A scientific temper; and brain-eating bacteria

Health matters newsletter: A scientific temper; and brain-eating bacteria

(This week in health, we read about brain-eating bacteria, confusion over the NEET- Undergraduate exam, Zika virus infection cases in Pune and more.)

Hello! Are we taller in the morning than when we go to bed? The beauty of science is that you can ask this with a straight face, and there will also be a perfectly reasonable explanation, based in science, fact and actual historical data. That is the joy of being in science, watching it grow, answer all our questions without dissing them as silly or a whim or a fantasy. And yes, if you want to know the answer to the question, yes, we all are indeed taller when we wake in the morning than when we go to bed at night. There are two components to this, you’ll learn if you click on the link: In a growing child, the growth hormone is secreted in pulses overnight. This acts through several intermediary steps to cause lengthening of the bones at the end-plates (epiphyses). Accurate measurements of the forearm or lower leg using specialised apparatus or X-rays can record this night-time growth.

The most marked effect, however, which occurs even after growth has ceased, is caused by postural compression of the spine under the effect of gravity. Another factor concerns the inherent curvatures of the spinal column. This has a convexity backwards in the thoracic or chest region, called a kyphosis, and a concavity in the lumbar region or base of the back called a lordosis. These curves vary with body weight and position. As a result, the spinal column tends to press downwards when in an upright position, altering these curvatures, and hence shortening the spinal length. When lying down, the reverse happens and the column lengthens again.

Like we said, Science takes its questions seriously.

Now that we’ve lobbed that curveball at you, it’s time to move on to the major health events of the past week, not least what has gained popularity in media as the ‘brain-eating bacteria’. The index case involved the death of a five-year-old girl from Malappuram district in Kerala who had been undergoing treatment for amoebic meningoencephalitis at the Government Medical College Hospital, on May 21. Another 13-year-old girl from Kannur died of the infection, within a month, and a 12-year-old boy died in Kozhikode of PAM on July 4. As news of this spread, so did fear in the community The detection of a total of four cases in the State so far, raised the profile of Primary Amoebic Meningoencephalitis (PAM), and neighbouring States sent out warnings to their residents, though the disease causing vector Naegleria folweri cannot spread from person to person. Director of Public Health in Tamil Nadu, issued an advisory on amoebic meningoencephalitis, warning the public of bathing or swimming in pools, lakes and waterbodies that had not been cleaned, as they might contain the disease causing pathogen. For a full-length explainer on what PAM is, do read this explainer by A.S. Jayanth Rare and fatal brain-eating amoeba infection.

We are tracking that story, but meanwhile, here’s an update on the recent Zika infection in the country. Six Zika virus infection cases in Pune; two are pregnant women. Since Zika in pregnancy can cause birth defects including microcephaly, a smaller head, disproportionate to the body, there is much concern about controlling this epidemic. Since it is known to be spread by infected mosquitoes of the Aedes genus, mosquito and larval control programmes are the need of the hour, particularly at a time when the monsoon showers leave puddles prone to harbouring mosquito larvae.  

From infectious diseases, it makes sense to segue into vaccines. We have been reporting hope emerging in the research on a HIV vaccine. Linda-Gail Bekker and Nadine Dreyer  report here on another breakthrough: researchers find new pre-exposure prophylaxis is 100% effective in trial. A large clinical trial in South Africa and Uganda has shown that a twice-yearly injection of a new pre-exposure prophylaxis drug gives young women total protection from HIV infection. The trial tested whether the six-month injection of lenacapavir would provide better protection against HIV infection than two other drugs, both daily pills. All three medications are pre-exposure prophylaxis (or PrEP) drugs, explained Bekker, principal investigator for the South African part of the study. For more on what this means, and what to expect next, do click on the link above.