Antibiotic use is closely linked to the prevalence of infections. It is important to monitor the general disease patterns and bacterial outbreaks within the health care setting, in the community and among animals, as well as resistance levels in the pathogens, to be able to address the problem of antibiotic resistance efficiently.
Why monitor infections?
Infectious diseases drive much of the antibiotic use in the world. In some cases, as in the treatment of sepsis and pneumonia, antibiotics are life-saving medicines. In other cases, such as in the treatment of uncomplicated upper respiratory tract infections or diarrhea, antibiotic use is often improper.
Knowing which diseases are causing the most illnesses in people and animals as well as those that require the most time and resources to cure, can guide decisions on which bacteria to include in surveillance and prevention initiatives, can help identify the sources of outbreaks and may facilitate work to make sure that the relevant diagnostic methods and correct treatments are available, to name only a few examples. Such information can also help in identifying the diseases which drive antibiotic consumption.
Infections, antibiotic use and resistance
Health care-associated infections
Health care-associated infections are infections that patients get within a healthcare facility, while receiving treatment for another condition. They can result in prolonged morbidity, in-hospital stay or even mortality for affected patients, as well as substantial excessive costs for health care and society (see more in UNDERSTAND: Antibiotic resistance – Health care-associated infections). Many of these infections are caused by resistant bacteria.
Every year around 4 million patients in Europe get a hospital-acquired infection. This leads to at least 37,000 deaths. More than 60% of these deaths are caused by antibiotic resistant bacteria. In low and middle income countries thorough estimates are more scarce. A WHO review reported a pooled prevalence of health care-associated infections around 10-15%. But data was highly variable with reports of up to 89% of patients in intensive care getting infected.
Community-acquired infections are infections obtained in the community for example from another person, contaminated food, or from a person’s own microbiota. A common definition is that community-acquired infections give symptoms or are diagnosed in patients within 48 hours of admission to a health facility. Examples of bacterial infections that are commonly obtained in the community are tuberculosis, pneumonia, urinary tract infections and food- and waterborne infections such as salmonellosis, campylobacter and cholera.
Increasing levels of resistance have been observed in many common community-acquired infections. Typhoid fever is a life-threatening disease that spreads through contaminated food and water. Burden is estimated to 20.6 million cases and 223,000 deaths. In Pakistan, more than 5000 cases of extensively antibiotic resistant typhoid were reported between November 2016 and December 2018. The only reliable and affordable oral antibiotic remaining for treatment is azithromycin.
Foodborne and zoonotic diseases
The global burden of foodborne diseases is considerable. Every year 600 million people fall ill and 420,000 die from foodborne illness. Particularly affected are children and persons living in low-income areas. More than 90 million people are affected in Africa alone.
Zoonotic diseases are diseases that can spread between animals and humans for example through contact with infected animals or by consuming contaminated food. Around 60% of all human diseases are said to have originated in animals. Food is also one route of transmission of antibiotic resistant bacteria. Both zoonotic bacteria and the normal gut microbiota of the animal can carry resistance genes. These bacteria can contaminate meat during slaughter, crops where untreated animal manure has been used as fertilizer or may end up in water sources.
Clean water and good sanitation reduce incidence of infection and need for antibiotics
Most acute diarrheal diseases are self-limiting and do not require antibiotic treatment (preferred treatment oral rehydration salts). Antibiotics are recommended only for severe bacterial diarrhea. However, inappropriate use of antibiotics for diarrhea is common.
Estimates suggest that 494 million cases of diarrhea are treated with antibiotics each year in Brazil, Indonesia, India and Nigeria alone. Universal access to improved water and sanitation could reduce this number by 60%.
Diseases in food animals
Diseases are one of the key constraints to animal productivity and is a driver of antibiotic use in animal production. Common production diseases include mastitis, diarrhea in young animals and respiratory illness (such as pneumonia).