List of infection Malaria

Protozoal Infection

Malaria

Definition

A parasitic infection in humans caused by plasmodium falciparum, p. Vivax, p. Oval and p. Malariae is called  Malaria. It is transmitted by bite of anapheles mosquito, which acts as a vector. The vector also acts as a reservoir of infection. The attack of malarial fever corresponds with the rupture of RBCs and release of merozoites in blood. The four species are indistinguishable from each other on examination of peripheral blood which is an important diagnostic tool.

Epidemiology

Mararia is endemic or sporadic throughout the tropics and subtropics. One hundred million people are attacked annually, of whom 1% die, mainly children. Woth effective WHO sponsored campaogns of prevention and comyrol, the invidence of malaria fell remarkably in 1950-60, but since 1970, there has been a resurgence of malaria. In 1980s, P. Falciparum became resistance to chloroquine over successive years in some areas especially in east Africa, which has spread through central Africa and, in 1989, reached most parts of west Africa. Malaria caused by P. Falciparum is more sevre than due to other parasites.

Malaria is primarily a disease of hot, humid climate. It is endemic in India, in parts of Africa and central America. Malaria may also be transmitted by importation of infected mosquitoes by air, so called airport malaria.
The parasite can also be transmitted by blood transfusion, through placenta from mother to foetus and increasingly through unstrilised syringes and needles among drug addicts.

Pathogenesis

• Life cycle of plasmodium in mosquito is called as sporogony since sexual cycle take place in mosquito thats why it is difinitive host this cycle length may be 8-24 days ( comonly 12 -14 days ) depending upon the spacies.
• In human being only asexual reproduction take place which is k/a shizogony it has two part - 

1. Exoerythrocytic cycle -take place in liver
2. Erythrocytic cycle -take place in blood { RBC } 

• Duration of erythrocytic cycle varies acording to the spacies.

P. vivex and ovale - 48 hours [ 2 days ]

P. Falciferum - 24-48 hours ( 1-2 fays )

P. Malariae -72 hours ( 3 days )

• When one erythrocytic cycle complited then large no of RBC burst to release Merozoite along with which Haemozoin granules are also release which are the prodection of Hb. Break down these granules are Purogenic in nature which produces High grade fever with chills and rigon.
•  In case of P. Vivax and ovale some Merozoits in the RBC develope to form hypnpzoits. It is the stage which may persist for month in the blood and can cause relapse of the Malaria.

Incubation Period 

• P. Vivax and P. Ovale 12-14 days
• P. Falciferum 10-12 days
• P. Malariae 18-28 days

In all of above P. Falciferum is most dangerous b/c infection of P. Falciferum make the RBCs like defarmable and less pliable and also it produses some changes in the cell Membtane which results into clumping of RBC ( Rodseting ) and this phenomina is k/a cytoadherence this can block the microcirculation of the organ resulting into the complicated Malaria and this is the reason why cerebral malaria is caused by only P. Falciferum.

Clinical features

Most important symptum is high gtade fever with chills and rigor which usualy occut in a carcadian rhythm in case of P. Vivax and P. Ovale fever occur at every alternate day ( Tertian fever ).

While in case of P. Malariae fever occur every 4th day ( querton fever ).

Fever is asociated with Headache, abdoninal pain, nausea, vomiting, mylgia, arthralgia prastation ( extreme weakness ).

In uncomplicated also there may be mild anemia and mild jaundice.

Mild to moderate splenomegaly especialy after 1st week of fever.

Investigation 

Specific

Blood -

1. Thick - for parasite
2. Thin -spacies

Sensitivity of this test in poor

• Card test :- ( Antigen test )

1. If -HRP ( Histidine rich protein ) - specific for P. Falciferum.
2. LGH - for all spacies

• This test also has poor sensitivity thats why diagnosis of malaria is largerly clinical.

Non specific 

C.B.C.

Hb. - decreases

TLC - increases ( in severe case)

PC - decreases 

USG - Hepato splenomegaly

In case of cerebral Malaria :- CT head-brain oedema.

CSF - usualy normal

In complicated case :-

Chest x-ray for pulmonary oedema 

ABG for acidosis lactate level, PO2, SO2.

Treatment of malaria

India is an endemic area for malaria and we have two species of malarial parasites seen commonly - The ubiquitous Pl. Vivax, and the recently increased Pl. Falciparum. Pl. Ovale is less common and its treatment is similar to Pl. Vivax.

1. Vivax Malaria

Pl. Vivax is benign, and only causes fever with chills. It responds quickly to chloroquine. There is no chloroquine resistance, but it has a hepatic dormant stage, which is not affected by chloroquine. So after a few dayd it recurs. Hence, for complete cure, tissue schizonticide i.e. primaquine should be given.

2. Falciparum malaria

This is a dangerous form of malaria affecting different organs, mainly the brain, causing crrebral malaria which can be fatal.

The second problem, which is of recent origin, is of chloroquine Resistance necessitating the use of othet drugs.

If falciparum malaria is chloroquine resistant

i.e. fever does not reduce within 2-3 days of above treatment or if the area is endemic for chloroquine resisyant malaria, then add two of the following drus-

1. Tab. Falcigo 50 mg. 2 bd *1, then 1 od *4 (Artesunate ) 

or

Cap. Larither 40 mg. 1 bd *1, then 1 od * 4 (Artemether )

2. Tab. Quinarsol 300 mg. * 2 tabs. * tds. * 7 ( quinine )

3. Tab. Amlar 3 tabs stat-single dose

4. Cap. Doxy-1 100 mg. 2 timrs/ days*7

 In severe case or cerebral malaria

1. Inj. Quininga 300 mg./ml* 4 ml in 5% dextrose drip * slow i.v. over 4 hrs * 8 hrly.

2. Inj. Falcigo ( 60 mg vial ) IM or iv stat ( Artesunate )

Then 60 mg im/iv after 6 hrs.

Then 60 mg im/iv daily * 4 days.

             Dr. Shamsheer Abbas