ASSALAMUALAIKUM..Today I want to SHARE about rodent.
The characteristic of rodents is
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Characterized by single pair of incisor teeth on
each jaw and by absence of canine teeth.
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Have tail with fine scales and few hairs.
The problems related with rodents :
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Spread serious diseases, including salmonellosis
(food poisoning), leptospirosis, rickettsialpox and lymphocytic
choriomeningitis.
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Carry fleas, ticks and other ectoparasites,
potentially spread diseases, such as bubonic plague.
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Consume or contaminate about 20 percent of the
world’s food supply.
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Gnaw, expensive structural damage, start fires
if they gnaw on electrical wires.
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Cause a great deal of anxiety for occupants
(people and pets) of infested buildings.
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Pose serious risks for food facilities. Single
rodent can cause fines, poor inspection scores, disgruntled employees and lost
business.
Types of rodent :
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Roof rats (Rattus rattus)
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Norway rats (Rattus norvegicus)
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House mice (Mus musculus)
These rodents are "commensal" because they tend to
live in close proximity to humans and eat the same food as we do.
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They destroy property, frighten people &
compete with human for food.
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Rats plague many store owners and farmers.
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Undesirable in feed and seed stores because
destroy the seed, corn etc.
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Undesirable in poultry houses and bird farms
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Destroy & contaminate structure as well as
harm young birds and chicks.
Different characteristic of rats :
CHARACTERISTIC
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NORWAY RAT
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ROOF RAT
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HOUSE RAT
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Nickname
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Sometimes called brown or sewer rats
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Sometimes called black rats
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Domestic house mouse
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Weight
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284 – 482g
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170 – 340g
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18 – 28g
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Total Weight
(Nose to tip of tail)
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12 to 18 inches
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13 to 17 inches
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6 to 7 inches
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Tail
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Shorter than head plus body,
6 to 8 inches
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Longer than head plus body, hairless
7 to 10 inches
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Equal to or a little longer than body plus head,
3 to 4 inches
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Ear
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Small, close set, appear half buried in fur
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Large, prominent, stand well out from fur
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Prominent, large for size of animal
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Fur
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Coarse, generally red- brown to gray-brown colour.
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Black to brownish, gray to white below.
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Silky, grayish-brown on top, light cream underside.
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Lifestyle
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7 – 8 young per litter;
3 – 6 litters a year. Gestation period of about 3 weeks.
10 – 12 weeks from birth to
sexual maturity.
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5 – 10 young per litter; 3 – 6 litters a year. Gestation period of
about 3 weeks.
12 – 16 weeks from birth to
sexual maturity.
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4 – 16 young per litter; 7 – 8 litters a year. Gestation period of
about 3 weeks.
8 – 12 weeks from birth to sexual maturity.
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Habits
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Usually ground living and burrowing, but sometimes climbs.
The only species to occur in
sewers in Malaysia.
Preferred food is cereals.
Will eat around 30g of food a
day and drink 60ml.
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Rare in Malaysia. Appearance confined mainly to ports.
Often climbs, agile, rarely burrowing and rarely outdoors in
Malaysia.
Preferred food is moist fruits.
Will eat around 15g of food a
day and drink 15ml.
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Usually ground living and burrowing, but often climbs.
Preferred food is cereals.
Will eat around 3g of food a day and can survive without any additional
water.
They will drink up to 3ml a day if their diet is particularly dry.
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| DIFFERENT TYPES OF RATS |
Signs of rats presence :
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Faeces
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Footprints
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Runway
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Smears
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Bitemarks
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Burrows
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Smell
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Urine
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Live rat
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Carcass
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Nest
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| EXAMPLE OF SIGNS OF RATS |
Public Health issues
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Rats play an important role as host for certain
infectious diseases
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Means of
disease spreading might be directly or indirectly.
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Direct –
Rats carry germs inside their body (organisma eg: bacilli, spirochaetes, rickettsia,
viruses, nematodes)
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Indirectly – Rats being a host for fleas,
mites etc.
Disease related to rodents:
Disease related to rodents:
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Hantavirus Pulmonary Syndrome
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Haemorrhagic Fever
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Leptospirosis
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Human Lymphocytic Choriomeningitis (LCM)
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Plague
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Rat-Bite Fever
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Salmonellosis
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Murine Typhus
What is Leptospirosis:
Leptospirosis is an infection in rodents and other wild and
domesticated species. Rodents are implicated most often in human cases. The
infection in man is contracted through skin abrasions and the mucosa of the
nose, mouth and eyes. Exposure through water contaminated by urine from
infected animals is the most common route of infection. Human-to-human
transmission is rare.
Outdoor and agricultural workers (rice-paddy and sugarcane
workers for example) are particularly at risk but it is also a recreational
hazard to those who swim or wade in contaminated waters. In endemic areas the
number of leptospirosis cases may peak during the rainy season and even may
reach epidemic proportions in case of flooding because the floods cause rodents
to move into the city.
Prevention strategies of human leptospirosis include wearing
protective clothing for people at occupational risk and avoidance of swimming
in water that may be contaminated. Leptospirosis control in animals is
dependent on the serovar and animal species but may be either vaccination, a
testing a culling programme, rodent control or a combination of these
strategies.
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| TRANSMISSION |
What is Plague
Cause : The plague bacillus, Yersinia pestis.
Transmission :
Plague is a zoonotic disease affecting rodents and
transmitted by fleas from rodents to other animals and to humans. Direct
person-to-person transmission does not occur except in the case of pneumonic
plague, when respiratory droplets may transfer the infection from the patient
to others in close contact.
Nature of the disease:
Plague occurs in three main clinical forms:
Bubonic plague is the form that usually results from the
bite of infected fleas. Lymphadenitis develops in the drainage lymph nodes,
with the regional lymph nodes most commonly affected. Swelling, pain and
suppuration of the lymph nodes produces the characteristic plague buboes.
Septicaemic plague may develop from bubonic plague or occur
in the absence of lymphadenitis. Dissemination of the infection in the
bloodstream results in meningitis, endotoxic shock and disseminated
intravascular coagulation.
Pneumonic plague may result from secondary infection of the
lungs following dissemination of plague bacilli from other body sites. It
produces severe pneumonia. Direct infection of others may result from transfer
of infection by respiratory droplets, causing primary pulmonary plague in the
recipients.
Geographical distribution :
There are natural foci of plague infection in rodents in many
parts of the world. Wild rodent plague is present in central, eastern and
southern Africa, South America, the western part of North America and in large
areas of Asia. In some areas, contact between wild and domestic rats is common,
resulting in sporadic cases of human plague and occasional outbreaks.
Risk for travellers :
Generally low except in rural areas of countries or areas at
risk, particularly if camping or hunting or if there is contact with rodents.
Prophylaxis :
A vaccine effective against bubonic plague is available
exclusively for individuals with a high occupational exposure to plague; it is
not commercially available in most countries.
Precautions: Avoid any contact with live or dead rodents.
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| DIFFERENT TYPES OF PLAGUE |
Rodent control measures :
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Eliminating sources of food
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Eliminating breeding and nesting places
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Rat-proofing buildings and other structures
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Killing them
References : http://www.who.int/ith/diseases/plague/en/
