Diagnosis

then obstruct the bloodstream and lead to abscess development with necrosis. The lung is

Clinical symptoms are related to the hepatic and intrathoracic implications. General symp‐ toms including fever, right upper quadrant pain, cough, chest pain are frequent in the lung amoebiasis. Pleural effusion could develop, following hepatobronchial fistula. The paren‐ chymal disease can present as pulmonary abscess with characteristic chocolate pus and air‐ space consolidation at chest radiograph. Elevation of right hemidiaphragm is an earlier

The accuracy of serodiagnosis is established in the tissue amoebiasis, mainly in non endemic populations. PCR should also be more contributive, even not routinely performed in many

Metronidazole is widely used, with established effectiveness. Lactoferrin and lactoferricins combined to low metronidazole doses has been proposed as an alternate therapeutic option.

Malaria is a public health problem in tropical and subtropical areas. With the increasing population travelling, mosquitos which transmit the disease can be carried out of the natural frontiers and cause illness in naïve, non exposed patients. Four species of *Plasmodium* are identified (*P falciparum, P. ovale, P. malariae, P. vivax*). *Plasmodium falciparum*, *vivax*, and *ovale* can cause acute lung injury, or acute respiratory distress syndrome (Mohan A et *al*, 2008).

The pathogen lives in the erythrocytes and could impair their functions. Impaired red cells motility, favored by exaggerated cytoadherence to the capillaries endothelium (Corbett CE et *al*, 1989), induce sequestration of the red and white blood cells in different organs, with subsequent deprivation in oxygen delivery, endothelial dysfunction, and enhancement of anaerobic metabolism. Multiple organ dysfunctions (MODS) is the condition leading to death. Red cells sequestration and destruction enhances the release of parasites and erythro‐

Pulmonary involvement extend from cough and dyspnoea, to fatal ARDS, non cardiogenic pulmonary edema, and intra-alveolar hemorrhages. Parenchymal disease due to plasmodial infections has not yet been clearly evidenced, due to numerous viral or bacterial co-infec‐

ARDS in malaria is more common in adults than in children, as well as in pregnant women

The pathogenesis of ARDS in severe malaria is poorly understood. Sequestration of parasi‐ tized red cells in small vessels seems not to be the only underlying mechanism. Recent study

cyte material in the bloodstream, inducing a vigorous inflammatory response

*E histolytica* may be identified in sputum, in stools specimen or pleural pus.

the most frequent site of extra-intestinal invasion.

152 Oncogenesis, Inflammatory and Parasitic Tropical Diseases of the Lung

radiographical feature in liver abscess.

institutions.

Treatment

*2.3.2. Pulmonary malaria*

Pathophysiology

tions, mainly in child under 5 years.

and non immune individuals

Systemic symptoms of malaria are: fever, myalgia, headache, loss of appetite, nausea, vomit‐ ing. Severe respiratory symptoms may be observed, following the onset of edema and respi‐ ratory distress syndrome.

Thick and thin stained blood smears are the routine laboratory examination to identify the plasmodium species.

Serodiagnosis and PCR of *plasmodium* in urine or saliva, may be contributive where available.

Chest radiograph demonstrates variable patterns such as lobar consolidation, pleural effu‐ sion, alveolar infiltrates suggesting pulmonary edema, or hemorrhages.

## Treatment

Parenteral quinine is the drug of 1st choice for the treatment of severe malaria. Artemisinine derivatives are an alternative in case of contra-indications. Adjunctive therapy with clinda‐ mycine or doxycycline has been proposed in complicated malaria.

General resuscitation measures could be indicated in life threatening cases.

Antivectorial eradication, using insecticide treated bed-nets is widely utilized in endemic re‐ gions.

#### *2.3.3. Pulmonary Toxoplasmosis*

The disease caused by the Protozoan parasite, *Toxoplasma gondii* infects the man, after inges‐ tion of cyst-contaminated food.

Immunocompromised individuals are at higher risk of developing toxoplasmosis with the central nervous system involvement as the most common complication.

Toxoplasma infection is asymptomatic in most immunocompetent humans. The pathogen is then destroyed by strong antibody dependent reactions or delayed type hypersensitivity mechanism. A strong Th1 cytokine profile is elicited by cells of innate immunity for efficient protection, and pathogen could be destroyed also by monocytes- derived mediators such as nitric oxide, which inhibits the parasite growth in different organs, mainly the lung and the central nervous system, as prominent targets.
