Malaria Introduction
Malaria – is an infective tropical disease transmitted by mosquito species P.vivax, P. malariae, P. ovale malaria, P.falciparum into the blood streams of human being. Malaria is very difficult to determinate from other infectious diseases, being a notorious imitator.
Malaria is endemic in all parts of Zambia and is the leading cause of morbidity and mortality.
It is the most common cause of outpatient attendance and hospital admission in all age groups. The true epidemiological picture of malaria in the country is underestimated.
Essentials of Diagnosis
Paroxysms (often periodic) of chills, fever, and sweating.
Splenomegaly, anemia, leucopenia.
Delirium, coma, convulsions, gastrointestinal disorders and jaundice.
Characteristic parasites in erythrocytes, identified in thick or thin blood films.
Diagnosis is not difficult when classical periodic paroxysms occur, but the clinical appearance is often modified by the degree of immunity.
Modified malaria must be distinguished from a variety of other diseases causing intermittent fevers.
Infections may cause few or no symptoms in hyper endemic areas. The certain diagnosis of malaria depends upon the detection of the parasites, usually in the peripheral blood.
General Considerations:
Four species of amoeboid protozoan parasites of the genus Plasmodium are responsible for human malaria. Today the infection is generally limited to the tropics and subtropics; in years past malaria transmission occurred in many temperate zones while temperate zone malaria is usually unstable and relatively easy to control or eradicate; tropical malaria is often more stable.
The most common parasites, P.vivax and P. falciparum, are found throughout the malaria belt,
P. malariae is also broadly distributed but less common.
The fourth parasite, P. ovale, is rare, but to the West it seems to replace P.vivax.
• The infection can be artificially transmitted by blood transfusion from an infected donor, but in nature infection takes place through the bite of an infected female.
Anopheles mosquito.
The mosquito is the host during the sexual phase of the life cycle; man is the host for the asexual development stages.
• The first stage of development in men takes place in the liver.
• Parasites escape from the liver into the blood stream 5-11 days later.
• Erythrocytes are invaded, the parasites multiply, and 48 hours later (or 72 in the case of P. malariae) the red cells rupture, releasing a new crop of parasites.
This cycle of invasion, multiplication, and red cell rupture may be repeated many times.
Symptoms do not appear until several of these erythrocytes’ cycles have been completed.
The incubation period varies considerably, depending upon the species and strain of parasite, the intensity of the infection, and the immune status of the host. For P.falciparum it is usually 10-15 days, but it may be much longer. The P.malariae incubation period averages about 28 days.
Any treatment which eliminates falciparum parasites from the blood stream will cure the infection.
Without treatment infection will terminate spontaneously in less than 2-3 years.
The other 3 species continue to multiply in liver cells long after the initial blood stream invasion.
Vivax and ovale infections may persist without treatment for as long as 5 years.
P.malariae infections which lasted for 40 years have been recorded.
Clinical Findings (symptoms and signs)
• The chill, lasting from 15 minutes to an hour (generation of parasites raptures their host red cells); (Nausea, vomiting and headache are common at this time)
• The succeeding hot stage (several hours); (spiking fever, (40°C) or higher).
The parasites invade new red cells.
• The third or sweating stage concludes the episode.
(The fever subsides, the patient frequently falls asleep).
In vivax (benign tertian malaria), ovale and falciparum (malignant tertian malaria) infections,
Red cells are ruptured and paroxysms every 48 hours.
In malariae infections (quartan malaria); the cycle takes 72 hours.
The early stages – fever patterns are irregular.
P.falciparum infection is more serious than the other because of the high frequency of severe or fatal complications with which it is associated.
B. Laboratory Findings:
The thick blood, stained with Giemsa’s stain or other Romanowsky’ stains, is the mainstay of malaria diagnosis.
The thin films are used for species differentiation.
In all, but falciparum infections the number of red cells infected seldom exceeds 2% of the total cells.
Very high red cell infection rates (falciparum infection (20-30% or more)).
For this reason anemia is frequently much more severe in falciparum malaria.
• The anemia is normocytic, with poikilocytosis and aniscytosis;
• Transient leukocytosis (leucopenia); (a relative increase in large mononuclear cells).
• Hepatic function tests often become abnormal;
• Hemolytic jaundice may develop in severe infections.
There are no specific blood chemical findings.
In P.malariae infections a form of nephrosis, with protein and casts in the urine in children.
Falciparum infections may cause renal damage.
Treatment:
• Chloroquine (An effective agent against all forms of malaria);
(causes few toxic symptoms when used in the doses given below).
• If symptoms severe, stop the drug and give ammonium chloride, 4Gm. (60 gr.) state
and 1Gm. (15 gr.) every 4 hours.
• Give chloroquine phosphate (Aralen) – 1Gm. as initial dose, 0.5 Gm in hours and
0.5 Gm daily for the next 2 days.
• In an emergency give Chloroquine hydrochloride 0.2 – 0.3 Gm.
2) Suppressive dosage – Chloroquine diphosphate, (0.5 Gm. weekly).
3) Amodraquin hydrochloride (Camoquin) 0.6 Gm of the base on the first day.
4) Quinine (0.4 Gm (10 gr.) orally for 5-7 days. Then 0.4 daily for next 2 days.
5) Proquanil hydrochloride (Paludrine)
(Toxicity is slight) large doses cause nausea, vomiting, diarrhoea, mild hematuria.
Give 0.4 Gm. daily or, for partially immune subjects – 0.3 Gm. once weekly.
6) Pyrimethamine (Paraquin): Toxicity is very low in the recommended dosage.
Give 25 mg. weekly or the same day of each week.
• Primaquine phosphate – the most effective agent. (The tissue forms of P. vivax,
P.malariae and P. ovale malaria).
Dosage 26.3 mg (15 mg of base) daily in single or divided doses is for 14 days.
The following criteria are an indication for referral:
• Patient who is too ill;
• Patient who is pregnant;
• Patient with fits/convulsions;
• Patient who does not respond to treatment in 3 days;
• Malnourished children, and chronically ill patients;
Malaria Prevention and Control:
• Provide health education information on malaria;
• Advice on personal protection measures;
• Promote general sanitation around the house;
(Reduction of bleeding sites)
Tasks for Management:
1) Take and record a confirmatory history or primary history.
2) Do a confirmatory clinical assessment including body temperature.
3) Make a diagnosis on clinical basis.
4) Take a finger prick blood specimen.
5) Prepare a thick and thin blood smear.
6) Decide on treatment and method of administration.
7) Decide on need to refer.
8) Give oral or intramuscular medication.
9) Monitor and correct fluid imbalance.
10) Keep records on treatment and follow-up. Record failures and side effects of treatment.
11) Keep CHW supplied with drugs, writing materials and health education materials.
12) Provide health information on the prevention and treatment of malaria.
Dose schedule used for intravenous quinine:
Whenever possible, intravenous quinine should be administered with 5% dextrose solution or any other solution containing glucose in the ratio 1:1 i.e. 1 mg. of quinine to 1 ml. of solution. Patient should be given quinine for duration of seven days. Particular attention should be given at this level to monitoring the parasitological (asexual form) response to treatment and to look for complications or associated conditions such as the following: (coma, hyperpyrexia, repeated convulsions, anemia, haemoglobinuria, acute pulmonary edema, acute renal failure, bleeding tendency).
Vocabulary
Morbidity [mo:`bǐdǐtǐ] – хворобливість; escape [ǐs`keǐp] – зникати;
outpatient attendance [a υt`peǐ∫nt ə`tendəns] – відвідування приймального відділення ; multiplication [məltǐplǐ`keǐ∫n] – примноження;
admission [əd`mǐ∫n] – прийом до лікарні; symptoms appear [`sǐmptəms ə`pǐə] – симптоми з`являються.
to underestimate [ǎndəstǐ`meǐt] – недооцінювати; averages [`ævǐrədзǐs] – середні показники;
paroxysms [`pærəksǐzms] – приступи; to eliminate [ǐlǐmǐ`neǐt] – усувати;
delirium [dǐ`li:rǐəm] – марення, нестяма; species [`spi:∫ǐz] – види;
gastrointestinal disorders
[`gǎstrəυǐn`testǐnl dǐs`o:dəz] – шлунково-кишкові захворювання; to cure [`kјυə] – лікувати;
jaundice [`dзo:ndǐs] – жовтяниця;
spontaneously [spən`tænǐəslǐ] – спонтанно;
to distinguish [dǐs`tǐngwǐ∫] – розрізняти; to persist [pə:`sǐst] – тривати;
intermittent [ǐn`tə:mǐtnt] – переривчастий; nausea [`no:sǐə] – нудота;
the detection of the parasites [ðə dǐ`tek∫n əv ðə`pærəsa ǐts] – виявлення
паразитів; stain [`steǐn] – спадкова риса;
amoeboid protozoan parasites
[əmə`bəυ i:d protəυ`z əυən`pærəsa ǐts] – амебоідні
простіші паразити; fever subsides [`fi:və səb`sa ǐdz] – спади
температури;
temperate [`tempǐrət] – помірний; benign tertian malaria [bǐ`na ǐn`tə:∫ǐən mə`l ærǐə] – доброякісна триденна малярія;
peripheral blood [pǐ`rǐfǐrl`blǎd] – периферійна кров; sweating stage [`swetǐŋ`steǐdз] – стадія спітніння;
clinical appearance [`klǐnǐkl ə`pǐərəns] – клінічний прояв; fever patterns irregular [`fi:və`pætəns ǐr`re gјυlə] – температурні зразки нерегулярні;
to occur [ə`kə:] – траплятися; mainstay [`meǐn`steǐ] – підтримка;
transmission [trəns`mǐ∫n] – передавання; transient leukocytosis
[`trænzǐənt lјυkəsa ǐ`təυzǐs] – лейкоцитоз, що протікає
to eradicate [ǐ`rædǐkeǐt] – викорінювати, виривати; Chemical findings [`kemǐkl`fa ǐndǐŋz] – хімічні результати;
to be artificially transmitted [α:tǐ`fǐ∫ǐəlǐ trəns`mǐtǐd] – передаватися штучно; urticaria [јυtǐ`kærǐə] – кропивниця, кропивна лихоманка;
life cycle [`la ǐf`sa ǐkl] – життєвий цикл; tissue forms [`ti:sјυ`fo:mz] – тканинні форми;
red cells rupture [`red`selz`rǎpt∫ə] – розривання еритроцитів; diuretic [dǐјu`retǐk] – сечогінний засіб;
casts in the urine [`kǎsts ǐn ðə јu`ri:n] – підрахунки у сечі; renal damage [`renl`dæmədз] – ниркове ушкодження;
suppressive dosage [sə`presǐv`dosədз] – дозування, яке стримує;
Tasks for Management of Malaria
As for previous levels, except more detailed records, history, greater, clinical ability regarding differential diagnosis, greater clinical judgment, laboratory support for biochemistry, hematology, and pathology.
Tasks:
1) Fluid balance monitoring
2) Correction of Shid imbalance.
3) Intravenous specific therapy.
4) Complete nursing care relative to complication.
5) Lumber puncture to be done if there is a need to exclude meningitis.
6) Ideally anemia should be corrected by packed cells or if packed cells are not available whole blood be given with a diuretic.
Training Exercises:
Ex.1 Complete the following conversation:
Dr:……..
Patient: Oh, doc. I’ve got a terrible fever. Yesterday I had vomiting and headache.
Dr:….....
Patient: Last year I had my blood samples tested. The findings were quite normal.
Dr:….....
Patient: The matter is that I don’t remember exact moment when this had happened.
Dr:….....
Patient: OK. Doctor I’ll follow your advice and go through the necessary examination for diagnostics.
Dr:….....
Ex.2 Answer the following questions:
1) What would you do if the patient developed an acute form of malaria?
2) Give the essentials of diagnosis of malaria.
3) Can the previous infection show any symptoms?
4) Which parasites participate actively in transmission of this infection?
5) What is the best way to analyze laboratory findings?
6) Does malaria have any complications in the course of development?
7) Describe the procedure of treatment of an acute form of disease.