Diseases that are transmitted from animals to humans and humans to animals are called “Zoonotic Diseases” and this phenomenon is called “Zoonosis”. The diseases that are transmitted from humans to animals are sometimes called “Reverse Zoonosis or Anthroponosis. Different animals have a potential to carry these diseases to humans. The diseases which are transmitted from animals to humans, they pose a serious threat to the communities of human populations particularly in those areas where veterinary infrastructure and services are poor. The transmission of these diseases is through several ways including meat, milk, infected blood, direct contact and indirectly by infected environment of farm.
An estimation was made in 2005 that there are 1407 species of infectious pathogens in humans and 58% of them are those which are common in humans and animals.
There is a long list of zoonotic diseases caused by bacteria, viruses, parasites and fungi. Some of the important zoonotic diseases are babesiosis, cholera, cowpox, Crimean-Congo haemorrhagic fever, leptospirosis, malaria, Q- fever, salmonellosis, toxocariasis and toxoplasmosis, etc. One of the biggest issue arising now a days in Pakistan and globally is “Swine Flu infection” which is also categorized under the zoonotic diseases. On the globe it is declared as pandemic and raised its pandemic alert level to “Phase-5” out of 6 maximum.
In Pakistan it was first reported in 2009 in people belonging to Rawalpindi and Kashmir and now a-days it’s a hot issue in Southern Punjab like Multan, DG Khan, Taunsa Sharif and Khanewal etc.
History and Zoonosis:
In early 1930, influenza virus was isolated in pigs in America. This was H1N1 subtype virus and its isolation from pigs was followed by 1918 human H1N1 influenza pandemic that claimed over 40 million lives around the world. Recent evidence clearly indicates that the 1918 human viruses and 1930s swine viruses were closely related. However it is still unclear that whether these viruses first appeared in humans and then spread to pigs or vice versa. Although the transmission of this virus from pigs to human is not very common. It is believed that swine have receptors for attachment of both avian and mammalian influenza viruses, which increase the potential for viruses to exchange their genetic material and produce new re-assorted sequences of viral genomes. In 1974, the zoonotic nature of this virus was confirmed when “classical swine influenza virus infections” were documented in U.S with fatal consequences. Swine flu is basically an RNA based viral respiratory infection of pigs as indicated by its name and it is also called as Pig flu, Hog Flu or Swine Influenza. It is caused by different strains of Swine Influenza Virus (SIV). This virus belongs to Influenza-A viruses in the family of Orthomyxoviridae. The most common subtypes of this virus are H1N1, H1N2, H3N2, which are seen in swine. Among these H1N1 is relatively stable subtype, mostly causing swine influenza. This strain is historically associated with classical swine influenza. This Influenza virus is able to infect Human, Swine and Avian (Birds) species. Virus comes from the infected pig/hog handlers into the environment and then itattaches to the surface of nose, throat, and lungs through aerosol/cough. After attachment, these are engulfed by the host cell.Inside the cell they overtake the function of cell and release their own genome for replication. They make their own viral proteins with the help of viral mRNA. These proteins and RNA then migrate to the cell surface, assemble into new virus particle. The new virus then comes out from the cell surface and released in the body causing infection. This viral infection is then again transmitted through cough and sneezing to other surrounding people. Its transmission is very rapid from humans to humans.
Swine Flu in Pakistan- an alarming situation:
Swine influenza is a deadly virus which spreads through pigs, birds and infected migrated people and this virus kills the humans within no time. On June, 2009 the health ministry confirmed the country’s first swine flu case in a young boy of 14 years old (Dawn News). In Sindh, 52 cases positive for swine flu were reported on Dec 24, 2009. In April, 2010 the ministry data showed 76 patients positive for this virus while nine deaths occurred. In 2011, 108 positive cases for swine flu were reposted in Swabi and Karachi (Dr. Rashid Juma Said in Central Asia Online). Now in 2014, swine flu outbreak is again seen in Multan, Khanewal, Taunsa and DG Khan districts of Southern Punjab.More than 10 cases of swine flu have been seen in these districts resulting in 5 mortalities (Dawn News: March 10, 2014). Swine Flu has been declared as pandemic by WHO and US CDC. In a Muslim country like Pakistan where there is no as such source of this virus, but the only source is, the migrant people from abroad. According to a survey on Aug, 2009 about 2 million Pakistanis live in Saudi Arabia, Europe, North America, and other countries where the swine flu pandemic has appeared. Similarly in our neighbor country India, In Oct. 2013 there were 13000 cases reported for swine flu with 444 deaths, starting from a 13 years old girl’s death. So where we are lacking of medical, technical and diagnostic facilities in developing country like Pakistan, to report such cases are really alarming situation and needs attention.
Signs & Symptoms in Humans:
In humans its signs and symptoms are same as seasonal influenzas. The Patient may suffer from fever, cough, sore throat, headache, muscle and joint pain, nasal congestion, body aches, chills and fatigue. However, 25% symptoms of diarrhea and vomiting are reported in this infection. Similar to seasonal influenza the patients which are considered at high risk include young children <5 years, the elderly >65 years, pregnant women, chronic issues of asthma, smokers, heart patients and who are immunosuppressed. It is also observed that affected person could be contagious for up to 10 days.
Diagnosis is made on the basis of clinical signs, but it is necessary to differentiate it with seasonal influenza due to its zoonotic and fatal property. For this purpose the persons are confirmed for swine flu if they have travelled from an area where swine flu was endemic, they have been exposed to infected pigs, pregnant women or immunosuppressed patients. Furthermore, the tests like antibody test in blood, PCR, ELISA, nasal swab and throat swab, culture of viral sample with the help of RT-PCR (Real Time PCR) can be performed. RT-PCR is authentic in rapid detection of virus and we can get results in 24 hours, but this facility is not available in Pakistan.
Antiviral drugs can only be used to cure this disease. They are effective against the disease and improve the condition of the patient. “Tami-flu” is an antiviral drug which is available for swine flu in Pakistan. Besides, supportive therapy should be applied for fever, dehydration and pain, if these conditions exist. Antibiotics can also be used if there is any secondary infection. All treatment should be under the consultancy and observation of a doctor.
Strategies and suggestions against Swine Flu:
- Govt. has introduced “trivalent seasonal flu vaccine” on all small and large govt. hospitals.
- Vaccination Program before travelling to the countries where swine flu is pandemic.
- A laboratory network has been established in Lahore, Karachi, Quetta, and Peshawar to sort out the problem of this virus.
- Apart from these strategies, there are certain suggestions that must be followed to cope with the problem of swine influenza.
- Govt. must play its role to aware people and to facilitate doctors with trainings and technologies.
- A specific amount must be fixed to import the vaccine stock against swine flu
- Media must play its role in awareness campaign against swine flu.
- Precautionary measures should be adopted at all international airports to check the passengers coming from infected countries.
Prevention from Swine Flu:
- Ensure washing of hands with soaps and water thoroughly and frequently
- Clean all the surfaces regularly
- Always carry tissues with you to cover your mouth and nose particularly during coughing or sneezing
- The person who has got the infection of swine flu should stay at home because he/she can transmit it to others within a duration of 24 hours
- Stay away from the crowd as much as possible particularly if you are less than 5 years old or more than 65 years old
- If someone has got the infection at home, he/she must minimize the exposure with households
- The patient of H1N1 must stay at home and should not go to school, college, university or on his/her job