Disease is most likely to occur in infants and young children who lack immunity to the strain of organism circulating and who subsequently acquire carriage of an invasive strain.By preventing susceptible contacts from acquiring infection by directly inhibiting colonization. Close contacts are defined as those persons who could have had intimate contact with the patients oral secretions such as through kissing or sharing of food or drink. The importance of the carrier state in meningococcal disease is well known. In developed countries the disease transmission usually occurs in day care, schools and large gatherings where usually disease transmission could occur. Because the meningococcal organism is transmitted by respiratory droplets and is susceptible to drying, it has been postulated that close contact is necessary for transmission. Therefore, the disease transmission to other susceptible person cannot be prevented. Meningitis occurs sporadically throughout the year, and since the organism has no known reservoir outside of man, asymptomatic carriers are usually the source of transmission.Additionally, basic hygiene measures, such as handwashing and not sharing drinking cups, can reduce the incidence of infection by limiting exposure. When a case is confirmed, all close contacts with the infected person can be offered antibiotics to reduce the likelihood of the infection spreading to other people. However, rifampin-resistant strains have been reported and the indiscriminate use of antibiotics contributes to this problem. Chemoprophylaxis is commonly used to those close contacts who are at highest risk of carrying the pathogenic strains.
When plant cells lose water they are hypotonic, because their inside is diluted(with more water) and the environment is concentrated so it needs water then the flexible cell membrane pulls away from the rigid cell wall, but remains joined to the cell wall at points called plasmodesmata. The cells often take on the appearance of a pincushion. In plant cells the terms isotonic, hypotonic and hypertonic cannot strictly be used accurately because the pressure exerted by the cell wall significantly affects the osmotic equilibrium point. Hypotonic solution
A hypotonic is when the concentration inside of the cell is lower than a solution outside of a cell is called hypotonic. If it has a lower concentration of solutes inside a cell then water is forced to move out. Due to this, water is removed out of the cell causing shrinking of the cell membrane. For cells without a cell wall such as animal cells, they lose water and shrivel. When plant cells are in a hypotonic solution, the central vacuole loses water and the cell membrane sticks against the cell wall. Isotonicity

A solution is isotonic when its effective osmole concentration is the same as that of another solution. In biology, the solutions on either side of a cell membrane are isotonic if the concentration of solutes outside the cell is equal to the concentration of solutes inside the cell. In this case the cell neither swells nor shrinks because there is no concentration gradient to induce the diffusion of large amounts of water across the cell membrane.