction in fecundity/fertility and increased developmental time of double homozygote resistant mosquitoes. Moreover, an increased proportion of double homozygote susceptible individuals was noted over 10 generations in the insecticide-free environment (χ2 = 6.3; P = 0.01) suggesting a reversal to susceptibility in the absence of selection. Such greater fitness cost imposed by multiple P450 genes shows that resistance management strategy based on rotation could help slow the spread of resistance.


Asunto(s)
Anopheles , Insecticidas , Malaria , Piretrinas , Animales , Anopheles/genética , Sistema Enzimático del Citocromo P-450/genética , Resistencia a los Insecticidas/genética , Insecticidas/farmacología , Malaria/genética , Mosquitos Vectores/genética , Piretrinas/toxicidad
19.
Nat Commun ; 12(1): 1742, 2021 03 19.
Artículo en Inglés | MEDLINE | ID: mdl-33741975

RESUMEN

A highly protective vaccine will greatly facilitate achieving and sustaining malaria elimination. Understanding mechanisms of antibody-mediated immunity is crucial for developing vaccines with high efficacy. Here, we identify key roles in humoral immunity for Fcγ-receptor (FcγR) interactions and opsonic phagocytosis of sporozoites. We identify a major role for neutrophils in mediating phagocytic clearance of sporozoites in peripheral blood, whereas monocytes contribute a minor role. Antibodies also promote natural killer cell activity. Mechanistically, antibody interactions with FcγRIII appear essential, with FcγRIIa also required for maximum activity. All regions of the circumsporozoite protein are targets of functional antibodies against sporozoites, and N-terminal antibodies have more activity in some assays. Functional antibodies are slowly acquired following natural exposure to malaria, being present among some exposed adults, but uncommon among children. Our findings reveal targets and mechanisms of immunity that could be exploited in vaccine design to maximize efficacy.


Asunto(s)
Inmunidad Humoral , Malaria/inmunología , Malaria/prevención & control , Receptores de IgG/inmunología , Esporozoítos/inmunología , Adulto , Anciano , Anticuerpos Antiprotozoarios/inmunología , Niño , Femenino , Humanos , Kenia , Vacunas contra la Malaria/inmunología , Masculino , Persona de Mediana Edad , Monocitos/inmunología , Neutrófilos/inmunología , Fagocitosis/inmunología , Plasmodium falciparum/inmunología , Receptores de IgG/metabolismo , Células THP-1 , Adulto Joven
20.
BMC Bioinformatics ; 22(1): 112, 2021 Mar 08.
Artículo en Inglés | MEDLINE | ID: mdl-33685401

RESUMEN

BACKGROUND: Manual microscopic examination of Leishman/Giemsa stained thin and thick blood smear is still the "gold standard" for malaria diagnosis. One of the drawbacks of this method is that its accuracy, consistency, and diagnosis speed depend on microscopists' diagnostic and technical skills. It is difficult to get highly skilled microscopists in remote areas of developing countries. To alleviate this problem, in this paper, we propose to investigate state-of-the-art one-stage and two-stage object detection algorithms for automated malaria parasite screening from microscopic image of thick blood slides. RESULTS: YOLOV3 and YOLOV4 models, which are state-of-the-art object detectors in accuracy and speed, are not optimized for detecting small objects such as malaria parasites in microscopic images. We modify these models by increasing feature scale and adding more detection layers to enhance their capability of detecting small objects without notably decreasing detection speed. We propose one modified YOLOV4 model, called YOLOV4-MOD and two modified models of YOLOV3, which are called YOLOV3-MOD1 and YOLOV3-MOD2. Besides, new anchor box sizes are generated using K-means clustering algorithm to exploit the potential of these models in small object detection. The performance of the modified YOLOV3 and YOLOV4 models were evaluated on a publicly available malaria dataset. These models have achieved state-of-the-art accuracy by exceeding performance of their original versions, Faster R-CNN, and SSD in terms of mean average precision (mAP), recall, precision, F1 score, and average IOU. YOLOV4-MOD has achieved the best detection accuracy among all the other models with a mAP of 96.32%. YOLOV3-MOD2 and YOLOV3-MOD1 have achieved mAP of 96.14% and 95.46%, respectively. CONCLUSIONS: The experimental results of this study demonstrate that performance of modified YOLOV3 and YOLOV4 models are highly promising for detecting malaria parasites from images captured by a smartphone camera over the microscope eyepiece. The proposed system is suitable for deployment in low-resource setting areas.


Asunto(s)
Algoritmos , Malaria , Parásitos , Animales , Pruebas Diagnósticas de Rutina , Malaria/sangre , Malaria/diagnóstico , Microscopía
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