The patient, identified only by a person in their 60s, was hospitalized with neuro-invasive illness, according to the city's Department of Health and Services.
"While the world is focused on COVID-19 prevention and response, this is an important reminder that we continue to see cases of West Nile Virus most years in Long Beach," said City Health Officer Dr. Anissa Davis in a statement. "We cannot let our guard down against mosquito-borne diseases."
The case is only the third human case reported so far this year in California. The first two cases were reported in Northern California's Stanislaus County in June.
No mosquitoes in #LongBeach have been found to be positive for WNV thus far this season. Here are some tips on how to prevent the spread of mosquito-borne diseases. ↓— City of Long Beach (@LongBeachCity) July 7, 2020
Report large amounts of mosquitoes by visiting https://t.co/ogNGOXWk6x. pic.twitter.com/DxtXOYmUrQ
Officials say no mosquitos in Long Beach have tested positive for West Nile so far this season.
Though most people who are infected show no symptoms, those that do can experience fever, body aches, nausea and vomiting. According to the department, one out of 150 people may develop brain inflammation or paralysis.
The virus is spread by the bite of an infected mosquito, and health officials warned residents to take preventative steps such as disposing of standing water that can attract the insects.
City News Service contributed to this report.