This is the first in a series of five posts leading up to my trip to India to examine issues of child survival with the International Reporting Project via Johns Hopkins University with significant funding from the Bill and Melinda Gates Foundation. For the duration of the trip, I am to consider my self a New Media Journalist with IRP.
Infectious diseases are common all over the world. You probably know them as generally communicable diseases of bacterial, viral or protozoan origin, that will enter the body, and infect it, causing illness and sometimes leading to death, especially if the body is weakened by malnutrition or stressful environmental factors.
Doctors and healers for a very long time could recognize symptoms of illness and would classify the illness and eventually name them, but they didn’t know what caused these illnesses. A big breakthrough in understanding that certain diseases were caused by extremely tiny organisms came through the work of Louis Pasteur and also Robert Koch. They both can be credited with establishing the Germ Theory of Disease. Koch applied rigorous scientific methods to understanding how microorganisms invade the host and cause disease. He determined what are known as Koch’s Postulates.
This long post will talk about diseases common to children in India that have a causautive agent and whose increased prevalence often has to do with issues of poverty, lack of education, unclean water, poor sanitation and malnutrition.
Let’s look at several diseases: diarrheal diseases (cholera, rotavirus), respiratory diseases (Pneumonia and Tuberculosis) and what I will just call “other” (Malaria, and HIV). Since Polio has been eradicated from India, I will address this in the vaccination post tomorrow.
I will describe the disease, it’s causative agent, how it is contracted, they symptoms and most often the occurrence in the children of India if I have that information. This information comes from several sources including WHO, UNICEF, The Gates Foundation and more. Note that the numbers, percentages, and other analyses to help us understand the rates of infection or mortality are necessarily a critical part of knowing how severe a disease is in any given population and if prevention and treatment tactics are working. Working with the “M” of STEM, Mathematics, especially statistics, but also including GIS (global information systems) and other types of mathematical modeling helps us paint a picture of the severity of a disease now and determine our next course of action. If numbers excite you, you could be of assistance in the improvement of conditions in developing nations such as India by providing the data to decision makers in health policy, for instance.
The description will include a few of the more notable scientists who have played a role in helping us understand the disease, including Nobel Prize winners. If you feel I’ve left someone out, be certain to send a note via my contact page, I’d love to hear from you.
How a disease is treated or prevented will be touched on briefly. Note that tomorrow’s post is about vaccinations and since many of the diseases I will discuss have vaccines, I will address those in more detail in that post. Some diseases are just more common where sanitation is poor so their solutions will be examined in the post on sanitation.
Finally, I will suggest books for further reading on the topic if I know of them. These will be what I consider adult popular science books, which a bright middle schooler or high schooler could read as well. But if you are looking for something at a middle reading level, there are many fantastic books at your library and I highly recommend you check them out. (BTW, I LOVE LIBRARIES!)
- Diarrheal disease is the second leading cause of death in children under five years old. It is both preventable and treatable.
- Diarrheal disease kills 1.5 million children every year and account for >10% if child mortality in India.
- Globally, there are about two billion cases of diarrheal disease every year.
- Diarrheal disease mainly affects children under two years old.
- Diarrhea is a leading cause of malnutrition in children under five years old.
- Diarrhea can be of bacterial origin (ex: cholera), viral origin (ex: rotavirus) or parasitic (ex: ameobic dysentery)
Preventing diarrheal diseases requires the following:
- access to safe drinking-water
- improved sanitation
- exclusive breastfeeding for the first six months of life
- good personal and food hygiene
- health education about how infections spread
- rotavirus vaccination.
“Cholera is a disease spread mostly through contaminated drinking water and unsanitary conditions. It is endemic in the Indian subcontinent, Russia, and sub-Saharan Africa. It is an acute infection of the intestines with the bacterium Vibrio cholerae. Its main symptom is copious diarrhea. Between 5% and 10% of those infected with the disease will develop severe symptoms, which also include vomiting and leg cramps. In its severe form, cholera can cause death by dehydration. An estimated 200,000 cases are reported to WHO annually.”
Best bet treatment: Most cases can be treated with rehydration salts. A vaccine exists but clean water and proper sanitation are the most effective measures to prevent the disease from taking hold in communities in the first place.
Book to read about cholera: The Ghost Map: The Story of London’s Most Terrifying Epidemic–and How It Changed Science, Cities, and the Modern World by Steven B. Johnson. Click on this image to watch a video about this book!
Famous Scientists: John Snow, who discovered the source of the main cholera infection in England and whom The Ghost Map book is about, and Robert Koch who discovered that Vibrio cholerae was the infectious agent.
Rotavirus is the most common cause of viral gastroenteritis (inflammation of the stomach and intestines) worldwide. It kills more than 600,000 children each year, mostly in developing countries. Symptoms include vomiting, watery diarrhea, fever, and abdominal pain. In India,
“The health burden of rotavirus in India is well established. WHO estimated that 98, 621 Indian children died from rotavirus gastroenteritis in 2008, representing about one third of deaths from diarrhoeal disease and 4% of all child deaths in India. More recent data from the Million Death Study, a nationally representative survey of 1.1 million Indian households, estimated that the virus causes 113 000 deaths a year.”
It was given its name because a scientist viewed it through an electron microscope, and thinking it looked like a wheel, called it rota (think rotation) –virus.
Best bet treatment: Most cases can be treated with rehydration salts. A vaccine exists and is incredibly effective!
Famous Scientists: In 1973, Ruth Bishop and colleagues described related viruses found in children with gastroenteritis.
Book to read: I don’t know of a good one solely about rotavirus, but if you want to learn more about viruses of all types, including RNA based ones like rotavirus, definitely read Carl Zimmer’s book, A Planet of Viruses.
I will limit this discussion to pneumonia and tuberculosis (which isn’t solely respiratory) for the sake of brevity.
Pneumonia is the leading global killer of children under five, responsible for almost 1.6 million deaths per year. In that vulnerable population, it is a disease of poverty and occurs most commonly when a child’s still-developing defense system is weakened by malnutrition, air pollution, co-infections with HIV/AIDS and measles, and low birthweight, with 43 million cases for children in India alone.
- Pneumonia is the leading cause of death in children worldwide.
- Pneumonia kills an estimated 1.2 million children under the age of five years every year – more than AIDS, malaria and tuberculosis combined.
- Pneumonia can be caused by viruses, bacteria or fungi.
- Pneumonia can be prevented by immunization, adequate nutrition and by addressing environmental factors.
- Pneumonia caused by bacteria can be treated with antibiotics, but around 30% of children with pneumonia receive the antibiotics they need.
Pneumonia occurs when the sacs of the lungs, known as alveoli, become filled with pus and fluid, limiting oxygen intake and making it hard to breathe.
Pneumonia is caused by a number of infectious agents, including viruses, bacteria and fungi. The most common are:
- Streptococcus pneumoniae – the most common cause of bacterial pneumonia in children;
- Haemophilus influenzae type b (Hib) – the second most common cause of bacterial pneumonia;
- respiratory syncytial virus is the most common viral cause of pneumonia;
- in infants infected with HIV, Pneumocystis jiroveci is one of the commonest causes of pneumonia, responsible for at least one quarter of all pneumonia deaths in HIV-infected infants.
Best Bet Treatments: There are many treatments based on the cause of the pneumonia.
Famous Scientists: (This information is modified from Wikipedia here:)
- “Edwin Klebs was the first who observed bacteria in the airways of persons who died of pneumonia in 1875.
- Initial work identifying the two common bacterial causes Streptococcus pneumoniae and Klebsiella pneumoniae was performed by Carl Friedländer and Albert Fränkel Friedländer’s initial work introduced the Gram stain, a fundamental laboratory test still used today to identify and categorize bacteria.
- Christian Gram’s paper describing the procedure in 1884 helped to differentiate the two bacteria, and showed that pneumonia could be caused by more than one microorganism.”
“Tuberculosis causes nearly 2 million deaths every year, and WHO estimates that nearly 1 billion people will be infected between 2000 and 2020 if more effective preventive procedures are not adopted. The TB bacteria are most
often found in the lungs, where they can cause chest pain and a bad cough that brings up bloody phlegm. Other symptoms include fatigue, weight loss, appetite loss, chills, fever, and night sweats.” It is caused by Mycobacterium tuberculosis.
Childhood or pediatric tuberculosis is often unrecognized due to lack of health care and lack of education on symptoms to look for. Tuberculosis has a safe haven in HIV patients, unfortunately, so eradication is difficult. Many cases of tuberculosis are also multi-drug resistant making it very difficult and expensive to treat.
Best Bet Treatment: Generally a cocktail of antibiotics, though this is becoming more difficult as the bacteria mutate and become resistant.
Prevention:There are several vaccines but the most common is the BCG vaccine which is only partially effective. New vaccines are constantly being tested.
Famous Scientists: The 1905 Nobel Prize in medicine and physiology went to Robert Koch for his investigations and discoveries in relation to tuberculosis. He is one of the founders of bacteriology. He discovered the anthrax disease cycle (1876) and the bacteria responsible fortuberculosis (1882) and cholera (1883)
The 1952 Nobel Prize in Medicine and Physiology went to Selman Abraham Waksman for his discovery of streptomycin, the first antibiotic effective against tuberculosis.
Book to Read: Spitting Blood: A History of Tuberculosis by Helen Bynum (horrible title, very well done book!)
Of interest about India and TB is that there was an India-initiated crowd-sourced effort to map and annotate the genome of the bacteria that causes TB. In other words, effort was put in to read and evaluate the DNA sequence, hoping that if this information is freely available online, it might be of use to those who design drugs and maybe a cure could be found. Of such importance to the people of India to eradicate this disease that thousands of smart people volunteered their time to finish this project. Very impressive!
“Malaria is a mosquito-borne disease that affects more than 500 million people annually, causing between 1 and 3 million deaths. It is most common in tropical and subtropical climates and is found in 90 countries—but 90% of all cases are found in Sub-Saharan Africa. Most of its victims are children. The first stage consists of shaking and chills, the next stage involves high fever and severe headache, and in the final stage the infected person’s temperature drops and he or she sweats profusely. Infected people also often suffer from anemia, weakness, and a swelling of the spleen. Malaria was almost eradicated 30 years ago; now it is on the rise again.”
The causative agent is the Plasmodium parasite with a complicated life cycle which
is transmitted via the bites of infected mosquitoes. In the human body, the parasites multiply in the liver, and then infect red blood cells.
Treatment: There are many antimalarial drugs, many derived from natural sources, but can also be chemically synthesized. If you want to know more, check out the Wikipedia page on the topic. Again, like the organism that causes tuberculosis, plasmodium is becoming increasingly resistant to drugs.
Prevention: Insecticides to control the vector mosquitoes, netting around beds at night, proper sanitation and drainage of water in the environment, and anti-malarial drugs taken in small doses as a preventative.
Famous Scientists: In 1902, Sir Ronald Ross received the Nobel Prize in Medicine and Physiology for his work on malaria, by which he has shown how it enters the organism and thereby has laid the foundation for successful resesarch on this disease and methods of combating it. He made his discovery while stationed in India in 1897.
In 1948, Paul Hermann Muller received the Nobel Prize in Medicine and Physiology for his discovery of the high efficiency of DDT as a contact poison against several arthropods. Unfortunately, it is also toxic to humans and use had to be discontinued, but until then it was very good at eliminating mosquitoes that carried the malarial parasite.
Cutting Edge Science: Of interest is a company called Amyris that has used synthetic biology to create yeast that can produce artemisinic acid — a precursor of artemisinin, an effective anti-malarial drug.
Books to Read: I recommend two recent books. First, The Fever: How Malaria has ruled human kind for 500,000 years by Sonia Shah and The Imaginations of Unreasonable Men: Inspiration, Vision, and Purpose in the Quest to End Malaria, which examines scientists’ quest to find a malaria vaccine.
Progress for children is slower
“Of the 4.8 million people living with HIV in Asia, nearly half (49%) are in India. Acquired Immune Deficiency Syndrome (AIDS) is a fatal and incurable disease caused by HIV (human immunodeficiency Virus), AIDS attacks and destroys the immune system, gradually leaving the individual defenseless against illnesses that lead to death.”
“While there have been gains in treatment, care and support available to adults, we note that progress for children is slower,” says Leila Pakkala, Director of the UNICEF Office in Geneva. “The coverage of HIV interventions for children remains alarmingly low. Through concerted action and equity-focused strategies, we must make sure that global efforts are working for children as well as adults”.
Treatment: The ihttps://web.archive.org/web/20160823192609/http://www.who.int/mediacentre/news/releases/2011/hiv_20111130/en/ntroduction of highly active antiretroviral (ARV) therapy in 1996 was a turning point for those with access to sophisticated health-care systems. The cost of these drugs are out of reach for the 95% of people living with HIV/AIDS in developing countries. Progress has recently been made in India, however, as Indian pharmaceutical companies are producing generic versions of ARVs and selling them for less than $1 a day. Another obstacle is that not everyone can tolerate the potent medications and their side effects.
Books to Read: I have not read any of these seven suggested books, so cannot personally recommend any of these, but if I had to choose, I think I would start with The Epidemic: A Global History of Aids by Jonathan Engel.
Famous Scientists: The 2008 Nobel Prize in Medicine and Physiology was awarded to Francoise Barre Sinoussi, and Luc Montagnier for their discovery of human immunodeficiency virus.
There are many more diseases that afflict children in India, but I believe this post is a decent treatment of many of them. Some of these will reappear as I post further topics over the next few days.
All images are creative commons sourced.
I offer huge thanks to the School of Integrative Biology at the University of Illinois for their support of my outreach. A huge dose of appreciation for GoPro cameras which has outfitted me with a new Hero3 with which I will share with you both the opulence and poverty of India in the upcoming days. This trip is fully funded by the International Reporting Project and the Gates Foundation.