What is communicable disease?

Communicable disease are diseases that can be spread from person to person.

What are non communicable diseases?

Non-communicable diseases are diseases that cannot be spread from one person to another via pathogens.

What does communicable disease mean?

Communicable disease are diseases that can be spread from person to person.

What causes communicable diseases?

Pathogens such as viruses, bacteria, protists and fungi all can cause communicable diseases.

What are the classification of communicable disease?

These diseases can be classified by the type of pathogens that cause them.

What is the difference between communicable and infectious diseases?

A communicable disease is caused by pathogens and can spread from one person to another. Conversely, an infectious disease is caused by pathogens but doesn't necessarily spread from one individual to another.

What are the three broad categories of factors causing Communicable Diseases?

The three broad categories of factors causing Communicable Diseases are Biological, Environmental, and Social and Behavioural causes.

What does Biological Factors in Communicable Diseases include?

Biological Factors in Communicable Diseases include the existence of infectious agents like bacteria, viruses, fungi, or parasites, and the transmission mechanism among hosts.

How do communicable diseases impact the long-term health of the human body?

They can impact various organ systems, cause psychological issues, and impair overall health.

What role do Social and Behavioural factors play in the spread of Communicable Diseases?

Social and Behavioural factors like lifestyle choices, cultural practices, and socio-economic conditions can influence the susceptibility of a person to certain communicable diseases, promoting their spread.

Communicable Diseases: Defintion & Examples

Understanding Communicable Diseases

Communicable Diseases are a vital topic in the study of Biology. You might hear about these diseases often, particularly in a worldwide health context. Naturally, you might wonder, what is a communicable disease? And why does it matter? Understanding these diseases can equip you with the knowledge to protect yourself and others.

Communicable Disease Definition

A communicable disease refers to a pathological condition that can be transmitted from one individual to another. These conditions are caused by infectious agents, including viruses, bacteria, and fungi.

Characterising the Terms: Infectious and Communicable

Often, the terms infectious and communicable are used interchangeably, but they do have distinctive features. An infectious disease is caused by pathogens and can affect a single individual without necessarily being passed on. On the other hand, a communicable disease is not only caused by pathogens but can also spread from one person to another.

Major Types of Communicable Diseases

Communicable diseases can manifest in countless forms. However, you can broadly split them into four major kinds, depending on the contagion's nature:

Direct Transmission: Diseases transmitted through immediate contact.
Indirect Transmission: Diseases spread via intermediate items, such as food, water, or surfaces.
Vector-Borne: Diseases transmitted by vectors, like mosquitoes.
Zoonotic: Diseases passed on from animals to humans.

Diseases like HIV (Human Immunodeficiency Virus), influenza, and COVID-19 are examples of direct transmission diseases. On the other hand, diseases like cholera and typhoid fever occur due to indirect transmission. Vector-borne examples include malaria and Zika, while zoonotic diseases encompass rabies and Lyme disease.

Prevalent Examples of Communicable Diseases

Having established their types, you may want to acquaint yourself with some common examples of communicable diseases.

Influenza: Known informally as "flu", it is a highly contagious respiratory illness caused by influenza viruses. It can cause severe illness and life-threatening complications in many people. Influenza viruses are spread by coughing and sneezing, and occasionally by touching a surface or object contaminated by the virus and then touching one's mouth or nose.

COVID-19: An unprecedented example surely is COVID-19, caused by the SARS-CoV-2 virus. It is speculated to have zoonotic origins and spreads mainly through droplets generated when an infected person coughs, sneezes, breathes, talks, or sings.

Malaria: Malaria is a mosquito-borne infectious disease affecting humans and other animals caused by single-celled microorganisms belonging to the Plasmodium group.

Delving into the Causes of Communicable Diseases

As you journey further into the crucial topic of Communicable Diseases, it becomes pertinent to explore the factors that cause these diseases. Grasping these causes can help to better comprehend the spread and control of such diseases. Generally, these factors are categorised into three broad collections: Biological, Environmental, and Social and Behavioural causes.

Biological Factors Causing Communicable Diseases

Naturally, biological aspects play a vital role in causing communicable diseases. The primary biological factors include the existence of infectious agents and the mechanism of transmission among hosts.

Biological Factor	Description
Infectious Agents	The existence of infectious agents, like bacteria, viruses, fungi, or parasites, is crucial for the onset of communicable diseases. These agents invade the host's body and cause illness.
Transmission Mechanisms	The method of transmission among hosts is another biological ingredient. It could be direct contact, indirect contact, airborne transmission, vector-borne spread, or zoonotic transmission.

For instance, Tuberculosis (TB) is caused by the bacterium Mycobacterium tuberculosis. It employs airborne transmission, spreading when an infected person coughs, sneezes, or talks, releasing droplets into the air, which can be inhaled by people nearby.

Environmental Causes of Communicable Diseases

Environmental conditions significantly contribute to the prevalence and propagation of communicable diseases. Three primary environmental causes include sanitation, climate, and population density.

Sanitation: Poor sanitation can increase the incidence of diseases, particularly those communicable via water and soil.
Climate: Certain diseases, especially vector-borne ones, are influenced by climatic conditions.
Population Density: High population density can facilitate disease transmission, particularly in urban settings.

Cholera is an acute diarrhoeal disease, often related to inadequate access to clean water and sanitation facilities. On the other hand, the incidence of mosquito-borne diseases like malaria and dengue is seen to rise with increasing temperatures associated with climate change. In bustling, crowded cities, the quick spread of respiratory diseases like influenza and COVID-19 is witnessed.

Social and Behavioural Factors Leading to Communicable Diseases

Social and behavioural factors interplay significantly in the spread of communicable diseases. These might include lifestyle choices, cultural practices, and socio-economic conditions.

Lifestyle choices refer to actions or behaviours that an individual chooses in their daily life, like dietary habits, physical activity, smoking, or drinking. These choices can influence the susceptibility of a person to certain communicable diseases.

Cultural practices relate to customs, traditions, or behaviours held by a societal group. Certain such practices might inadvertently promote the spread of communicable diseases.

Socio-economic conditions often dictate healthcare access levels, nutritional status, and living conditions that might affect the prevalence and management of communicable diseases.

Unhealthy lifestyle choices, like smoking or substance abuse, can compromise an individual's immune system, making them more prone to infections like pneumonia or tuberculosis. Cultural practices like unhygienic rituals or mass gatherings can enhance disease transmission. Furthermore, socio-economic disparities often lead to unequal access to healthcare, inadequate nutrition, and poor living conditions, underpinning a cycle of disease and poverty.

Effective Methods to Prevent Communicable Diseases

In the landscape of Communicable Diseases, prevention holds pinnacle importance. By adopting certain strategic measures and habits, you can shield yourself and others around you from a multitude of these diseases. Let's dive into the mechanisms that can safeguard against communicable diseases and their remarkable efficacy.

Which Method Helps Prevent Communicable Diseases

This intrigue can be satisfied by exploring some fundamental methods that have effectively curtailed the transmission of varied communicable diseases. These can be broadly classified into two categories: general prevention strategies and specific prevention techniques.

General Prevention Strategies refer to broad-based measures aimed at improving overall health and reducing the risk of various diseases, not restricted to a particular disease.

Specific Prevention Techniques instead target a single disease or class of diseases with certain shared characteristics, deploying a more focused approach.

Some general strategies include maintaining good personal hygiene, adopting a healthy lifestyle, and creating and fostering a clean environment. Specific strategies largely encompass immunisation, use of protective barriers, targeted hygiene practices, chemoprophylaxis, and post-exposure prophylaxis.

For instance, hand hygiene is a general practice suggested to prevent a wide array of diseases from the common cold to more serious infections like hepatitis A and meningitis. Immunisation, on the other hand, is a specific prevention technique, where vaccines are used to protect against specific diseases like measles, mumps, rubella or influenza.

The Role of Vaccines in the Prevention of Communicable Diseases

You may have often heard healthcare professionals advocate for immunisation. So, what role do vaccines play in the prevention of communicable diseases? Let's delve in.

A vaccine introduces a weakened or harmless version of a pathogen (the organism causing the disease) or its components into the body. This stimulates the immune system to produce a response, including the production of antibodies, which will protect the body against future infections with the same pathogen.

Bluntly speaking, vaccines operate on a simple "memory" principle. When exposed to a pathogen, our immune system "remembers" how to fight off that specific pathogen. So, if we encounter it again, our immune system can swiftly respond, preventing the disease. This approach is extremely rewarding when dealing with communicable diseases, particularly those with potential severe consequences.

Consider the example of the measles vaccine. A child receiving the measles vaccinated gets a weakened version of the measles virus. This prompts the immune system to produce a robust response, including the production of antibodies that recognize the virus. If the child is later exposed to the actual measles virus, the immune system can speedily recognize and fight off the virus, preventing illness.

Furthermore, vaccines play a significant role in 'herd immunity'. When a critical portion of a community gets immunized against a contagious disease, most members of the community are protected against that disease. Essentially, this reduces the amount of the disease-spreading agent in the environment, offering a cloak of protection around even those individuals not vaccinated, for instance, newborns, allergic individuals, or those who cannot receive vaccines due to some health conditions. It's an indirect yet highly effective method of disease control.

Importance of Good Hygiene Practices

Good hygiene practices form the bedrock of general tactics to hold back communicable diseases. They are uncomplicated, adaptable but incredibly powerful tools in the prevention armoury.

Hygiene essentially refers to conditions and practices that help to maintain health and prevent the spread of diseases. It can be personal (pertaining to bodily hygiene practices) or environmental (related to cleanliness of one's living and working surroundings).

Certain practices like frequent and proper hand washing, safe food handling, appropriate waste disposal, and effective respiratory hygiene, among others, are instrumental in curbing the spread of communicable diseases. Heating or boiling water and food are potent ways to kill pathogens, significantly reducing the risk of disease. Personal cleanliness and proper sanitation are crucial in preventing diseases transmitted through direct or indirect contact. Furthermore, the use of insect repellants, wearing appropriate clothing and vaccination can prevent vector-borne diseases.

Consider the simple act of handwashing. Hand hygiene is a highly floated term these days, especially amidst the COVID-19 pandemic. Washing your hands frequently with soap and water for at least 20 seconds can significantly cut down the risk of disease transmission, not only for COVID-19 but also for a host of other diseases like diarrhoea, cholera, eye and skin infections, and even some types of pneumonia and influenza.

Treatment and Control of Communicable Diseases

When it comes to communicable diseases, effective treatment and rigorous control measures are paramount in managing outbreaks and minimising human suffering. Treatment strategies are primarily aimed at curing or managing the disease, while control measures focus on preventing the spread of the disease to others. Let's unearth these practices to better understand how communicable diseases are managed today.

Common Treatments for Various Types of Communicable Diseases

Treatment strategies for communicable diseases are diverse, much like the diseases themselves. The treatment plan is solidified based on factors such as the type of disease, the pathogen involved, the patient's overall health, and the severity of the disease. The most common types of treatments include antiviral drugs, antibiotics, antiparasitic drugs, and antifungal medications. To explain this further:

Antiviral drugs are used for treating diseases caused by viruses, such as influenza or HIV. They work by suppressing the virus's ability to reproduce, thereby reducing its impact on the patient.

Antibiotics are potent against bacterial infections. They inhibit the bacteria's ability to grow and reproduce, effectively helping the immune system to eliminate the infection. An important note here: antibiotics are not effective against viral infections.

Antiparasitic drugs are used to treat diseases caused by parasites, such as malaria or giardiasis. They operate in various ways, like interrupting the parasite's lifecycle, damaging the parasite's cells, or effectively bolstering the host's immune response.

Antifungal medications help tackle fungal infections. They can kill fungi directly, or they can prevent them from growing and flourishing.

A classic example of treatment is Tuberculosis (TB), a bacterial infection that primarily affects the lungs. TB is generally treated with a regimen of antibiotics administered over six to nine months. The antibiotics primarily used for TB treatment are isoniazid, rifampin, ethambutol, and pyrazinamide.

Control Measures for Preventing the Spread of Communicable Diseases

Preventing a disease from spreading is as critical as treating the disease itself. Containment measures often entail isolating patients with the disease, practising good hygiene, and making judicious use of protective equipment. Let's delve into some of these significant steps:

Isolation: Patients diagnosed with the disease are often kept isolated to prevent the illness from spreading to others. Isolation measures can range from staying at home for mild cases to hospital isolation for severe cases.
Good Hygiene Practices: As we have already explored, good personal and environmental hygiene practices are integral in preventing the spread of many communicable diseases.
Use of Personal Protective Equipment (PPE): PPE, such as masks, gloves, and gowns, are used to provide a barrier between the infectious agent and the person. This is extremely relevant in healthcare settings, particularly amidst the ongoing COVID-19 pandemic.

In an outbreak situation, additional control measures like travel restrictions, closure of public places, and widespread screening may also be implemented to slow the spread of the disease. These measures were prominently seen during the COVID-19 pandemic, where countries across the globe imposed lockdowns, closed borders, and carried out mass testing and contact tracing efforts to try and control the virus's spread.

Role of Public Health Policies for Communicable Disease Control

Beyond individual actions, effective public health policies play a monumental role in controlling communicable diseases. These can include surveillance systems, immunisation programmes, investment in research, and educational campaigns. A deeper look at these strategies:

Strategy	Description
Surveillance Systems	Accurate and robust disease surveillance systems support early detection of outbreaks, allowing health authorities to act swiftly and decisively.
Immunisation Programmes	Immunisation programmes are central to controlling, and often eradicating, communicable diseases. The availability, accessibility, and use of vaccines are crucial to these programmes' success.
Investment in Research	Investments in research can lead to new treatments, better understanding of disease spread, more efficient diagnostic tools, and breakthroughs in vaccines.
Educational Campaigns	Informative and accurate public health campaigns can raise awareness, drive behaviour change, promote early detection, and boost treatment outcomes.

Take the eradication of smallpox as an example. Considered one of the biggest achievements in public health, the eradication of smallpox was largely due to an aggressive worldwide vaccination campaign led by the World Health Organisation. This achievement hinged on international cooperation, effective public health policies, investment in vaccine development, and extensive vaccination campaigns.

Exploring the Impact of Communicable Diseases

Communicable Diseases undeniably have a profound impact, both on global health and at the individual level. Their effect can ripple through societies and economies, and their footprint on the human body can linger for years. To grasp the magnitude and depth of this issue, let's investigate how these diseases affect global health and the long-term effects they can impose on the human body.

How Communicable Diseases Affect Global Health

The effect of communicable diseases on global health is far-reaching and multifaceted. They account for a significant proportion of illnesses and deaths worldwide, particularly in low and middle-income countries. Their impact on global health can be assessed under three broad categories: health consequences, economic implications, and social disruptions.

Health Consequences: Communicable diseases pose a serious threat to public health, leading to morbidity (illness) and mortality (death) on a grand scale. They can overburden health systems, stretch resources thin, and expose gaps in public health infrastructure.

Economic Implications: The economic burden of communicable diseases is immense. They can exact heavy costs, not just in terms of healthcare expenditure, but also in lost productivity, hindrance to economic growth, and perpetuation of cycles of poverty.

Social Disruptions: Communicable diseases can disrupt societies, creating fear and stigma, impeding education, and contributing to social inequality.

Consider the HIV/AIDS pandemic. In terms of health consequences, as of end-2020, AIDS-related illnesses have caused an estimated 32.7 million deaths worldwide, with an estimated 38 million people currently living with the virus. Economically, it is estimated that the global GDP could be reduced by over \$7 billion by 2030 due to HIV/AIDS. Socially, the disease has disrupted communities, resulted in millions of orphans, and deepened inequality.

The global health impact is more daunting when considering the interaction of communicable diseases with other health and developmental issues. For instance, malnutrition can exacerbate the effect of diseases like tuberculosis and measles, while the presence of communicable diseases can increase susceptibility to malnourishment. They can reinforce each other in a vicious cycle, amplifying each other's impact, and leading to a formidable challenge in global health.

The Long-Term Effects of Communicable Diseases on the Human Body

While the immediate symptoms of communicable diseases are often recognised, the long-term effects on the human body may not be as widely understood. It's essential, however, to acknowledge that these diseases can impact the body's functions long after the acute illness has passed.

The chronic effects of communicable diseases are largely contingent on the type of disease, the severity of the original illness, and the individual's health status. But they can entail influences on various organ systems, psychological wellbeing, and overall health.

Organ System Impact: Many communicable diseases can lead to chronic conditions in various organ systems of the body. For example, untreated strep throat (caused by bacteria) can lead to rheumatic heart disease, hepatitis C virus infection can lead to chronic liver disease, and certain types of Human Papillomavirus (HPV) can lead to cervical cancer.

Psychological Impact: The psychological impact of communicable diseases should not be overlooked. People with communicable diseases often encounter stigma, discrimination, and depression. Furthermore, people living with chronic diseases can face an increased risk of mental health problems.

Overall Health: The cumulative effect of chronic conditions arising from communicable diseases can impair overall health, reduce life expectancy, and decline the quality of life. They can also render individuals more susceptible to other illnesses due to compromised immunity.

Take the case of Tuberculosis. While the acute illness mostly affects the lungs, long-term effects can impact multiple organ systems. Pulmonary TB can lead to chronic lung disease, while Extrapulmonary TB can affect the lymphatic system, bones, and joints. This can lead to debilitating chronic conditions with tremendous impact on overall health and quality of life.

Communicable Diseases - Key takeaways

Communicable diseases, such as Tuberculosis (TB), are often caused by bacteria and spread through airborne transmission methods such as coughing, sneezing or talking.
Environmental conditions, social and behavioural factors, and lifestyle choices can significantly influence the prevalence and spread of communicable diseases. Poor sanitation, climate changes, and population density are primary environmental factors. Cultural practices and socio-economic conditions are major social factors.
The prevention of communicable diseases can be done through general prevention strategies and specific prevention techniques. General strategies include maintaining hygiene and leading a healthy lifestyle, while specific techniques include immunisation and targeted hygiene practices.
Vaccines play a crucial role in the prevention of communicable diseases by introducing a harmless version of a pathogen into the body to stimulate an immune response. This helps protect the body against future infections with the same pathogen.
Good hygiene practices, including frequent handwashing, safe food handling, and environmental cleanliness can help prevent the spread of communicable diseases.
Treatment of communicable diseases varies based on the type of disease, the pathogen involved, and the patient's overall health. Common treatments include antiviral drugs, antibiotics, antiparasitic drugs, and antifungal medications.
Control measures for communicable diseases include patient isolation, maintaining good hygiene, and using personal protective equipment. In outbreak situations, additional control measures like travel restrictions and closure of public places may also be implemented.
Public health policies, including robust disease surveillance systems, immunisation programmes, investment in research, and educational campaigns play a significant role in controlling communicable diseases. They support early detection of outbreaks, control and eradication of diseases, and promotion of awareness and behaviour change.

Communicable Diseases

StudySmarter Editorial Team