Nontuberculous mycobacteria (NTM), also known as environmental mycobacteria, atypical mycobacteria and mycobacteria other than tuberculosis (MOTT), are mycobacteria which do not cause tuberculosis or leprosy (also known as Hansens disease). NTM do cause pulmonary diseases that resemble tuberculosis. Mycobacteriosis is any of these illnesses, usually meant to exclude tuberculosis. They occur in many animals, including humans and are commonly found in soil and water. Introduction
Mycobacteria are a family of small, rod-shaped bacilli that can be classified into three main groups for the purpose of diagnosis and treatment:

Mycobacterium tuberculosis complex, which can cause tuberculosis: M. tuberculosis, M. bovis, M. africanum, M. microti and M. canetti
M. leprae and M. lepromatosis,  which cause Hansens disease, also called leprosy
Nontuberculous mycobacteria (NTM) are all the other mycobacteria that can cause pulmonary disease resembling tuberculosis, lymphadenitis, skin disease, or disseminated disease. Although over 150 different species of NTM have been described, pulmonary infections are most commonly due to Mycobacterium avium complex (MAC), Mycobacterium kansasii, and Mycobacterium abscessus (see image). Taxonomy
In 1959, botanist Ernest Runyon put these human disease-associated bacteria into four groups (Runyon classification):
Photochromogens develop pigments in or after being exposed to light. Examples include M. kansasii, M. simiae, and M. marinum. Scotochromogens become pigmented in darkness. Examples include M. scrofulaceum and M. szulgai. Nonchromogens include a group of prevalent opportunistic pathogens called M. avium complex (MAC). Other examples are M. ulcerans, M. xenopi, M. malmoense, M. terrae, M. haemophilum, and M. genavense.
The first practical use of fractional dose yellow fever vaccination was in response to a large yellow fever outbreak in the Democratic Republic of the Congo in mid-2016.In March 2017, the WHO launched a vaccination campaign in Brazil with 3.5 million doses from an emergency stockpile. In March 2017 the WHO recommended vaccination for travellers to certain parts of Brazil. In March 2018, Brazil shifted its policy and announced it planned to vaccinate all 77.5 million currently unvaccinated citizens by April 2019. Compulsory vaccination
Some countries in Asia are considered to be potentially in danger of yellow fever epidemics, as both mosquitoes with the capability to transmit yellow fever as well as susceptible monkeys are present. The disease does not yet occur in Asia. To prevent introduction of the virus, some countries demand previous vaccination of foreign visitors who have passed through yellow fever areas. Vaccination has to be proved by a vaccination certificate, which is valid 10 days after the vaccination and lasts for 10 years. Although the WHO on 17 May 2013 advised that subsequent booster vaccinations are unnecessary, an older (than 10 years) certificate may not be acceptable at all border posts in all affected countries. A list of the countries that require yellow fever vaccination is published by the WHO. If the vaccination cannot be given for some reason, dispensation may be possible. In this case, an exemption certificate issued by a WHO-approved vaccination center is required.