A rapidly mutating seasonal respiratory virus known for triggering widespread flu outbreaks, Influenza viruses are highly infectious respiratory pathogens belonging to the Orthomyxoviridae family. They are enveloped, spherical viruses classified into three genera: Influenza A, B, and C. While Influenza A and B are responsible for seasonal outbreaks and global pandemics, Influenza C typically causes milder infections.

Influenza spreads mainly through airborne droplets from coughing, sneezing, or talking, and via contaminated surfaces. Symptoms appear in 1-2 days, with contagiousness lasting 4-5 days. However, many cases are mild or subclinical and only one-third develop a fever. So, infections often go unnoticed.

Influenza typically presents with fever, chills, sore throat, coughing, and muscle aches. Some cases may also include vomiting, diarrhea, and extreme fatigue. While many infections are mild or even subclinical (showing no symptoms), Influenza A and B can cause severe complications, especially in vulnerable groups including primary viral pneumonia, hospitalization, and in rare cases, death.

The best protection against influenza is the annual flu vaccine, which is updated to match circulating strains. Practicing respiratory hygiene, such as covering coughs and sneezes, helps reduce droplet spread. Regular disinfection of high-touch surfaces and isolating infected individuals are also key to preventing outbreaks, especially in healthcare and crowded settings.

Streptococcus pneumoniae is an aerobic, Gram-positive bacterium belonging to the Streptococcaceae family. Morphologically, it appears as oval to lancet-shaped cocci, often found in pairs (diplococci) or short chains. It is a major cause of respiratory and invasive infections, particularly affecting vulnerable populations such as young children, the elderly, and immunocompromised individuals. A growing concern is its increasing resistance to penicillins and macrolides, which complicates treatment and necessitates the use of broader-spectrum or alternative antibiotics. This resistance underscores the importance of vaccination and antimicrobial stewardship in controlling pneumococcal disease.

Transmission occurs mainly through respiratory droplets released when an infected person coughs or sneezes. These droplets can be inhaled directly or transferred via contact with contaminated surfaces and then introduced to the respiratory tract through the hands, nose, or mouth.

Streptococcus pneumoniae commonly causes pneumonia with symptoms like fever, cough, chest pain, and breathing difficulty. In severe cases, it can lead to meningitis or sepsis, especially without timely treatment. The severity of infection depends on host factors, bacterial strain, and early access to appropriate treatment.

Preventive strategies include vaccination, particularly in high-risk groups such as children under 5 and adults over 65. In addition, maintaining good respiratory hygiene, prompt isolation of infected individuals, and regular disinfection of shared surfaces are key to minimizing transmission in both community and healthcare settings.

Rotavirus is a non-enveloped virus from the Reoviridae family, known for its environmental resistance. It is a major global cause of gastroenteritis in infants and young children, especially those under the age of two.

Mainly through faecal-oral transmission, often via contaminated hands or surfaces. Airborne and saliva-based transmission have also been reported. It spreads easily in hospitals and childcare settings, especially among infants. Infected children are often the primary source of transmission, as they can carry and shed the bacteria asymptomatically, facilitating its spread to caregivers, family members, and other children in close-contact environments.

After an incubation of 1-3 days, symptoms like diarrhoea, vomiting, fever, and abdominal pain can appear. Severity ranges from mild to life-threatening dehydration, particularly in infants.

WHO recommends starting vaccination at the age of 6 weeks. In addition, proper hand and surface disinfection using virucidal agents and strict hygiene are key to reducing spread, especially in healthcare environments.

Salmonella Typhi is a Gram-negative, rod-shaped bacterium from the Enterobacteriaceae family. It is a facultative anaerobe and an obligate pathogen responsible for causing typhoid fever.

Transmission occurs primarily through ingestion of contaminated food or water, especially in regions with inadequate sanitation and hygiene practices. The pathogen can survive in unsanitary conditions, increasing the risk of outbreaks in densely populated or underserved areas.

S. Typhi causes typhoid fever, a serious systemic illness characterized by high fever, weakness, stomach pain, and constipation or diarrhea. Without prompt treatment, it can lead to severe complications.

Preventive measures include safe food and water practices, proper hand hygiene, and vaccination in high-risk areas. Disinfection with bactericidal properties is essential in controlling spread, especially in healthcare and food-handling environments.

Pseudomonas aeruginosa is a Gram-negative, rod-shaped, facultative anaerobe belonging to the Pseudomonadaceae family. It is a common opportunistic pathogen, especially in healthcare settings.

Transmission occurs via direct contact with infected individuals or indirect contact through contaminated surfaces, medical instruments, or hospital environments. It is especially common in healthcare settings where invasive procedures increase the risk of exposure.

It can lead to catheter-associated urinary tract infections, ventilator-associated pneumonia, wound infections, and even sepsis, particularly in immunocompromised or hospitalized patients. A major concern is its ability to form biofilms, which enhance its resistance to antibiotics and the host immune response. These biofilms create a protective barrier, making infections chronic, persistent, and difficult to eradicate. The damage caused by biofilm-associated infections includes prolonged inflammation, tissue destruction, and delayed wound healing.

Prevention involves strict hand hygiene, disinfection of medical equipment and surfaces, and isolation protocols for infected individuals. Its resistance to multiple antibiotics makes environmental disinfection and infection control critical in hospitals.

Acinetobacter baumannii is an aerobic, Gram-negative, rod-shaped bacterium from the Moraxellaceae family. It is a notable hospital-acquired pathogen known for its persistence and adaptability.

Transmission occurs mainly through contaminated water, food, and surfaces, particularly in healthcare environments where the pathogen can persist and spread easily among vulnerable patients.

It commonly causes catheter-associated urinary tract infections and pneumonia, particularly in hospitalized or ventilated patients.

Due to its growing antibiotic resistance, effective prevention includes rigorous hand hygiene, thorough surface and medical equipment disinfection. It also involves monitoring air and water quality, implementing antimicrobial surface coatings, managing waste properly, and maintaining optimal ventilation and humidity levels to limit bacterial survival and spread.

Dengue virus is an enveloped virus with a spherical, icosahedral capsid, belonging to the Flaviviridae family. It exists in four distinct serotypes, each capable of causing infection.

The virus is primarily transmitted through the bite of infected Aedes mosquitoes, especially Aedes aegypti and Aedes albopictus, which are active during daylight hours and thrive in urban and semi-urban areas.

Dengue virus causes dengue fever, marked by high fever, severe body aches, and rash. In severe cases, it can lead to dengue haemorrhagic fever or dengue shock syndrome, which may involve bleeding, organ failure, and can be life-threatening.

Prevention relies on mosquito control measures, such as eliminating breeding sites, using insect repellents, and protective clothing. Early detection through laboratory testing and clinical monitoring in hospitals and clinics is crucial. Supportive care, including fluid management, fever control, and monitoring for severe symptoms such as plasma leakage or organ dysfunction, is essential, particularly in intensive care units (ICUs) and infectious disease wards, where high-risk patients require close observation.

Klebsiella pneumoniae is a facultative anaerobic, Gram-negative, rod-shaped bacterium belonging to the Enterobacteriaceae family. It is a significant opportunistic pathogen, especially in healthcare settings. Furthermore, K. pneumoniae is known to produce extended-spectrum β-lactamases (ESBLs), which confer multidrug resistance, particularly against cephalosporins, including ceftazidime. This resistance limits treatment options, often requiring the use of carbapenems or combination therapies, emphasizing the need for strict infection control and antibiotic stewardship in clinical settings.

Transmission occurs via direct contact with infected individuals or indirect contact with contaminated surfaces or medical equipment, making it a common threat in hospital and clinical settings. These include intensive care units (ICUs), neonatal units, surgical wards, and long-term care facilities, where immunocompromised patients, those on ventilators, or those with invasive devices such as catheters and central lines are particularly vulnerable. Strict infection control measures are essential in these high-risk areas to prevent outbreaks and antimicrobial resistance. A growing concern is its increasing resistance to penicillin and ampicillin, making treatment more challenging.

Common infections include lower respiratory tract infections (such as pneumonia) and catheter-associated urinary tract infections, particularly in hospitalized or immunocompromised patients.

Preventive measures include strict hand hygiene, disinfection of medical devices and surfaces, and isolation protocols. Given its multi-drug resistance, especially as an ESBL-producing strain, infection control is critical to limiting its spread. The use of disinfectants with strong bactericidal properties, such as hydrogen peroxide with silver nitrate (Baccishield), or quaternary ammonium compounds (Korso Plus, Mikrobac forte), is essential to effectively eliminate K. pneumoniae from hospital environments and prevent contamination.

Clostridioides difficile (formerly Clostridium difficile) is an anaerobic, spore-forming, Gram-positive, rod-shaped bacterium from the Clostridiaceae family. It is a major cause of healthcare-associated infections.

Transmission occurs via the fecal-oral route, direct or indirect contact with contaminated individuals, objects, or surfaces. Its resilient spores can survive up to five months, increasing the risk of persistent outbreaks, especially in healthcare settings.

C. difficile commonly causes antibiotic-associated diarrhoea, particularly after broad-spectrum antibiotic use. These antibiotics disrupt the normal intestinal flora, reducing competition and allowing C. difficile to overgrow, leading to infection and toxin production. Some strains, like ribotype 027, produce high levels of toxins A and B, leading to severe colitis, antibiotic-associated diarrhea, inflammation of the intestine, and even sepsis in severe cases. Early diagnosis and prompt medical intervention are crucial to managing complications.

Key prevention strategies include judicious antibiotic use, hand hygiene, and sporicidal surface disinfection in healthcare settings to control its persistent and resilient spores.

Methicillin resistant or multi resistant Staphylococcus aureus strain is a strain of Staphylococcus aureus, an aerobic, spherical, Gram-positive bacterium in the Staphylococcaceae family, that is resistant to all beta-lactam antibiotics, including penicillin and methicillin.

MRSA spreads via direct or indirect contact with infected individuals, contaminated surfaces, or medical equipment. The highest risk is found in high-risk hospital areas, such as intensive care units (ICUs), surgical wards, burn units, and long-term care facilities, where patients with open wounds, invasive devices, or weakened immune systems are most vulnerable. MRSA commonly thrives in warm, moist environments, including skin folds, surgical sites, wound dressings, and medical devices such as catheters and ventilators, making infection control measures, such as strict hand hygiene, proper wound care, and surface disinfection, essential to prevent its spread.

MRSA is a major cause of skin infections such as cellulitis and boils, as well as muscle inflammation. It is also a leading pathogen in surgical site and wound infections, which are difficult to treat due to its antibiotic resistance.

Preventing MRSA involves strict hand hygiene, surface and equipment disinfection, and adherence to infection control protocols. Outbreaks are most common in high-risk healthcare settings, including intensive care units (ICUs), surgical wards, burn units, dialysis centers, and long-term care facilities, where patients are more vulnerable due to invasive procedures, open wounds, or weakened immune systems. Strict screening, isolation of infected patients, and judicious antibiotic use are essential to controlling MRSA spread in these critical areas.

Mycobacterium tuberculosis is an anaerobic, Gram-positive, rod-shaped bacterium from the Mycobacteriaceae family. It is the causative agent of tuberculosis (TB), one of the world’s most widespread infectious diseases.

Transmission occurs mainly through airborne droplets expelled when an infected person coughs, sneezes, or talks, allowing the bacteria to enter the lungs or respiratory tract of others especially in crowded or poorly ventilated spaces.

The bacterium causes tuberculosis, typically affecting the lungs and leading to symptoms such as persistent cough, fever, night sweats, and weight loss. Without treatment, TB can spread to other organs and become life-threatening.

Preventive strategies include early detection, respiratory hygiene, proper ventilation, and isolation of infected individuals. In healthcare settings, disinfection and use of protective equipment are vital, especially due to the rise of multidrug-resistant TB (MDR-TB).

Key preventive actions include:

• Hand hygiene: Regular handwashing with Baktolin 5.5 or using alcohol-based hand rubs like Sterillium to prevent cross-contamination.
• Surface disinfection: Cleaning and disinfecting frequently touched surfaces with tuberculocidal disinfectants to reduce transmission ( For example: Bacillol 25)
• Linen disinfection: Proper handling, laundering, and disinfection of contaminated bed linens and clothing to prevent the spread of M. tuberculosis spores. (For example: Linotox)
• Use of protective equipment: Healthcare workers should wear N95 respirators and follow strict infection control protocols in high-risk areas such as TB isolation rooms and pulmonary wards.Use of protective equipment: Healthcare workers should wear N95 respirators and follow strict infection control protocols in high-risk areas such as TB isolation rooms and pulmonary wards.