Epidemiology of Diseases of Public Health Significance Group 2 PDF

EPIDEMIOLOGY OF DISEASES OF PUBLIC HEALTH SIGNIFICANCE GROUP 2  OBJECTIVES 1. Students should be able to define the natural history of Communicable diseases. 2. Be able to correlate the natural history of the particular communicable diseases to their prevention. 3. Determine possible...

EPIDEMIOLOGY OF DISEASES OF PUBLIC HEALTH SIGNIFICANCE GROUP 2  OBJECTIVES 1. Students should be able to define the natural history of Communicable diseases. 2. Be able to correlate the natural history of the particular communicable diseases to their prevention. 3. Determine possible treatment problems related to some infectious diseases based on knowledge of common resistant organisms.  NATURAL HISTORY OF COMMUNICABLE DISEASES The natural history of communicable diseases refers to the progression and dynamics of infectious diseases within populations, encompassing various stages from exposure to resolution, understanding disease patterns, transmission dynamics, and the impact of interventions. This includes several stages: 1.Exposure: The initial contact with a pathogen, which occurs through various routes. 2.Incubation Period: This is a period during which the pathogen replicates without causing symptoms.  CONTD....... 3.Clinical Disease: Symptoms begin to manifest, which can vary in severity. 4.Recovery or Resolution: Depending on the disease and the individual's health status, recovery may occur, often leading to immunity 5.Transmission Dynamics: The disease may spread to other individuals during various stages, particularly during the incubation and clinical phases  FACTORS AFFECTING NATURAL HISTORY OF DISEASES Host Factors: Genetics, immune status, age, and underlying health conditions influence susceptibility and disease progression Pathogen Factors: Virulence, mode of transmission, and mutation rates affect how diseases spread and manifest. Environmental Factors: Climate, population density, sanitation, and healthcare access play critical roles in disease transmission dynamics.  HIV/AIDS HIV (Human Immunodeficiency Virus) weakens the immune system by targeting CD4 T cells, leaving individuals vulnerable to infections and cancers. It spreads through body fluids like blood, semen, vaginal fluids, and breast milk, but not through casual contact like hugging or sharing food. Without treatment, HIV progresses through several stages. While there is no cure, antiretroviral therapy (ART) controls the virus, allowing people to live long, healthy lives. Early diagnosis and consistent treatment help prevent the progression to AIDS.  STAGES DIAGNOSIS AND PREVENTION 1.Acute HIV Infection: Occurs shortly after transmission with flu-like symptoms; highly contagious, though Rapid diagnostic tests and self-testing are available. Prevention methods include symptoms can be mild or unnoticed. condoms, regular testing, and 2. Chronic HIV Infection: Virus remains active, 3. antiretroviral drugs (PrEP, ART). gradually weakening the immune system, often without symptoms for years. Symptomatic : Immune system weakens further, leading to frequent infections, illnesses, 4. AIDS: Final and most severe stage, marked by significant immune system damage, resulting in life-threatening infections and cancers.  RUBELLA Rubella, also known as German measles, is a highly contagious viral infection primarily spread through respiratory droplets when an infected person coughs or sneezes. The virus can survive on surfaces for up to two hours, increasing the risk of transmission. While rubella typically presents mild symptoms in most individuals, it poses a significant threat to pregnant women, as infection during pregnancy can lead to miscarriage, stillbirth, or congenital malformations in the baby, collectively known as congenital rubella syndrome (CRS).  SYMPTOMS PREVENTION Common symptoms include fever, mild Immunization with the MMR (measles, mumps, and rubella) vaccine has conjunctivitis, rash that starts on the face significantly reduced rubella cases in Jamaica and worldwide. and spreads, swollen lymph glands, and occasionally joint pain in adults. RISKS Symptoms generally appear 2-3 weeks The most significant risk after exposure, and infected individuals associated with rubella is congenital rubella syndrome are contagious from 7 days before to 7 (CRS), which can lead to severe birth defects, including heart days after the rash appears. problems, deafness, and developmental delays.  RUBEOLA Rubeola, also known as Measles, is a highly contagious disease caused by the Morbillivirus that affects the respiratory system. It spreads via direct contact with the drainage from the nose and throat (spit) and it can also spread through airborne droplets from the infected. Infected persons will display symptoms like a runny nose, rash, conjunctivitis, cough and high fever. Incubation period for rubeola is 7 to 18 days and by day 14, the rashes will start to appear.  treatment PREVENTION Some treatment for measles is to A better prevention against increase fluid intake and provide Rubeola overall is to take a patients with vitamin A, as it will help vaccine. The Rubeola vaccine is a stop or slow any eye damage. combination vaccine with mumps RISKS and rubella called the MMR This disease can cause: an ear vaccine. infection, diarrhea and even inflammation of the brain.  POLIOMYELITIS Poliomyelitis is an acute infection caused by a poliovirus, which is from the family Enterovirus. It invades the nervous system and can cause paralysis via the fecal-oral route and even through contaminated water or food. This virus then multiplies in the oropharynx and the intestines. Infected persons display flu-like symptoms: slight fever for 1-3 days, headache, sore throat and vomiting.  POLIOMYELITIS The two common types of poliomyelitis can be Paralytic or Nonparalytic poliomyelitis. Paralytic poliomyelitis attacks the Nonparalytic poliomyelitis can brain and spinal cord, causing cause swelling around the paralysis after incubating for 7–21 brain after incubating for 3-6 days. days. This disease can cause post-polio symptoms. This includes scoliosis, muscle atrophy and fatigue.  POLIOMYELITIS PREVENTION RISKS The only prevention polio is the This disease can cause post- vaccine. The polio vaccine is to be polio symptoms. This includes by the age of 7 years old, in 5 scoliosis, muscle atrophy, bone doses. shortening and fatigue.  MUMPS The mumps virus causes mumps, a member of the Paramyxoviridae family. Symptoms typically appear 16–18 days after exposure and include swollen parotid glands, fever, muscle aches, fatigue, and loss of appetite. This disease is often mild, however it can lead to serious complications, including orchitis (inflammation of the testes), oophoritis (inflammation of the ovaries), meningitis, and encephalitis.  MUMPS The introduction of the MMR (measles, mumps, rubella) the vaccine has been crucial in controlling mumps outbreaks. In Jamaica, The Ministry of Health has implemented vaccination programs that have reduced the incidence of mumps significantly.  SMALLPOX Smallpox is caused by the variola virus. It was historically endemic in many parts of the world, including the Caribbean. Smallpox is transmitted via respiratory droplets and direct contact with contaminated surfaces or infected individuals. The incubation period of smallpox typically lasts 7 to 17 days, wit an average of about 12 days.  SMALLPOX There are two stages: 1. Prodromal Stage: fever, malaise, and body aches, lasting about 2-4 days. 2. Rash Stage: A rash emerges that typically lasts about 10 to 16 days. The disease can be severe, with mortality rates historically between 20% and 30%. With the aid of The World Health Organization (WHO) and widespread vaccination Smallpox is no longer a threat to humans. INFLUENZA/H1N1 INFLUENZA/H1N1 Influenza/H1N1 Influenza/H1N1 Influenza/H1N1  HERPES Herpes is a common infection caused by the Herpes Simplex Virus that can result in painful blisters or ulcers. Skin-to-skin contact is the main method by which it transmits. There are two types of Herpes Simplex Virus: 1. Herpes Simplex Virus Type 1 (HSV-1): This is primarily transmitted through oral contact and produces infections in or around the mouth (oral herpes and cold sores). It may also cause genital herpes. 2. Herpes Simplex Virus Type 2 (HSV-2): Transmitted through sexual contact and causes genital herpes  SYMPTOMS Herpes Simplex Virus infections typically take six to eight days to manifest symptoms, but can take up to twenty-six days. COMMON SYMPTOMS include blisters, fever, body aches, enlarged lymph nodes, sore throat, and headache. Tingling, itching, or burning near where the sores will appear are often the first signs of an outbreak.  HERPES HSV infection has three stages: Primary infection - HSV infects nearby nerve cells and replicates, typically affecting the trigeminal nerve in the mouth or the sacral plexus in the genital region. Latency - The virus remains dormant in nerve cells, with most infected cells inactive. Reactivation - Infected cells wake up and trigger an immune response.  HERPES treatment PREVENTION The frequency of breakouts may be To prevent the Herpes Simplex Virus, decreased by taking these drugs at a patients should refrain from oral lower daily dose. Medications for pain contact or sexual activity with others in management include benzocaine, order to stop the disease from lidocaine, ibuprofen, naproxen, and spreading. paracetamol.  DENGUE Dengue is a viral infection caused by the Dengue virus (DENV). The primary vector responsible for transmitting the dengue virus is the Aedes mosquito, particularly Aedes aegypti and, to a lesser extent, Aedes albopictus.  DENGUE Treatment: Symptoms include: Hydration is encouraged A high fever Rest Nausea Paracetamol (for fever and pain relief) Body aches Joint pain DHF and DSS in severe cases  DENGUE Mitigation strategies: Vaccination: Vector control Making the public aware Dengvaxia was the first Fogging dengue vaccine developed Encouraging the use of mosquito but is only recommended for repellents ages 9-24 with a prior dengue infection Meningitis is the MENINGITIS Transmission of Meningitis inflammation of the 1. Viral meningitis- spread through direct leptomeninges which are contact with respiratory secretions. the arachnoid and pia 2. Bacterial meningitis- spread through respiratory droplets, direct contact with maters. infected individuals or through the blood stream 3. Fungal meningitis is the least common and is spread through environmental exposure  MENINGITIS Symptoms: Diagnosis: Headache Blood tests stiff neck Lumbar puncture or spinal tap Photophobia Clinical evaluation of infected person confusion Nausea and vomiting Mitigation Strategies: Wash hands regularly Disinfect surfaces often Raise awareness by educating the public  Treatment: MENINGITIS Vaccination: Viral meningitis needs For viral meningitis MMR vaccine supportive care as most may prevent mumps related cases resolve on their own meningitis Fungal meningitis is treated For bacterial meningitis 3 vaccines with antifungal medications are available Meningococcal, Bacterial meningitis requires immediate antibiotic pneumococcal and Haemophilus treatment influenzae type b  HEPATITIS The term hepatitis describes an inflammation of the liver that is often brought on by viral diseases, namely hepatitis A, B, C, D and E. Hepatitis B and C are most often mentioned throughout the Caribbean.  HEPATITIS Hepatitis A: An acute illness spread by tainted food and water. Hepatitis A is a member of the family Picornaviridae. Hepatitis B: May develop into chronic hepatitis or manifest acutely. Transmission happens through biological fluids, such as blood. Hepatitis B belongs to the Hepadnaviridae family. Hepatitis C: Mostly chronic, contracted by blood transfusions or sharing needles, among other means. Although the symptoms are minor, they can eventually cause cancer or cirrhosis. Hepatitis C belongs to the Flaviviridae family.  HEPATITIS Hepatitis D: Can make the prognosis worse and only appears when there is a hepatitis B infection. Hepatitis D is a member of the Deltaviridae family and necessitates co-infection with hepatitis B. Hepatitis E: is uncommon in Jamaica but is mostly observed in places with inadequate sanitation. It induces a transient infection that goes away quickly. Hepatitis E belongs to the Hepeviridae family.  HEPATITIS The main method of hepatitis A and E transmission is fecal- oral (infected food or drink). very contagious, but avoidable with good cleanliness. Via blood transfusions, sex interactions and perinatal transmission (mother to child), hepatitis B, C and D can spread. ARTHROPOD BORNE VIRAL DISEASE Arboviral illnesses or arthropod-borne viral diseases, are infections that are mostly transmitted by ticks and mosquitoes. The ones frequently encountered in Jamaica/Caribbean are dengue, chikungunya and Zika virus. ARTHROPOD BORNE VIRAL DISEASE Dengue: Aedes Aegypti mosquitoes carry the acute virus dengue. High temperature, excruciating headache, aches in the joints and muscles, and in extreme situations, shock or bleeding are among the symptoms. ARTHROPOD BORNE VIRAL DISEASE Chikungunya: Another viral illness spread by Aedes aegypti and Aedes albopictus mosquitoes. It results in rash, fever, and discomfort in the muscles and joints. Chikungunya is a member of the family Togaviridae. ARTHROPOD BORNE VIRAL DISEASE Zika: Aedes mosquitoes transmit this mild virus, which can cause fever, rash, joint discomfort, and conjunctivitis. Zika is a member of the family Flaviviridae.  Coronavirus Disease (COVID-19) is an illness caused by the virus severe acute respiratory syndrome coronavirus 2 (SARS-CoV2). COVID-19 It was first reported in Wuhan, China in December 2019 and has continued to spread since then, achieving a pandemic status in 2020.  COVID-19 VIRUS TRANSMISSION SYMPTOMS An incubation period: 2-14 days The virus that causes COVID-19 can enter an (average 5 days) individual’s body through the mouth, nose or Fever eyes Cough Fatigue It is transmitted via airborne droplets or hand- Loss of taste/ smell to-face contact Severe cases: pneumonia/ acute respiratory distress syndrome (ARDS)  COVID-19 DIAGNOSIS TREATMENT Diagnosis for COVID-19 are based on Treatment for the virus depends laboratory tests: on the severity of one’s symptoms Non-hospitalized patients: No 1. Molecular (PCR) Tests: Detect geentic antiviral treatment is material recommended 2. Antigen Tests/rapid COVID-19 tests: Detect Hospitalized patients: some viral protein may require oxygen and other A sample is usually collected from the nose, therapies. throat or saliva.  VACCINATION MITIGATION STRATEGIES COVID-19 vaccines are preventative The implementation of: treatments that teaches the body how Mask mandates to identify and combat the infection. Social distancing Development and distribution of these Lockdowns Travel restrictions vaccines began in Emphasis on hand hygiene late 2020. and vaccination  CHIKUNGUNYA/CHIK-V Chikungunya is a mosquito- borne disease first identified in 1952 in the United Republic of Tanzania. The virus first appeared in the Caribbean in 2013 and later made its way to Jamaica in 2014 infecting the island with Chikungunya fever. TRANSMISSION Transmitted primarily by: Aedes Aegypti and Aedes Albopictus mosquitoes. Bites infected human Virus replicates New host infection  SYMPTOMS Chikungunya has an incubation period of 2-12 days (on average: 4-8 days). Symptoms include: Sudden onset fever Severe joint pain Joint swelling, headache, rash, fatigue, nausea  PREVENTION STRATEGIES Key preventative methods include: Mosquito control Clean drainage systems to eliminate stagnant water for mosquito breeding Use of insecticides and repellants Installing window and door screens Wearing protective clothing Educating the community on causes, effects and prevention methods Encouraging individuals with knowledge to minimize risks  DIAGNOSIS, DIAGNOSIS TREATMENT MANAGEMENT Testing Methods: There is no specific & TREATMENT antiviral treatment for Blood samples can detect CHIKV CHIKV within the first Symptoms can be week managed by: RT-PCR Test: Confirm 1. Taking paracetamol/ presence of the virus acetaminophen for pain Antibody levels can and fever indicate infection within 2. Staying hydrated and the first week post-onset resting  ZIKA VIRUS The Zika virus is a mosquito- borne virus that was first discovered in Uganda in 1947 (World Health Organization, 2022). The primary vectors for this virus are Aedes mosquitoes, which typically feed during daylight hours. SYMPTOMS Rash Fever Muscle and joint pain Headache that usually last for 2-7 days  TRANSMISSION It can be transmitted through sexual contact with an infected individual, even in the absence of symptoms. It can be transmitted from a pregnant woman to her fetus, as the virus can cross the placenta and enter the fetal bloodstream. transmission through blood transfusion is also possible if the donor is infected, although this mode of transmission is considered rare. DIAGNOSIS AND Diagnosis Treatment TREATMENT Zika virus may be Currently, there is no suspected based on targeted treatment for symptoms, if a person is Zika virus infection or asymptomatic, disease, so individuals confirmation can only be infected with the virus achieved through should seek medical laboratory tests of blood attention. or urine  PREVENTIONS Preventive measures include controlling mosquito populations by eliminating breeding sites, applying insect repellent and wearing protective clothing, ideally in light colors that cover as much skin as possible. As of now, no vaccine is available for Zika virus infection.  ENCEPHALITIS Encephalitis is an inflammatory disorder of the brain, usually resulting from either an infection or an autoimmune reaction. In which the immune system attacks the brain, causing swelling.  TRANSMISSION Coughing or sneezing by an infected individual releases airborne viruses that can be inhaled by others. Bites from infected insects (such as mosquitoes or ticks) and animals can directly inject certain viruses into the bloodstream. Contact with an infected individual, which can also result in transmission.  SYMPTOMS Infectious encephalitis frequently COMMON begins with symptoms resembling those of the flu or a headache, headache, fever, eventually leading to changes in seizure, stiffness in the mental status and challenges with neck and loss of memory, and reasoning. consciousness  TREATMENT - Antiviral medications to address viral infections affecting the brain - A breathing tube, urinary catheter, or feeding tube DIAGNOSIS if the patient has lost consciousness due to encephalitis. A diagnosis of encephalitis can be established when a patient exhibits a combination of symptoms, including fever, seizures, or changes in behaviour and movement. To confirm encephalitis, a healthcare professional may conduct tests such as a brain MRI or CT scan, carry out medical examination, and assess the patient's medical history. And also through blood, urine test and stool test to detect antibodies associated with the infection.  COMPLICATIONS = Low blood pressure - Decreased oxygen levels in the blood - Bleeding within the brain - Permanent brain damage - Mortality PREVENTIONS Maintaining good hygiene and washing hands regularly to reduce the transmission of viruses and bacteria. Taking precautions to avoid exposure to mosquitoes and ticks.  REFERENCE 1. CHAPTER 15: MUMPS. (2024). EPIDEMIOLOGY AND PREVENTION OF VACCINE-PREVENTABLE DISEASES. HTTPS://WWW.CDC.GOV/PINKBOOK/HCP/TABLE-OF-CONTENTS/CHAPTER-15-MUMPS.HTML 2. MAYO CLINIC. (2023). RUBELLA (GERMAN MEASLES): SYMPTOMS AND CAUSES. HTTPS://WWW.MAYOCLINIC.ORG/DISEASES-CONDITIONS/RUBELLA/SYMPTOMS-CAUSES/SYC-20377310 3. SMALLPOX”, (2021). CENTERS FOR DISEASE CONTROL AND PREVENTION CDC. (N.D.-B). HTTPS://WWW.CDC.GOV/SMALLPOX/INDEX.HTML 4. WORLD HEALTH ORGANIZATION (2024). HIV AND AIDS. HTTPS://WWW.WHO.INT/NEWS-ROOM/FACT-SHEETS/DETAIL/HIV-AIDS 5. WORLD HEALTH ORGANIZATION. (2023). RUBELLA. HTTPS://WWW.WHO.INT/NEWS-ROOM/FACT-SHEETS/DETAIL/RUBELLA 6. WORLD HEALTH ORGANIZATION (WHO). (1980). "THE GLOBAL ERADICATION OF SMALLPOX,” HTTPS://WWW.WHO.INT/ 7. SMALLPOX”, (2021). CENTERS FOR DISEASE CONTROL AND PREVENTION CDC. (N.D.-B). HTTPS://WWW.CDC.GOV/SMALLPOX/INDEX.HTML  REFERENCE 8. WORLD HEALTH ORGANIZATION (2022) ZIKA VIRUS HTTPS://WWW.WHO.INT/NEWS-ROOM/FACT-SHEETS/DETAIL/ZIKA-VIRUS? GAD_SOURCE=1&GCLID=CJ0KCQJWJY64BHCAARISAIFC7YYYGIN08UPDD6OON56ZHMDXHICCXSYVUCHEWO1U9D3B B6HZXEPC8J8AAJA2EALW_WCB CLEVELAND CLINIC (2024).POLIO. HEALTH AND CONDITIONS. HTTPS://MY.CLEVELANDCLINIC.ORG/HEALTH/DISEASES/15655-POLIO PHILADELPHIA, C. H. O. (2024). MEASLES (RUBEOLA). CHILDREN’S HOSPITAL OF PHILADELPHIA. HTTPS://WWW.CHOP.EDU/CONDITIONS-DISEASES/MEASLES-RUBEOLA