Morning MEDtalks with Dr KK Aggarwal 6th August 2018

Even low air pollution levels are linked with serious changes in heart structure

A study, led by Professor Steffen Petersen from Queen Mary University of London has shown that people exposed to air pollution levels well within UK guidelines have changes in the structure of the heart, similar to those seen in the early stages of heart failure. The study part-funded by the British Heart Foundation (BHF) and published August 3, 2018 in the journal Circulation examined data from around 4,000 participants in the UK Biobank study, where healthy volunteers provided a range of personal information, including their lifestyles, health record and details on where they have lived. Participants also had blood tests and health scans, and heart MRI was used to measure the size, weight and function of the participants hearts at fixed times.

There was a clear association between those who lived near loud, busy roads, and were exposed to NO2 or PM2.5 and the development of larger right and left pumping ventricles in the heart. Similar heart remodelling is seen in the early stages of heart failure. For every 1 extra µg per cubic metre of PM2.5 and for every 10 extra µg per cubic metre of NO2, the heart enlarges by around 1%.

In the study, average annual exposures to PM2.5 were well within UK guidelines (25 µg/m3). The WHO guidelines for PM 2.5 are up to 10 µg/m3. The UK aim is to halve the number of people living in areas where PM2.5 levels exceed the WHO guidelines by 2025.

The safe limit of PM2.5 for India is 60 µg/m3, but we face up to 1000 on multiple times in a year. We are having an epidemic of atrial fibrillation and diastolic dysfunction in the country, which I strongly believe is linked to pollution.

Air pollution is a modifiable risk factor. But, how can we expect people to move homes to avoid air pollution? The Indian Government must act now to make all areas safe and protect the population from these harms.

Leptospirosis outbreak in Kerala: 538 cases, 28 deaths this year

Leptospirosis is a potential zoonosis with protean manifestations, caused by pathogenic spirochetes of the genus Leptospira. The organism infects a variety of wild and domestic mammals, especially rodents, cattle, swine, dogs, horses, sheep and goats.

Animals can be asymptomatic or develop clinical infection, which can be fatal. Reservoir animals shed the organism in their urine intermittently or continuously throughout life, resulting in contamination of water.

Routes of infection

1. Humans gets infected after exposure to animal urine, contaminated water or soil, or infected animal tissue through cuts or abraded skin, mucous membranes, or conjunctiva. Controversy exists as to whether Leptospira can penetrate the intact skin.

2. The infection may rarely be acquired by ingestion of food contaminated with urine or via aerosols.

3. Large outbreaks are associated with increased rainfall or flooding, which presumably increased the risk of exposure to contaminated water

Risk factors are occupations like farmers, pet traders, military personnel, laboratory workers; recreational activities like freshwater swimming, canoeing, kayaking, trail biking; household exposure with pet dogs, domesticated livestock, rainwater catchment systems, infestation by infected rodents and walking barefoot through surface water or skin lesions contact with wild rodents.

Clinical presentation

1. The clinical course is variable. The disease may manifest as a subclinical illness followed by seroconversion or a severe, potentially fatal illness with multiorgan failure.

2. Clinically, it presents with the abrupt onset of fever, rigors, myalgias, and headache in most patients. Conjunctival suffusion in a patient with a nonspecific febrile illness should raise suspicion.

3. Most cases are mild to moderate. However, the course may be complicated by renal failure, uveitis, hemorrhage, acute respiratory distress syndrome with pulmonary hemorrhage, myocarditis, and rhabdomyolysis.

4. A high index of suspicion is required to make the diagnosis as lab findings are nonspecific. The microscopic agglutination test is a reference standard assay

5. In the absence of a definitive laboratory diagnosis, administration of empiric treatment is appropriate.

6. All over India doctors seeing travellers returning from vacations involving recreational activities associated with potential environmental Leptospira exposure in high-risk regions should consider the possibility of leptospirosis.

Treatment

1. Antibiotics shorten the duration of illness and reduce shedding of the organism in the urine.

2. Treatment of choice in mild leptospirosis is oral doxycycline or azithromycin. Both agents are also effective for rickettsial disease, which can be difficult to distinguish from leptospirosis. Doxycycline should be avoided in children <8 years of age unless no other treatment options are available and in pregnant women; reasonable alternatives include azithromycin or amoxicillin.

3. In severe leptospirosis the antibiotics are parenteral penicillin, doxycycline and third-generation cephalosporins. Penicillin and cephalosporins lack activity against rickettsiae.

Prevention

1. There is no human vaccine widely available.

2. Prevention include avoiding potential sources of infection, administration of doxycycline prophylaxis for individuals at high risk of exposure, and animal vaccination.

Around the globe

1. Around 138 million women are affected by a distressing but treatable fungal infection world-wide, according to a research review by University of Manchester scientists. And the incidence of recurrent thrush, warns lead researcher Dr. Riina Rautemaa-Richardson, is set to rise to an estimated 158 million people by 2030.

2. The superbug vancomycin-resistant enterococcus (VRE) is growing increasingly immune to alcohol-based disinfectants.

3. Vaginal rejuvenation: in which energy-based devices, employing laser or radiofrequency, are used to stimulate vaginal tissue and allegedly help it to regain firmness, elasticity, and lubrication. US FDA has issued a warning stating that energy-based devices for "vaginal rejuvenation" can be unsafe and their use should be avoided.

4. Mayo Clinic has introduced a new skill for Amazon Alexa, giving a hands-free way to access first-aid information. A skill is a new capability a person can add to their Amazon Alexa-enabled devices which creates a more personalized user experience.

5. From 2014 through 2017, there was an increase in U.S. poison control calls related to the intentional abuse and misuse of tianeptine (stablon), an unapproved antidepressant drug, the U.S. Centers for Disease Control and Prevention said in a report. There have been reports that recreational abuse might result in severe side effects including vomiting, confusion, coma and kidney failure. The drug can be lethal in rare cases. Tianeptine produces effects similar to opioids, and officials suspect that people are taking the drug as an alternative to those narcotics. The opioid-overdose drug naloxone is effective in reversing a tianeptine overdose.

Video to watch: Wheat disorders

https://www.facebook.com/drkkaggarwal/videos/1945381452149815/

Dr KK Aggarwal

Padma Shri Awardee

President HCFI

Vice President CMAAO