World MALARIA Day     

               April 25

Malaria is a protozoal disease caused by infection with parasites of the genus Plasmodium and transmitted to man by certain species of infected female Anopheline mosquito.

A typical attack include 3 stages

·         COLD STAGE

·         HOT STAGE

·         SWEATING STAGE

ETIOLOGY

Caused by

·         P.vivax

·         P. falciparum

·         P.malariae

·         P.ovale (rare)

LIFE CYCLE OF MALARIAL PARASITE

They undergo two cycles of development

·         Human cycle/asexual cycle/endogenous phase

·         Mosquito cycle/sexual cycle/exogenous phase

Man is the intermediate host and mosquito is the definite host

The asexual cycle has (– the asexual cycle begins when infected mosquito bites and injects “sporozoites”)

1.   HEPATIC PHASE – the sporozoites disappear within 60 minutes from peripheral circulation, most of them are destroyed by phagocytes, some reaches liver cell. After two weeks they become hepatic schizonts which eventually burst releasing a number of merozoites

2.   ERYTHROCYTE PHASE-significant merozoites penetrate the RBC and pass through the stages of trophozoites and schizont. The erythrocyte phase ends with the liberation of merozite, which infects fresh RBC.

3.   GAMETOGENY-some erythrocyte forms don’t divide but become male and female gametocyte.

The sexual cycle

The mosquito cycle begins when gametocytes are ingested by the vector when feeding on an infected person. Exflagellation of the male gametocyte is the first vent taking place in mosquito’s stomach, where 4-8 thread like filaments called “micro gametes” are developed.

Female gametocyte matures and becomes “macro gametes”. The resulting zygote is at first immotile and then becomes motile in 18-24 hours, which is known as OOKINETE which develops into oocyst and then to sporozoites. Many sporozoites migrate to the salivary gland and mosquito becomes infective.

EXTRINSIC INCUBATION PERIOD- the time period required for the development of parasite from gametocyte to sporozoite stage (10-20 days)

MODE OF TRANSMISSION

·         Vector transmission

·         Direct transmission

·         Congenital malarial

SYMPTOMS AND DIAGNOSIS

 Early and accurate diagnosis of malaria is essential for effective disease management and malaria surveillance. High-quality malaria diagnosis is important in all settings as misdiagnosis can result in significant morbidity and mortality.

WHO recommends prompt parasitological confirmation of diagnosis either by microscopy or malaria rapid diagnostic test (RDT) in all patients with suspected malaria before treatment is administered. On World Malaria Day 2012, WHO launched a new initiative called T3: Test. Treat. Track

CLINICAL FEATURES

·         COLD STAGE  - temperature rises to 39-41⁰c

                     Headache, nausea, vomiting

                     Skin is initially cold and later becomes hot

                        Stage lasts for ¼-1 hour

·         HOT STAGE – feels burning hot

                     Skin is hot and dry to touch

                     Intense headache and no vomiting

                     Lasts for 2-6 hours

·         SWEATING STAGE – fever

                            Skin is cold and moist

                            Patients feel relief and often fall asleep

 PREVENTION

MEDICATION