Symptoms of zoonotic swine flu in humans are similar to those of influenza and influenza-like illness and include chills, fever, sore throat, muscle pains, severe headache, coughing, weakness, shortness of breath, and general discomfort.

[13] According to the United States Centers for Disease Control and Prevention (CDC), in humans the symptoms of the 2009 "swine flu" H1N1 virus are similar to influenza and influenza-like illness.

"[16] A diagnosis of confirmed swine flu requires laboratory testing of a respiratory sample (a simple nose and throat swab).

[22] People who work with poultry and swine, especially those with intense exposures, are at increased risk of zoonotic infection with influenza virus endemic in these animals, and constitute a population of human hosts in which zoonosis and reassortment can co-occur.

[25] This study, among others, forms the basis of a recommendation that people whose jobs involve handling poultry and swine be the focus of increased public health surveillance.

The antiviral drugs Relenza and Tamiflu target NA by inhibiting neuraminidase and preventing the release of viruses from host cells.

[41] In August 2012, the Center for Disease Control and Prevention confirmed 145 human cases (113 in Indiana, 30 in Ohio, one in Hawaii and one in Illinois) of H3N2v since July 2012.

Because much of the illness and death associated with swine flu involves secondary infection by other pathogens, control strategies that rely on vaccination may be insufficient.

[54] The CDC warned against touching mucosal membranes such as the eyes, nose, or mouth during the 2009 H1N1 pandemic, as these are common entry points for flu viruses.

[58] Influenza can spread in coughs or sneezes, but an increasing body of evidence shows small droplets containing the virus can linger on tabletops, telephones, and other surfaces and be transferred via the fingers to the eyes, nose, or mouth.

Anyone with flu-like symptoms, such as a sudden fever, cough, or muscle aches, should stay away from work or public transportation and should contact a doctor for advice.

During active outbreaks, avoiding large gatherings, increasing physical distance in public places, or if possible remaining at home as much as is feasible can prevent further spread of disease.

[60] Studies by the National Institutes of Health show a single dose creates enough antibodies to protect against the virus within about 10 days.

Antibiotics are also used to treat the disease, which, although they have no effect against the influenza virus, do help prevent bacterial pneumonia and other secondary infections in influenza-weakened herds.

Vaccination of sows is common practice and reveals also a benefit to young pigs by prolonging the maternally level of antibodies.

Beside antivirals, supportive care at home or in a hospital focuses on controlling fevers, relieving pain and maintaining fluid balance, as well as identifying and treating any secondary infections or other medical problems.

Moreover, the ensuing increased surveillance uncovered another strain in circulation in the U.S.: A/Victoria/75 (H3N2), which spread simultaneously, also caused illness, and persisted until March.

[80] Alarmed public health officials decided action must be taken to head off another major pandemic, and urged President Gerald Ford that every person in the U.S. be vaccinated for the disease.

[83] There were reports of Guillain–Barré syndrome (GBS), a paralyzing neuromuscular disorder, affecting some people who had received swine flu immunizations.

This outbreak confirmed that pigs can serve as a crucible where novel influenza viruses emerge as a result of the reassortment of genes from different strains.

[98][99][100][101][102] On August 20, 2007, Department of Agriculture officers investigated the outbreak of swine flu in Nueva Ecija and central Luzon, Philippines.

On July 27, 2007, the Philippine National Meat Inspection Service (NMIS) raised a hog cholera "red alert" warning over Metro Manila and five regions of Luzon after the disease spread to backyard pig farms in Bulacan and Pampanga, even if they tested negative for the swine flu virus.

This closely corresponds to the 19 patients who had died in the year prior due to swine flu, where 18 of the 19 were determined to have lowered immune systems.

[114] As of 22 April 2015 the Nepal Ministry of Health reported that 2,498 people had been treated in Jajarkot, of whom 552 were believed to have swine flu, and acknowledged that the government's response had been inadequate.

[citation needed] Seven cases of swine flu were reported in Punjab province of Pakistan, mainly in the city of Multan, in January 2017.

[116] As of March 16, 2017, over a hundred confirmed cases of swine flu and at least six deaths were reported in the Maldivian capital of Malé and some other islands.

[118] An official visit by Saudi King Salman bin Abdulaziz Al Saud to the Maldives during his Asian tour was also cancelled last minute amidst fears over the outbreak of swine flu.

[119] A peer-reviewed paper from the Proceedings of the National Academy of Sciences (PNAS) stated that "G4 EA H1N1 viruses possess all the essential hallmarks of being highly adapted to infect humans ...

Controlling the prevailing G4 EA H1N1 viruses in pigs and close monitoring of swine working populations should be promptly implemented.

[123] Between 2016 and 2018, a serum surveillance program screened 338 swine production workers in China for exposure (presence of antibodies) to G4 EA H1N1 and found 35 (10.4%) positive.