The Covid-19 pandemic necessitated transmission prevention measures like hand washing, mask-wearing and social distancing. These measures have typically decreased the transmission of infectious diseases, such as the sexually transmitted disease (STD) chlamydia. This has not, however, been the case with syphilis.
The 2020 Sexually Transmitted Disease Surveillance document, recently published by the US Centres for Disease Control and Prevention (CDC), illustrates the impact of the Covid-19 pandemic on common STDs such as chlamydia, gonorrhoea and syphilis. Despite Covid-19 and its associated measures of disease prevention, syphilis case counts in the US increased from 2019 to 2020, and the trend continued into last year. GlobalData epidemiologists anticipate a continued increase in cases in the US, unless major public health measures are imposed.
Syphilis is caused by the spirochete Treponema pallidum and spread by either sexual contact or from mother to baby (congenital). Case counts in the US declined dramatically after the institution of penicillin treatment in the 1940s and 1950s, but are now increasing again. According to GlobalData epidemiologists, nearly 100,000 diagnosed incident cases of syphilis were forecast for 2020, but recent data suggest that these estimates have been surpassed.
The CDC STD 2020 Surveillance found that there were 133,945 diagnosed incident cases of syphilis in the US in 2020, a 3.3% increase from 2019. This was primarily driven by increases in primary and secondary syphilis in women (20.5%) and men (4.0%). Case rates were lower in April–July 2020 than in the same months of 2019, but by August 2020, cases had surpassed those of 2019 and the trend continued almost uninterrupted until December.
The increasing burden of syphilis in women is resulting in the rise of congenital syphilis. At 2,138 reported cases, congenital syphilis cases rose by 14.6% from 2019 to 2020, while cases among women aged 15–44 years rose by 24.1%. This surge is part of a trend: from 2011 to 2020, congenital syphilis cases increased by 500% according to the CDC. Infant deaths and stillbirths attributed to congenital syphilis rose from 130 in 2019 to 149 in 2020, while cases of symptomatic syphilis in infants rose from 711 in 2019 to 791 in 2020.
This rise of congenital syphilis is due in large part to a lack of prenatal screening. An increasing number of women in the US do not receive adequate prenatal care, and this issue has been exacerbated by disruptions to testing and treatment stemming from the Covid-19 pandemic.
Preliminary data from the CDC indicate that this trend of increased cases will continue. Cases of primary and secondary syphilis rose by 36.2% in women and 8.7% in men from 2020 to 2021. Data from March this year found there were 2,268 reported cases of congenital syphilis in 2021, surpassing 2020 case counts. This has resulted in 166 infant deaths and stillbirths attributed to congenital syphilis.
Major public health efforts must be undertaken to stay this increase. Educational programmes must be employed, emphasising condom usage and other safer sex practices. Increased access to STD screens, treatments and barrier protection may also aid in reducing transmission.