Gastroenteritis

You have devoured your favorite shrimp salad at dinnertime. In a few hours you might be racked by stomach cramps and diarrhea. You will probably experience vomiting and low grade fever too. This is a classic case of gastroenteritis - a condition where the intestines are inflamed due to bacterial or viral infection. Gastroenteritis infection can also be caused due to food poisoning, food allergy, intestinal parasites, viral infection, medication or food consumed while you are traveling. Gastroenteritis can affect anyone but it is usually more severe in infants, the elderly and immunosuppressed people. Gastroenteritis in children can be serious if left unattended. It is the leading cause of death among children worldwide.

Viral and Bacterial Gastroenteritis

Viral gastroenteritis is caused by a viral infection that affects the stomach and intestines. In fact, viral gastroenteritis is one of the most common ailments in the U.S. A person can contract this viral gastroenteritis infection from contaminated food or drinking water. Within a few hours, the first symptoms are noticed. While viral gastroenteritis infections usually clear up without medicines within a few days, bacterial gastroenteritis needs to be treated. Rotavirus is the most common cause for viral gastroenteritis. It affects infants and young children and can surface as an outbreak during some seasons. Rotavirus can also affect other age groups. The Norwalk Virus is another cause of infectious gastroenteritis. It is common in school-going children. Viral gastroenteritis is usually treated with self care measures. Bacterial gastroenteritis infection can be caused by Salmonella, Escherichia coli (E coli), Campylobacter or Shigella. These bacteria can be found in poultry, eggs or meat. Once they enter the body, they multiply and produce toxins. After a few hours of eating, symptoms of bacterial gastroenteritis appear.A stool assay can help in identifying the specific agent for the gastroenteritis and aid treatment.

Treating Gastroenteritis

Usually the reaction to gastroenteritis infections hinges on your immune system’s ability to resist the infection. A person suffering from gastroenteritis will probably feel nauseous and experienced a bloated feeling. Abdominal cramps and mild to severe watery stools may be noticed for a couple of days. Severe cases of gastroenteritis can result in dehydration. Signs of dehydration to look out for are dry skin, excessive thirst and absence of urination for many hours. If a person suffering from gastroenteritis experiences severe abdominal pain or high fever or blood in the stools, consult a health professional at once. With little children, it is essential to give them clear fluids to replace lost fluids due to vomiting and diarrhea. Infants can be breast fed normally. Gastroenteritis can be very serious in infants. If you notice dry mouth, sunken eyes and irritability, consult a doctor immediately.

• Drink plenty of water and fluids to restore fluid and salt requirements of the body
  
• Avoid milk and dairy products
  
• Take adequate rest till symptoms persist
  
• Consume bland foods and avoid spicy foods, fried foods and alcohol
  
• Consume electrolyte solutions
  
• Avoid aspirin and ibuprofen as they irritate the gastrointestinal system
  
• Avoid sharing food and water and utensils with others for fear of spreading the infection
  

Urine based HIV test

This was approved in 1996 by FDA as a screening test for HIV. This test uses urine samples to detect HIV antibodies using ELISA method. This test is not considered as accurate as blood test in detecting HIV infection. Urine based test could give false positive result in one or two persons out of hundred. Therefore a positive ELISA screening test must be followed by a confirmatory western blot test or IFA or RIPA and then results confirmed.

CD4 test: The CD4 count in individuals not affected by HIV is normally above 500 cells per cubic milliliter of blood. In HIV infected people, CD4 count is less than 200 cells per milliliter of blood. These patients are referred to as immunosuppressed. HIV people do not run the risk for complications until CD4 cells are fewer than 200 cells per milliliter of blood. A declining number of CD4 count indicates the advancement of the disease. A low CD4 cell count signals that the person is at risk for one of the many unusual infections that occur in individuals who are immunosuppressed. CD4 count is also indicative of the type of therapy the person should undergo to prevent 'opportunistic infections'.

Viral load: The viral load predicts whether or not the CD4 cells will decline in the coming months. Knowledge of the amount of viral load can be instrumental in predicting the development of the disease. Those persons with high viral loads are more likely to experience a decline in CD4 cells and progression of the disease than those with lower viral loads. The viral load is also a vital tool for monitoring the effectiveness of the new therapies and determining when the drug stops working. The greater the decline of viral load after beginning therapy, the longer it will remain suppressed. In general it can be said that a poor response to HIV therapy or treatment failure would include individuals who fail to experience a decline in viral load of approximately 100 fold in the first 8 weeks and have a viral load of greater than 500 copies per ml by week 12 or have levels greater than 50 -75 copies per ml by week 24.

Drug resistance testing: This test is being used in individuals who are experiencing poor response to HIV therapy or treatment failure. The US department of health and human services (DHHS) in their recent guidelines have suggested that 'resistance testing' can be considered in individuals who have never been on therapy particularly in the first months or even years of infection to determine if they might have acquired HIV that is resistant to drugs. DHHS even formally recommend such testing to be performed in individuals starting therapy for the first time.

Chikungunya

Chikungunya is a viral disease caused by the chikungunya virus (CHIKV), which belongs to the genus Alphavirus, family Togaviridae. The disease was first identified in 1953 in Tanzania and is named after the Makonde language, where "chikungunya" roughly translates to "to walk bent" or "to carry a child" due to its characteristic symptoms of joint pain and swelling.

Epidemiology:
Chikungunya is primarily spread by the bite of infected mosquitoes of the Aedes genus, particularly Aedes albopictus (Asian tiger mosquito) and Aedes aegypti. The virus is endemic in Africa, Asia, and the Indian subcontinent, but outbreaks have also been reported in Central and South America, as well as the Caribbean.
Typically these mosquitoes are infected due to feeding on infected humans, monkeys or other animals. It however does not get transmitted among people. Daytime mosquitoes are the main carriers.
Transmission occurs when an infected mosquito bites a human host, and then the virus replicates in the mosquito's body before being transmitted to another individual through a subsequent bite. The incubation period is typically 2-7 days, during which time the person may experience no symptoms or mild ones. Once symptoms appear, they can persist for several weeks.

Clinical Features:
The majority of individuals infected with CHIKV will develop symptoms within 1-3 days after being bitten by an infected mosquito. The clinical presentation varies in severity but typically includes:

1. Fever: A high-grade fever (>38 degree C) that may be accompanied by sweating, chills, and rigors.
   
2. Joint pain and swelling: This is the most characteristic symptom of chikungunya, often described as intense, burning, and debilitating pain in multiple joints (hands, feet, ankles, knees, elbows, and wrists). Swelling and inflammation are common.
   
3. Rash: A pink or maculopapular rash may appear on the skin, particularly on the trunk and limbs.
   
4. Headache: Mild to moderate headache is a frequent complaint.
   
5. Muscle pain: Generalized muscle ache and stiffness can occur.
   
6. Eye involvement: Conjunctivitis (pink eye) or uveitis (inflammation of the iris or retina) may develop in some cases.
   

In rare instances, chikungunya can lead to more severe complications, such as:
1. Neurological symptoms: Encephalitis (inflammation of the brain), meningoencephalitis (inflammation of the membranes surrounding the brain and spinal cord), or Guillain-BarrΘ syndrome (a type of autoimmune neuropathy).
2. Cardiac issues: Congestive heart failure, arrhythmias, or myocardial infarction (heart attack) have been reported in some cases.

Diagnosis of chikungunya :
A diagnosis of chikungunya is typically made through a combination of clinical evaluation and laboratory testing. The following methods are used:
1. Clinical features: A careful history and physical examination can help identify the characteristic symptoms.
2. Laboratory tests:
Serological tests (ELISA or IgM/IgG antibodies) to detect CHIKV-specific antibodies in blood or serum.
Molecular detection (RT-PCR, PCR, or whole-genome sequencing) to identify the virus in blood, urine, or cerebrospinal fluid.

Treatment and Management :
There is no specific antiviral treatment for chikungunya. Supportive care focuses on managing symptoms and preventing complications. Treatment options include:
1. Pain management: Nonsteroidal anti-inflammatory drugs (NSAIDs) like aspirin, ibuprofen, or naproxen can help alleviate joint pain.
2. Rest and hydration: Patients are advised to rest, avoid strenuous activities, and maintain adequate fluid intake to prevent dehydration.
3. Physical therapy: Gentle exercises and physical therapy may be recommended to maintain joint mobility and reduce stiffness.

Prevention of chikungunya:
Preventing mosquito bites is the most effective way to avoid contracting chikungunya. Strategies for prevention include:
1. Wear protective clothing: Cover exposed skin with light-colored, loose-fitting clothing and a hat.
2. Use insect repellent: Apply insect repellents containing DEET (20-30%), picaridin, or oil of lemon eucalyptus to exposed skin and clothing.
3. Eliminate breeding sites: Remove standing water around homes and neighborhoods to prevent mosquito populations from growing.

Vaccination:
Several chikungunya vaccines are currently in development, with some having received approval for use in specific countries. The most advanced vaccine candidate is the Sanofi-Pasteur recombinant vaccine, which has shown promising results in clinical trials.