Tuesday 31 July 2018

NUCLEIC-ACID AMPLIFICATION TESTS

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NUCLEIC-ACID AMPLIFICATION TESTS

Nucleic-acid amplification tests, also known as NATs or NAATs, are used to identify small amounts of DNA or RNA in test samples. When it comes to STD testing, there are NATs available that can detect a variety of different STDs. In fact, most urine tests for STDs are performed using nucleic-acid amplification tests.


MECHANISM

A NAT uses a series of repeated chemical reactions to make numerous copies of the DNA or RNA that doctors are trying to detect. These reactions amplify the signal of the nucleic acids in the test sample so that they are easier to identify. It's much simpler to find 10,000 copies of a gene than 10. 
once the amount of DNA or RNA has been increased in the sample using PCR or LCR, more conventional tests are used to detect it. These tests usually involve some form of nucleic acid hybridization. In those tests, the sample is probed with an artificially produced complementary strand of DNA or RNA that has been labelled in some way that makes it easy to detect. It may help to picture it as a glow in the dark tag that only sticks to one very specific piece of identifying information.

STD TESTING

Nucleic-acid amplification tests are incredibly useful for STD testing. They allow doctors to detect an STD pathogen even when only a very small number of organisms are present. It is this sort of technology that has made it possible to do urine testing for STDs that were previously only detectable by swab.

Furthermore, since nucleic-acid amplification tests are incredibly sensitive to even small amounts of viral DNA, they are very important for screening the blood supply. These tests make it possible to detect tiny amounts of HIV and other blood-borne pathogens that might otherwise be missed.

There are also non-amplified nucleic acid tests available for certain STDs, such as gonorrhea and chlamydia. Non-amplified nucleic acid hybridization tests are more likely to be used when large amounts of bacterial or viral DNA (or RNA) would be expected to be present, such as in a urethral swab or in a bacterial culture sample. In such circumstances, no amplification is necessary. In these samples, if DNA or RNA is present, it should be present in detectable amounts.


Call for abstracts: https://std-hiv-aids.cmesociety.com/call-for-abstracts
Abstract submission: https://std-hiv-aids.cmesociety.com/abstract-submission
Registration: https://std-hiv-aids.cmesociety.com/registration
 


Friday 27 July 2018

Human Papillomavirus and Cancer

Human Papillomavirus (HPV)

The human papillomavirus, or HPV, is a type of virus that infects the skin and the cells lining body cavities. For most people, the infection will get better on its own and they will never know they had it. 

There are different types of HPV:

Some infect the skin, usually on the fingers and hands. These can cause minor problems, such as common skin warts and verrucas.

Others infect the genitals, mouth and throat. These can cause genital warts, or more rarely, cancer.
From this point onwards, the discussion is on genital and oral HPV, as these types are the ones which can cause cancer.

HPV is a very common infection. Around 8 out of 10 people will be infected with the virus at some point in their lives. It usually doesn’t cause any symptoms and most people will never know they had it. HPV spreads through close skin-to-skin contact, usually during sexual activity including oral sex. Having a high number of sexual partners does increase the chances of infection. 

HPV infection usually causes no problems at all. But in some people the infection will stay around for a long time and become persistent. Around 13 types of HPV can cause cancer. These are called ‘high-risk’ types. People with persistent infections with ‘high-risk’ HPV types are those who are most likely to go on to develop cancer.

HPV & Cancer

The main type of cancer linked to HPV infection is cervical cancer. Virtually all cases of cervical cancer are caused by HPV. About 3,100 cases of cervical cancer are diagnosed in the UK each year.
HPV can also cause cancer in other genital areas, like the vagina, vulva, penis, and anus. It can also cause some types of cancer of the mouth and throat.

The majority of vaginal, vulval, penile and anal cancers are caused by HPV. But they are less common than cervical cancer. Men who have sex with men may be at increased risk of anal cancer.
HPV infection also increases the risk of some types of mouth and throat cancers. Rates of mouth cancer, especially tongue and tonsil cancers, are on the increase, particularly in people in their 40s, 50s and 60s.30–34 And the evidence suggests that the proportion of cases linked to HPV is rising.

How HPV leads to Cancer

HPV can cause cells to divide more than usual. Fast cell growth can cause warts to develop, but often it doesn’t cause any symptoms at all. The types of HPV that cause warts are not the same types that cause cancer.

In persistent ‘high-risk’ HPV infections, the virus can damage DNA and cause cells to start dividing and growing out of control. This can lead to cancer.

HPV Vaccine

HPV can cause changes to the DNA in our cells that make them more likely to turn cancerous. So by protecting against HPV infection, we can help prevent those changes and reduce the risk of cervical cancer.

HPV Vaccination for Women

Since 2008, girls aged 11-13 have been offered a vaccination against the two most common ‘high-risk’ types of HPV, HPV 16 and 18. Together, these two types cause about 7 out of 10 cervical cancers. Girls up to the age of 18 can request vaccination through the NHS if they weren’t vaccinated routinely. The HPV vaccine has been proven to be safe and effective.
The HPV vaccine currently used in the UK (Gardisil) also protects against HPV 6 and 11, which are the HPV types that cause most genital warts.
The HPV vaccine doesn’t protect against all types of HPV, so screening is still important, even if you have been vaccinated.

HPV Vaccination for Men

As HPV is linked to cancers in men as well as women, offering HPV vaccination to men would help reduce the risk of disease. Men who have sex with men have a higher risk of anal cancer than men who don’t.

From April 2018, the vaccine is being rolled out men who have sex with men in all sexual health and HIV clinics across the UK.

The Joint Committee for Vaccination and Immunisation are also currently considering whether to offer HPV vaccination to all teenage boys as well as girls.

Cervical Screening for HPV

Cervical screening aims to pick up early cell changes that are caused by HPV and remove these cells before they have a chance to become cancerous. This is done by taking a sample of cells and sending them to a lab where they are tested to see if they are normal (cytology). If the cells look abnormal, they will be tested for HPV to see if they are more likely to become cancerous. If they test positive for HPV, the cells will be removed.

Call for abstracts: https://std-hiv-aids.cmesociety.com/call-for-abstracts
Abstract submission: https://std-hiv-aids.cmesociety.com/abstract-submission
Registration: https://std-hiv-aids.cmesociety.com/registration

Wednesday 25 July 2018

STD 2018: Scientific Sessions

Session 1: Types of STDs
Sexually transmitted diseases (STDs) are infectious diseases that are transmitted from a person to another through sexual contact or blood of an infected person. The pathogens such as bacteria, virus, fungi, protozoa are responsible for the disease transmission. Bacterial STDs are Syphilis, Gonorrhoea, Chlamydia, Chancroid. Viral STDs include HIV/AIDS, Human papillomavirus, Hepatitis, Genital Herpes. Trichomoniasis is a STD caused by parasitic protozoan. Candidiasis is considered to be an fungal STD which is spread by fungus Candida albicans. Most of the sexually transmitted diseases such as viral STDs have no cure but the disease can be controlled with proper treatment while bacterial, fungal and protozoan STDs can be cured with antifungals and antibiotics.
  • Bacterial STDs
  • Viral STDs
  • Protozoan STDs
  • Fungal STDs

Session 2Evolution of STDs
The evolution of the STD pathogens are caused by the selective pressures of the host-immune response, modern drugs, vaccines or by microbial competition. Through evolutionary phase, a pathogen can become more or less virulent. The phylogeny, epidemiology and origin studies on sexually transmitted diseases provides valuable data on the genetic transition traits in both host and pathogen. The evolutionary study of the disease-causing pathogen provides the disease transmission and diversity among the human population. The clinical epidemiologyand phylogenetic study paves way for new insights for the development of drugs and therapies against the multiple drug resistance.
  • Origin
  • Phylogenetics
  • Epidemiology
  • Diversity
Session 3: Immunopathogenesis
The immune system helps in elimination of the invading microbial pathogens in the body through a series of defense mechanism. The innate immune response of the body provides first line of defense against the pathogens which is fast and non-specific response while adaptive immune response is specific and slow. The study of immunopathogenesis allows us to explore the disease transmission process, pathogen-host interactions, immune defense against the STD pathogens. This allows us to understand the pathological condition and progression of the disease and also the genetic factors influencing the immune defense against STD transmission. The genetic factors influence can be used for the development of gene therapies that triggers immune reaction against the disease-causing pathogens in the body.
  • Disease Transmission
  • Pathogen-Host Interaction
  • Innate Immune Response
  • Adaptive Immune Response
  • Genetic Factors
Session 4Treatment Strategies
Antibiotics are used for treating the STDs caused by bacteria and protozoa. The bacterial STDs can be cured if the infection is properly diagnosed and treated. Several antibiotic resistant strains of pathogens have developed which pose a serious threat for health of the STD affected individuals. For viral STDs, there are no complete cure but progression of the disease can be controlled by antiretroviral therapies which use multiple antiretroviral drugs to decrease the disease proliferation and reduce other opportunistic infections. Gene therapy involves gene editing approaches which can provide a better and safer alternative to other existing drugs. Novel and emerging treatment strategies can provide a solution for the increasing drug resistance in the pathogens.
  • Antibiotic Therapy
  • Antiretroviral Combination Therapy
  • Immunotherapy
  • Gene Therapy

Session 5STDs Prevention
Sexually Transmitted Diseases are transmitted from a person to another through sexual contact or blood transfusions from an infected person or needle sharing, or from mother to infant during pregnancy, labor and breastfeeding. STDs can be prevented through vaccination, screening and through promoting safer sexual behaviour, early health-care seeking behaviour, prevention and care activities. Pregnant women affected with STD must take proper treatment to prevent the vertical transmission of STD. Most STDs cannot be cured and leads to infertility, birth defects in infants, co-infections, opportunistic infections and many other health issues.
  • Effective Healthcare Systems
  • Vaccination
  • Preconception Care
  • Prenatal Care

Diagnosis of STDs are done by serological assays, amplification techniques, immunological diagnosis attains accurate result of the diagnosis. Point-of-care test enables rapid screening of Syphilis and allows treatment without delay. Nucleic acid amplification tests monitor the infection trends and helps in the adaptation of treatment protocols. Drug-resistance test provides the provisions for identifying drug resistance in the STDswhich aids in overcoming the resistance and provide a better treatment. Further improvements in the diagnosis method can help in rapid and cost-effective method for screening of the STDs.
  • Nucleic acid Tests
  • Serological Assays
  • Amplification Techniques
  • Immunological Diagnosis
  • Drug-Resistance Testing
  • Point- of-Care Test

Drug development and research is the development and invention of new drugs and improvement of existing drugs. Continuous progress in drug development and research field is necessary for invention of new drugs and drug targets for STDs. Identification of the drug target is the basis of the drug development process, this can be done through various computational approaches. Gene editing technology such as CRISPR seeks to eliminate the latent as well active HIV infection in the human which would be more effective in the treatment of AIDS. Various viral inhibitors such as entry inhibitors, maturation inhibitors are designed to inhibit the replication of the virus inside the host cell.
  • New Drugs and Drug Targets
  • Integrase Inhibitors
  • Entry Inhibitors
  • Maturation Inhibitors
  • Gene Editing
Session 8Vaccines Development
A highly effective method for controlling infectious diseases is vaccination, it helps in prevention of high risk health issues. Prophylactic vaccines are those used for prevention while therapeutic vaccines are used for treatment of the specific disease. Sexually transmitted diseases are spread by pathogens such as bacteria, virus, fungi and protozoa. Many viral STDs doesn't have cure hence preventing the infection through vaccination is a best method. Vaccines are developed for Hepatitis and Human Papillomavirus (HPV) infection and for HIV and Herpes virus vaccines are being developed. Vaccination is the primary solution for eradication of sexually transmitted diseases in human.
  • Pre-Exposure Prophylaxis
  • Post-Exposure Prophylaxis
  • Therapeutic Vaccines
  • Advancements in Vaccine Technology
  • HIV and Genital herpes Vaccine Development

Nanotechnology is the science and engineering of structures that are 1–100 nm in size. Nanomedicine is a branch of medicine which is employed in preventive, diagnostic and therapeutic purposes. Using nanoparticles, effective timely release of drugs to the infected areas/organs are possible which improves specificity of drug action. HIV/AIDS patients face a major problem where the virus resides in latent reservoirs makes it hard to reach for drugs. Nanoparticles has the ability to travel through the body with less interruption which aids in effective release of drugs at HIV virus reservoirs at the specific target. Therapeutic nanoparticles have higher specificity for the drug targets which enhances the treatment efficiency and better cure for the affected individual.
  • Drug Delivery System
  • Drug Nanosuspension
  • Therapeutic Nanomaterials
  • Nanoparticle Based Vaccines

Plants contain a wide range of substances that are used for treating chronic as well as acute infectious diseases. Many modern drugs in use have been developed from the medicinal plants which has been used by indigenous people. Phytochemicals are chemicals secreted by plants that have disease preventive properties that is used by the plants to protect itself from diseases. Antimicrobial activity of the plant sources can act as a better drug for the strains that has developed multiple drug resistance to antibiotics. Many bacterial STDs can be combated using phytochemicals produced by the medicinal plants. Pharmacological effects of the bio active compounds in the plants must be explored to produce a cure for the multiple drug resistant bacterial STDs.
  • Antimicrobial Effect of Phytochemicals
  • Phytoconstituents and its Effects on STDs
  • Novel Therapeutic Drugs
  • Multi-Drug Resistance and Phytochemical Drugs

The infectious pathogens mutate under certain circumstances to overcome the pressure inflicted upon them. Such organisms develop resistance to the drug in use. This proves to be a major problem in the treatment of sexually transmitted diseases. Human immunodeficiency virus has developed resistance to the antiretroviral drug provided. Hence combination antiretroviral therapies are used for treating AIDS which involves using two or more antiretroviral drugs together. Several bacterial species has also developed resistance to the antibiotics provided for the treatment. The mutation of the pathogens has led to development of drug resistance against many antibiotics and antiretroviral drugs.
  • Nucleoside Reverse Transcriptase Inhibitors Resistance
  • Non-Nucleoside Reverse Transcriptase Inhibitors Resistance
  • Protease Inhibitors Resistance
  • Antibiotic Resistance
  • Antiviral Drug Resistance

Session 12: STDs and Cancer
Sexually transmitted diseases increases the risk of being affected by cancer. Among the STDs which lead to cancer, human papillomavirus infection is found to cause cervical cancer in women and penile cancer in men. It is also responsible for the development of oropharyngeal cancer in both sexes. Untreated STDs has a higher risk for leading to development of cancer. The progression of cancer in people affected by STD must be analyzed to understand the causative agents of the cancer.
  • Oropharyngeal Cancer
  • Cervical Cancer
  • Penile Cancer
  • Prostate Cancer
Session 13: Co-Infection of STDs
Gonorrhoea, chlamydia and trichomoniasis cause immune reactions which leads to inflammation that can easily be infected with HIV. Co-infection is a condition where a person actively infected with STD is infected with another STD. when a STI infected individual is prone to another infection due to immune compromise they are less able to mount a protective response against sexually transmitted pathogens. Treating co-infected individuals can be challenging and the treatment methods must be analyzed and modified to their needs.
  • HIV and Gonorrhea
  • HIV and Hepatitis
  • HIV and Kidney disease
  • HIV and Tuberculosis

When an STD infection is left untreated in women, it may be lead to pelvic inflammatory disease (PID). Being affected by pelvic inflammatory disease may lead to infertility or ectopic pregnancy in pregnant women. When the mother is infected by STD, the fetus or new born is mostly infected. STDs during pregnancy can lead to miscarriage, birth defects including blindness, deafness, bone deformities, and intellectual disability, stillbirth, premature birth. In males, reduced fertility or infertility is most common side effect of the disease.
  • Ectopic Pregnancy
  • Premature Birth
  • Neonatal Sepsis
  • Neurological Defects
Vertical STD transmission is the process of transfer of STD from a mother to infant perinatally or postnatally. During delivery, when the baby passes through the infected canal, it can contract the STDs such as chlamydia, gonorrhoea, genital herpes from the infected mother. Syphilis and HIV can be contracted from the mother during fetus development. Postnatal transmission of the disease is possible through breastfeeding the baby. Vertical STD transmission poses serious threat to the health of the baby.
  • Perinatal Transmission
  • Postnatal Transmission
  • Prevention of STD Transmission
  • Pregnancy Care and Treatment

Session 16: Paediatric STDs
Sexually Transmitted Diseases are an important cause of morbidity in paediatric patients. The transmission occurs via transplacental, intrapartum, and postpartum exposure. When an infant contracts STD from mother, it can affect the skin, eyes, mouth, central nervous system, and can also lead to organ failure. With treatment, the chances of transmitting HIV from mother to infant is low. Proper awareness, treatment and diagnosis is needed to prevent the transmission of STDs among young people.
  • Clinical Manifestation
  • Early Diagnosis
  • Risk Factors
  • Preventive Measures

Multi-morbidities is the presence of two or more chronic diseases at the same time. Super infection or re-infection is the condition where a person with HIV infection acquires infection with the sub-type of HIV. Re-infection affects the treatment which can deteriorate the health of the affected individual. The STDs affected individual suffers from other social and emotional complications which may also have adverse effects in the health of the individual. Multiple morbidities associated with the disease causes more damage to the health as the immune system would be compromised by the STD.
  • Opportunistic Infection
  • Superinfection/Reinfection
  • Behavioral Complications
  • Social Complications

Educational and awareness programs must be conducted to improve the public knowledge about the sexually transmitted diseases. People affected by sexually transmitted diseases have dramatically increased, millions of people are affected by the disease due to lack of awareness. Public must be aware about the impact of STDs on the lives of the affected people and the importance of preventing, screening and treating STDs. Poor knowledge about the STDs lead to increased health issues such as ectopic pregnancies, infertility and other complications. STDs are a major health issue that affects mostly young people, not only in developing countries but in developed countries also.
  • Impact of STDs
  • STD Screening
  • Risk Awareness
  • Prevention Education
  • Community Awareness