- adherence
Compliance with a regimen (chemoprophylaxis or treatment) or with procedures and practices prescribed by a health care worker
- adverse drug reaction
A response to a medicine that is harmful and unintended and which occurs at doses normally used in humans
- adverse event
Any untoward medical occurrence in a person exposed to a biological or chemical product, which does not necessarily have a causal relationship with the product
- adverse event, serious
Any untoward medical occurrence in a person exposed to a biological or chemical product, which is not necessarily causally related to the product, and results in death, requirement for or prolongation of inpatient hospitalization, significant disability or incapacity or is life-threatening
- aestivation
A process by which mosquitoes at one or several stages (eggs, larvae, pupae, adults) survive by means of behavioural and physiological changes during periods of drought or high temperature
- age group
Subgroup of a population classified by age. The following grouping is usually recommended:
0–11 months
12–23 months
2–4 years
5–9 years
10–14 years
15–19 years
≥ 20 years
- age, physiological
Adult female mosquito age in terms of the number of gonotrophic cycles completed: nulliparous, primiparous, 2-parous, 3-parous et seq.
- age-grading, of female adult mosquitoes
Classification of female mosquitoes according to their physiological age (number of gonotrophic cycles) or simply as nulliparous or parous (parity rate)
- age-grading, of mosquito larvae
Classification of mosquito larvae as instars (development stages) 1, 2, 3 and 4
- annual blood examination rate
The number of people receiving a parasitological test for malaria per unit population per year
- Anopheles, infected
Female Anopheles mosquitoes with detectable malaria parasites
- Anopheles, infective
Female Anopheles mosquitoes with sporozoites in the salivary glands
- anopheline density
Number of female anopheline mosquitoes in relation to the number of specified shelters or hosts (e.g. per room, per trap or per person) or to a given period (e.g. overnight or per hour), specifying the method of collection
- anthropophilic
Description of mosquitoes that show a preference for feeding on humans, even when non-human hosts are available
- antimalarial medicine
A pharmaceutical product used in humans for the prevention, treatment or reduction of transmission of malaria
- artemisinin-based combination therapy
A combination of an artemisinin derivative with a longer-acting antimalarial drug that has a different mode of action
- basic reproduction number
The number of secondary cases that a single infection (index case) would generate in a completely susceptible population (referred to as R0)
- bioassay
In applied entomology, experimental testing of the biological effectiveness of a treatment (e.g. infection, insecticide, pathogen, predator, repellent) by deliberately exposing insects to it
- biological insecticide*
Pesticides made from natural materials that are meant to kill or control insects. These natural source materials may include animals, plants, bacteria or minerals
- biting rate
Average number of mosquito bites received by a host in a unit time, specified according to host and mosquito species (usually measured by human landing collection)
- capture site
Site selected for periodic sampling of the mosquito population of a locality for various purposes
- case, confirmed
Malaria case (or infection) in which the parasite has been detected in a diagnostic test, i.e. microscopy, a rapid diagnostic test or a molecular diagnostic test
- case, fever
The occurrence of fever (current or recent) in a person
- case, imported
Malaria case or infection in which the infection was acquired outside the area in which it is diagnosed
- case, index
A case of which the epidemiological characteristics trigger additional active case or infection detection. The term “index case” is also used to designate the case identified as the origin of infection of one or a number of introduced cases
- case, indigenous
A case contracted locally with no evidence of importation and no direct link to transmission from an imported case
- case, induced
A case the origin of which can be traced to a blood transfusion or other form of parenteral inoculation of the parasite but not to transmission by a natural mosquito-borne inoculation
- case, introduced
A case contracted locally, with strong epidemiological evidence linking it directly to a known imported case (first-generation local transmission)
- case, locally acquired
A case acquired locally by mosquito-borne transmission
- case, malaria
Occurrence of malaria infection in a person in whom the presence of malaria parasites in the blood has been confirmed by a diagnostic test
- case, presumed
Case suspected of being malaria that is not confirmed by a diagnostic test
- case, recrudescent
Malaria case attributed to the recurrence of asexual parasitaemia after antimalarial treatment, due to incomplete clearance of asexual parasitaemia of the same genotype(s) that caused the original illness. A recrudescent case must be distinguished from reinfection and relapse, in the case of P. vivax and P. ovale
- case, relapsing
Malaria case attributed to activation of hypnozoites of P. vivax or P. ovale acquired previously
- case, suspected malaria
Illness suspected by a health worker to be due to malaria, generally on the basis of the presence of fever with or without other symptoms
- case detection
One of the activities of surveillance operations, involving a search for malaria cases in a community
- case detection, active
Detection by health workers of malaria cases at community and household levels, sometimes in population groups that are considered at high risk. Active case detection can consist of screening for fever followed by parasitological examination of all febrile patients or as parasitological examination of the target population without prior screening for fever
- case detection, passive
Detection of malaria cases among patients who, on their own initiative, visit health services for diagnosis and treatment, usually for a febrile illness
- case follow-up
Periodic re-examination of patients with malaria (with or without treatment)
- case investigation
Collection of information to allow classification of a malaria case by origin of infection, i.e. imported, indigenous, induced, introduced, relapsing or recrudescent
- case management
Diagnosis, treatment, clinical care, counselling and follow-up of symptomatic malaria infections
- case notification
Compulsory reporting of all malaria cases by medical units and medical practitioners to either the health department or the malaria control programme, as prescribed by national laws or regulations
- catchment area
A geographical area defined and served by a health programme or institution, such as a hospital or community health centre, which is delineated on the basis of population distribution, natural boundaries and accessibility by transport
- cerebral malaria
Severe P. falciparum malaria with impaired consciousness (Glasgow coma scale < 11, Blantyre coma scale < 3) persisting for > 1 hour after a seizure
- certification of malaria-free status
Certification granted by WHO after it has been proved beyond reasonable doubt that local human malaria transmission by Anopheles mosquitoes has been interrupted in an entire country for at least three consecutive years and a national surveillance system and a programme for the prevention of reintroduction are in place
- chemoprevention, seasonal malaria
Intermittent administration of full treatment courses of an antimalarial medicine during the malaria season to prevent malarial illness. The objective is to maintain therapeutic concentrations of an antimalarial drug in the blood throughout the period of greatest risk for malaria.
- chemoprophylaxis
Administration of a medicine, at predefined intervals, to prevent either the development of an infection or progression of an infection to manifest disease
- cluster
Aggregation of relatively uncommon events or diseases in space and/or time in numbers that are considered greater than could be expected by chance
- combination therapy
A combination of two or more classes of antimalarial medicine with unrelated mechanisms of action
- coverage
A general term referring to the fraction of the population of a specific area that receives a particular intervention
- coverage, optimal
Optimal coverage is the outcome of an explicit prioritization process guiding resource allocation decisions. The process combines the analysis of impact and value for money with extensive stakeholder engagement and discussion that explicitly outlines the trade-offs involved in the selection of interventions and combining them in an intervention package. The process should take into account a country’s programmatic goals, context-specific factors, and should consider equity implications of the resource allocation decisions.
- coverage, universal health
Ensuring all individuals and communities receive the health services they need without suffering financial hardship. It includes the full spectrum of essential quality health services from health promotion to prevention, treatment, rehabilitation, and palliative care.
- cure
Elimination from an infected person of all malaria parasites that caused the infection
- cure, radical
Elimination of both blood-stage and latent liver infection in cases of P. vivax and P. ovale infection, thereby preventing relapses
- cure rate
Percentage of treated individuals whose infection is cured
- cyto-adherence
Propensity of malaria-infected erythrocytes to adhere to the endothelium of the microvasculature of the internal organs of the host
- diagnosis
The process of establishing the cause of an illness (for example, a febrile episode), including both clinical assessment and diagnostic testing
- diagnosis, molecular
Use of nucleic acid amplification-based tests to detect the presence of malaria parasites
- diagnosis, parasitological
Diagnosis of malaria by detection of malaria parasites or Plasmodium-specific antigens or genes in the blood of an infected individual
- diapause
Condition of suspended animation or temporary arrest in the development of immature and adult mosquitoes
- dosage regimen (or treatment regimen)
Prescribed formulation, route of administration, dose, dosing interval and duration of treatment with a medicine
- dose
Quantity of a medicine to be taken at one time or within a given period
- dose, loading
One or a series of doses that may be given at the start of therapy with the aim of achieving the target concentration rapidly
- drug efficacy
Capacity of an antimalarial medicine to achieve the therapeutic objective when administered at a recommended dose, which is well tolerated and has minimal toxicity
- drug resistance
The ability of a parasite strain to survive and/or multiply despite the absorption of a medicine given in doses equal to or higher than those usually recommended
- drug safety
(see Medicine safety)
- drug, gametocidal
A drug that kills male and/or female gametocytes, thus preventing them from infecting a mosquito
- drug, schizontocidal
A drug that kills schizonts, either in the liver or the blood
- endemic area
An area in which there is an ongoing, measurable incidence of malaria infection and mosquito-borne transmission over a succession of years
- endemicity, level of
Degree of malaria transmission in an area
- endophagy
Tendency of mosquitoes to blood-feed indoors
- endophily
Tendency of mosquitoes to rest indoors
- entomological inoculation rate (EIR)
Number of infective bites received per person in a given unit of time, in a human population
- epidemic
Occurrence of a number of malaria cases highly in excess of that expected in a given place and time
- epidemiological investigation
Study of the environmental, human and entomological factors that determine the incidence or prevalence of infection or disease
- erythrocytic cycle
Portion of the life cycle of the malaria parasite from merozoite invasion of red blood cells to schizont rupture. The duration is approximately 24 h in P. knowlesi, 48 h in P. falciparum, P. ovale and P. vivax, and 72 h in P. malariae.
- exophagy
Tendency of mosquitoes to feed outdoors
- exophily
Tendency of mosquitoes to rest outdoors
- experimental huts
For vector investigations, simulated house with entry and exit traps for sampling mosquitoes entering and exiting, blood-feeding indoors (when a host is present), and surviving or dying in each sub-sample, per day or night
- fixed-dose combination
A combination in which two antimalarial medicines are formulated together in the same tablet, capsule, powder, suspension or granule
- focus, malaria
A defined circumscribed area situated in a currently or formerly malarious area that contains the epidemiological and ecological factors necessary for malaria transmission
- gametocyte
Sexual stage of malaria parasites that can potentially infect anopheline mosquitoes when ingested during a blood meal
- gametocyte rate
Percentage of individuals in a defined population in whom sexual forms of malaria parasites have been detected
- geographical reconnaissance
Censuses and mapping to determine the distribution of the human population and other features relevant for malaria transmission in order to guide interventions
- gonotrophic cycle
Each complete round of ovarian development in the female mosquito, usually after ingestion of a blood meal, to yield a batch of eggs. Gonotrophic harmony is achieved when every blood meal results in one batch of eggs from the gonotrophic cycle.
- gonotrophic discordance (dissociation)
Female mosquitoes that take more than one blood meal per gonotrophic cycle
- hibernation
Process in which mosquitoes at one or several stages (eggs, larvae, pupae, adults) survive by means of behavioural or physiological changes during cold periods
- house
Any structure other than a tent or mobile shelter in which humans sleep
- household
The ecosystem, including people and animals occupying the same house and the accompanying vectors
- house-spraying
Application of liquid insecticide formulation to specified (mostly interior) surfaces of buildings
- human landing catch
A method for collecting vectors as they land on individuals
- hyperparasitaemia
A high density of parasites in the blood, which increases the risk that a patient’s condition will deteriorate and become severe malaria
- hypnozoite
Persistent liver stage of P. vivax and P. ovale malaria that remains dormant in host hepatocytes for variable periods, from three weeks to one year (exceptionally even longer), before activation and development into a pre-erythrocytic schizont, which then causes a blood-stage infection (relapse)
- importation rate
Rate of influx of parasites via infected individuals or infected Anopheles spp. mosquitoes
- importation risk
Probability of influx of infected individuals and/or infective anopheline mosquitoes
- incidence, malaria
Number of newly diagnosed malaria cases during a defined period in a specified population
- incubation period
Period between inoculation of malaria parasites and onset of clinical symptoms
- index, host preference
Proportion of blood-fed female Anopheles mosquitoes that feed on the host species and/or individual of interest
- index, human blood
Proportion of mosquito blood meals from humans
- index, parasite-density
Mean parasite density on slides examined and found positive for a sample of the population; calculated as the geometric mean of individual parasite density counts
- indoor residual spraying
Operational procedure and strategy for malaria vector control involving spraying interior surfaces of dwellings with a residual insecticide to kill or repel endophilic mosquitoes
- indoors
Inside any shelter likely to be used by humans or animals, where mosquitoes may feed or rest
- infection, chronic
Long-term presence of parasitaemia that is not causing acute or obvious illness but could potentially be transmitted
- infection, mixed
Malaria infection with more than one species of Plasmodium
- infection, reservoir of
Any person or animal in which Plasmodium species live and multiply, such that they can be transmitted to a susceptible host
- infection, submicroscopic
Low-density blood-stage malaria infections that are not detected by conventional microscopy
- infectious
Capable of transmitting infection, a term commonly applied to human hosts
- infective
Capable of producing infection, a term commonly applied to parasites (e.g., gametocytes, sporozoites) or to the vector (mosquito)
- infectivity
Ability of a given Plasmodium strain to establish infection in susceptible humans and develop in competent Anopheles mosquitoes *[and undergo development until the mosquito has sporozoites in its salivary glands]
- insecticide
Chemical product (natural or synthetic) that kills insects. Ovicides kill eggs; larvicides (larvacides) kill larvae; pupacides kill pupae; adulticides kill adult mosquitoes. Residual insecticides remain active for an extended period
- insecticide, cross-resistance
Resistance to one insecticide by a mechanism that also confers resistance to another insecticide, even when the insect population has not been selected by exposure to the latter
- insecticide discriminating dose, or diagnostic dose for resistance
Amount of an insecticide (usually expressed as the concentration per standard period of exposure), which, in a sample of mosquitoes containing resistant individuals, distinguishes between susceptible and resistant phenotypes and determines their respective proportions
- insecticide, dose
Amount of active ingredient of insecticide applied per unit area of treatment (mg/m2) for indoor residual spraying and treated mosquito nets, or per unit of space (mg/m3) for space spraying and per unit area of application (g/ha or mg/m2) or per volume of water (mg/L) for larvicides
- insecticide, mixture
Insecticide product consisting of two or more active ingredients mixed as one formulation so that, when applied, the mosquito will contact both simultaneously
- insecticide mosaic
Strategy for mitigating resistance, whereby insecticides with different modes of action are applied in different parts of an area under coverage (usually in a grid pattern), so that parts of the mosquito populations are exposed to one insecticide and others to another
- insecticide resistance
Property of mosquitoes to survive exposure to a standard dose of insecticide; may be the result of physiological or behavioural adaptation
- insecticide rotation
Strategy involving sequential applications of insecticides with different modes of action to delay or mitigate resistance
- insecticide tolerance
Less-than-average susceptibility to insecticide but not inherited as resistance
- insecticide, contact
Insecticide that exerts a toxic action on mosquitoes when they rest on a treated surface; the insecticide is absorbed via the tarsi (feet).
- insecticide, fumigant
Insecticide that acts by releasing vapour from a volatile substance
- insecticide, residual
Insecticide that, when suitably applied onto a surface, maintains its insecticidal activity for a considerable time by either contact or fumigant action
- integrated vector management (IVM)
Rational decision-making for optimal use of resources for vector control
- intermittent preventive treatment in infants (IPTi)
A full therapeutic course of sulfadoxine-pyrimethamine delivered to infants in co-administration with DTP2/Penta2, DTP3/Penta3 and measles immunization, regardless of whether the infant is infected with malaria
- intermittent preventive treatment in pregnancy (IPTp)
A full therapeutic course of antimalarial medicine given to pregnant women at routine prenatal visits, regardless of whether the woman is infected with malaria
- invasive species
A non-native species that establishes in a new ecosystem, and causes, or has the potential to cause, harm to the environment, economy, or human health
- larval source management
Management of aquatic habitats (water bodies) that are potential habitats for mosquito larvae, in order to prevent completion of development of the immature stages
- larvicide
Substance used to kill mosquito larvae
- latent period
For P. vivax and P. ovale infections, the period between the primary infection and subsequent relapses. This stage is asymptomatic; parasites are absent from the bloodstream but present in hepatocytes.
- long-lasting insecticidal net (LLIN)
A factory-treated mosquito net made of material into which insecticide is incorporated or bound around the fibres. The net must retain its effective biological activity for at least 20 WHO standard washes under laboratory conditions and three years of recommended use under field conditions.
- malaria case
(See Case, malaria)
- malaria, cerebral
(See Cerebral malaria)
- malaria control
Reduction of disease incidence, prevalence, morbidity or mortality to a locally acceptable level as a result of deliberate efforts. Continued interventions are required to sustain control.
- malaria elimination
Interruption of local transmission (reduction to zero incidence of indigenous cases) of a specified malaria parasite in a defined geographical area as a result of deliberate activities. Continued measures to prevent re-establishment of transmission are required.
- malaria eradication
Permanent reduction to zero of the worldwide incidence of infection caused by human malaria parasites as a result of deliberate activities. Interventions are no longer required once eradication has been achieved.
- malaria infection
Presence of Plasmodium parasites in blood or tissues, confirmed by diagnostic testing
- malaria mortality rate
Number of deaths from malaria per unit of population during a defined period
- malaria pigment (haemozoin)
A brown-to-black granular material formed by malaria parasites as a by-product of haemoglobin digestion. Pigment is evident in mature trophozoites and schizonts. It may also be phagocytosed by monocytes, macrophages and polymorphonuclear neutrophils.
- malaria prevalence (parasite prevalence)
Proportion of a specified population with malaria infection at one time
- malaria receptivity
Degree to which an ecosystem in a given area at a given time allows for the transmission of Plasmodium spp. from a human through a vector mosquito to another human.
- malaria reintroduction
The occurrence of introduced cases (cases of the first-generation local transmission that are epidemiologically linked to a confirmed imported case) in a country or area where the disease had previously been eliminated
- malaria risk stratification
Classification of geographical areas or localities according to factors that determine receptivity and vulnerability to malaria transmission
- malaria stratification
Classification of geographical areas or localities according to epidemiological, ecological, social and economic determinants for the purpose of guiding malaria interventions
- malaria, cross-border
Malaria transmission associated with the movement of individuals or mosquitoes across borders
- malaria-free
Describes an area in which there is no continuing local mosquito-borne malaria transmission and the risk for acquiring malaria is limited to infection from introduced cases
- malariogenic potential
Potential level of transmission in a given area arising from the combination of malaria receptivity, importation rate of malaria parasites and infectivity
- malariometric survey
Survey conducted in a representative sample of selected age groups to estimate the prevalence of malaria and coverage of interventions
- malarious area
Area in which transmission of malaria is occurring or has occurred during the preceding three years
- mass drug administration (MDA)
Administration of antimalarial treatment to all age groups of a defined population or every person living in a defined geographical area (except those for whom the medicine is contraindicated) at approximately the same time and often at repeated intervals
- mass screening
Population-wide assessment of risk factors for malaria infection to identify subgroups for further intervention, such as diagnostic testing, treatment or preventive services
- mass screening, testing and treatment
Screening of an entire population for risk factors, testing individuals at risk and treating those with a positive test result
- mass testing and focal drug administration
Testing a population and treating groups of individuals or entire households in which one or more infections is detected
- mass testing and treatment
Testing an entire population and treating individuals with a positive test result
- medicine safety
Characteristics of a medicine that reflects its potential to cause harm, including the important identified risks of a drug and important potential risks
- merozoite
Extracellular stage of a parasite released into host plasma when a hepatic or erythrocytic schizont ruptures; the merozoites can then invade red blood cells.
- monotherapy
Antimalarial treatment with a single active compound or a synergistic combination of two compounds with related mechanisms of action
- national focus register
Centralized database of all foci of malaria infection in a country, which includes relevant data on physical geography, parasites, hosts and vectors for each focus
- national malaria case register
Centralized database with individual records of all malaria cases registered in a country
- net, insecticide-treated (ITN)
Mosquito net that repels, disables or kills mosquitoes that come into contact with the insecticide on the netting material. The three categories of insecticide-treated net are:
conventionally treated net: a mosquito net that has been treated by dipping it into a WHO-recommended insecticide. To ensure its continued insecticidal effect, the net should be re-treated periodically.
long-lasting insecticidal net: a factory-treated mosquito net made of netting material with insecticide incorporated within or bound around the fibres. The net must retain its effective biological activity for at least 20 WHO standard washes under laboratory conditions and three years of recommended use under field conditions.
pyrethroid-PBO net: a mosquito net that includes both a pyrethroid insecticide and the synergist piperonyl butoxide. To date, pyrethroid-PBO nets have not met required thresholds to qualify as long-lasting insecticidal nets.
- oocyst
The stage of malaria parasite that develops from the ookinete; the oocyst grows on the outer wall of the midgut of the female mosquito.
- oocyst rate
Percentage of female Anopheles mosquitoes with oocysts on the midgut
- ookinete
Motile stage of malaria parasite after fertilization of macrogamete and preceding oocyst formation
- parasitaemia
Presence of parasites in the blood
- parasitaemia, asymptomatic
The presence of asexual parasites in the blood without symptoms of illness
- parasite clearance time
Time between first drug administration and the first examination in which no parasites are present in the blood by microscopy
- parasite density
Number of asexual parasites per unit volume of blood or per number of red blood cells
- parasite density, low
Presence of Plasmodium parasites in the blood at parasite density below 100 parasites/μl
- patent period
Period during which malaria parasitaemia is detectable
-
Plasmodium
Genus of protozoan blood parasites of vertebrates that includes the causal agents of malaria. P. falciparum, P. malariae, P. ovale and P. vivax cause malaria in humans. Human infection with the monkey malaria parasite P. knowlesi and very occasionally with other simian malaria species may occur in tropical forest areas.
- population at risk
Population living in a geographical area where locally acquired malaria cases have occurred in the past three years
- population, target
An implementation unit targeted for activities or services (e.g., prevention, treatment)
- pre-erythrocytic development
Development of the malaria parasite from the time it first enters the host and invades liver cells until the hepatic schizont ruptures
- pre-patent period
Period between inoculation of parasites and the first appearance of parasitaemia
- prequalification
Process to ensure that health products are safe, appropriate and meet stringent quality standards for international procurement
- preventive chemotherapy
Use of medicines either alone or in combination to prevent malaria infections and their consequences
- prophylaxis
Any method of protection from or prevention of disease; when applied to chemotherapy, it is commonly termed “chemoprophylaxis”.
- prophylaxis, causal
Complete prevention of erythrocytic infection by destroying the pre-erythrocytic forms of the parasite
- public health value*
A product has public health value if it has proven protective efficacy to reduce or prevent infection and/or disease in humans, at the individual level, community level or both
- rapid diagnostic test (RDT)
Immunochromatographic lateral flow device for rapid detection of malaria parasite antigens
- rapid diagnostic test, combination
Malaria rapid diagnostic test that can detect a number of different malaria species
- rapid diagnostic test positivity rate
Proportion of positive results among all rapid diagnostic tests performed
- reactive focal screening, testing, treating or drug administration
Screening, testing, treating or administering drugs to a subset of a population in a given area in response to the detection of an infected person
- recrudescence
Recurrence of asexual parasitaemia of the same genotype(s) that caused the original illness, due to incomplete clearance of asexual parasites after antimalarial treatment
- recurrence
Reappearance of asexual parasitaemia after treatment, due to recrudescence, relapse (in P. vivax and P. ovale infections only) or a new infection
- reinfection
A new infection that follows a primary infection; can be distinguished from recrudescence by the parasite genotype, which is often (but not always) different from that which caused the initial infection
- reintroduction risk
The risk that endemic malaria will be re-established in a specific area after its elimination
- relapse
Recurrence of asexual parasitaemia in P. vivax or P. ovale infections arising from hypnozoites
- repellent
Any substance that causes avoidance in mosquitoes, especially substances that deter them from settling on the skin of the host (topical repellent) or entering an area or room (area repellent, spatial repellent, excito-repellent)
- resistance
(See Drug resistance, Insecticide resistance)
- ring form (ring stage, ring-stage trophozoite)
Young, usually ring-shaped malaria trophozoites, before pigment is evident by microscopy
- schizont
Stage of the malaria parasite in host liver cells (hepatic schizont) or red blood cells (erythrocytic schizont) that is undergoing nuclear division by schizogony and, consequently, has more than one nucleus
- screening
Identification of groups at risk that may require further intervention, such as diagnostic testing, treatment or preventive services
- selection pressure
The force of an external agent that confers preferential survival; examples are the pressure of antimalarial medicines on malaria parasites and of insecticides on anopheline mosquitoes
- sensitivity (of a test)
Measured as the proportion of people with malaria infection (true positives) who have a positive result
- serological assay
Procedure used to measure antimalarial antibodies in serum
- severe anaemia
Haemoglobin concentration of < 5 g/100 mL (haematocrit < 15%)
- severe falciparum malaria
Acute falciparum malaria with signs of severe illness and/or evidence of vital organ dysfunction
- single-dose regimen
Administration of a medicine as a single dose to achieve a therapeutic objective
- slide positivity rate
Proportion of blood smears found to be positive for Plasmodium among all blood smears examined
- specificity (of a test)
Measured as the proportion of people without malaria infection (true negatives) who have a negative result
- sporozoite
Motile stage of the malaria parasite that is inoculated by a feeding female anopheline mosquito and may cause infection
- sporozoite rate
Percentage of female Anopheles mosquitoes with sporozoites in the salivary glands
- spray round
Spraying of all sprayable structures in an area designated for coverage in an indoor residual spraying programme during a discrete period
- sprayable
In the context of a malaria vector control programme, a unit (dwelling, house, room, shelter, structure, surface) suitable for spraying or required to be sprayed
- spraying cycle
Repetition of spraying operations at regular intervals, often designated in terms of the interval between repetitions, e.g., a 6-month spraying cycle when spraying is repeated after a 6-month interval
- spraying frequency
Number of regular applications of insecticide per house per year, usually by indoor residual spraying
- spraying interval
Time between successive applications of insecticide
- spraying, focal
Spray coverage by indoor residual spraying and/or space spraying of houses or habitats in a limited geographical area
- spraying, residual (IRS)
Spraying the interior walls and ceilings of dwellings with a residual insecticide to kill or repel endophilic mosquito vectors of malaria
- surveillance
Continuous, systematic collection, analysis and interpretation of disease-specific data and use in planning, implementing and evaluating public health practice
- synergist*
A substance that does not itself have insecticidal properties, but that, when mixed and applied with insecticides of a particular class, considerably enhances their potency by inhibiting an enzyme that normally acts to detoxify the insecticide in the insect system
- testing, malaria
Use of a malaria diagnostic test to determine whether an individual has malaria infection
- tolerance
A response in a human or mosquito host to a given quantum of infection, toxicant or drug that is less than expected
- transmission intensity
The frequency with which people living in an area are bitten by anopheline mosquitoes carrying human malaria sporozoites
- transmission season
Period of the year during which most mosquito-borne transmission of malaria infection occurs
- transmission, re-establishment of
Renewed presence of a measurable incidence of locally acquired malaria infection due to repeated cycles of mosquito-borne infections in an area in which transmission had been interrupted
- transmission, interruption of
Cessation of mosquito-borne transmission of malaria in a geographical area as a result of the application of antimalarial measures
- transmission, perennial
Transmission that occurs throughout the year with no great variation in intensity
- transmission, residual
Persistence of malaria transmission following the implementation in time and space of a widely effective malaria programme
- transmission, seasonal
Transmission that occurs only during some months of the year and is markedly reduced during other months
- transmission, stable
Epidemiological type of malaria transmission characterized by a steady prevalence pattern, with little variation from one year to another except as the result of rapid scaling up of malaria interventions or exceptional environmental changes that affect transmission
- transmission, unstable
Epidemiological type of malaria transmission characterized by large variation in incidence patterns from one year to another
- trap, mosquito
Device designed for capturing mosquitoes with or without attractant components (light, CO2, living baits, suction)
- treatment failure
Inability to clear malarial parasitaemia or prevent recrudescence after administration of an antimalarial medicine, regardless of whether clinical symptoms are resolved
- treatment, anti-relapse
Antimalarial treatment designed to kill hypnozoites and thereby prevent relapses or late primary infections with P. vivax or P. ovale
- treatment, directly observed (DOT)
Treatment administered under the direct observation of a health care worker
- treatment, first-line
Treatment recommended in national treatment guidelines as the medicine of choice for treating malaria
- treatment, second-line
Treatment used after failure of first-line treatment or in patients who are allergic to or unable to tolerate the first-line treatment
- treatment, presumptive
Administration of an antimalarial drug or drugs to people with suspected malaria without testing or before the results of blood examinations are available
- treatment, preventive
Intermittent administration of a full therapeutic course of an antimalarial either alone or in combination to prevent malarial illness by maintaining therapeutic drug levels in the blood throughout the period of greatest risk
- treatment, radical
Treatment to achieve complete cure. This applies only to vivax and ovale infections and consists of the use of medicines that destroy both blood and liver stages of the parasite.
- trophozoite
The stage of development of malaria parasites growing within host red blood cells from the ring stage to just before nuclear division. Trophozoites contain malaria pigment that is visible by microscopy.
- uncomplicated malaria
Symptomatic malaria parasitaemia without signs of severity or evidence of vital organ dysfunction
- vector
In malaria, adult females of any mosquito species in which Plasmodium undergoes its sexual cycle (whereby the mosquito is the definitive host of the parasite) to the infective sporozoite stage (completion of extrinsic development), ready for transmission when a vertebrate host is bitten
- vector competence
For malaria, the ability of the mosquito to support completion of malaria parasite development after zygote formation and oocyst formation, development and release of sporozoites that migrate to salivary glands, allowing transmission of viable sporozoites when the infective female mosquito feeds again
- vector control
Measures of any kind against malaria-transmitting mosquitoes, intended to limit their ability to transmit the disease
- vector susceptibility
The degree to which a mosquito population is susceptible (i.e., not resistant) to insecticides
- vector, principal
The species of Anopheles mainly responsible for transmitting malaria in any particular circumstance
- vector, secondary or subsidiary
Species of Anopheles thought to play a lesser role in transmission than the principal vector; capable of maintaining malaria transmission at a reduced level
- vectorial capacity
Number of new infections that the population of a given vector would induce per case per day at a given place and time, assuming that the human population is and remains fully susceptible to malaria
- vigilance
A function of the public health services for preventing reintroduction of malaria. Vigilance consists of close monitoring for any occurrence of malaria in receptive areas and application of the necessary measures to prevent re-establishment of transmission.
