Sin nombre virus particle. Coloured transmission electron micrograph (TEM) of a section through a sin nombre virus particle (virion). This virus is a type of hantavirus. It consists of a single-stranded RNA (ribonucleic acid) genome surrounded by a nucleocapsid and an envelope. Sin nombre causes hantavirus pulmonary syndrome (HPS), a potentially fatal disease that is contracted through the inhalation of infected mouse faeces. Symptoms can develop between one and five weeks after exposure and include fever, fatigue and muscle aches, sometimes accompanied by headaches and nausea. As the infection progresses respiratory symptoms appear, including coughing and shortness of breath.