May 25, 2014

14 lessons from HIV Update 2014

HIV update 2014 was held in Seremban on 22nd May 2014. 

1. As of 2011, there were approximately 34 million people living with HIV infection in the world.
2. In 2011, the incidence of new HIV cases in Malaysia was 12.2 per 100000 people. The state of Johor had reported the greatest number of new cases that year. 

3. Antiretroviral therapy should be started according to the CD4 cell count or when there is “double trouble” (HIV infection plus another condition). If we decide to start antiretroviral therapy based on the CD4 count, then for practical purposes, in Malaysia, we start when the CD4 count is below 350 cells per cubic mm. The ideal is probably to start when the count is below 500 cells per cubic mm. Conditions that constitute double trouble include: HIV plus active tuberculosis infection; HIV plus HBV infection; when an HIV patient has a sexual partner who is not positive; when a woman with HIV is pregnant or breastfeeding; when the patient with HIV is a child below 5 years of age.

4. A template for initiating antiretroviral therapy is: Efavirenz plus Tenofovir plus Lamivudine or Efavirenz plus Tenofovir plus Emtricitabine. Other combinations involving the cheaper drug zidovudine are also possible. An important update is that Efavirenz is no longer considered teratogenic now. Important points to remember are: Efavirenz causes CNS toxicity and skin rashes.

5. The HIV viral load (HIV RNA count) is more important for decision making than the CD4 count. This is because the CD4 count is subject to variations caused by factors other than HIV infection.

6. The gold standard for the diagnosis of HIV used to be the ELISA test (for detection of antibodies) and the Western Blot test (for detection of antigens).  Nowadays different methods (rapid assay tests) are used to detect antibodies and antigens.

7. One quarter of new deaths from HIV infection are due to tuberculosis in the world. The WHO recommendation is to give co-trimoxazole (Bactrim) for all patients who have both tuberculosis and advanced HIV infection because co-trimoxazole protects against infections that such people with advanced immunosuppression are also susceptible to. The drug should be given for at least six months.
8. Diagnosing tuberculosis can be difficult when resources to do so are not easily available. A useful aphorism to remember is: If patients do not have all these 4 symptoms of cough, fever, night sweats and loss of weight, they are unlikely to have tuberculosis. Conversely if they have one or more of these symptoms, the diagnosis of tuberculosis should be suspected and options to confirm or rule out the diagnosis should be explored.

9. It has been found that 57 percent of all people being treated for tuberculosis develop hepatitis. In this regard, pyrazinamide and isoniazid are more likely than rifampicin to be the cause of the hepatitis. Ethambutol and Streptomycin are very unlikely to cause hepatitis.

10. When Efavirenz is used along with Ethambutol, the serum levels of Efavirenz will decrease.
11. Efavirenz should be avoided in people prone to depression.
12. When a patient on antiretroviral therapy develops proteinuria or acute kidney injury, suspect Tenofovir induced damage to the proximal convoluted tubules of the kidney.
13. When a patient on antiretroviral therapy develops anemia, suspect zidovudine as a cause.


14. Failure of antiretroviral therapy can be defined thus: Virological failure is said to be present when the viral load is more than 1000 copies per millilitre on 2 occasions, more than 3 months apart. Immunological failure is said to be present when the CD4 count remains less than the baseline (before treatment) or remains less than 100 cells per millilitre persistently. Clinical failure is said to be present when a new illness due to immunosuppression occurs after 6 months of treatment. 

May 8, 2014

Using rubrics for decision making

Daniel Kahneman, the Nobel Prize winning Professor of Psychology from Princeton University, has written a book titled “Thinking, fast and slow”. In this book there is a chapter called “Intuitions versus Formulas”.  He explains that our evaluation of complex problems can sometimes be standardised by the use of algorithms or formulas with numerical values attached to them.  There are two examples that I wish to quote from that book because I feel it is relevant to how we can use rubrics (or formulas with scores) for standardising the evaluation of student portfolios.

1. How do you evaluate the stability of a marriage?
The formula (frequency of lovemaking – frequency of quarrels) will give a fair idea of marital stability. If the answer is not a negative number, the marriage is probably stable. 

2. How do you evaluate the chances of survival in a new born child?
Obstetricians have always known that infants who do not breathe well within a few minutes of birth are at high risk of brain damage or death. But until the anaesthetist Virginia Apgar wrote a simple algorithm incorporating five variables to observe in all new born infants, with a score assigned to each variable, doctors and midwives used their clinical judgement to determine whether babies were in distress. Some watched for breathing problems while others focused on how soon the baby cried. Without a standardised procedure, danger signs were often missed and many new born infants died. The Apgar scoring system gave everyone a consistent standard for determining risk and helped everyone evaluate this risk in the same way as experienced obstetricians. The Apgar test is credited with helping to reduce infant mortality.