Emerging and Reemerging Infectious Diseases

Emerging and Reemerging Infectious Diseases

Filmie Fladento - MDCCC- 143

Worldwide, outbreaks of newly emerging and reemerging infectious diseases have continued to cause significant human misery and fatalities. There have been a number of significant developments in the study of infectious illnesses with epidemic potential over the past 20 years. Other lethal infectious diseases with pandemic potential have received less attention as a result of the World Health Organization's (WHO) and international media focus on the Zika virus epidemic at the 2016 Olympic Games in Rio de Janeiro and the 2015 Ebola virus outbreak in West Africa. The threat that several new and reemerging infectious diseases and the growth of antibiotic-resistant bacterial infections pose to the safety of the global health system has recently drawn more attention.

Novel Human Corona virus Infections

In the last 17 years, there have been two novel human anthropogenic corona viruses with the ability to spread epidemically. In China, a new b corona virus known as the severe acute respiratory syndrome corona virus first appeared in November 2002 as a deadly zoonotic human infection before swiftly spreading over the world until going extinct in 2004. The Middle East Respiratory Syndrome coronavirus (MERSCoV) was initially discovered in a lung sample taken from a 60-year-old patient who had passed away in Jeddah, Saudi Arabia, from respiratory and multiorgan failure, in 2012. Since then, MERS-CoV has continued to be a concern for international public health authorities due to frequent nosocomial and community outbreaks, as well as its link to serious illness and high mortality rates. With 186 confirmed MERS cases and 38 fatalities between June 1 and July 31, 2015, the Republic of Korea had the greatest epidemic of MERSCoV outside of the Arabian Peninsula. This happened when a Korean traveller returning from a trip to Qatar, the United Arab Emirates, Saudi Arabia, and Bahrain was unwell with a respiratory ailment and sought treatment at numerous hospitals in Seoul before being identified as having MERS-CoV infection. This outbreak amply demonstrated the MERS-CoV virus's capacity for pandemic propagation from person to person. In the Middle East, MERS-CoV is still circulating and occasionally produces outbreaks in both communities and hospitals. 848 fatalities, or 34% of cases, were reported to the WHO as of July 2019 out of 2458 cases of MERS-CoV that have been confirmed in the lab.

Influenza Viruses

Before spreading to other continents, human infections caused by highly virulent avian influenza A(H5N1) were first discovered in Hong Kong in 1997, with a case fatality rate close to 60%. The influenza A(H1N1)pdm09 virus first appeared in 2009, sparking a pandemic and continuing to circulate ever since. In contrast to the rising number of rare human cases of avian A(H5N6), A(H10N8), and A(H6N1) since 1997, the new avian influenza A(H7N9) virus first infected humans in China in March 2013.In the early spring of 2013, a unique H7N9 virus epidemic led to a zoonotic illness in eastern China. Through September 2017, China saw six outbreaks of human instances of the H7N9 virus infection, with 1564 laboratory-confirmed cases and 612 fatalities.

Viral Hepatitis

Numerous millions of individuals throughout the world are afflicted by viral hepatitis. Hepatitis A virus, hepatitis B virus (HBV), hepatitis C virus (HCV), and hepatitis D (delta) virus are the five biologically unrelated hepatotropic viruses that account for the majority of viral hepatitis cases worldwide.(HDV) and hepatitis E viruses (HEV). Hepatitis B and C account for a significant fraction of viral hepatitis-related mortality. There were 257 million people living in the world, according to estimates.61 million individuals had HBV, and 71 million had HCV. 90% of the burden of viral hepatitis-related deaths in 2017 was caused by cirrhosis and hepatocellular cancer, which are side effects of chronic hepatitis B and C, respectively. Chronic infection can also result from HBV, HCV, HDV, and sometimes HEV.

Antibiotic-Resistant Bacterial Infections

Antibiotic-resistant bacteria are becoming a major worldwide public health concern that threatens the security of the whole world's health system. More than 500,000 persons globally have multidrug-resistant tuberculosis (MDRTB), which has a high morbidity and death rate. Only a small portion of the projected 558,000 new MDR-TB patients that were identified in 2018 were reported internationally. The fact that the number of MDR-TB patients is rising yearly is concerning. Hope for better treatment results has recently been raised by the development of all-oral, shorter treatment regimens and quick point-of-care diagnostics.

Globally, common organisms causing community-acquired pneumonia (CAP) include Mycoplasma pneumoniae, Staphylococcus aureus, Legionella pneumophila, and Enterobacteriaceae. In the Asia Pacific areas, Klebsiella pneumoniae, Burkholderia pseudomallei, and Acinetobacter baumanii are also significant CAP-causing agents. The necessity for more careful antibiotic usage has been impacted by the incidence of antimicrobial resistance in S pneumoniae and M pneumoniae throughout time. Margaret and Jeffery provide an overview of antimicrobial resistance linked to the typical bacterial infections that cause CAP and the known mechanisms of resistance.

Opportunistic Infections in Transplant Recipients

Transplanting organs is a common practice all around the world. More than 120,000 solid organ transplants are reportedly conducted worldwide, with the kidney, liver, heart, and lung ranking first through fourth. Despite the organ transplantation centers’ aggressive application of preventive and treatment protocols, the possibility of opportunistic known and unknown Infectious exist constantly. A growing number of infections acquired from donors and the community may now be diagnosed in transplant recipients because to developments in molecular microbiology.

SUMMARY

The article in this issue of Infectious Disease Clinics of North America on "Emerging and Reemerging Infectious Diseases" demonstrates the ongoing danger posed by a variety of pathogens that can appear to doctors anywhere in a variety of clinical situations. A high level of awareness of the risk for an infection with microorganisms with epidemic potential or antibiotic resistance is essential for doctors and other healthcare professionals everywhere. A global readership of health care professionals, infectious disease and tropical medicine internal medicine trainees, pulmonologists, microbiologists, family doctors, and public health practitioners in both developed and developing countries are the target audience for this series of current articles written by authoritative and renowned experts in their specialist fields.