Potential and Demonstrated Impacts of the COVID-19 Pandemic on Sexually Transmissible Infections

Olaitan T. Ogunbodede; Iryna Zablotska-Manos; David A. Lewis


Curr Opin Infect Dis. 2021;34(1):56-61. 

In This Article

Abstract and Introduction


Purpose of Review: This review considers the potential and demonstrated impacts of SARS-CoV-2 on the sexually transmissible infection (STI)/HIV transmission.

Recent Findings: COVID-19 increases the vulnerability of those at highest risk of acquiring STI/HIV. Altered health-seeking behaviour, reductions in STI/HIV clinic capacity, service disruptions and redeployment of human resources to assist COVID-19 control efforts have impacted on STI/HIV control programmes. Reports of reduced STI incidence are emerging, but it is hard to determine whether this is real or due to decreased testing during COVID-19 lockdown periods. Fear of COVID-19 and implemented control measures have altered STI/HIV transmission dynamics. Sexual health services adapted to the pandemic by reducing face-to-face patient encounters in favour of telehealth and mail-based initiatives as well as more stringent triage practice. Many sexual health and HIV treatment services now operate at reduced capacity and experience ongoing service disruptions, which necessarily translates into poorer outcomes for patients and their communities.

Summary: In the short-term, COVID-19 related sexual behaviour change is driving STI/HIV transmission downwards. However, the impacts of the global COVID-19 response on sexual health-seeking behaviour and STI/HIV services threaten to drive STI/HIV transmission upwards. Ultimately, the expected rebound in STI/HIV incidence will require an appropriate and timely public health response.

Video Abstract: https://links.lww.com/COID/A31.


The emergence of a novel coronavirus, termed severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), in late 2019 has caused a pandemic of unprecedented proportions.[1] The global threat of untreatable Coronavirus Disease 2019 (COVID-19) has changed the world as we know it, with substantial impacts on population health, national economies and human behaviour as a result of COVID-19 related restrictions. Some suggest that second waves of the COVID-19 pandemic may be more widespread and severe, with greater impact on health economies, clinical services and individuals' behaviour and health-seeking choices.[2] The postpandemic outcome could be continued seasonal COVID-19 resurgences, with the global impact hopefully minimised through annual vaccination against SARS-CoV-2 infection.

Although the negative effect of COVID-19 on intimate partner violence and mental health has been well described, minimal attention has been paid to its impact on sexual health. Sexually transmissible infections (STIs), including HIV infection, continue to generate substantial morbidity, as well as mortality, on a worldwide scale. If left untreated, these highly prevalent infections result in reproductive tract sequelae, adverse pregnancy outcomes, neonatal infections and enhanced HIV acquisition and onward transmission.

The purpose of this review is to consider the potential and demonstrated impacts of SARS-CoV-2 on the transmission of STIs, including HIV. The review will highlight key impacts on service delivery and service utilization by those at highest risk of these infections.

Impact of COVID-19 on Sexually Transmissble Infection Incidence

Substantial effects of COVID-19 on STI incidence are expected given that sexual networks and relationships within communities have been disrupted due to fear of acquiring SARS-CoV-2 and the strategies implemented to control its transmission. The impact on incidence may vary depending on how tough the restrictions are, how long they last and whether sexual behaviour will change once restrictions are lifted. Some have suggested that we could witness a decline in the incidence of infectious bacterial STIs, such as syphilis, chlamydia or gonorrhoea, as well as blood-borne viruses due to reduced opportunities to have sex and, for some, reduced use of recreational drugs to enhance sexual activity ('chemsex' and 'slamsex') during periods of lockdown.[3–6]

On the contrary, the COVID-19 pandemic has increased the vulnerability of those at higher risk of STI/HIV acquisition; examples include MSM, sex workers, migrant domestic workers, prisoners, refugees and youth. Many of these individuals now face additional COVID-19 associated challenges, such as a heightened risk of sex-based violence and rape, loss of income and reduced access to trusted sexual and reproductive health (SRH) services.[7–10]

To date, few publications exist that describe trends in STI incidence during the COVID-19 pandemic. One such early report describes the reconfiguration of services in Milan's two main Sexual Health clinics.[11] When the lockdown restrictions began in March 2020, only symptomatic patients or those asymptomatic patients at a higher risk of STIs were allowed 'walk-in' access to the clinics' services. Cusini et al.[11] reported on trends for specific STIs by comparing identical 1-month time periods in 2019 and 2020. Although a decline in nonacute cases was observed in 2020, the number of acute bacterial STIs in MSM increased, particularly chlamydial infections. This led the authors to conclude that acute STIs were not affected by COVID-19 control strategies. However, elsewhere in Italy, Latini et al.[12] reported a reduction in STI diagnoses, particularly early syphilis, among patients attending STI/HIV services in Rome at the time that lockdown measures were introduced across the country.

Despite the scarcity of scientific publications or surveillance reports in the public domain, there have been several mainstream media reports of declines in STI case numbers.[13,14] For example, in Australia, a reduction in STI case numbers was reported for the first half of 2020.[13] Anecdotal reports of large reductions in the number of both new STI and HIV diagnoses have also been reported in the UK, presenting what sexual health advocates have called a 'once in a lifetime opportunity' for reducing STI/HIV transmission.[14] In the USA, members of the STI control workforce expressed their concerns that STI rates will increase as a result of people's inability to get tested or treated. They also highlighted the redeployment of skilled contact tracers from positions within STI/HIV services to support local COVID-19 public health responses.[15]

The interpretation of these data is fraught with challenges, as it is very difficult to determine whether any observed reduction in case numbers is indicative of a real decrease in incidence or whether this simply reflects a decrease in STI testing, either as a result of reduced access to services or changes in patients' health-seeking behaviours in the COVID-19 era.

Impact of the COVID-19 Pandemic on the Transmission Dynamics of Sexually Transmssble Infections

The reproductive rate concept, first described by Anderson and May, is governed by three key factors, namely pathogen transmissibility, the rate of sexual partner exchange and the duration of infectiousness.[16] Whereas transmissibility is an inherent biological property of each STI pathogen, the remaining two factors are easily modulated by changes in an individual's sexual or health-seeking behaviour as well as health service activities. The impact of the COVID-19 pandemic on both the rate of sexual partner exchange and the duration of infectiousness is described in more detail in the following section.

Impact of COVID-19 on the Rate of Sexual Partner Exchange

Prolonged lockdown measures, in operation in many countries, have restricted opportunities for people to meet new sexual partners.[17] Unanticipated job losses, particularly affecting young adults, compounded by closure of restaurants and bars, have also resulted in social isolation. Population movement restrictions, enforced in many countries through border closures and quarantine requirements, have also dramatically reduced travel for sexual encounters and therefore opportunities for mixing of populations with different STI/HIV prevalence. Finally, the closure of brothels and sex-on-premises venues during the peak of lockdown have limited opportunities for individuals to engage in recreational sexual activities.

By the same token, widespread lockdowns have increased the time cohabiting couples spend with each other. Although some studies report increased sexual activity within established co-habiting partnerships, others cite unsatisfying partner relationships and low sexual desires.[18,19] It has also been reported that the types of sexual activities being practiced by at risk individuals are generally safer during the lockdown, with fewer individuals engaging in condomless sex and fewer presentations to sexual health services for HIV postexposure prophylaxis.[5,20] COVID-19-related 'safe sex' practice guidance has emphasized the SARS-CoV-2 transmission risks associated with touching, kissing and direct personal contact.[21,22] As a response to personal safety concerns, there are emerging reports of increased internet use as a means of achieving sexual satisfaction through both webcam and phone sex, which may be accompanied by use of recreational drugs to enhance sexual experience 'digital chemsex'.[6,17]

Interestingly, it has also been suggested that SARS-CoV-2 infection itself may also produce immunological, psychological or systemic effects on sexual drive, libido and sexual intercourse frequency.[23] Although this concept is plausible, robust supportive data are lacking. It is known that angiotensin-converting enzyme II, which serves as an entry receptor for SARS-CoV-2 to infect lung alveolar epithelial cells, is also a constitutive product of adult-type Leydig cells.[24–26] It is therefore theoretically possible that testosterone secretion could be reduced during COVID-19 infections, which may impact on sexual function.[26]

Furthermore, the observation that SARS-CoV-2 has been detected in the semen of patients with COVID-19, as well as those recovering from the infection, raises the question as to whether or not SARS-CoV-2 may eventually be declared an STI in its own right.[27] Further studies are required to increase our understanding of viral persistence in semen and the likelihood of sexual transmissibility.[27] Given the phenomenon of 'serosorting' observed earlier in the HIV epidemic, it is interesting to speculate as to whether individuals might choose to select new sexual partners based either on a history of past SARS-CoV-2 infection or, when an efficacious vaccine becomes available, prior vaccination against COVID-19.[28,29]

Impact of COVID-19 on the Duration of Infectiousness

The duration of infectiousness is dependent upon the time it takes for an infected individual to receive effective therapy for their STI. During the COVID-19 pandemic, this entity has been impacted by changes in patients' health-seeking behaviour, the accessibility and availability of testing and treating service(s) as well as revised turn-around-times for laboratory-based STI diagnostic testing.

Pathway models of health-seeking behaviour assume that individuals employ cost-benefit principles to determine the best course of action; in doing so, they rely on a logical sequence of steps starting with perception and/or self-evaluation of their symptoms.[30] In a COVID-19 era characterized by fear of contagion, individuals may no longer see the benefit of travelling to and attending sexual health services, particularly if they are asymptomatic and sexual activity has decreased during times of lockdown. Several key cultural, social, economic, geographical and organizational determinants may influence individuals' decision to engage with sexual health services.[30] Determinants impacting on health-seeking behaviour during the COVID-19 pandemic include cultural and age perceptions of risk, individuals' current state of health and financial concerns related to cost of travel or care, made worse for many by COVID-19 related job losses.

The deficiencies in the healthcare systems of many nations have been exposed and exacerbated by the COVID-19 pandemic. There is no doubt that we could be facing a major challenge in the management and control of STIs, including HIV, in most low and middle-income countries (LMICs) as a result of pressures on the existing workforce and competition for scarce resources.[31] Basic service provision including contraceptive counselling, reproductive health services and STI/HIV management are now threatened by the health system demands of COVID-19 related care. The WHO recently undertook a survey of relevant policies, drug stocks, service disruptions to treatment, testing and prevention and country responses in order to assess the degree of disruption to HIV, hepatitis and sexual health services during the COVID-19 pandemic.[32] Data for the period April to June 2020 were obtained for 144 countries, although only limited data were received in respect of sexual health service provision. STI service disruption was reported in nine countries and a few countries reported possible stock-outs of syphilis rapid diagnostic testing kits (Ethiopia, Uganda) and STI drugs (Madagascar, Papua New Guinea, Uganda). In addition, service disruptions were reported for HIV testing (38 countries), key population services (17 countries), condom provision (12 countries) and supply of HIV preexposure prophylaxis (PrEP) (seven countries).[32]

The impact of COVID-19 on sexual health service provision is not limited to resource poor countries. The British Association for Sexual Health and HIV circulated a survey to members in April 2020 to provide a snapshot as to how the UK's COVID-19 situation was affecting the capacity and ability of sexual health services to provide clinical care.[33] Analysis of responses from 196 respondents indicated that more than half of local clinics had closed completely and capacity for face-to-face consultations was substantially reduced. Services had adapted through expansion of telehealth on-line and phone services, use of phone triage to restrict in-person attendance, closure of smaller services and continued service provision from larger hub clinics, as well as increased mail-based delivery of STI/HIV home-testing kits and prescriptions to patients.

Changes in the way sexual health services are delivered have anecdotally occurred in other countries. At the authors' own clinic in Sydney, for example, walk-in patients were restricted to only the most urgent cases; other patients were triaged and offered appointments only if they were symptomatic or met the priority population criteria for free HIV/STI screening within publicly-funded sexual health services in New South Wales. Patients receiving HIV PrEP were mailed their prescriptions and advised to wait for 6 months (rather than the usual 3 months) for repeat HIV/STI screening. In addition, outreach STI/HIV screening activities ceased due to a combination of staff safety concerns as well as the impact of COVID-19 lockdown measures which forced temporary closure of sex-on-premises venues and massage parlours.

Delays in undertaking HIV/STI testing can also extend the duration of infectiousness of patients and thereby facilitate increased community STI/HIV transmission. During the COVID-19 pandemic, many laboratories have had to re-deploy staff away from routine diagnostic duties in order to run manually intensive molecular and serological screening assays for SARS-CoV-2. In addition, reduction in air travel and lockdown measures have impacted on the availability of reagents and kits for both laboratory and point-of-care testing.[32] For some facilities, this has resulted in longer turn-around-times for routine STI testing, and in some cases, temporary cessation of some molecular STI diagnostic assays (Lewis DA, personal communication).

Impact of the COVID-19 Pandemic on the HIV Epidemic

The impact of the COVID-19 pandemic on previous global gains in HIV treatment and prevention cannot be underestimated. A recent WHO survey has highlighted COVID-19 related service disruptions in the provision of antiretroviral therapy in 36 countries; these countries provide antiretroviral therapy to 11.5 million people living with HIV (PLHIV), which represents 45% of all PLHIV on treatment.[32] In addition, 73 countries reported being at risk of antiretroviral supply disruptions; 24 of these, with 8.3 million PLHIV (33% of all PLHIV on treatment), subsequently experienced actual disruptions with critically low stock levels. In order to mitigate the impact of service disruptions, most countries have adopted a policy of 3 or 6-monthly dispensing of antiretrovirals.[32]

Another survey, conducted through an on-line social networking application and which gathered responses from over 10 000 MSM across 20 countries, demonstrated that the most stringent government responses to COVID-19 were associated with decreased access to HIV testing, prevention and treatment services.[34] For those respondents living with HIV, approximately 20% reported being unable to access their healthcare provider via face-to-face or telehealth appointments and 65% were unable to obtain prescriptions remotely.

A WHO and UNAIDS convened modelling group utilized five well described models of HIV epidemics to estimate the effect of disruptions to HIV treatment and prevention services on HIV-related deaths and new infections in sub-Saharan Africa.[35] Their modelling predicts that a 6-month disruption to antiretroviral drug supply, compared with no disruption, could lead to more than 500 000 extra deaths from AIDS-related illnesses in the region over a 1-year period. This represents an approximate two-fold increase in death overall (range 1.87 to 2.80-fold across models). Their data also predict an approximate doubling in the number of new HIV infections among children. Although cognoscente that social distancing measures might reduce HIV transmission rates, the Group still predicted disruptive COVID-19 related impacts on HIV transmission at the population level, due to reduced access to HIV testing, condoms and peer education.[35]