Vulvitis and vaginitis is defined as a spectrum of conditions that cause vulval and/or vaginal symptoms. Candida is the most common cause of vulvovaginal complaints for which women seek medical advice, especially during pregnancy.

Vulvovaginal candidiasis (VVC) is an opportunistic mucosal mycosis, and one of the most common causes of vulvovaginal itching and discharge caused by Candida species (C. albicans, C. glabrata. C. krusei, C. parapsilosis and C. tropicalis).

Candida albicans causes 80–90 per cent of vaginal fungal infection.

Ten to twenty per cent of reproductive-age women who harbour Candida species are asymptomatic and do not require therapy.

Vaginal candidiasis, commonly called ‘yeast infection, or moniliasis’, is relatively common during pregnancy (especially during the second trimester). with an estimated prevalence of 10–75 per cent.

Approximately 75 per cent of all pregnant women experience at least one episode of VVC during their lifetime, and 50 per cent of them suffer recurrent events.

Viruses are small, non-living parasites, which cannot replicate outside a host cell.

Viruses are grouped according to their genetic material: DNA or RNA.

DNA viruses are mostly double-stranded while RNA viruses are single-stranded.

A virus injects its genetic information into a host cell and then takes control of the cell’s machinery. This process enables the virus to make copies of its DNA or RNA and make the viral proteins inside the host cell. A virus can quickly make multiple copies of itself in one cell, release these copies to infect new host cells and make even more copies. In this way, a virus can replicate very quickly inside a host.

The World Health Organization defines puerperal sepsis as ‘infection of the genital tract occurring at any time between the onset of the rupture of membranes or labor and the 42nd day postpartum’.

Sepsis in the puerperium is still an important cause of maternal morbidity and mortality.

In the UK, according to the 2012–14 maternal mortality report, it accounts for 10 deaths per year.

Globally, puerperal sepsis is a major cause of maternal death and accounts for 15 per cent of all maternal deaths in developing countries. It is also a major cause of morbidity (long-term health problems, e.g. chronic pelvic pain, chronic pelvic inflammatory disease (PID) and infertility.

Severe sepsis with acute organ dysfunction has a mortality rate of 20–40 per cent, rising to around 60 per cent if septicaemic shock develops.

In the UK, 2012–14 maternal mortality report, direct sepsis (genital tract sepsis and other pregnancy-related infections) and indirect sepsis (influenza, pneumonia, others) accounted for seven maternal deaths, being the second cause of maternal mortality after cardiac disease.

In the general population, Listeria infection is relatively uncommon, with a prevalence of approximately 4 per million in Canada, 0.27 per million in the USA and between 0.1 and 11.3 per million population in different parts of Europe.

Pregnant women have a 12- to 18-fold increased risk in pregnancy (12/100 000), compared with the non-pregnant population.

Out of all infections with Listeria, 16–27 per cent occur in pregnant women.

The exact cause of its higher prevalence in pregnancy is not known. Immunosuppression associated with pregnancy results in suppression of cell-mediated immunity in the placenta, due to high concentration of maternal hormones and other unknown mechanisms.

Approximately 20 per cent of Listeria infections involve neonatal infection with potentially severe complications, therefore it is important to stop the outbreaks in pregnant woman and the unwanted consequences for their unborn fetuses.

Chlamydia trachomatis genitourinary infection is a sexually transmitted infection affecting the uterus, the salpinges, the cervix, the urethra and the epididymis.

The infection is the most commonly reported bacterial sexually transmitted disease (STD) in the United States and a leading cause of infertility in women.

It can cause several sequelae, including chronic pelvic pain, pelvic inflammatory disease (PID) and tubal factor infertility.

Chlamydia trachomatis is commonly diagnosed in pregnancy. It has been linked to several pregnancy complications (premature rupture of membranes (PROM), preterm labour and birth, low birthweight, intrauterine growth retardation and postpartum endometritis).

In infected pregnant women, infants are at risk for acquiring C. trachomatis pneumonitis, conjunctivitis and nasopharyngeal infection.

Influenza is a contagious viral respiratory illness caused by influenza viruses that infects the nose, throat and sometimes the lungs. It can cause mild to severe illness, and at times can lead to significant morbidity and mortality.

Vaccination is one of the most cost-effective successful public health interventions. Maternal vaccination protects both mother and baby from the morbidity of certain preventable diseases.

Antibiotics are a group of medicines used for treating infections caused by bacteria and certain parasites but are not effective against viral or fungal infection.

They are also called antibacterial or antimicrobials and work by killing the organisms or stopping them from multiplying.

Antibiotics are commonly prescribed during pregnancy; however, the specific medication must be chosen carefully as most antibiotics might be safe while some are not.

Safety depends on various factors, including the type of antibiotic, gestational age, dose and duration of the use of the antibiotics.

They are usually grouped together based on mode of action as each only works against certain types of organisms; therefore, different antibiotics are used for different infections.

Dengue fever is a mosquito-transmitted viral infection. It is common in most tropical and subtropical countries.

Approximately 390 million dengue virus infections occur each year, of which 500 000 require hospitalisation.

The Aedes aegypti mosquito is the primary host of dengue.

The virus is transmitted to humans through the bites of infected female mosquitoes of the species Aedes aegypti. This vector can also transmit other infections (chikungunya, yellow fever and Zika infection).

The virus has an incubation period of 4–10 days.

An infected mosquito can transmit the virus for the rest of its life.

Severe dengue (also known as dengue haemorrhagic fever) was first recognised in the 1950s during dengue epidemics in the Philippines and Thailand.

Today, severe dengue is one of the leading causes of hospitalisation and death among children and adults in these regions.

There are four distinct, closely related, serotypes of the virus that cause dengue (DEN-1, DEN-2, DEN-3 and DEN-4). Recovery from infection by one provides lifelong immunity against that particular serotype. Cross-immunity to the other serotypes after recovery is only partial and temporary.

Further infections by other serotypes increase the risk of developing severe dengue.

Ebola virus disease (EVD) was first recognised in 1976, when there was an outbreak of viral haemorrhagic fever near the Ebola River in Zaire (now the Democratic Republic of the Congo (DRC)) with multiple subsequent outbreaks confined to sub-Saharan Africa and spread to Europe and the USA by human transportation.

Ebola disease is rare but causes severe viral haemorrhagic disease.

EVD is a filovirus infection, thought to be transmitted to humans from an unknown animal reservoir. Bats or non-human primates are suggested to be the most likely species involved in the occurrence of sporadic human outbreaks.

There are five identified species of EVD. Zaire ebolavirus is the most lethal strain.

Animal-to-human transmission is thought to be through the wild animal meat consumption. Human-to-human transmission is through mucosal contact with infected body fluids.

Incubation period is up to 21 days (median five to nine days).

Molluscum contagiosum (MC) is a benign, skin infection.

It presents as pearly dome‐shaped papules, with a central dell or depression. It is caused by the molluscum contagiosum virus (MCV) which is the most common poxvirus to infect humans.

Poxviruses are brick-shaped (240 nm by 300 nm) and have a complex internal structure including a double-stranded DNA genome (130–260 kb) and associated enzymes.

Poxvirus infections are characterised by the production of skin lesions. Smallpox, a poxvirus with serious consequences, has been eradicated since 1980.

Varicella or chickenpox is not the same group as the smallpox and other poxviruses. The virus has three genotypes, but the MCV genotype 1 is responsible for 98 per cent of cases of MC in the United States. The genotype MCV 2 is responsible for sexually transmitted MC, and consequently is not detected in children prior to sexual debut. Genotype 3 is also associated with congenital infection.

The genotype MCV 2 has been detected in vaginal lesion specimens.