For the mother of a three-year-old-girl studying at a school in Bengaluru's Indira Nagar, Monday turned out to be the worst nightmare in her life. When she picked up her child on Monday afternoon, the child was crying inconsolably and complained of pain in her private parts. The mother noticed swelling in the region and with her husband, registered a complaint at the Indiranagar police station stating that their three-year-old daughter was sexually assaulted in the school premises.The Bengaluru police on Tuesday arrested the culprit involved in the sexual assault of a three-year-old girl studying at a school in Indiranagar. The man in his twenties, hailing from Kokata was identified by the child, according to the police.The accused has been booked under different sections of the Protection of Children from Sexual Offences (POCSO) Act. In this case, the mother suspected sexual assault immediately as the child was injured to an extent. Compare this to the case of a six-year-old who had been raped at her school in the city in July 2014. Her parents discovered about the assault almost a week after the incident had taken place when the child complained of stomach ache and they then registered a complaint. How do parents know if their child has been sexually assaulted? Is it necessary that a child, when sexually assaulted, will bear physical marks or injuries on his/her body?Parents need to understand that a child who has been physically assaulted or even raped, may not bear any physical signs of injury.Speaking to The News Minute, forensic medicine professor in Vydehi Medical College, Bengaluru, Dr Jagdish Reddy said that in cases of child sexual abuse (CSA), even two-thirds of penetrative acts bear no physical signs of injury or trauma.Also depending on how the culprit misleads or coaxes the child before or after abusing, the child may not even know that he/she was sexually abused. In cases of incest, it has been noted that the relative often make the child believe it is a game or a gift.Children are also prone to infections resulting from such assaults. Infections, which may include sexually transmitted diseases, can be seen in such cases after some days or weeks, depending on the type of infection."Physical injuries also depend on what perpetrators use during the act. At times, abusers use lubricants and protection due to which there may be an absence of physical injury. Sometimes they may also clean up the children," stated Dr Reddy.He further explained that in cases of CSA, it is difficult to collect immediate trace evidence. This means that proving a case of a sexual assault becomes all the more difficult. However, changes to laws have made it possible for culprits to be convicted even when there is no medical proof of violence.There are several reasons due to which cases of child sexual abuse go unreported or are reported very late as parents may not realise their child has been abused due to lack of physical injuries.Of all cases of CSA, just 33 per cent have some form of physical injuries, said Dr Shaibya Saldanha, co-founder of Enfold Trust. This could be why most parents are unaware of symptoms of sexual abuse."People feel that home and school are the safest place for their children. They entrust their children with others. By the time many parents realise that their child has been sexually abused, they are too shocked to react in a coherent manner. They approach the doctor, and then talk to close friends and relatives before deciding on taking the next logical step."," asserted Saldanha.With studies proving that many children may not bear any injury marks, how can parents ensure that they get to know if the child has been assaulted or someone has been misbehaving with the child?"Constant dialogue with the child, that's the only solution. Make your child talk to you," says Dr Saldanha.Experts point out that if a child does confide about sexual harassment, parents should not discard the child's version, in the absence of physical injuries.A study titled Behind the Net: Technology and the Forensic Interview by Ribert Giles, 2012, on National District Attorney’s Association website reads, "Further affecting the view of jurors in child abuse cases is the belief that sexual assault will produce either medical injury or scientific evidence. In the vast majority of cases where there is credible evidence that a child has been penetrated, only between 5 and 15 percent of those children will have genital injuries consistent with sexual abuse."Also read- Peadophile FB pages that use innocent kids' pictures: Why you should not stop at just blocking or reporting such pages. What activities constitute child sexual abuse?According to Medline Plus, a service of the US National Library of Science, "Child sexual abuse is the deliberate exposure of minor children to sexual activity. This means a child is forced or talked into sex or sexual activities by another person." Such abuse includes:Oral sexPornographySexual intercourseTouching (fondling)According to the National Crime Records Bureau (NCRB), 12,363 child rape cases were recorded in 2013 in India.(A version of this story was earlier published on The News Minute on July 19, 2014.)