Diseases Knowledgebase
CDCR information bank initiative
Chickenpox, also known as varicella, is a highly contagious viral infection caused by the varicella-zoster virus (VZV). It primarily affects children but can also occur in adults who have not been previously exposed to the virus. Chickenpox is characterized by a distinctive itchy rash and is usually a mild illness. However, it can lead to more severe complications in certain cases.
Chickenpox is primarily transmitted through respiratory droplets when an infected person coughs or sneezes. It can also be spread through direct contact with the fluid from the blisters on the skin of an infected individual. People with chickenpox are contagious from about 1-2 days before the rash appears until all the blisters are crusted over, which typically takes around 5-7 days.
The incubation period for chickenpox is usually 10-21 days after exposure. The initial symptoms may include a low-grade fever, headache, and fatigue. Shortly after, a red, itchy rash develops, starting as small red spots that quickly transform into fluid-filled blisters. These blisters eventually burst, crust over, and heal within a few weeks.
Other common symptoms of chickenpox include:
1. Severe itching
2. Loss of appetite
3. Muscle aches
4. Sore throat
5. Feeling unwell or generally uncomfortable
In most cases, the characteristic appearance of the rash is sufficient for the diagnosis of chickenpox. However, in some cases, especially in adults, individuals with weakened immune systems, or pregnant women, further testing may be necessary. Testing methods such as polymerase chain reaction (PCR) or blood tests can confirm the presence of the varicella-zoster virus.
In most cases, chickenpox is a self-limiting illness that improves with time. Most treatments aim to relieve symptoms and prevent complications. Some recommended measures include:
1. Calamine lotion or antihistamines to reduce itching
2. Over-the-counter pain relievers (excluding aspirin) to alleviate fever and discomfort
3. Keeping the affected individual cool to reduce itching
4. Regularly trimming nails to minimize scratching and prevent secondary skin infections
5. Administering antiviral medications (such as acyclovir) to individuals at high risk of complications, including adults, pregnant women, and people with weakened immune systems
It is important to note that chickenpox can sometimes lead to severe complications, especially in vulnerable populations. These complications can include bacterial skin infections, pneumonia, encephalitis (inflammation of the brain), and in rare cases, death. Therefore, it is vital to seek medical attention if you suspect you or someone you know has chickenpox, particularly if any complications arise.
Cholera is an acute diarrhoeal disease caused by Vibrio cholerae; a gram negative rod-shaped bacterium. It is a potentially life-threatening, primarily waterborne disease. There are many serogroups of V. cholerae, but only two (O1 and O139) cause outbreaks. There have been seven pandemics of cholera worldwide, the last of which began in Indonesia in 1961, with an estimate of between 1.3 to 4.0 million cases and 21,000 to 143,000 deaths globally due to cholera every year. The World Health Organization has estimated that officially reported cases represent only 5-10% of actual cases. This “tip `of the iceberg reporting†is likely due to poor surveillance systems and inadequate disease notification systems in low and middle-income countries which are disproportionately affected by the disease.
Cholera can be both endemic and epidemic. A cholera-endemic area is an area where confirmed cholera cases were detected during 3 out of the last 5 years with evidence of local transmission. A cholera outbreak/epidemic can occur in both endemic countries and in countries where cholera does not regularly occur. A cholera hotspot is a geographically limited area where environmental, cultural and/or socioeconomic conditions facilitate the transmission of the disease and where cholera persists or re-appears regularly. Hotspots play a central role in the spread of the disease to other regions or areas.
In Nigeria, cholera is an endemic and seasonal disease, occurring annually mostly during the rainy season and more often in areas with poor sanitation, with the first series of cholera outbreaks reported between 1970 and 1990. Major epidemics also occurred in 1992, 1995-1996, and 1997. The Federal Ministry of Health reported 37,289 cases and 1,434 deaths between January and October 2010, while a total of 22,797 cases of cholera with 728 deaths and case-fatality rate of 3.2% were recorded in 2011. Outbreaks were also recorded in 2018 with the Nigeria Centre for Disease Control (NCDC) reporting 42,466 suspected cases including 830 deaths with a case fatality rate of 1.95% from 20 out of 36 States from the beginning of 2018 to October 2018.
Cholera is an epidemic prone disease for immediate notification on the Integrated Disease Surveillance and Response (IDSR) platform in Nigeria.
Humans are the main reservoir of Vibrio cholerae but water, mollusc, fish and aquatic plants are potential reservoirs.
The bacteria are transmitted mainly through the faeco-oral route via ingestion of contaminated food or water. Cholera transmission is closely linked to inadequate access to clean water and sanitation facilities. Typical at-risk areas include peri-urban slums, where basic infrastructure is not available, as well as camps for internally displaced persons or refugees. Humanitarian crises and the attendant displacement of populations to inadequate and overcrowded camps can increase the risk of cholera transmission.
Cholera has an incubation period of between two hours and five days, and is asymptomatic or mild in 80% of cases, with only about one in 10 infected people developing the typical signs and symptoms of cholera disease, usually within a few days of infection. Cholera is characterised by rapid onset of profuse watery diarrhoea (rice water stools), with or without vomiting. It is usually not associated with fever and is highly contagious. Severe cases can lead to death within hours due to dehydration. Case fatality ratios can be up to 50% especially in people without access to treatment but this drops to 1% with adequate treatment. People with low immunity such as malnourished children or people living with HIV are at a greater risk of death if infected.
The Technical Guidelines for IDSR in Nigeria gives the following standard case definitions:
Suspected case:
In a patient aged 5 years or more, severe dehydration or death from acute watery diarrhea.
If there is a cholera epidemic, a suspected case is any person age 5 years or more with acute watery diarrhoea, with or without vomiting.
Confirmed case:
A suspected case in which Vibrio cholerae O1 or O139 has been isolated in the stool.
NCDC also developed additional case definitions in September 2017 for the community as well as for health workers as follows:
Community case definition:
Any person 2years and above with lots of watery diarrhea
Suspected case:
Any patient aged ~2 years presenting with acute watery diarrhoea and severe dehydration or dying from acute watery diarrhoea with or without vomiting.
In areas where a cholera outbreak is declared, any person presenting with or dying from acute watery diarrhea with or without vomiting.
Stool samples should be collected once the patient presents and before antibiotics have been administered. The gold standard is culture of V. cholerae, for example on selective media such as thiosulfate citrate bile sucrose (TCBS) agar, with serogrouping and serotyping by antibody agglutination to confirm an outbreak strain. This also allows for antimicrobial susceptibility testing and advice on appropriate antibiotic administration. Stool samples can be enriched in alkaline peptone water to help with recovery, and field samples can be sent in Cary-Blair transport media.
Rapid diagnostic tests (RDT) can be used for screening before confirmation in the laboratory, and there any several lateral flow devices available, however their low specificity (and sometimes low sensitivity) can limit their utility. Darkfield microscopy of fresh rice-water stools can also be used to identify the motile V. cholerae bacteria.
The majority of affected people can be treated successfully through prompt administration of oral rehydration solution (ORS). Severely dehydrated patients are at risk of shock and require the rapid administration of intravenous fluids. Such patients should also be given appropriate antibiotics to diminish the duration of diarrhoea, reduce the volume of rehydration fluids needed, and shorten the amount and duration of V. cholerae excretion in their stool. Rapid access to treatment is essential during a cholera outbreak. Antibiotics may also shorten the duration and severity of symptoms and are a useful adjunctive therapy, the choice includes macrolides, fluoroquinolones, and tetracyclines depending on resistance profile.
Infection Prevention and Control (IPC)
Good personal hygiene should be emphasised, as well as proper disposal of sewage and refuse, good hand washing practices and consumption of safe water and food. Enhanced epidemiological and laboratory surveillance to identify endemic areas and detect, confirm, and quickly respond to outbreaks help in control of infection. Community engagement for behavioral changes and improved hygiene practices, as well as quick access to treatment are essential. Immunisation with Oral Cholera Vaccine (OCV) can play an important role in outbreak prevention and control, and in the long-term control of cholera. The vaccines should always be used in conjunction with other cholera prevention and control strategies in areas with endemic cholera, in humanitarian crises with high risk of cholera, and during cholera outbreaks.
Nigeria References
Adagbada AO, Adesida SA, Nwaokorie FO, Niemogha M, Coker AO. Cholera Epidemiology in Nigeria: an overview. Pan African Medical Journal 2012; 12:59
Federal Ministry of Health Nigeria. Weekly Epidemiology Report. 2011.
Nigeria Centre for Disease Control. Situation Report. Cholera Outbreak in Nigeria. 29 October 2018
Oyedeji KS, Nwaokorie FO, Bamidele TA, Ochoga M, Akinsinde KA, Brai BI, et al. Molecular Charactrization of the Circulating Strains of Vibrio cholerae during 2010 Cholera Outbreak in Nigeria. J Heal Popul Nutr. 2013; 31(2):17 84.
World Health Organization. Nigeria. Borno, Adamawa and Yobe States Declare End of Cholera Outbreaks. 21 January 2019. https://www.afro.who.int/news/borno-adamawa-and-yobe-states-declare-end-cholera-outbreaks
Further Reading
NCDC: https://www.ncdc.gov.ng/themes/common/docs/protocols/45_1507196550.pdf
CDC: https://www.cdc.gov/cholera/index.html
WHO: https://www.who.int/news-room/fact-sheets/detail/cholera
https://www.afro.who.int/health-topics/cholera
COVID-19 is a respiratory illness caused by the novel coronavirus SARS-CoV-2. It was first identified in Wuhan, China in December 2019 and quickly spread across the globe, leading to a pandemic. COVID-19 can range from mild to severe and in some cases can be life-threatening, especially for older adults and individuals with underlying health conditions.
The virus primarily spreads through respiratory droplets when an infected person coughs, sneezes, talks, or breathes heavily. It can also be transmitted by touching surfaces or objects contaminated with the virus and then touching the face, particularly the eyes, nose, or mouth. Close contact with an infected individual, within about 6 feet or two meters, poses the highest risk of transmission.
COVID-19 presents a wide range of symptoms, ranging from mild to severe. Common symptoms include fever, cough, sore throat, shortness of breath, fatigue, body aches, loss of taste or smell, headache, and congestion. Some individuals may experience gastrointestinal symptoms like diarrhea or nausea. It is important to note that some individuals infected with COVID-19 may remain asymptomatic, which makes it challenging to control the spread of the virus.
COVID-19 diagnosis is typically confirmed through a laboratory test called a polymerase chain reaction (PCR) test. This test detects the presence of viral genetic material in a sample collected from the throat, nose, or saliva. Rapid antigen tests are also available, providing faster results, but they may have a higher chance of false negatives. Serological tests, also known as antibody tests, detect antibodies produced in response to the virus, indicating previous infection. These tests are used to determine past exposure to the virus rather than active infection.
There is currently no specific antiviral treatment for COVID-19. Most cases of the illness are mild and can be managed at home with rest, hydration, and over-the-counter pain relievers to alleviate symptoms. Severe cases may require hospitalization, where supportive care, such as supplemental oxygen and in severe cases, ventilator support, is provided. In some instances, investigational treatments, like antiviral therapies or monoclonal antibody treatments, may be used under certain circumstances.
Prevention measures such as practicing good hand hygiene, wearing masks, maintaining physical distance, avoiding crowded places, and getting vaccinated are crucial in reducing the spread of COVID-19. It is important to follow guidelines and recommendations from local health authorities to protect oneself and others from infection.
It is important to note that the information provided here is a general overview and should not replace professional medical advice. If you suspect you have covid-19 or have any concerns, please consult with a healthcare provider for an accurate diagnosis and appropriate treatment.
Ebola virus disease (EVD) also known as Ebola hemorrhagic fever (EHF) is a severe disease of humans and other primates caused by an RNA virus of the family Filoviridae and genus Ebola virus. The disease has a high fatality rate killing between 25%-90% of those infected. Research conducted in 2005 suggested fruit bats to be the likely reservoir due to their ability to spread the virus without being affected by it.
The largest outbreak to date took place in West Africa between March 2014 to June 2016, affecting primarily Guinea, Liberia, Sierra Leone, Senegal, and Nigeria. A total of 11,296 cases were recorded including suspected and probable cases.
The first case of EVD in Nigeria was confirmed in Lagos on 23 July 2014 and spread to involve 20 laboratory-confirmed EVD cases. 8 of the confirmed cases of EVD in Nigeria eventually died (case fatality rate of 42.1%) and 12 were nursed back to good health. In Nigeria, the rapid control of the EVD was facilitated by the rapid detection of the index case, the comprehensive contact tracing measures and the isolation and treatment of the secondary cases. On October 20th, 2014 Nigeria was declared free of EVD by the World Health Organization
Infection in the index case occurs after human contact with fruit bats or intermediate infected hosts, such as non-human primates, rodents, antelopes or their carcasses.
Human to human transmission occurs through contact with body fluids: Vomitus, diarrheal stool, blood, sweat, semen, saliva, breast milk, and tears. Contact with objects, such as needles or soiled clothing contaminated with infected secretions can also cause infection. The average incubation period of the virus is 2 to 21 days.
It may take up to three days for the virus to reach a detectable level in the blood. The onset of illness is sudden, with fever, nausea, diarrhea, headache, joint and muscle pain, sore throat and intense weakness. Some patients may develop a rash, red eyes, hiccups, impaired kidney and liver function, and internal and external bleeding.
According to the WHO, samples from patients with Ebola are an extreme biohazard risk. Testing should be conducted under maximum biological containment conditions.
Before Ebola can be diagnosed, other diseases should be ruled out, and, if Ebola is suspected, the patient should be isolated. Public health professionals should be notified immediately. Ebola virus infections can be diagnosed definitively in a laboratory through several types of tests, including:
- Antigen-capture enzyme-linked immunosorbent assay (ELISA) testing.
- IgM ELISA.
- Polymerase chain reaction (PCR).
- Virus isolation.
In the more advanced stages of the disease or after recovery, diagnosis is made using IgM and IgG antibodies. Ebola can be diagnosed retrospectively in deceased patients by other forms of testing.
Up until recent, treatment for Ebola was limited to intensive supportive care and includes:
- Balancing the patient's fluids and electrolytes
- maintaining their oxygen status and blood pressure
- treating a patient for any complicating infections
In a major trial in Guinea during 2015, an experimental vaccine rVSV-ZEBOV, developed in 2014 was highly protective against the deadly virus.
In May 2017, officials in the Democratic Republic of the Congo approved the use of the experimental Ebola vaccine in the hopes of stemming the spread of a recent outbreak of the deadly virus.
References
"Ebola virus disease Fact sheet No. 103". World Health Organization. September 2014. http://www.who.int/mediacentre/factsheets/fs103/en/
Nassos Stylianou (27 November 2014). "How world's worst Ebola outbreak began with one boy's death". 27 November 2014.
Hannah Nichols Reviewed by Jill Seladi-Schulman, Tue 23 May 2017. Medical news today.
BBC. October 2014. Why Ebola is so dangerous. Retrieved 07, 21, 2017, from BBC http://www.bbc.com/news/world-africa-26835233
Margaret Lamunu, Olushayo Oluseun Olu, et al. Epidemiology of Ebola virus disease in the western Area region of Sierra Leone, 2014-2015 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5332373/
Hepatitis B is a viral infection that affects the liver. It is caused by the hepatitis B virus (HBV) and is a major global health problem. Hepatitis B can range in severity from a mild illness lasting a few weeks to a chronic condition that can lead to serious liver damage, including cirrhosis, liver failure, and even liver cancer. It is estimated that over 257 million people worldwide are living with chronic hepatitis B infection.
Hepatitis B is primarily transmitted through contact with infectious blood or body fluids of an infected person. The most common modes of transmission include unprotected sexual contact, sharing contaminated needles or other drug paraphernalia, and mother-to-child transmission during childbirth or breastfeeding. The virus can also spread through close personal contact, such as sharing razors or toothbrushes with someone who is infected.
Many individuals with acute hepatitis B infection do not exhibit symptoms and may only discover their infection through routine blood tests. However, when symptoms do occur, they can include fatigue, loss of appetite, nausea, vomiting, abdominal pain, dark urine, clay-colored stools, joint pain, and jaundice (yellowing of the skin and eyes). Symptoms can vary in severity and may last for several weeks to months.
Diagnosing hepatitis B involves several tests. Blood tests are used to detect the presence of specific antigens and antibodies related to the virus. These tests can determine whether a person has an acute or chronic hepatitis B infection. Additional tests may be conducted to assess the extent of liver damage, such as liver function tests and imaging studies like ultrasound or elastography.
The treatment for hepatitis B depends on whether it is an acute infection or a chronic condition. Acute hepatitis B generally does not require specific treatment, and symptoms improve on their own. However, individuals with severe symptoms or complications may need supportive care, such as intravenous fluids and antiemetic medications. Chronic hepatitis B infection may require long-term management. Antiviral medications, such as oral antiviral drugs (e.g., entecavir, tenofovir) or injectable interferon, can help suppress viral replication and reduce the risk of liver damage. Regular monitoring of liver function tests and screenings for liver cancer are crucial for those with chronic infection in order to detect any potential complications or disease progression. Available vaccines for hepatitis B provide effective protection against the virus and are recommended for all infants, children, and high-risk adults. Vaccination is considered the best method of preventing hepatitis B infection. In conclusion, hepatitis B is a viral infection that affects the liver and can result in acute or chronic illness. Early diagnosis, appropriate medical care, and vaccination are key to managing and preventing the transmission of hepatitis B.
It is important to note that the information provided here is a general overview and should not replace professional medical advice. If you suspect you have hepatitis B or have any concerns, please consult with a healthcare provider for an accurate diagnosis and appropriate treatment.
Hepatitis C is a viral infection that primarily affects the liver. It is caused by the hepatitis C virus (HCV) and is a leading cause of chronic liver disease, cirrhosis, and hepatocellular carcinoma. Hepatitis C is a global health concern, with an estimated 71 million people living with chronic infection.
Hepatitis C is primarily transmitted through contact with infected blood. The most common modes of transmission include sharing contaminated needles or other drug paraphernalia, receiving unscreened blood transfusions or blood products before 1992, and mother-to-child transmission during childbirth. Sexual transmission is possible but less common than for other hepatitis viruses
Many individuals with acute hepatitis C infection do not experience symptoms, and the infection often goes undiagnosed. However, when symptoms occur, they can include fatigue, fever, loss of appetite, nausea, vomiting, abdominal pain, dark urine, gray-colored stools, jaundice, and joint pain. Chronic hepatitis C infection may not cause noticeable symptoms for years or even decades, but it can lead to gradual liver damage over time.
Hepatitis C is diagnosed through blood tests that detect the presence of antibodies against the virus. If positive, additional tests are conducted to confirm the infection and determine the viral load. These tests measure the amount of HCV RNA in the blood and can help determine the severity of the infection and guide treatment decisions. Liver function tests and imaging studies may also be performed to assess liver health and detect any potential complications.
Treatment for hepatitis C has evolved significantly in recent years, leading to high cure rates for most individuals. Antiviral medications, known as direct-acting antivirals (DAAs), are the standard treatment for hepatitis C. These medications target specific steps in the HCV lifecycle and can cure the infection in as little as 8-12 weeks in most cases. Treatment is personalized based on the genotype of the virus and the individual's overall health and may involve a combination of different antiviral drugs.Lifestyle changes, such as avoiding alcohol and certain medications that can worsen liver damage, are recommended for individuals with hepatitis C. Vaccination against hepatitis A and B is also encouraged to prevent co-infection and further liver damage.In conclusion, hepatitis C is a viral infection that affects the liver and can lead to chronic liver disease if left untreated. Early diagnosis, appropriate medical care, and access to antiviral treatment are essential in managing and curing hepatitis C. Education, prevention measures, and harm reduction strategies are important to prevent the transmission of HCV, especially among high-risk populations.
It is important to note that the information provided here is a general overview and should not replace professional medical advice. If you suspect you have hepatitis C or have any concerns, please consult with a healthcare provider for an accurate diagnosis and appropriate treatment.
HIV/AIDS, which stands for Human Immunodeficiency Virus/Acquired Immunodeficiency Syndrome, is a global health issue caused by the HIV virus. It was first identified in the early 1980s and has since become a major public health concern. HIV attacks the immune system, specifically CD4 cells (also known as T cells), which are crucial for fighting off infections and diseases. If left untreated, HIV can progress to AIDS, a condition where the immune system is severely compromised.
HIV can be transmitted through various routes, including unprotected sexual intercourse (vaginal, anal, or oral) with an infected person, sharing needles or syringes contaminated with the virus, mother-to-child transmission during childbirth or breastfeeding, and less commonly, through blood transfusions or organ transplants from infected donors. It is important to note that HIV cannot be transmitted through casual contact such as hugging, shaking hands, or sharing utensils.
The symptoms of HIV can vary from person to person and may not always be apparent in the early stages. Some individuals may experience flu-like symptoms within 2-4 weeks after infection, including fever, fatigue, sore throat, swollen lymph nodes, and rash. However, these symptoms are not specific to HIV and can be easily mistaken for other illnesses. As the infection progresses, more severe symptoms may occur, such as persistent diarrhea, weight loss, recurrent infections, and opportunistic infections.
Various tests are available to diagnose HIV infection. The most common method is the HIV antibody test, which detects the presence of antibodies produced by the immune system in response to the virus. This test can be done using blood, oral fluid, or urine samples. In some cases, a combination test that detects both antibodies and antigens (proteins produced by the virus) may be used for early detection. Additionally, nucleic acid tests (NAT) can directly detect the presence of the virus in the blood.
While there is currently no cure for HIV/AIDS, significant progress has been made in managing the infection and improving the quality of life for those living with the virus. Antiretroviral therapy (ART) is the standard treatment for HIV/AIDS. ART involves a combination of medications that suppress the replication of the virus, allowing the immune system to recover and function effectively. Adherence to ART is crucial for its effectiveness. Additionally, other supportive treatments may be provided to manage opportunistic infections and associated complications.
In conclusion, HIV/AIDS is a complex viral infection that affects the immune system. It can be transmitted through various routes, and early diagnosis is important for timely intervention. While there is no cure, effective treatment options exist to manage the infection and improve the overall health outcomes for individuals living with HIV/AIDS.
Influenza, commonly known as the flu, is a highly contagious respiratory illness caused by influenza viruses. It affects millions of people worldwide each year, leading to significant morbidity and mortality. Influenza viruses are categorized into types A, B, and C, with type A being the most common cause of seasonal flu outbreaks.
Influenza is primarily transmitted through respiratory droplets when an infected person coughs, sneezes, or talks. These droplets can be inhaled by individuals in close proximity to the infected person or can contaminate surfaces, leading to indirect transmission through hand-to-face contact.
The symptoms of influenza can vary in severity but typically include fever, cough, sore throat, runny or stuffy nose, body aches, headache, fatigue, and sometimes vomiting or diarrhea. These symptoms usually appear suddenly and can last for about a week, although fatigue and weakness may persist for several weeks.
Diagnosing influenza is often based on clinical symptoms and the presence of influenza activity in the community. However, laboratory testing can be performed to confirm the diagnosis and identify the specific influenza virus type or subtype. The most common diagnostic tests include rapid influenza diagnostic tests (RIDTs) and molecular tests like reverse transcription-polymerase chain reaction (RT-PCR).
W