Malaria

For medical students2 min readUpdated 2026-10-10

The study of any infectious pathology is based on understanding the general patterns of interaction between the pathogen and the host macroorganism. Within the course of pathological anatomy, the cyclic nature of diseases, systemic morphological changes, and the specifics of quarantine and especially dangerous infections are examined in detail.

CyclicityAn obligatory characteristic of the phases of development of the infectious process

Quarantine infectionsSpecial rules for autopsy and burial of deceased patients

SepsisRequires the study of initial mechanisms and morphological parallels

General Patterns of Infectious Diseases

Any infectious disease is characterized by certain general features that must be taken into account during pathomorphological analysis. A key concept is the cyclicity of infectious diseases. To properly assess pathogenesis, it is necessary to provide a clear definition of this term and a detailed description of all phases of the infectious process.

Furthermore, the introduction of a pathogen elicits a series of stereotyped reactions in the macroorganism. When studying this topic, it is essential to compile an exhaustive list and characterize the systemic changes in the body that predictably develop against the background of an infectious lesion.

Specifics of Respiratory and Intestinal Infections

Although the principles of pathogenesis are uniform, different pathogens form a unique morphological picture:

Influenza: The study of this nosology requires a classification of the clinical and morphological forms of influenza and their detailed pathomorphological characterization. The pathogenesis and morphogenesis of the disease are directly determined by the properties of the influenza virus itself, which dictate specific morphological manifestations.
Typhoid fever: The pathomorphology of this disease is inextricably linked to the stages of its course. Special attention is paid to the morphogenesis of intestinal lesions — a detailed pathogenetic justification of the causes leading to the development of necrosis of Peyer's patches in the small intestine is required.

Pathomorphology of Tuberculosis

Tuberculosis remains one of the most important problems in infectology. The course covers the general epidemiological characteristics of this disease and the classification of its clinical and morphological forms.

Three main categories are distinguished, each with its own features of progression and course:

Primary tuberculosis: specific forms of its progression are examined.
Hematogenous tuberculosis: requires knowledge of classification and developmental variants.
Secondary tuberculosis: forms and specific features of the course are studied.

An important aspect is the concept of pathomorphosis — one must understand the essence of the changes in the classical clinical and morphological picture of modern tuberculosis under current conditions.

Especially Dangerous and Quarantine Infections

A separate group consists of diseases representing an exceptional epidemiological threat. It is necessary to clearly distinguish between the definitions of especially dangerous infections (EDIs) and quarantine infections, as well as to know the exact list of nosologies belonging to each of these groups.

In pathomorphological practice, work with such infections is regulated by strict protocols. The specifics of autopsy rules for bodies of individuals who died from quarantine infections, as well as special sanitary and epidemiological requirements for their subsequent burial, must be studied.

Sepsis and Comorbid Infections: Study Base

For an in-depth understanding of the pathological anatomy of sepsis and severe infections, a specialized scientific database is used. When studying sepsis, its pathological anatomy, classification issues, initial mechanisms of development, and clinical-morphological parallels are considered (based on the works of authors such as Yu.G. Parkhomenko, V.S. Paukov, M.G. Rybakova).

Additionally, within the framework of specialized infectology, the epidemiology and prevention of HIV infection, the spectrum of AIDS-associated diseases, the features of Klebsiella infections, acute non-influenza respiratory pathologies, and sexually transmitted diseases are investigated.

Frequently asked questions

What macroscopic and microscopic changes occur in the spleen in acute malaria?

In acute malaria, the spleen significantly increases in size, and its mass can reach up to 3 kg (splenomegaly). Macroscopically, the organ becomes soft. Microscopic changes are characterized by marked congestion and hyperplasia of reticular cells. In addition, disintegrating erythrocytes enter the spleen, where macrophages and cells of the reticuloendothelial system engulf the released heomomelanin and hemoglobin fragments, giving the organ a dark grey, almost black color.

What specific pigment is formed upon the destruction of erythrocytes by malaria plasmodia and accumulates in organs?

Upon the destruction of erythrocytes by malaria plasmodia, a specific malaria pigment is formed — heomomelanin (hemozoin). It is an amorphous brown pigment synthesized from the prosthetic part of hemoglobin as a result of its hydrolysis by parasite enzymes. After entering the blood, heomomelanin is phagocytosed by macrophages and accumulates in the organs of the reticuloendothelial system (spleen, liver, bone marrow, lymph nodes) and in glial cells of the brain. Due to the deposition of this pigment, the organs acquire a characteristic slate-grey color.

What are Dürck's granulomas and in which organ do they localize in malaria?

Dürck's granulomas are specific nodular accumulations of cells formed by proliferating oligodendrogliocytes and macrophages. In malaria, they localize in the brain. Their formation is associated with the development of cerebral ischemia, which leads to neuronal death. These pathomorphological changes are characteristic of severe falciparum malaria and are one of the causes of high mortality among children.

What pathomorphological changes develop in the liver in malaria?

In malaria, hepatomegaly develops in the liver, and the nature of the changes depends on the stage of the disease.

Acute stage — macroscopically, the organ is enlarged, congested, and dark grey on cross-section. Microscopically, hyperplasia of stellate endothelial cells (Kupffer cells) is observed with deposition of heomomelanin and hemosiderin pigments.
Chronic course — marked fibrosis develops in the liver. Prolonged engulfment of heomomelanin by macrophages leads to heomomelanosis and hemosiderosis, which ultimately contributes to organ sclerosis.

What is the pathogenesis and morphological picture of malarial coma in severe falciparum malaria?

The pathogenesis of malarial coma in falciparum malaria is caused by impaired microcirculation in the central nervous system. Capillaries of the brain become occluded by parasitic thrombi, causing ischemia and subsequent neuronal death.

getAttribute The morphological picture is characterized by:

Dürck's granulomas — nodules formed by proliferating oligodendrogliocytes and macrophages.
Pigmentation — deposition of malaria pigment (heomomelanin) in glial cells of the brain.

Clinically, the process progresses through stages of encephalopathy (somnolence, sopor, and coma) and frequently leads to a fatal outcome.

What kidney changes are characteristic of blackwater fever (a complication of malaria)?

In blackwater fever, resulting from massive intravascular hemolysis, marked pathomorphological changes develop in the kidneys, leading to acute kidney injury (AKI). Morphologically, congestive hyperemia is observed, malaria pigment (heomomelanin) is deposited in the renal glomeruli, and hemoglobin casts form within the tubular lumens. A severe course is accompanied by profound damage to renal tissue up to tubular necrosis. Clinically, these changes manifest as dark brown or black urine, oliguria, anuria, as well as marked proteinuria, cylindruria, and microhematuria.

In which cells of the macroorganism does tissue (exoerythrocytic) schizogony of malaria plasmodia occur?

Tissue (exoerythrocytic) schizogony of malaria plasmodia occurs in liver cells — hepatocytes. Following an infected mosquito bite, sporozoites enter the bloodstream and penetrate hepatocytes within 30 minutes. Inside these cells, plasmodia multiply to form tissue schizonts. This stage is asymptomatic and lasts from 1 to 12 weeks, resulting in the production of over 30,000 merozoites from a single sporozoite, which are then released into the blood.

What characterizes the pathomorphological picture of chronic malaria?

The pathomorphological picture of chronic malaria is characterized by systemic damage to the organs of the reticuloendothelial system (RES) resulting in sclerosis. As a result of constant erythrocyte destruction, macrophages engulf the pigment, leading to marked heomomelanosis and hemosiderosis. The prolonged duration of these processes causes the following changes:

Spleen — sclerotic changes and tissue densification develop.
Liver — marked hepatic fibrosis is formed.
Kidneys — during Plasmodium malariae infection, the chronic course is accompanied by the development of nephrotic syndrome.

What are the main causes of death in patients with severe malaria?

The main cause of death in patients with severe malaria is the development of the cerebral form (malarial coma) against the background of falciparum malaria. Approximately 80% of all fatal outcomes are associated with this complication. In addition, fatal consequences can result from:

Infectious-toxic shock (ITS) — accompanied by progression to acute heart failure.
Acute kidney injury (AKI) — frequently develops as a consequence of blackwater fever (massive intravascular hemolysis).
Pulmonary edema — one of the most severe complications.

Which malaria plasmodium species causes the most severe form of the disease with CNS involvement?

The most severe form of the disease with central nervous system involvement is caused by Plasmodium falciparum — the causative agent of tropical (falciparum) malaria. This is the only species of malaria plasmodium capable of running a malignant course and leading to a fatal outcome. The severe clinical course is frequently complicated by cerebral malaria (malarial coma), which is caused by microcirculatory impairment and occlusion of brain capillaries by parasitic thrombi.

What is the cyclicity of the infectious process?

It is the predictable sequence of phases in the development of an infection from the moment the pathogen enters until the outcome of the disease, determining morphological changes at each stage.

What is the pathomorphosis of tuberculosis?

It is a persistent alteration in the clinical and morphological picture of modern tuberculosis compared to its classical descriptions.

What is the specificity of autopsy in quarantine infections?

Autopsy and subsequent burial of bodies of individuals who died from quarantine infections are carried out according to strict, specific rules to prevent an epidemiological threat.

Go deeper

Pathogenetic rationale for necrosis of Peyer's patches in typhoid fever
Properties of the influenza virus and their impact on disease morphogenesis
Forms of progression of primary and hematogenous tuberculosis
Initial mechanisms of sepsis development
Pathological anatomy of AIDS-associated diseases