A Resisted Pill to Prevent H.I.V.
In addition to treating patients who have HIV, you might be surprised to hear that Truvada can also be given to HIV-negative people in an attempt to prevent them from getting HIV. An HIV-negative patient takes the medication daily. This strategy is called “PrEP”, short for Pre-Exposure Prophylaxis. "Pre-Exposure" obviously means done before someone is exposed to HIV; “Prophylaxis” is a protective measure to prevent disease. For example, condoms are prophylactic. So PrEP is a drug given before exposure to prevent someone from getting HIV. (On the other side there is PEP: Post-Exposure Prophylaxis. Given to someone after exposure, commonly to medical providers who stick themselves with a needle; that is an occupational exposure.)
The public health community had expectations that those at high-risk for HIV would use it, especially gay and bisexual men (MSM). But uptake among MSM has been low according to the NY Times. Some reasons the article mentions for low uptake:
* Stigmatization of the drug.
* Unawareness by consumers of the option.
* Potential side effects
* Lackadaisical attitude towards HIV
Of worry to me, PrEP does send mixed messages to consumers. Some might see it as a reason not to need condoms. (I don’t, but I don’t speak for the entire public health community.) You have to take PrEP everyday for it to be effective; if you don’t, and you don’t use condoms because you feel you are safe, you are obviously at risk for infection.
In the latest example of technology using syndromic surveillance, “Sickweather” uses self-reports of illness on social media sites to help map where illnesses are occurring. According to Mashable, the system scans over 600,000 records on Facebook and Twitter every month to map “sick zones”.
The creator likens the system to Waze, the GPS navigation system that helps to navigate you around accidents and traffic.
The concept is interesting but it is difficult to see how it could work. Unlike accidents, people migrate. Also the epidemiological properties of a disease are important. Some disease will be highly contagious while others are less so.
Take the example screenshot posted below. The information about flu being reported isn’t necessarily actionable information. Do I know if the infected person is still there? What if it is a multistory building? Just because I walk along that street does not mean I am in danger.
The service also suffers from an issue that plagues (no pun intended) epidemiologist. While the system, like Google Flu Trends, uses syndromic surveillance and can thus make interferences before data is reported to health authorities, there is still the issue that people shed the influenza virus before they are symptomatic. Thus, even if the system can track every person with symptoms of a disease, it will always underreport in terms of actual number of infectious people.
Still though the idea is intriguing and another example of how technology can be used to protect health. What may be helpful to know is what geographic locations are experiencing higher than normal levels of an illness.
See also: Influenzanet
Measles Still Threatens Health Security | CDC
From the CDC:
Usually there are about 60 cases per year [of measles], but 2013 saw a spike in American communities – some 175 cases and counting – virtually all linked to people who brought the infection home after foreign travel.
Three-fold increase since last year. Why is this so? What happened in Brooklyn helps tell the story:
A total of 58 cases were identified, including six generations of measles infection in two neighborhoods of the borough of Brooklyn. All cases were in members of the orthodox Jewish community. No case was identified in a person who had documented measles vaccination at the time of exposure; 12 (21%) of the cases were in infants too young (aged <12 months) for routine immunization with measles, mumps, and rubella (MMR) vaccine.
Of note, they were all aged 0-32. The 12 who were too young to be vaccinated could have been protected via herd immunity.
This is what the anti-vaccine movement has brought us.
I’ve created this blog along with my new Twitter account. With both I’ll discuss a wide-array of topics relating to public health, including:
- Social media
- Health communication and social marketing
- Qualitative research methods
- History of public health