Entomological Surveillance in Former Malaria-endemic Areas of Southern Italy.
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ABSTRACT:
SUBMITTER: Raele DA
PROVIDER: S-EPMC8619560 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:BACKGROUND:China has achieved zero indigenous malaria case report in 2017. However, along with the increasing of international cooperation development, there is an increasing number of imported malaria cases from Chinese nationals returning from malaria-affected countries. Previous studies have focused on malaria endemic areas in China. There is thus limited information on non-endemic areas in China, especially on the performance of malaria surveillance and response in health facilities. METHODS:A comparative retrospective study was carried out based on routine malaria surveillance data collected from 2013 to 2017. All imported malaria cases reported within the mainland of China were included. Variables used in the comparative analysis between cases in former endemic and former non-endemic areas, included age, gender and occupation, destination of overseas travel, Plasmodium species and patient health outcome. Monthly aggregated data was used to compare seasonal and spatial characteristics. Geographical distribution and spatial-temporal aggregation analyses were conducted. Time to diagnosis and report, method of diagnosis, and level of reporting/diagnosing health facilities were used to assess performance of health facilities. RESULTS:A total of 16 733 malaria cases, out of which 90 were fatal, were recorded in 31 provinces. The majority of cases (96.2%) were reported from former malaria endemic areas while 3.8% were reported from former non-malaria endemic areas. Patients in the age class from 19 to 59 years and males made the highest proportion of cases in both areas. There were significant differences between occupational categories in the two areas (P < 0.001). In former endemic areas, the largest proportion of cases was among outdoor workers (80%). Two peaks (June, January) and three peaks (June, September and January) were found in former endemic and former non-endemic areas, respectively. Time between the onset of symptoms and diagnosis at clinics was significantly different between the two areas at different level of health facilities (P < 0.05). CONCLUSIONS:All the former non-endemic areas are now reporting imported malaria cases. However, the largest proportion of imported cases is still reported from former endemic areas. Health facilities in former endemic areas outperformed those in former non-endemic areas. Information, treatment, and surveillance must be provided for expatriates while capacity building and continuous training must be implemented at health facilities in China.
| S-EPMC6610923 | biostudies-literature
Project description:BackgroundThe Lao PDR National Strategic Plan for malaria control and elimination for year 2021-2025 emphasizes the importance of routine entomological surveillance being conducted in areas with high transmission and in active malaria foci in elimination targeted areas. The collection of entomological surveillance data that is closely linked to recent epidemiological data is crucial for improving impact, as it contributes to the evidence package that supports operational and strategic decision-making of national malaria programmes, as they accelerate their last mile of elimination.MethodsThe Center for Malariology Parasitology and Epidemiology (CMPE) entomology team conducted entomological surveillance activities at 13 sentinel sites in 8 provinces and at active transmission foci sites from 2018 to 2020. The techniques used for the mosquito collection were indoor and outdoor human landing collections (from houses and from cultivation areas) and cattle baited net trap collections.ResultsThere were 5601 Anopheles mosquito females captured and identified throughout the study, on both human and cow bait. They represented 15 different species or species complexes. The primary malaria vectors as well as the secondary vectors were present in all collection sites in the south, indicating that people living in these rural areas with high malaria incidence are exposed to the vectors. The vectors were highly zoophilic, but they still bite humans throughout the night with a high peak of activity before midnight, both indoors and outdoors. Overall, 17% of the malaria vectors were collected indoors when the people are sleeping. This confirms the importance of bed net use during the night. Thirty-two percent of primary and secondary vectors were collected outdoors at times when people are usually awake and outdoors, which shows that people are exposed to potentially infectious mosquitoes and the importance of personal protection at these times. The findings showed that residual transmission may occur outdoors in the villages, and outside the villages in cultivation fields and forested areas. Epidemiological data showed that transmission was higher in surveillance sites which were targeted as part of a malaria response rather than sentinel sites.ConclusionsUnderstanding where and how transmission is persisting, monitoring and mapping vector species distribution in areas with active transmission, monitoring biting trends, and designing evidence based and effective vector control interventions are critical to accelerating progress toward malaria elimination. In this context, the role of entomological surveillance combined with epidemiological data should be considered as a cornerstone in achieving malaria elimination.
| S-EPMC10589990 | biostudies-literature
Project description:The emergence and spread of multidrug resistant (MDR) malaria caused by Plasmodium falciparum or Plasmodium vivax have become increasingly important in the Greater Mekong Subregion (GMS). MDR malaria is the heritable and hypermutable property of human malarial parasite populations that can decrease in vitro and in vivo susceptibility to proven antimalarial drugs as they exhibit dose-dependent drug resistance and delayed parasite clearance time in treated patients. MDR malaria risk situations reflect consequences of the national policy and strategy as this influences the ongoing national-level or subnational-level implementation of malaria control strategies in endemic GMS countries. Based on our experience along with current literature review, the design of ecotope-based entomological surveillance (EES) and molecular xenomonitoring of MDR falciparum and vivax malaria parasites in Anopheles vectors is proposed to monitor infection pockets in transmission control areas of forest and forest fringe-related malaria, so as to bridge malaria landscape ecology (ecotope and ecotone) and epidemiology. Malaria ecotope and ecotone are confined to a malaria transmission area geographically associated with the infestation of Anopheles vectors and particular environments to which human activities are related. This enables the EES to encompass mosquito collection and identification, salivary gland DNA extraction, Plasmodium- and species-specific identification, molecular marker-based PCR detection methods for putative drug resistance genes, and data management. The EES establishes strong evidence of Anopheles vectors carrying MDR P. vivax in infection pockets epidemiologically linked with other data obtained during which a course of follow-up treatment of the notified P. vivax patients receiving the first-line treatment was conducted. For regional and global perspectives, the EES would augment the epidemiological surveillance and monitoring of MDR falciparum and vivax malaria parasites in hotspots or suspected areas established in most endemic GMS countries implementing the National Malaria Control Programs, in addition to what is guided by the World Health Organization.
| S-EPMC4198816 | biostudies-literature
Project description:BackgroundMining activities have environmental impacts due to sediment movement and contamination of areas and may also pose risks to people's food security. In Brazil, the majority of coal mining activities are in the south, in the Santa Catarina carboniferous region. In this region, previously mined areas contaminated with heavy metals frequently occur nearby inhabited zones. Mining is part of the daily lives of local communities, and its environmental impacts are visible in the landscape; however, plants with medicinal and food use from these areas can be still consumed. Heavy metals are contaminants that do not have odor, color, or taste, and are therefore difficult to detect. We aimed to verify whether people use plants from contaminated mine areas, and understand which factors can influence the use of these resources, even from areas visibly impacted.MethodsWe conducted 195 semi-structured interviews with residents from 14 areas nearby abandoned mines in the main municipalities of the Santa Catarina carboniferous region. We asked each interviewee about the length of time they lived in the region, their perception of the quality of the environment, and what plant species were used and for what purpose. We constructed generalized multivariate linear models to verify which variables can affect the group of species mentioned and generalized linear models to verify which variables can affect the total number of citations. We estimated the frequency of citing species collected using the Smith index.ResultsFrom all interviewees, 127 (65%) reported collecting plants for medicinal and food use, directly from contaminated mine areas. Long-term residents, as well as those who noticed more environmental changes (positive and negative), cited more plants used and had more detailed knowledge of plant use in their communities. When asked if they were aware of the possible contamination of mined areas, 85% said they knew about it. However, only 10% associated negative health effects with the use of plant species collected in contaminated mined areas.ConclusionsOur study demonstrates that people living nearby contaminated areas use and consume locally sourced plants, e.g., people know little about the danger of this contamination in their food and the risk of these contaminants to their health. These results also reveal a lack of information about contamination, as well as a lack of actions that include local communities in contaminated area restoration strategies. This situation poses a risk to the food security of the people living nearby former coal mining areas.
| S-EPMC7427890 | biostudies-literature
Project description:African populations are characterized by high degree of genetic diversity. This high genetic diversity could result from the natural selection pressure. Several studies have described an association between some genetic diversities and difference of susceptibility to infectious diseases like malaria. It seems therefore important to consider genetic diversity impact when interpreting results of clinical trials in malaria endemic areas. This study aimed to determine the genetic polymorphism with erythrocyte traits in different populations of malaria endemic area in Mali. The cross-sectional surveys were carried out in different ethnic groups living in malaria endemic areas in Mali. Six milliliters of whole blood were collected in EDTA vials from each participant after informed consent has been obtained. The ABO, RH, Kell, MNSs, Kidd and Duffy systems phenotypes were assessed by the technique of gel filtration. A total of 231 subjects were included from six villages. The blood groups phenotypes O (40.7%) and A (31.2%) were more frequent with respective allele frequencies of 0.65 and 0.21. In the RH system the haplotypes R0 (0.55), r (0.20) and R1 (0.13) were the most frequent. Seven percent (7%) of Duffy positive and 4% of Glycophorin B deficiency (S-s-) were observed among participants. All participants were Kell negative. ABO and RH systems were polymorphic in these ethnic groups in Mali. Their implication in susceptibility to malaria should be taken into account in clinical trials interpretation, and for prevention of blood transfusion risks during anemia frequently caused by malaria in children.
| S-EPMC6319707 | biostudies-literature
Project description:BackgroundMalaria is a major public health problem in Angola, with Anopheles gambiae sensu lato (s.l.) and An. funestus s.l. being the primary vectors. This study aimed to clarify the information gaps concerning local Anopheles mosquito populations. Our objectives were to assess their abundance, geographical dispersion, and blood-feeding patterns. We also investigated their insecticide resistance. Molecular methods were used to identify sibling species, determine the origin of blood meals, measure Plasmodium falciparum infection rates, and detect the presence of knockdown resistance (kdr) mutations.MethodsAdult mosquitoes were collected indoors using CDC light traps from nine randomly selected households at two sentinel sites with distinct ecological characteristics. The samples were collected from 1 February to 30 June 2022. Anopheles mosquitoes were morphologically identified and subjected to molecular identification. Unfed Anopheles females were tested for the presence of P. falciparum DNA in head and thorax, and engorged females were screened for the source of the blood meals. Additionally, members of An. gambiae complex were genotyped for the presence of the L1014F and L1014S kdr mutations.ResultsIn total, 2226 adult mosquitoes were collected, including 733 Anopheles females. Molecular identification revealed the presence of Anopheles coluzzii, An. gambiae senso stricto (s.s.), An. arabiensis, and An. funestus s.s. Notably, there was the first record of An. coluzzii/An. gambiae s.s. hybrid and An. vaneedeni in Benguela Province. Plasmodium falciparum infection rates for An. coluzzii at the urban sentinel site and An. funestus s.s. at the rural site were 23.1% and 5.7%, respectively. The L1014F kdr mutation was discovered in both resistant and susceptible An. coluzzii mosquitoes, while the L1014S mutation was detected in An. gambiae s.s. for the first time in Benguela Province. No kdr mutations were found in An. arabiensis.ConclusionsThis study provides valuable insights into the molecular characteristics of malaria vectors from the province of Benguela, emphasising the need for continuous surveillance of local Anopheles populations regarding the establishment of both kdr mutations for tailoring vector control interventions.
| S-EPMC10918887 | biostudies-literature
Project description: Not available
| S-EPMC7829491 | biostudies-literature
Project description:Malaria is a responsible for approximately 600 thousand deaths worldwide every year. Appropriate and timely treatment of malaria can prevent deaths but is dependent on accurate and rapid diagnosis of the infection. Currently, microscopic examination of the Giemsa stained blood smears is the method of choice for diagnosing malaria. Although it has limited sensitivity and specificity in field conditions, it still remains the gold standard for the diagnosis of malaria. Here, we report the development of a fluorescence in situ hybridization (FISH) based method for detecting malaria infection in blood smears and describe the use of an LED light source that makes the method suitable for use in resource-limited malaria endemic countries. The Plasmodium Genus (P-Genus) FISH assay has a Plasmodium genus specific probe that detects all five species of Plasmodium known to cause the disease in humans. The P. falciparum (PF) FISH assay and P. vivax (PV) FISH assay detect and differentiate between P. falciparum and P. vivax respectively from other Plasmodium species. The FISH assays are more sensitive than Giemsa. The sensitivities of P-Genus, PF and PV FISH assays were found to be 98.2%, 94.5% and 98.3%, respectively compared to 89.9%, 83.3% and 87.9% for the detection of Plasmodium, P. falciparum and P. vivax by Giemsa staining respectively.
| S-EPMC4558036 | biostudies-literature
Project description:Malaria remains a life-threatening disease in many tropical countries. Honduras has successfully reduced malaria transmission as different control methods have been applied, focusing mainly on indoor mosquitoes. The selective pressure exerted by the use of insecticides inside the households could modify the feeding behavior of the mosquitoes, forcing them to search for available animal hosts outside the houses. These animal hosts in the peridomicile could consequently become an important factor in maintaining vector populations in endemic areas. Herein, we investigated the blood meal sources and Plasmodium spp. infection on anophelines collected outdoors in endemic areas of Honduras. Individual PCR reactions with species-specific primers were used to detect five feeding sources on 181 visibly engorged mosquitoes. In addition, a subset of these mosquitoes was chosen for pathogen analysis by a nested PCR approach. Most mosquitoes fed on multiple hosts (2 to 4), and 24.9% of mosquitoes had fed on a single host, animal or human. Chicken and bovine were the most frequent blood meal sources (29.5% and 27.5%, respectively). The average human blood index (HBI) was 22.1%. None of the mosquitoes were found to be infected with Plasmodium spp. Our results show the opportunistic and zoophilic behavior of Anopheles mosquitoes in Honduras.
| S-EPMC7412045 | biostudies-literature
Project description:BackgroundMalaria remains a major threat, to both travellers and military personnel deployed to endemic areas. The recommendations for travellers given by the World Health Organization is based on the incidence of malaria in an area and do not take the degree of exposure into account. The aim of this article is to evaluate the exposure of travellers by entomologic methods, which are the commonly used measures of the intensity of malaria transmission.MethodsFrom February 2004 to June 2004, five groups of 30 military personnel were stationed in up to 10 sites in western Côte d'Ivoire, from one week to several months. Adult mosquitoes were collected by human landing catches at each site during the five months and the level of exposure to malaria transmission of each group was estimated.ResultsThe level of transmission varied from one site to another one from less than one to approximately more than 100 infective bites per month. In the majority of sites, at least two anopheline species were involved in transmission. The cumulative EIR over the study period varied according to the groups from 29 infected bites per person/per mission to 324.ConclusionThe level of malaria transmission and malaria risk varies widely (varying by a factor of eleven) between groups of travellers travelling in the same region and at the same time. Physicians involved in travel medicine or supporting expatriated populations or refugees should consider this heterogeneity and emphasize the importance of combining appropriate measures, such as chemoprophylaxis and protective measures against mosquitoes.
| S-EPMC2726180 | biostudies-literature