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Home , Coleopterology, Entomology, Lepidopterology, Medical entomology, Melittology, Myrmecology

Medical in Brief

Dr. Alfatih Saifudinn Aljafari Assistant professor of College of Medicine- Al Jouf University Aim and objectives

• Aim: – To bring attention to medical entomology as important biomedical

• Objective: – By the end of this presentation, audience could be able to: • Understand the scope of Medical Entomology • Know medically important • Understand the basic of transmission dynamic •

Medical Entomology in Brief- Dr. Aljafari (CME- January 2019) In this presentation

• Introduction • Classification of arthropods • Examples of medical and public health important • • Dynamic of disease transmission • Other application of entomology

Medical Entomology in Brief- Dr. Aljafari (CME- January 2019) Definition

• Entomology: – The branch of concerned with the study of .

• Medical Entomology: – Branch of Biomedical concerned with “ArthrobodsIn the past the term "insect" was more vague, and historically the definition of entomology included the study of terrestrial in other groups or other phyla, such, as , myriapods, earthworms, land snails, and slugs. This wider meaning may still be encountered in informal use.

• At some 1.3 million described species, insects account for more than two-thirds of all known organisms, date back some 400 million years, and have many kinds of interactions with humans and other forms of life on earth

Medical Entomology in Brief- Dr. Aljafari (CME- January 2019) Arthropods and Human

• Transmission of infectious agents • Allergy • Injury • Inflammation • Agricultural damage • • • Silk

Medical Entomology in Brief- Dr. Aljafari (CME- January 2019) Phylum Arthropods

• Hard exoskeleton, segmented bodies, jointed appendages • Nearly one million species identified so far, mostly insects • The exoskeleton, or cuticle, is composed of chitin. • Acute senses include simple and compound eyes, brains, and many ganglia. • Arthropods use pheromones to communicate. • They have open circulatory systems, complete digestive system, and efficient means of wastes excretion by Malpighian tubes. • Arthropods reproduce sexually, but some exhibit parthenogenesis.

Medical Entomology in Brief- Dr. Aljafari (CME- January 2019) 300 million years old fossil with Insect perfectly preserved in amber full body impression

Medical Entomology in Brief- Dr. Aljafari (CME- January 2019) Medical Entomology in Brief- Dr. Aljafari (CME- January 2019) Science for every insect

• - • Dipterology - • Odonatology - and damselflies • Hemipterology - true bugs • Isopterology - termites • - and • (or Apiology) - • - • - , crickets, etc. • Trichopterology - caddis flies • Vespology - Social

Medical Entomology in Brief- Dr. Aljafari (CME- January 2019) Phylum: Arthropoda

Sub-Phylum: Chelicerata Sub-Phylum: Mandibulata (Antennata)

Class: Arachnida/Octapoda; e.g., Spider, Mites and

Class: Insecta/ Class: Class: Crustacea; two pairs of antennae. e.g. Crayfish, Crabs, lobsters, shrimps

Sub-class: (4 Orders) Sub-class: Chilopoda; e.g. Centipedes Sub-class: Pterygota (27 Orders) Sub-class: Diplopoda; e.g. Millipedes

Medical Entomology in Brief- Dr. Aljafari (CME- January 2019) Medical Entomology in Brief- Dr. Aljafari (CME- January 2019) Class Arachnida

• A typical adult has two distinct body regions: Cephalothorax and abdomen. – Ticks and mites have only one body segment.

• Cephalothorax, bears 4 pairs of legs; a pair of chelicerae that are; a pair of pedipalps and simple eyes.

• They have no antennae and no wings.

• large abdomen with no external gills or locomotor organs. – Excretion by Malpighian tubules. – Respiration by book lungs and trachea. • Spiders, mites, ticks, scorpions.

Medical Entomology in Brief- Dr. Aljafari (CME- January 2019) Medical Entomology in Brief- Dr. Aljafari (CME- January 2019) Examples Arachinds of medically important for Human

Hottentotta tamulus Poisonous (neurotoxin)

Sarcoptes scabiei -Lays its eggs in dermal layer -Severe itching - Causing (Sarcoptic mange) OR

Black widow (Latrodectus mactans)

Poisonous

Medical Entomology in Brief- Dr. Aljafari (CME- January 2019) Ornithodoros Dermacentor species Bacterial Borrelia burgdorferi Ixodes species Relapsing fever Borrelia hermsii Ornithodoros species Rocky Mountain spotted fever Rickettsia rickettsii Dermacentor variabilis

Viral -borne encephalitis (TBEV) Ixodes species

Protozoan Babesiosis microti Ixodes species

Toxin Tick paralysis Toxins Dermacentor andersoni Medical Entomology in Brief- Dr. Aljafari (CME- January 2019) Class Crustacea

• Most are aquatic and use gills for gas exchange. • 2 pairs of antennae for sensing. • Mandibles for crushing food that move side to side. • Eyes are located on movable stalks. • Many have five pairs of walking legs used for seizing prey and cleaning other appendages. • First pair is often modified into strong claws.

Water (cyclops)

Transmission of Guinea warm (Dracunculus medinensis)

Medical Entomology in Brief- Dr. Aljafari (CME- January 2019) Class Insecta

• A typical adult insect has three distinct body regions: head, thorax and abdomen. • head, which bears one pair of compound eyes, one pair of unbranched antennae and paired mouthparts. • the thorax, which is composed of three segments each bears a pair of legs, in many groups the second and third segments each bear a pair of wings. • the abdomen, segments and having mating organ. – Excretion by Malpighian tubules; – respiration by pipe-like tracheae, exoskeleton or by gill; – digestion by tubular digestive tract; – blood circulation by open circulatory system; – reproduction by paired reproductive organs. – Muscular system, nervous systems also present.

Medical Entomology in Brief- Dr. Aljafari (CME- January 2019) Medical Entomology in Brief- Dr. Aljafari (CME- January 2019) Subclasses of Insecta

• Apterygota – Wingless – One pair or more than one pair of appendages present in front of genital opening – Mandible is attached into a specific position of head capsule – Moulting continuous after sexual maturity.

• Pterygota – Winged or secondarily wingless insects – No appendage present in front of genital opening – Mandible is attached into two specific position of head capsule – Sexually matured adults do not moult.

Medical Entomology in Brief- Dr. Aljafari (CME- January 2019) There are more than 31 different orders of insects in the class Hexapoda, sixteen of which are considered of economic importance to agriculturists. Among them (according to Holly Quran)

English (common) Scientific Order عربي Hymenoptera النمل Hymenoptera النحل الفراش Grasshoppers Orthoptera الجراد Diptera الذباب Diptera البعوض (lice) Phthiraptera القمل Isoptera دابة األرض spider Arachnida العنكبوت

Medical Entomology in Brief- Dr. Aljafari (CME- January 2019) Diptera Phthiraptera Sand fly Head Louse: Transmission of Leishmania -Transmission of

Tsetse fly (Glossina) Treansmission of

Siphonaptera Rat flea (Xenopsylla cheopis) Blackfly Transmission of Yersinia pestis Transmission of Onchocerca volvulus Cause of Pleaque The cause of (river blindness)

Deer fly (Crysops) Transmission of Loa loa Tritomine bug (kissing bug) Transmission of American trypanosomiasis

Medical Entomology in Brief- Dr. Aljafari (CME- January 2019) • • Lymphatic filariasis • • West Nile fever • Lymphatic filariasis

• • • Lymphatic filariasis • • • Zika

Medical Entomology in Brief- Dr. Aljafari (CME- January 2019) Ethology

• Circadian rhythm • Feeding preference • Host preference • Ambience and humidity

• CO2 vs O: Female mosquitoes have nerve cells called cpA neurons that have a receptor to detect carbon dioxide.

Medical Entomology in Brief- Dr. Aljafari (CME- January 2019) Medical Entomology in Brief- Dr. Aljafari (CME- January 2019) Medical Entomology in Brief- Dr. Aljafari (CME- January 2019) -borne diseases

• Vector-borne diseases are human illnesses caused by parasites, viruses and bacteria that are transmitted by arthropods and snails.

• The major vector-borne diseases, together, account for around 17% of all infectious diseases

• Every year there are more than 700 000 deaths from diseases

Medical Entomology in Brief- Dr. Aljafari (CME- January 2019)

•Arthropod-borne viruses are viruses that can be transmitted to man by arthropod vectors. The WHO definition is as follows •“Viruses maintained in nature principally, or to an important extent, through biological transmission between susceptible vertebrate hosts by haematophagus arthropods or through transovarian and possibly venereal transmission in arthropods.”

Medical Entomology in Brief- Dr. Aljafari (CME- January 2019) Dynamic of pathogen transmission

• Feeding habits: – Most of insect biological vectors are Heamtophagous

• Periodicity – Nocturnal – Diurnal – Sub periodic

• Host preferences: – Zoophilic – Anthopophilic – Zoonotic

• Type of transmission: – Biological – Mechanical – Vertical and transstadial

Medical Entomology in Brief- Dr. Aljafari (CME- January 2019) Feeding habits: Most of insect biological vectors are Heamtophagous

Periodicity Nocturnal Diurnal Sub periodic

Host preferences: Zoophilic Anthopophilic Zoonotic

Type of transmission: Biological Mechanical Vertical and transstadial

Medical Entomology in Brief- Dr. Aljafari (CME- January 2019) Dynamic of pathogen transmission

• Complex demographic, environmental and social factors. – Global travel and trade, – unplanned urbanization and – environmental challenges such as climate change • Changes in agricultural practices due to variation in temperature and rainfall can affect the transmission of vector-borne diseases

– Factors affecting pathogen transmission, making transmission season longer or more intense or causing diseases to emerge in countries where they were previously unknown.

Medical Entomology in Brief- Dr. Aljafari (CME- January 2019) A. bromeliae

A. Africanus Rural cycle

Medical Entomology in Brief- Dr. Aljafari (CME- January 2019) mosquito habitat Yellow fever transmission zone in Africa

Medical Entomology in Brief- Dr. Aljafari (CME- January 2019)

• The scientific study of the invasion of the succession pattern of arthropods with their developmental stages of different species found on the decomposed cadavers during legal investigations

• Identification of insects at various stages of their life cycle, such as eggs, , and adults.

• Collection and preservation of insects as evidence.

• Determining an estimate for the postmortem interval or PMI (the time between death and the discovery of the body) using factors such as insect evidence, weather conditions, location and condition of the body, etc.

Medical Entomology in Brief- Dr. Aljafari (CME- January 2019) ~ 10 days

Histerid beetles Predator of fly eggs

~20 days ~15 days

Ham & Checkered Beetles Skin Beetles (Dermestidae) (Cleridae) Feed on dried skin & tissues Predator of flies & beetles; also feed on dead tissue

Medical Entomology in Brief- Dr. Aljafari (CME- January 2019)

• Myiasis is an infestation of the skin by developing larvae (maggots) of a variety of fly species within the arthropod order Diptera . • Worldwide, the most common flies that cause the human infestation are: – Dermatobia hominis (human botfly) – and Cordylobia anthropophaga (tumbu fly).

Medical Entomology in Brief- Dr. Aljafari (CME- January 2019) Medical Entomology in Brief- Dr. Aljafari (CME- January 2019) Control and prevention

• Nets • Insecticides • Repellants • Natural enemies • Sterilization

Medical Entomology in Brief- Dr. Aljafari (CME- January 2019) • • winner of the 1973 Nobel Prize in or Medicine (ethology of bees)

Medical Entomology in Brief- Dr. Aljafari (CME- January 2019)