Avian Influenza (Bird Flu):
Bird Flu, more properly called avian influenza, is an infectious disease that primarily affects birds but can also infect several kinds of mammal, including humans. Characterized by rapid prevalence, avian influenza has a variety of symptoms, ranging from simple to lethal.
Many species of wild bird – particularly migratory waterfowl, and, especially, ducks - seem able to carry bird flu without coming to any apparent harm, but infection with avian influenza causes other species, including domestic chickens, turkeys and geese, to become seriously ill. In poultry, the sickness caused by bird flu comes in two different types, one mild, widespread and barely noticeable, the other uncommon, deadly and very difficult to overlook. The incubation period of avian influenza ranges from 1 to 7 days. It is worth mentioning that the recent Bird Flu outbreaks in South East Asia and some European countries (like Turkey), as well as Iraq, are basically attributed to the direct contact with domestic, migratory and water birds.
Avian influenza (H5N1) has epidemically prevailed among birds and poultry in many countries around the world, including Hong Kong, Vietnam, Cambodia, Thailand, Indonesia, and recently China, Russia and Kazakhstan. It is for this reason that millions of birds and poultry have been culled, in an endeavor to put end to the pandemic prevalence, and prevent it from transmission to humans, considering that human-to-human infection has not yet been proven.
Causes:
The avian influenza A encompasses numerous subclasses and strains (15 strains so far), undergoing several genetic mutations and leading up to the appearance of several avian epidemics in South East Asia, the Americas, and, recently, Russia. These viral strains have been reduced to one stain (H5N1), which can affect several mammals, including humans. All bird species are prone to the H5N1 infection, but at varying degrees. At present, several spots around the world are hit by H5N1 outbreaks, leading up to the death and culling of millions of birds.
Besides, a number of humans, those in contact with infected birds, have been detected to be carriers of the virus. The contact with the live infected birds, either direct or indirect, is considered the main cause of infection. The virus could be transmitted through the birds' mouth secretions and excretion. Human infection could also caused by the contamination of the tools or clothes of the workers at poultry farms with the virus included in the birds' secretions and wastes. The virus can live for relatively long time in low-temperature environments.
Incubation Period:
1-7 days.
Ways of Transmission:
- The contact with the live infected birds, either direct or indirect, is considered the main cause of infection. The virus could be transmitted through the birds' mouth secretions and excretion.
- The virus can live for relatively long time in low-temperature environments.
- Human infection could also caused by the contamination of the tools or clothes of the workers at poultry farms with the virus included in the birds' secretions and wastes.
Symptoms of Avian Influenza (H5N1):
The symptoms of avian influenza include: high temperature (38° C, or more), throat pains, cough, dyspnea (caused by viral inflammation in the lungs). Other digestive disorders could occur, such as vomiting and diarrhea. These symptoms usually continue for 3-7 days, and may end up with death.
Diagnosis:
Taking blood and respiratory samples to be examined for avian influenza (H5N1). The result would be positive on the occurrence of one (at least) of the following results:
- The farm is positive to the virus.
- The PCR is positive to H5N1.
- The IFA is positive to the antiviral.
- Higher by for times of the specific antiviral.
Remedial Action:
I) Towards the Patient:
Treatment could be conducted by treating the major symptoms, which are: pneumonia, fever, and secondary inflammations.
- Taking samples for the laboratory testing of avian influenza and other inflammations.
- Giving antivirals to the patient. Antivirals could be used for treatment, as well as prevention of those in contact with patients, and those who are vulnerable to infection. Tamiflu (Oseltamivir) is recommended (tablets, 75mg, twice a day, for 5 days), whereas amantadine and rimantadine are not recommended, since the virus already has resistance against them. Likewise, ribavirin is unfavorable. The Tamiflu treatment begins on the first or second day of the appearance of symptoms (36 hours after the symptom appearance).
Therapeutic Doses:
A) Adults: tablets, 75mg, twice a day, for 5 days.
B) Children:
- Children weighing less than 15 kg: tablets, 30mg, twice a day for 5 days.
- Children weighing 15-23 kg: tablets, 45mg, twice a day for 5 days.
- Children weighing 23-40 kg: tablets, 60mg, twice a day for 5 days.
- Children weighing more than 40 kg: tablets, 75mg, twice a day for 5 days.
- Using broad spectrum antibiotics for the treatment of secondary bacterial infections.
- Avoiding sodium aspirin for people under 18 years old, and using, instead, paracetamol (Panadol) and ibuprofen when need be.
- Assigning an isolated room with negative pressure for the patient. And if not possible, patients could be put together in one room, with cloth separators between them.
- In case the patient is unwilling to receive medicament at the hospital, he (and his family) should be well aware of the disease, and ways of transmission, as well as adopting the means of personal protection (washing hands, using a facemask, and avoiding social visits). It is highly recommended, also, to ask for medical help in case of the occurrence of any complications.
II) Towards those in Contact with Patients:
- Following up those in direct contact with patients for 7 days. It is recommended to measure temperature twice a day.
- Immediately applying the therapeutic plan in case the temperature goes higher than 38° C, or when breathing becomes difficult.
III) Towards the Health Workers in Contact with Patients:
- Using protective clothes (surgical facemasks, gloves, aprons, etc.)
- Washing hands well, by using a disinfectant or water and soap.
- Giving antivirals for prevention.
- Measuring temperature twice a day.
- Immediately applying the therapeutic plan in case the temperature goes higher than 38° C, or when breathing becomes difficult.
Instructions on Tamiflu Doses:
A) Patients with Renal Disorders:
- Patients whose creatinine clearance is higher than 30 ML/min will require no therapeutic variations.
- Patients whose creatinine clearance is 10-30 ML/min will have to reduce the dose to 75mg a day, for 5 days.
- The medication is not recommended for patients whose creatinine clearance is lower than10 ML/min, or those who suffer from very poor kidney function, or undergo dialysis.
- The medication is not recommended for children with renal failure.
B) Patients with impairment of liver function:
No dose variations, either in case of treatment of prevention.
C) Elderly patients:
No dose variations, either in case of treatment of prevention.
D) Children:
The safety and efficiency of the drug is not yet verified for children under 1 year old.
E) Pregnancy and breastfeeding:
- There is no sufficient data, so far, about its effect in case of pregnancy and breastfeeding.
- The drug can be used in case of pregnancy and breastfeeding, if only the desired benefit is equal to the expected danger on the fetus or infant.
Drug Contradictions:
Sensitivity to any of the drug components.
Side Effects:
Digestive symptoms (vomiting and nausea), in addition to headache, fatigue, insomnia, conjunctivitis, nosebleeds (epistaxis)
Preventive Measures:
The preventive measures are intended to reduce the infection sources in poultry farms, and prevent the infection transmission to other farms, and to humans accordingly. In this spirit, the following precautionary measures are highly recommended:
- Raising the health awareness for those working in the field of aviculture, and providing them with the necessary information, tips and preventive measures.
- Giving the anti-avian influenza drug (Tamiflu, 75ML, one dose a day, for 7 days; in addition to the antivirals necessary for human influenza, as recommended by the WHO) to the most vulnerable persons (poultry workers, laboratory workers dealing with avian influenza, and health workers in contact with patients infected with H5N1)
- Enforcing the instructions and regulations of infection control in hospitals and laboratories.
- Coordinating between the relevant authorities (e.g. the Ministry of Agriculture, the Ministry of Health, the Ministry of Commerce & Industry and the Ministry of Rural and Municipal Affairs), so as to take the proper action with the aim to prevent the disease from entering the Kingdom, and raise the level of surveillance and early detection of the potential sources of the disease.
