A 2010 study examining co-infection of influenza in co-housed ferret pairs found that the influenza increased both incidence and severity of pneumococcal infection. These findings exhibited pneumococcal strain dependence. A separate 2010 study examining intra-litter transmission, with influenza co-infection in infant mice, found that the influenza co-infection is a facilitator for pneumococcal susceptibility, transmission, and disease via bacterial shedding. A third study of note, from 2016, was able to examine pneumococcal transmission without co-infection of an URT infection. This study utilized intra-litter transmission in infant mice during bacterial mono-infection with pneumococcus. The results of this study indicated higher rates of shedding for infections in younger mice. These studies, along with the animal models that they utilize have enhanced our understanding of the transmission of pneumococcus. Inflammation induced by Influenza A Virus (IAV) stimulates the flow of mucus through the expression of glycoproteins, prompts secretion, and increases shedding. Streptococcus is found in the inflammation-generated mucus layers covering the URT and increased pneumococci are observed in nasal secretions with IAV co-infection. Levels of shedding have correlations with IAV induced URT inflammation. Pro-inflammatory effects are exhibited by the single pneumococcal toxin, pneumolysin (Ply); use of anti-Ply antibodies result in decreased inflammation. Studies have found transmissible levels of bacterium only in young mice, exhibiting that shedding increases with incidences of contact and proximity. Shedding is shown to decrease in the presence of agglutinating antibodies such as IgG and IgA1 unless cleavage occurs via an IgA1-specific pneumococcal protease.
Pneumococcal pneumonia is a type of bacterial pneumonia that is caused by Streptococcus pneumoniae (pneumococcus). It is the most common bacterial pneumonia found in adults, the most common type of community-acquired pneumonia, and one of the common types of pneumococcal infection. The estimated number of Americans with pneumococcal pneumonia is 900,000 annually, with almost 400,000 cases hospitalized and fatalities accounting for 5-7% of these cases. Symptoms
The symptoms of pneumococcal pneumonia can occur suddenly, presenting as a severe chill, followed by a severe fever, cough, shortness of breath, rapid breathing, and chest pains. Other symptoms like nausea, vomiting, headache, fatigue, and muscle aches could also accompany initial symptoms. The coughing can occasionally produce rusty or blood-streaked sputum. In 25% of cases, a parapneumonic effusion may occur. Chest X-rays will typically show lobar consolidation or patchy infiltrates. Treatment
In most cases, once pneumococcal pneumonia has been identified, doctors will prescribe antibiotics. These antibiotics usually help alleviate and eliminate symptoms between 12 and 36 hours after the initial dose. Despite most antibiotics effectiveness in treating the disease, sometimes the bacteria can resist the antibiotics, causing symptoms to worsen. Age and health of the infected patient can also contribute to the effectiveness of the antibiotics. A vaccine has been developed for the prevention of pneumococcal pneumonia, recommended to children under age five as well as adults over the age of 65.