Botulism is a disease caused by the exotoxin of Clostridium botulinum , which is a spore- forming, gram-positive anaerobe. Human disease is usually caused by types A, B & E. The incubation period ranges from a few hours to 10 days.
The disease usually follows the ingestion of contaminated preserved food-stuffs, but may develop from infected wounds or following gastrointestinal colonization in infants. Symptoms include descending weakness or paralysis , gastrointestinal symptoms, postural hypotension, dry mouth and dilated pupils. Death usually occurs from respiratory arrest.
Strict hygienic steps when canning foods. Avoid consumption of salted fish from unknown sources.
Botulinum Antitoxin, ventilation & rehabilitation.
Cholera is an acute illness caused by infection of the intestine with the bacterium Vibrio cholera .
The incubation period is 1-3 days.
A person may get cholera by consumption of water or food contaminated with the cholera bacterium. Ingestion of raw shell-fish has been reported as a source of infection. Infection is often mild or asymptomatic, however sometimes it can be severe. Approximately one in twenty infected persons suffers severe disease and presents with profuse watery diarrhea (rice water diarrhea), vomiting and leg cramps. In these persons, rapid loss of body fluids & electrolytes leads to dehydration and shock. Without treatment, death may occur within hours.
Avoid consumption of contaminated food and water. Cholera vaccine is recommended for travelers to endemic areas and food handlers. Repeated vaccination is required or advised sometimes for laboratory workers and ship crews.
The prompt administration of oral rehydration solutions containing salts nearly always results in cure. In especially severe cases, intravenous administration of fluids & electrolytes may be required to save the patient's life.
Chicken Pox is an infectious disease caused by herpes virus, a member of the subfamily Alphaherpesvirinae. The incubation period is 14- 21 days. Varicella is a highly contagious disease which is caused by air-borne spread of infectious virions released from skin or respiratory mucosa of patients.
There is usually a short prodromal period, for 1 –2 days, presented by malaise and fever before the appearance of the characteristic rash. The rash appears in crops and usually progresses rapidly from macules to papules, vesicles, pustules and finally crusts.The rash has a central distribution mainly over the trunk, scalp and face. Rare complications of varicella infection include pneumonia, cerebellar ataxia and encephalitis.
The chickenpox vaccine protects against infection in 70 to 90% of those who are vaccinated. The vaccine is given at the age of 12 months or older.
Treatment of chickenpox is by managing symptoms & may necessitate targeting the infection with acyclovir (Zovirax) & Vidarabine.
Diphtheria is an infectious disease caused by a potent exotoxin elaborated by Corynebacterium diphtheriae.
The incubation period is 7 days. Diphtheria primarily affects the pharynx and in minor instances larynx, nasal lining, skin, conjunctiva or vagina. The disease results in acute inflammation, pseudomembrane formation and lymphadenopathy. It may be associated with systemic toxicity, as myocarditis and neuritis. Death may occur due to heart failure (Toxic myocarditis) or due to respiratory airway obstruction by the formed pseudomembrane.
DPT vaccine is given for children at 2, 4, 6 and 18 months & it provides protection for about 10 years. Td vaccine is given for certain medical conditions and also for adults more than 7 years. A booster dose is given every 10 years.
Diphtheria is a serious illness. Treatment should be immediate and aggressive with diphtheria antitoxin, antibiotics & supportive measures.
Gas Gangrene is an infectious disease caused by anaerobic organisms mainly Clostridium perfringens, Clostridium septicum & Clostridium oedematiens.
The incubation period ranges from hours to 6 weeks.
Patients become infected through contamination of wounds with soil and dirt after trauma, operations or normal labor. The disease is characterized by myonecrosis presented with pain and oedema in the region of the wound, with a serous or sero-sanginous exudate and a local crepitus sensation.
The draining lymph nodes enlarge markedly.
Associated systemic manifestations as toxemia, irregular feeble pulse, mild to moderate pyrexia, hypotension and collapse usually associate the local infection. The disease usually terminates with death due to circulatory failure.
Proper & deep cleaning of contaminated wounds & proper antibiotics.
Antibiotic therapy with Penicillin G is the drug of choice. Currently, a combination of penicillin and clindamycin is widely used. Gas gangrene antitoxin is also used as a treatment.
Hepatitis A an acute infectious disease caused by a single stranded RNA virus of the Picornaviridae family, genus Hepatavirus.
The incubation period is 2 – 6 weeks.
Man gets infection through consumption of contaminated food or drink.
The disease usually commences with a brief prodromal illness lasting for several days and characterized by fatigability, malaise, loss of appetite, nausea and vomiting. In most patients the first objective sign of illness is darkening of urine, yellowing of sclera (jaundice), or passage of pale-colored stools. Enlarged tender liver and elevated serum transaminases are always present. When disease does occur, it is usually mild and recovery is complete within 1-2 weeks. Occasionally, the symptoms are severe and convalescence may take several months.
Rare deaths occur in the elderly.
Good sanitation and hygiene, Avoid consumption of contaminated food and water. Vaccination with hepatitis A is vaccine, especially for Travelers to endemic areas, Residents in institutions and homes for handicapped, Medical& paramedical and day care centers personnel, Food handlers & Military personnel.
No specific medicines are used however; drinking plenty of fluids, getting rest & well nourishment and avoiding fatty meals & alcohol completely.
Hepatitis B is an infectious disease caused by a double stranded, enveloped DNA virus of the Hepadenaviridae family.
The incubation period ranges from 6 weeks to 6 months.
The development of clinical manifestations is highly age dependent; being more manifested in adults. Clinical signs and symptoms of acute HBV infection include anorexia, nausea, malaise, vomiting, jaundice, dark urine, clay colored stool and abdominal pain. Occasionally, extra-hepatic manifestations occur and include rash, arthralgia and arthritis. Fulminant hepatitis occurs in 1 - 2% of cases. Chronic hepatitis develops in 6 - 10% of cases and causes liver cirrhosis.
Using disposable syringes, Avoid contact with blood contaminated stuff. Hepatitis B vaccine is the best method of prevention. It is one of the childhood compulsory vaccines. It is also indicated for high risk groups as health care personnel, laboratory workers, patients with chronic renal failure, haemophilics, close contacts to cases or carriers & infants born to mothers who are hepatitis B carriers.
Receiving an injection of Hepatitis B immune globulin within 24 hours of coming in contact with the virus may help to protect from developing hepatitis B. Using antiviral drugs for targeting the infection as Interferon-α often in combination with other antiviral drugs such as Lamivudine.
Influenza (viral) is an infectious disease caused by members of the family Orthomyxoviridae that comprises three immunologically distinct types: A, B and C.
The incubation period ranges from 1-3 days.
Influenza is characterized by abrupt onset of constitutional symptoms and signs as fever, myalgia, headache, severe malaise, non-productive cough, sore throat and rhinitis. Pulmonary complications are the most common serious consequences. The clinical picture is essentially the same for influenza A and influenza B whereas the clinical characteristics of influenza C are generally milder. Epidemics of influenza occur during winter months nearly every year and are responsible for high rates of deaths and work absence days all over the world. Rate of infection is highest among children and young adults, while rate of deaths is highest among old ages and high risk people with chronic diseases.
Influenza vaccine is the most effective way to reduce the chance of infection. Keep the room well areated. Avoid contact with sick people.
Symptomatic treatment as antipyretics & decongestants Using Amantadine, or other antiviral drugs for targeting the infection. Antibiotics may be required for secondary infection.
Measles is an infectious disease caused by a member of Morbilivirus in the family of Paramyxovirus.
Incubation period is 10-12 days.
The virus is transmitted by droplet infection. The prodromal stage is manifested by fever, malaise, conjunctivitis, coryza and tracheo-bronchitis that last for 2-4 days. Koplik spots are pathognomonic for measles and appear 1-2 days before the onset of rash. The rash is an erythematous maculopapular eruption that spreads all over the body within 3-4 days and is associated with a sudden rise of temperature up to 40ºC. The most common complications of measles include otitis media, pneumonia, diarrhea and encephalitis.
The best prevention of measles is the measles vaccine, (one of the components of the MMR vaccine), which is a compulsory vaccine given at 18 m & a booster dose is given at the age of 4 years.
There is no specific treatment for measles. Once the rash starts, patient needs to rest and to be given - symptomatic treatment until the immune system fights off the virus.
Meningococcal meningitis is an infectious disease caused by Neisseria meningitidesa gram- negative kidney shaped cocci, commonly seen in pairs intra-cellularly.
The incubation period ranges from 7-9 days.
The organism spreads by droplet infection. The most common manifestations of meningococcal meningitis are sudden onset of fever, malaise, myalgia and headache. Seizures occur in 20% of cases together with vomiting and photophobia. A macular eruption, which progresses to peticheal and ecchymotic rash, is present in the majority of cases. The disease may be associated with myocarditis, endocarditis or pericarditis. Septicemia may be fulminant and is associated with hypotension and extensive purpura. Complications are mostly neurological including sensori-neural deafness and permanent disabilities.
Meningococcal polysaccharide vaccine provides immunity for 3 years.
Bacterial meningitis requires treatment at a hospital, including antibiotics & anticonvulsants.
Mumps is an infectious disease caused by a member of the genus Rubulavirus in the family Paramyxovirus.
The incubation period is 14-18 days. The classic symptom of mumps is swelling in the salivary glands, however it may also affect the sub-mandibular and sub-lingual salivary glands. It is associated with fever, headache, malaise, myalgia and anorexia. Complications of mumps are more common in adults and include pancreatitis, deafness,meningo-encephalitis and orchitis/oophoritis that may result in infertility.
Mumps vaccine is usually given as a combined measles-mumps-rubella (MMR) which is a compulsory vaccine given at 18 m & a booster dose is given at the age of 4 years.
Supportive care includes warm compresses ,ibuprofen or Paracetamol , plenty of fluids & eating soft foods.
Pneumococcal pneumoniais an infectious disease caused by Streptococcus pneumoniae, a group of anaerobic gram-positive organisms that grow as diplococci, or in short chains. The incubation period is 7 days.
The major clinical manifestations are otitis media, sinusitis, tracheo-bronchitis, and pneumonia. Pneumonia is manifested by high fever, chills and chest pain. Cough is dry in early stages and then becomes productive. Cyanosis, sweating and increased respiratory rate may also occur. Pneumococci may invade the blood stream resulting in meningitis and endocarditis.
Pneumococcal vaccine is recommended against Streptococcus pneumoniae bacteria (pneumococcus) for everyone older than age 65, as well as for people of any age residing in nursing homes and long-term care facilities.
Antibiotic therapy after doing culture and sensitivity test. Penicillin remains the drug of choice for treatment of pneumococcal pneumonia.
Poliomyelitis is an infectious disease caused by poliovirus types I, II or III. The incubation period is 7-14 days. Infection primarily spreads by the feaco-oral route but may also spread by droplet transmission.
Approximately 90 -95% poliovirus infections are asymptomatic. Non-specific illness with low-grade fever and sore throat (minor illness) occurs in 4 - 8% of infections. Aseptic meningitis occurs in 1- 5% of patients few days after the minor illness has resolved. Rapid onset of asymmetric acute flaccid paralysis occurs in 0.1- 0.2% of infections. Lower limb muscles are the most common to be affected; however bulbar and respiratory muscles may also be involved.
Polio prevention begins with polio vaccination. Polio vaccine is a compulsory vaccine that is highly effective in producing immunity to the poliovirus and protection from paralytic polio. It is provided at ages of 2, 4, 6 and 18 months. A booster dose is given at the age of 4 years & at the vaccination campaigns.
Because there is no cure for polio, treatment usually consists of physical therapy until the patient improves. Mobility aids & breathing equipment may be required.
Rabies is an infectious disease caused by rhabdovirus of the genus Lyssavirus .
The rabies virus is usually transmitted by the bite of an infected animal or contamination of broken skin by its saliva.
The incubation period varies from a few days to several months (according to the site of the bite) usually 1-3 months.
Human rabies is a fatal disease once symptoms have appeared.
The disease is characterized by hyper-excitability and severe spasms of larynx and pharynx that may lead to hydrophobia. Other manifestations include hyper- salivation, fever and convulsions. The disease usually progresses to coma and death.
Keep rabies vaccinations up to date for all dogs and cats. This is important not only to keep your pets from getting rabies, but also to provide a barrier of protection for you, if your animal is bitten by a rabid animal. Pre-exposure immunisation of all persons at risk e.g Veterinarians and their assistants, gatekeepers, hunters, forest rangers and slaughter-house personnel Subjects living in enzootic areas and travelers visiting these areas.
1. Prompt local treatment of the wound.
2. Passive immunization with rabies immunoglobulin After confirmed or suspected exposure to a bite by a rabid animal, vaccination with rabies vaccine, must be started immediately in a rabies-treating center.
Rubella is an infectious disease caused by a member of the toga family.
The incubation period is 14-21 days.
The disease is transmitted by droplet infection. It is usually mild and is characterized by lymphadenopathy (usually occipital & post-auricular) and maculopapular erythematous rash on the face and neck. The rash spreads down and fades within 1– 3 days. Complications include arthritis, encephalitis, Guillian Barre syndrome and thrombocytopenia. The most serious problem with rubella virus is on the developing fetus if a pregnant woman is exposed to infection during the first trimester. It causes congenital rubella syndrome which is characterized by sensori-neural deafness, cataract, cardiovascular anomalies and mental retardation of the newborn.
The MMR vaccine is a live, attenuated (weakened) combination vaccine that protects against the measles, mumps, and rubella viruses. It is a compulsory vaccine given at 18 m & a booster dose is given at the age of 4 years.
Only symptomatic & supportive treatment.
Tetanus is a disease caused by an exotoxin elaborated by Clostridium tetani.
The incubation period is 7-21 days.
Patient can get infection through wound contamination by C. tetani spores that are widely distributed in soil, intestine and feaces of horses, sheep and cattle. The disease is manifested primarily by neuromuscular dysfunction in the form of convulsions and severe muscular spasm. The muscle spasm usually involves the jaw (lock jaw) and neck and then becomes generalized.
Tetanus is completely preventable by active immunization with Tetanus toxoid vaccine, DT & DTP vaccines.
Immunoglobulin, given intramusc0ularly, is the immediate treatment of unimmunized individuals exposed to material likely to contain the tetanus bacteria. Treatment includes bed rest, quiet conditions & the necessary symptomatic treatment as sedation with certain medications, and mechanical ventilation to control the spasms. Antimicrobial drugs, such as penicillin, are used to eradicate the bacteria.
Tuberculosis is an infectious disease that is caused by an acid-fast bacillus known as Mycobacterium tuberculosis . Mode of infection and incubation period vary according to the site of the disease as it may involve any part of the body. Survey studies in Egypt showed that around 90 % of cases are pulmonary and 10 % are extra-pulmonary. Cases of active pulmonary tuberculosis show constitutional and local chest manifestations that vary according to stage and severity of the disease. Manifestations are non specific, but only suggestive, e.g. night low-grade fever, night sweats, anorexia & mild loss of weight. Haemoptysis may occur in advanced stages. Cases usually become chronic and may show exacerbations and remissions.
For most people, the BCG vaccination provides protection against TB. It is given as early as 40 days after birth.
Isoniazid, rifampicin (also known as rifampin, pyrazinamide, and ethambutol, then isoniazid and rifampicin alone for a further four months. For latent tuberculosis, the standard treatment is isoniazid alone.
Typhoid fever is an infectious disease caused by Salmonella typhi.
The incubation period is 10-14 days.
Infection results from the consumption of food or water contaminated by excreta of an acute case or a carrier. S.typhi can invade the human intestinal mucosa ultimately leading to bacteraemia. The patient starts to develop symptoms such as: fever, myalgia, anorexia, abdominal discomfort, headache and rose spots on the trunk. Diarrhea in young children and constipation in older children are common manifestations. Less common and most severe complications are intestinal perforation, hemorrhage and death. Infection of gall bladder can lead to chronic carrier state in 2-4 % of acute cases.
Avoid risky foods and beverages (especially when traveling to the developing world) is another way to reduce the risk. Typhoid vaccine for anyone above the age of two years, especially those at high risk as: Displaced population living in camps, People with limited access to safe water and proper sanitation, People living in or travelling to endemic or epidemic areas, Food handlers& Workers in microbiological laboratories.
Several antibiotics are used to treat typhoid. The specific one chosen depends on the severity of symptoms and strain of bacteria involved.
Whooping cough is an infectious disease caused by a gram negative cocco-bacillus Bordetella pertussis.
The incubation period ranges from 7-10 days.
The disease is highly communicable and is transmitted by direct contact with airborne discharges from the respiratory mucous membranes of infected persons. It is manifested by episodes of forceful repetitive cough followed by a sudden massive inspiratory effort, which produces the characteristic whoop. It is often accompanied with cyanosis and vomiting. In young infants the cough may be absent and the disease may manifest with spells of apnea. Major complications include pneumonia, encephalitis and malnutrition (due to repeated vomiting).
The best way to prevent pertussis (whooping cough) among infants is to get vaccinated with DTP vaccine a combination with diphtheria, tetanus & Pertussis. It is a compulsory vaccine given at the age of 2, 4 & 6 months. A booster dose is given at the age of 18 months. Keep infants and other people at high risk for pertussis complications away from infected people.
Erythromycin, clarithromycin, and azithromycin are preferred for the treatment of pertussis.
Yellow fever is an infectious disease caused by single stranded RNA virus, a prototype member of the family flaviviridae.
The incubation period ranges from 3-6 days.
It is transmitted to man by mosquito or ticks. The disease resembles many other arbo-viral infections and is characterized by fever, headache, malaise and myalgia. It progresses to result in hepatic, renal and myocardial injuries, hemorrhage and death.
Yellow fever, a single dose of the vaccine provides protection for at least 10 years. It is recommended for travelers to endemic areas Mosquitoes repellents help to avoid mosquito bites.
There is currently no treatment for yellow fever that can kill the virus. Therefore, treatment is focused on symptomatic as bed rest, drinking plenty of fluids, and taking acetaminophen (not aspirin) to relieve fever and discomfort. In severe cases, treatment of yellow fever requires hospitalization for intensive supportive care.