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Rochelle Veronica Miravalles
BSN IV – F
San Lazaro Hospital
Aida Iran RN, MAN
Leptospirosis
LEPTOSPIROSIS
Leptospirosis, also known as canicola fever, hemorrhagic jaundice, infectious
jaundice, mud fever, spirochetal jaundice, swamp fever, swineherd's disease,
caver's flu or sewerman's flu, is a disease that is caused by pathogenic spirochetes
of the genus Leptospira. It is considered the most common zoonosis in the world.
Leptospirosis has recently been recognized as a re-emerging infectious disease
among animals and humans1 and has the potential to become even more prevalent
with anticipated global warming. Leptospirosis is distributed worldwide (sparing the
polar regions) but is most common in the tropics.
Humans and a wide range of animals, including mammals, birds, amphibians,
and reptiles can develop Leptospira infection. However, humans are rarely chronic
carriers and are therefore considered accidental hosts. Leptospirosis is transmitted
via direct contact with the body fluid of an acutely infected animal or by exposure to
soil or fresh water contaminated with the urine of an animal that is a chronic carrier.
Human leptospirosis is often acquired via contact with fresh water
contaminated by bovine, rat, or canine urine as part of occupational contact with
these animals. The disease is also acquired during adventure travel or vacations
that involve water sports or hiking, or even as a consequence of flooding.
is a bacterial infection resulting from exposure to the Leptospira interrogans
bacterium. Human leptospirosis can be a difficult infection to describe, as the
symptoms can vary dramatically between patients. Some symptoms are extremely
common, but only a small number of patients will experience the severe life-
threatening illness known as Weil's disease. The severity of the infection depends
on the age and general health of the patient, plus the serovar (strain) of bacteria
involved and the number of bacteria that entered the patient's body.
The infection is usually systemic (affecting the whole body) and causes a
sudden fever. In mild cases it lasts a few days, following a pattern similar to flu but
often in two phases - a period of illness lasting a few days, then a slight recovery,
then a second period of illness. In mild cases the second phase lasts a short time
and the patient recovers, but in severe types the illness develops and progresses
rapidly, leading to organ failure and often death if not treated with intervention and
support.
Leptospirosis is primarily an occupational disease that affects farmers,
veterinarians, sewer workers or others whose occupation involves contact with
animals, especially rats. It is spread mainly by the urine of infected animals and is
generally not transmitted from person to person.
INCUBATION TIME
From the time you were infected with the bacteria, there is a period where it
has to reproduce enough to cause illness - called the 'incubation time'. With human
leptospirosis this is typically 3 to 21 days, with most patients developing illness
after about 3 to 14 days. It does not usually take more than 28 days, but in rare
cases very long incubation periods have been reported. It generally cannot show
illness in less than 24 hours unless the volume of bacteria taken into the
bloodstream was massively larger than normal.
PERIOD OF COMMUNICABILITY
Leptospira are found in the urine between 10 – 20 days after onset.
SOURCES OF INFECTIONS
Contaminated food and water, and infected wild life and domestic animals
especially rodents.
RATS ( L. leterohemoragaie) – the Weil;s disease frequently observed among
miners,
sewer, and abattoir workers.
DOGS ( L. canicola) – observed in veteranians, breeders, and owners of the
dogs.
MICE ( L. grippotyphosa) – attacks farmers and flax workers.
RATS ( L. bataviae) – attacks rice – field worker.
MODE of TRANSMISSION
It can be accuired through ingestionor contact with the skin and mucous
membrane such as eyes, nose, mouth or through a break on skin with the infected
urine or carcasses of wild and domestic animals. Leptospira enters the blood to
cause damge therafter, the kidneys, the liver, meniges and conjuctivae. It is
contagious as long as it is still moist. Although rats, mice and voles are important
primary host, a wide range of other mammals including deer, rabbits, hedgehog,
cows, sheep, raccoons, possums, skunks, and even certain marine mammals are
also able to carry and transmit the disease as secondary hosts.
Dogs may lick the urine of an infected animal off the grass or soil, or drik
from an infected puddle. There have been reports of “ house dogs” contracting
leptospirosis apparently from licking the urine of infected mice that entered the
house. The type of habitats most likely to carry infective bacteria are muddy
riverbanks, ditches, gulleys and muddy livestock rearing areas where there is a
regular passage of either wld or farm mammals.
There is a direct corellation between the amount of rainfall and the incidence
of leptospirosis, amking it seasonal in emperate climates and year – round in
tropical climates. It is also transmitted by the semen of infected animals. Workers
can contract the disease through contact with infected blood or body fluids.
PATHOPHYSIOLOGY
The leptospires are thin, coiled, gram-negative, aerobic organisms 6-20 µm in
length. They are motile, with hooked ends and paired axial flagella (one on each
end), enabling them to burrow into tissue. Motion is marked by continual spinning
on the long axis. They are unique among the spirochetes in that they can be
isolated on artificial media.
Leptospires belong to the order Spirochaetales and the family
Leptospiraceae. Traditionally, the organisms are classified based on antigenic
differences in the lipopolysaccharide envelopes that surround the cell wall.
Serologic detection of these differences, therefore, is based on identifying serovars
within each species. Based on this system, the genus Leptospira contains two
species—the pathogenic Leptospira interrogans, with at least 218 serovars, and the
nonpathogenic, free-living, saprophytic Leptospira biflexa, which has at least 60
serovars.
Although not fully understood, leptospires are believed to enter the host
through abrasions in healthy skin, through sodden and waterlogged skin, directly
through intact mucus membranes or conjunctiva, through the nasal mucosa and
cribriform plate, through the lungs (after inhalation of aerosolized body fluid), or
through the placenta during pregnancy. Virulent organisms in a susceptible host
gain rapid access to the bloodstream through the lymphatics, resulting in
leptospiremia and spread to all organs. The incubation period is usually 5-14 days
but has been described from 72 hours to a month or more.
If the host survives the acute infection, septicemia and multiplication of the
organism persist until the development of opsonizing immunoglobulin in the
plasma, followed by rapid immune clearance. However, after clearance from the
blood, leptospires remain in immunologically privileged sites, including the renal
tubules, brain, and anterior chamber of the eye, for weeks to months. In humans,
leptospires in the renal tubules and resulting leptospiruria rarely persist longer than
60 days.
CLINICAL MANIFESTATIONS
During acute infection, leptospires are thought to multiply in the small blood
vessel endothelium, resulting in damage and vasculitis. The major clinical
manifestations of the disease are believed to be secondary to this mechanism,
which can affect nearly any organ system.
In the kidneys, interstitial nephritis, tubular necrosis, and impaired capillary
permeability, as well as the associated hypovolemia, result in renal failure.
Liver involvement is marked by centrilobular necrosis and Kupffer cell
proliferation, with hepatocellular dysfunction.
Pulmonary involvement is secondary to alveolar and interstitial vascular
damage resulting in hemorrhage. This complication is considered to be the
major cause of leptospirosis-associated death.
The skin is affected by epithelial vascular insult.
Skeletal muscle involvement is secondary to edema, myofibril vacuolization,
and vessel damage.
The damage to the vascular system as a whole can result in capillary
leakage, hypovolemia, and shock. Many patients with leptospirosis may
develop disseminated intravascular coagulation (DIC), hemolytic uremic
syndrome (HUS), thrombotic thrombocytopenic purpura (TTP), and vasculitis.
Thrombocytopenia indicates severe disease and should raise suspicion for a
risk of bleeding.
Clinical manifestations of leptospirosis after the acute infection are the result
of the inflammatory response, as well as action of the remaining organisms in
the aqueous humor.
THREE STAGES OF LEPTOSPIROSIS
First stage ( Septic Stage)
Leptospirosis starts suddenly, with a severe headache, redness in the eyes,
muscle pains, fatigue and nausea and a fever of 39°C (102°F) or above. There is
sometimes a red non-blanching pinprick rash on the skin, similar to that seen in
meningitis. Young children can be tired or distressed and may show an aversion to
bright light. The severe headache is almost always present and can be
incapacitating. Nausea may or may not cause vomiting. Muscle pains can be
extreme and are often particularly bad in the calf and back areas - muscles will be
sore to move and to touch. A rapid pulse is also common in the first few days.
The skin rash develops in the first one or two days and often the skin is warm and
pink just beforehand, with the patient complaining of feeling warm. Rashes can
occur anywhere but in some cases are confined to local regions of skin such as the
front of the legs. Sometimes they will be itchy, but rashes are only seen in about
30% of all cases so the lack of any rash is not too significant.
Psychological changes are often seen, with patients feeling depressed, confused,
aggressive and sometimes psychotic - with schizophrenia and hallucinations,
personality changes and violence.
This phase lasts between three and five days, then the patient (temporarily)
recovers. During this phase the bacteria are active in the patient's bloodstream (so
it is sometimes called the septecaemic phase) and so can be detected by lab tests.
Second stage (Immune or Toxic Stage)
In many mild cases this doesn't happen at all, but where the infection is more
severe, the patient enters a second phase of illness after a few days of apprent
recovery. The initial symptoms and fever return, accompanied with chest and
abdominal pain, some renal problems and psychological changes. Increased
symptoms of meningitis are often seen with neck stiffness and vomiting, but in most
mild cases the patient will not suffer kidney or liver failure and will eventually
recover. There may be a sore throat and dry cough, with a litle blood. With
treatment, mild cases will recover within a few weeks.
During this second phase the bacteria are only really active in the tissues of the
patient, and so can be difficult to find in the bloodstream, making lab tests a
problem. This second phase is usually called the 'tissue' or 'immune' phase.
Severe infections
In cases of particularly virulent serovars or patients with poor health, the
infection follows a different pattern and the patient develops very rapid and severe
symptoms from the start, without much of a remission. Symptoms are the same as
for the mild type but more pronounced, and multiple organs are damaged - liver
and kidney failure can occur within 10 days, leading to jaundice and death if not
treated. Hemorrhages are common (including bleeding from the mouth, eyes and
other mucous membranes), plus infection of the heart and significant internal
bleeding. Dialysis is the most important intervention and the patient will require
antibiotics and hospital admission in order to stand a chance of survival. Death,
when it occurs, is usually due to heart, liver or respiratory failure. Severe infections
are often called 'icteric' because of the presence of jaundice, and these are the only
cases that can really be called Weil's disease.
Symptoms can take 2 – 26 days ( average 10 days) to develop, and may
include :
Dry cough
Fever
Headache
Muscle pain
Nausea, vomiting and
diarrhea
Shaking chills.
Less common symptoms include:
Abdominal pain
Abnormal lung sounds
Bone pain
Conjunctivitis
Enlarged lymph glands
Enlarged spleen or liver
Joint aches
Muscle rigidity muscle tenderness
Skin rash
Sore throat
Recovery
Patients with mild infections recover quite quickly, so are usually feeling OK
after a few weeks, but they can suffer from fatigue and depression for a while and
may be at risk from persistent infection. Patients with the more severe infections
can take several weeks to recover, as removing the bacteria is not the problem -
they will have caused damage to the body's tissues that take time to heal. Although
some patients can die, with medical treatment the chances of survival are good -
though patients that have had a severe illness may suffer long-term symptoms due
to organ damage that cannot completely heal. Psychological changes (mood
swings, depression, psychoses) are common for a few months following recovery.
MANAGEMENT
1. Medical
Leptospirosis tretment is a relatively complicated process comprising two
main components:
a) Suppressing the causative agent
b) Figting possible complications
Aetiotropic drugs are antibiotics, such as cefotaxime, doxycycline,
penicillin, ampicillin, and amoxicillin.
There are no human vaccines; animal vaccines are only for few strains,
and are only effective for a few months.
Human therapeutic dosage of drugs is as follows:
a) Doxycycline 100 mg orally every 12 hours for 1 week.
b) Penicillin 1 – 1.5 MU every 4 hours for 1 week.
c) In dogs, penicillin is most commonly used to end the
leptospiremic phase ( infection of teh blood), and doxycyline is
used to eliminate the carrier state.
Supportive therapy measures
a) Detoxication and normalization of the hydroelectrolytic balance.
Glucose and salt solution infusions may be administered;
b) Dialysis is used in serious cases. Elevation of the serum
potassium are common and if the potassium level gets too high
special measures must be taken. Serum phosphorus levels may
likewise increase to unacceptable levels due to renal failure.
c) Corticosteroids administration in gradually reduced doses
during 7 – 10 days is reccomended by some specialist in cases
of severe haemorrhagic effects.
d) Organ soecific care and treatment are essential cases of renal,
liver or heart involvement.
2. Nursing
a) Isolate the patient, urine must be properly disposed
b) Keep patient under close surveillance
c) For home car, cleaning near dirty places, pools, and stagnant water
d) Eradicate rats and rodents
PREVENTION AND CONTROL
1. Sanitaion in homes, workplaces and farms
2. Proper drainage system and control of rodents
3. Vaccination of animals ( cattle, dog, cats and pigs)
4. Treatment of infected human and pets
5. Effective information – dissemination campaign