• Hepatitis A is a liver infection caused by a virus.
• The virus is easily transmitted by contaminated food or water but can also be transmitted through sexual contact.
• A safe and very effective vaccine is available that affords long-lasting protection.
• Hepatitis A vaccination is recommended for all travelers going to tropical or subtropical countries, and for risk groups.

Hepatitis A occurs all over the world, but the risk of infection is higher in countries with poor hygiene standards. There is an increased risk in most tropical and subtropical countries, as well as in some countries in Eastern Europe and around the Mediterranean.

In recent years, there have also been increasing cases in North America and Europe, including Switzerland, especially among men who have sex with men (MSM). Outbreaks in northern European countries can also occur when unvaccinated children become infected during family visits to tropical and subtropical countries. Upon return, they may transmit the virus within their care facilities.

There is a safe and very effective vaccine that consists of two injections at least 6 months apart. It provides lifelong protection after the second dose. Hepatitis A vaccination can also be given in combination with hepatitis B vaccination (3 doses required).

Vaccination against hepatitis A is recommended for all travellers to risk areas, as well as for persons at increased personal risk: persons with chronic liver disease, men who have sex with men, people who use or inject drug, persons with increased occupational contact with persons from high-risk areas or populations, and others.

• Ufficio federale della sanità pubblica (UFSP). Epatite A. https://www.bag.admin.ch/bag/it/home/krankheiten/krankheiten-im-ueberblick/hepatitis-a.html 
• Epatite Svizzera: https://it.hepatitis-schweiz.ch/tutto-sull-epatite/epatite-a 

• Polio is a vaccine-preventable viral disease of the nervous system that is acquired mainly through the consumption of food or water contaminated by feces.
• The infection with the polio virus can affect children and adults and may lead to permanent limb or respiratory muscle paralysis and death.
• An effective, well- tolerated vaccine is available! Check if booster doses are recommended for the travel destination (on top of completed basic vaccination schedule).

Regular hand washing after using the bathroom and before eating or preparing food. Avoidance of undercooked or raw food that is potentially contaminated with fecal material.

The most important prevention is vaccination. A very effective and well-tolerated vaccine against polio is available (inactivated (killed) polio vaccine (IPV)), which is part of the basic vaccination schedule during childhood. Combination vaccines (e.g. with diphtheria and tetanus) are also available. After basic vaccination, a booster dose is recommended every 10 years for travel to certain countries (see country page recommendations). WHO recommends a yearly vaccination for residents or long-stay visitors (minimum 4 weeks) in a country with ongoing polio infections or circulating vaccine-derived polio viruses. This recommendation not only targets individual protection, but aims to prevent the international spread of the virus.

WHO: https://www.who.int/news-room/fact-sheets/detail/poliomyelitis

FOPH Switzerland: Swiss vaccination plan: https://www.bag.admin.ch/bag/de/home/gesund-leben/gesundheitsfoerderung-und-praevention/impfungen-prophylaxe/schweizerischer-impfplan.html

• Typhoid fever, also called enteric fever, is caused by the bacteria Salmonella Typhi and Salmonella Paratyphi.
• Infected persons shed the bacteria in their feces. In countries with low sanitation standards, the bacteria can then enter the drinking water system and lead to infections in other people.
• Frequent sources of infection are contaminated food and beverages.
• The main preventive measure therefore is “cook it, peel it, boil it or forget it” – meaning: avoid drinking uncooked water or water from unsealed bottles; avoid cooled/frozen products (e.g. ice cubes in drinks, ice cream) unless from a known safe source; avoid uncooked vegetables, peel and clean fruit and vegetables yourself and only with known safe drinking water.
• A vaccine is available and recommended: a) for travelers to the Indian subcontinent or to West Africa, b) for travelers visiting friends and relatives or for long-term travelers also to other sub-/tropical areas.

“Cook it, boil it, peel it or forget it” – this simple slogan would be sufficient to prevent typhoid fever nearly entirely. However, only few travelers fully adhere to this advice. Nevertheless, the value of food and water hygiene cannot be stressed enough: avoid buying water bottles without proper sealing, avoid drinking tap water from unknown sources, avoid eating cooled / frozen foods (i.e. ice cubes in water or ice cream) and avoid eating raw fruits and vegetables that you yourself have not peeled and washed with clean drinking water.

Two types of vaccines are available:

• Oral (live) vaccine consisting of three capsules to be taken on alternate days on empty stomach. These capsules require refrigeration before use. Protection from this vaccine is approximately 70% and starts 10 days after the third dose. After 1 to 3 years, the vaccine needs to be taken again before a new travel into at-risk areas. This vaccine cannot be given to patients with a severe chronic gastrointestinal disease (such as Crohn’s disease or ulcerative colitis) or with severe immunosuppression.
• The single-dose vaccine is an inactivated vaccine and is injected intramuscularly. Protection also reaches around 70% and starts 14 days after the injection. This vaccine can be given to patients who should not take the oral vaccine. However, it is not registered in Switzerland, but most doctors with specialization in tropical and travel medicine and all travel health centres have the vaccine on stock. Duration of protection is around 3 years.

• La rabbia è trasmessa principalmente dai cani (e dai pipistrelli), ma qualsiasi mammifero può essere infettivo.
• È invariabilmente fatale nel momento in cui si manifestano i sintomi.
• La rabbia si previene meglio con una vaccinazione prima del viaggio e con un comportamento adeguato verso i mammiferi.
• La vaccinazione prima del viaggio è consigliata anche perché spesso i vaccini e le immunoglobuline non sono disponibili in molti Paesi in cui si viaggia. La vaccinazione prima del viaggio è altamente raccomandata soprattutto in caso di
  • soggiorni di lunga durata in paesi endemici,
  • viaggi brevi ad alto rischio individuale, come i viaggiatori su "due ruote", trekking in regioni remote o viaggi con neonati e bambini fino a 8 anni,
  • lavori professionali con animali o esploratori di grotte (pipistrelli!).
• Attenzione: una ferita da morso o da graffio e il contatto con la saliva di un mammifero sono un'emergenza! Scoprite di seguito le azioni necessarie!

Non esiste un trattamento specifico contro la malattia causata dal virus della rabbia.

Misure post-esposizione: Pulizia immediata della ferita con abbondante acqua e sapone per 10-15 minuti, seguita da disinfezione (ad es. Betadine, Merfen) e vaccinazione post-esposizione d'emergenza nell’ospedale più vicino entro 24 ore. È inoltre raccomandata la vaccinazione di richiamo contro il tetano se non è aggiornata. Per coloro che hanno ricevuto la vaccinazione antirabbica completa pre-esposizione prima del viaggio, sono sufficienti due dosi aggiuntive di un vaccino contro la rabbia (di qualsiasi marca) a un intervallo di 3 giorni. Se non è stata effettuata la vaccinazione completa pre-esposizione, oltre alla vaccinazione è necessaria l'immunizzazione passiva con immunoglobuline. Va notato che le immunoglobuline (e a volte i vaccini) spesso non sono disponibili in ambienti con scarse risorse, causando stress e incertezza.

È consigliato evitare di accarezzare animali domestici e di astenersi dal toccare animali selvatici, non familiari o morti.
Tutti i viaggiatori che si recano verso luoghi in cui la rabbia terrestre può manifestarsi e/o che probabilmente faranno viaggi ripetuti in zone in cui la rabbia è presente dovrebbero sottoporsi alla vaccinazione pre-esposizione. Inoltre, la vaccinazione pre-esposizione è altamente raccomandata per i viaggiatori particolarmente a rischio:

• soggiorni di lunga durata in paesi endemici,
  
• viaggi brevi ad alto rischio individuale, come viaggiatori su "due ruote", trekking in regioni remote, viaggi con neonati e bambini fino a 8 anni di età,
  
• professionisti che lavorano con gli animali o esploratori di grotte (pipistrelli!).

Lo schema di vaccinazione abbreviato può essere proposto alla maggior parte dei viaggiatori: 2 vaccinazioni, la prima possibilmente un mese prima della partenza (minimo 8 giorni prima della partenza). Una terza vaccinazione di richiamo per la rabbia è raccomandata prima del viaggio successivo, con un intervallo almeno di un anno.

• Informarsi a tempo opportuno sulla prevenzione della rabbia prima del viaggio.
• In caso di viaggi programmati per più di qualche settimana, prevedere una consultazione di medicina da viaggio al più tardi 4 settimane prima della partenza.
• Dopo un'eventuale esposizione (morso, graffio) sono necessari un trattamento della ferita e la somministrazione di dosi aggiuntive di vaccino contro la rabbia anche per coloro che hanno completato la serie di vaccinazioni di base.
• Questo foglio informativo dovrebbe essere stampato e tenuto a portata di mano durante il viaggio!

• UFSP Svizzera (tedesco): https://www.bag.admin.ch/dam/bag/de/dokumente/mt/infektionskrankheiten/tollwut/bag-bulletin-15-2021-tollwut-prep-und-pep.pdf.download.pdf/210412_BAG_Bulletin_15_2021_Tollwut%20PrEP%20und%20PEP_d.pdf 
• UFSP Svizzera (francese):https://www.bundespublikationen.admin.ch/cshop_mimes_bbl/14/1402EC7524F81EDBA5D6C3EBC18BA9FB.pdf 

• Regioni: Tutto il paese.
  
  

Misure preventive: Protezione contro le zanzare e profilassi medicamentosa.
Discutere con uno specialista di medicina dei viaggi quale farmaco profilattico è adatto per lei. Lo specialista di medicina dei viaggi prescriverà il farmaco e il dosaggio appropriato.

• Malaria is a life-threatening parasitic infection, which is transmitted by mosquitoes at night.
• Great care should be given to preventive mosquito protection from dusk to dawn in all malaria risk areas.
• In high-risk areas, the intake of prophylactic medication is strongly advised.
• For stays in low risk areas: discuss with a travel health advisor whether carrying an emergency self-treatment against malaria is necessary.
• If you belong to a special risk group (pregnant women, small children, senior citizens, persons with pre-existing conditions and/or with immune deficiency): seek medical advice before the trip as malaria can quickly become very severe.
• If you have a fever >37.5°C on axillary or tympanic measurement (a functioning thermometer is indispensable!) during or after the trip, see a doctor / hospital immediately and have a blood test done for malaria! This applies regardless of whether you have used prophylactic medication or not!

Fever during or after a stay in a malaria-endemic area is an emergency! Prompt diagnosis and treatment are required as the health of people with malaria can deteriorate very quickly. That means: if you have fever >37.5° (use a thermometer!) you need to test for malaria within a maximum time-frame of 24 hours, regardless of whether or not you have used prophylactic medication (malaria chemoprophylaxis). Try to reach a doctor or hospital where you can reliably receive such a test. If the first test is negative, it should be repeated on the following day if the fever persists.

Prevention of malaria requires a combination of approaches:

1. Diligent mosquito-bite protection at dusk and at night until dawn is of key importance. Use it for all regions where malaria is present, including areas where the risk is minimal. Bite protection is also effective against other insect-borne diseases that often occur in the same region. It consists of the following measures:
   • Clothing: Wear long-sleeved clothes and long trousers. For additional protection, impregnate the clothes beforehand with insecticides containing the active ingredient permethrin (e.g. Nobite® Textile).
   • Mosquito repellents: Apply a mosquito repellent to uncovered skin.
   • Sleeping room: Sleep in an air-conditioned room or under an impregnated mosquito net. Cautiously use ‘knockdown’ sprays indoors or burn mosquito coils strictly outside, e.g. under a table in the evening.
   • Chemoprophylaxis: Depending on the region and season, it may be necessary to take a prophylactic medication. This is recommended for all destinations with a high risk of malaria (marked as red on our maps). It needs to be taken with food before, during, and after your stay. Discuss with your travel health advisor to ascertain if you need to take chemoprophylaxis for your trip. The appropriate medication and the right dosage will be prescribed.
     
2. Taking standby emergency self-treatment (SBET, drugs used to self-treat malaria) with you is recommended for special risk situations (stay in regions with low malaria risk and if there is no or uncertain medical care available). Following such a course of SBET, please consult a doctor as soon as possible. Talk to your travel health advisor to determine whether carrying SBET is necessary, especially if you plan a trip where reliable medical infrastructure is not assured.
3. For some risk groups, malaria can quickly develop to a dangerous disease. If you are pregnant, if you are travelling with small children, or if you are a senior citizen and / or if you have other illnesses /pre-existing conditions and / or you are immunocompromised, you should seek advice from a specialist in travel medicine to determine whether chemoprophylaxis is recommended for your trip – even if the area is marked as low risk malaria zone.
   

For travellers, there is currently no malaria vaccination available.

• Take a functioning clinical thermometer with you!
• Malaria symptoms develop at the earliest 7 days after entering the malaria area. A fever > 37.5° always means suspicion of malaria!
• In case you have fever during or even months after a stay in a malaria area:
  • Immediately consult a health care facility to rule out malaria through a blood test.
  • This should be done within a maximum of 24 hours and applies regardless of whether you have used prophylactic medication or not!
  • The blood tests should be repeated if the result is negative or doubtful and fever persists or recurs.

• For persons having visited a malaria area with low risk and for whom SBET was prescribed:
  • If you have fever: immediately try to get tested for malaria.
  • If this is not possible, and fever persists for longer than 24 hours or recurs: start taking the standby emergency-self-treatment as it was prescribed by your travel health advisor.
  • Even if you have started your self-treatment against malaria: seek medical advice as quickly as possible to get the cause of your fever diagnosed.

• La febbre dengue è la malattia trasmessa dagli insetti più comune al mondo.
• Bisogna prestare molta attenzione alla protezione dalle zanzare durante il giorno!
• La malattia può causare febbre alta, dolori muscolari e articolari ed eruzioni cutanee. In rari casi possono manifestarsi emorragie. Non esiste un trattamento specifico.
• Per sicurezza personale, si consiglia fortemente di informarsi dettagliatamente sulla dengue.

In 3 casi su 4, l'infezione con il virus rimane asintomatica. Dopo un breve periodo di incubazione (5-8 giorni), 1 persona infetta su 4 presenta una brusca insorgenza di febbre, mal di testa, dolori articolari, agli arti e ai muscoli, oltre a nausea e vomito. Tipico è anche il dolore al movimento degli occhi. L'eruzione cutanea si manifesta di solito il 3° o il 4° giorno di malattia. Dopo 4-7 giorni, la febbre si riduce definitivamente, ma la stanchezza può persistere per diversi giorni o settimane.

In rari casi, la dengue può essere grave. Particolarmente sensibili sono i bambini e gli anziani locali, come anche le persone che hanno avuto una precedente infezione da dengue. I turisti presentano molto raramente una dengue grave. Nei primi giorni, la malattia assomiglia al decorso della classica febbre dengue, ma al 4°/5° giorno, di solito dopo che la febbre si è abbassata, le condizioni peggiorano. La pressione arteriosa si abbassa e i pazienti lamentano mancanza di respiro, disturbi addominali, epistassi e lievi emorragie cutanee o mucose. Nei casi più gravi, può presentarsi uno shock potenzialmente letale.

Non esiste un trattamento specifico per l'infezione da virus dengue. Il trattamento si limita alla mitigazione e al monitoraggio dei sintomi: riduzione della febbre, sollievo dal dolore agli occhi, alla schiena, ai muscoli e alle articolazioni e monitoraggio della coagulazione e del volume del sangue. I pazienti con sintomi gravi devono essere ricoverati in ospedale.

Per la riduzione della febbre o del dolore, si consigliano rimedi con il principio attivo paracetamolo o acetaminofene (ad esempio Acetalgin® Dafalgan®). I farmaci contenenti il principio attivo acido acetilsalicilico (ad esempio Aspirina®, Alcacyl®, Aspégic®) devono essere evitati.

Una protezione efficace contro le zanzare durante il giorno e soprattutto nelle ore del crepuscolo (cioè al tramonto) è la migliore misura preventiva:

• Abbigliamento: indossare indumenti ben coperti, a maniche lunghe e pantaloni lunghi e applicare preventivamente uno spray insetticida sugli indumenti (vedi foglio informativo "prevenzione delle punture di artropodi").
  
• Repellente per zanzare: Applicare più volte al giorno un repellente per zanzare sulla pelle scoperta (vedi foglio informativo "prevenzione delle punture di artropodi").
  
• Igiene ambientale: Non lasciare contenitori con acqua ferma (sottobicchieri per vasi di fiori, ecc.) nel proprio ambiente per evitare siti di riproduzione delle zanzare.

Per ulteriori informazioni, consultare il foglio informativo "Protezione dalle punture di zanzare e zecche".

Nota sui vaccini contro la dengue:
Sono in commercio due vaccini contro la dengue: Qdenga® e Dengvaxia®. Il vaccino Qdenga® è stato approvato dall'Unione Europea nel dicembre 2022. Tuttavia, a causa della situazione dei dati, molti Paesi europei e il Comitato svizzero di esperti in medicina dei viaggi (CEMV) raccomandano attualmente la vaccinazione con Qdenga® solo per alcuni viaggiatori e in situazioni particolari. Si raccomanda pertanto di consultare uno specialista in medicina tropicale e dei viaggi.

A nota:

• Qdenga® non è ancora autorizzato in Svizzera e le raccomandazioni per i viaggiatori saranno limitate una volta che Qdenga® sarà autorizzato in Svizzera.
  
• Il vaccino Dengvaxia® non è un vaccino per i viaggiatori.
  

La protezione costante dalle zanzare durante il giorno (vedi sopra) è ancora considerata la misura preventiva più importante contro la febbre dengue!

• La chikungunya è una malattia virale trasmessa dalle zanzare Aedes.
• La chikungunya può essere prevenuta proteggendosi dalle punture di zanzara.
• Si presenta tipicamente con forti dolori articolari alle mani e ai piedi. In alcuni pazienti, questi possono durare per settimane o mesi.

L'infezione può presentarsi con alcuni o tutti i seguenti sintomi: improvvisa manifestazione di febbre di grado elevato, brividi, mal di testa, arrossamento degli occhi, dolori muscolari e articolari ed eruzione cutanea. L'eruzione cutanea si manifesta di solito dopo la comparsa della febbre e coinvolge tipicamente il tronco e le estremità, ma può includere anche i palmi delle mani, le piante dei piedi e il viso.

Spesso la febbre si presenta in due fasi della durata massima di una settimana, con un intervallo di uno o due giorni senza febbre. La seconda fase può presentarsi con dolori muscolari e articolari molto più intensi, che possono essere gravi e debilitanti.  Questi sintomi sono tipicamente bilaterali e simmetrici e coinvolgono principalmente mani e piedi, ma possono anche coinvolgere le articolazioni più grandi, come le ginocchia o le spalle.

Circa il 5-10% delle persone infette continuano ad avere forti dolori articolari anche dopo che la febbre si è abbassata, in alcuni casi durando fino a diversi mesi o, anche se raramente, addirittura anni.

• UFSP CH: https://www.bag.admin.ch/bag/it/home/krankheiten/krankheiten-im-ueberblick/chikungunya.html 
• WHO - Chikungunya factsheet: https://www.who.int/news-room/fact-sheets/detail/chikungunya 
• Center for Disease Control and Prevention (CDC): https://www.cdc.gov/chikungunya/index.html 

• Zika is a viral disease transmitted by mosquitoes that bite during the day.
• Zika virus infection during pregnancy (any trimester) can cause fetal malformation.
• In areas at increased risk of transmission (epidemic), specific recommendations must be given to women who are – or wish to become – pregnant.
  

The Zika virus was identified in 1947 in monkeys from the Zika forest in Uganda. Virus circulation has long been limited (a few cases each year) in Africa and South-East Asia. In May 2015, the American continent was affected for the first time, with an epidemic in Brazil that rapidly spread to South America, Central America, and the Caribbean. Since then, the disease has been reported in most tropical and subtropical regions.

The risk of infection is currently low in most regions and does not require specific measures. However, epidemics may occasionally reappear. During epidemics, the risk of transmission is high, and specific recommendations for the traveller are necessary.

In case of fever, it is recommended to consult a doctor. The symptoms of a Zika virus infection may seem similar to those of malaria, for which urgent treatment is necessary, or dengue fever. Treatment for Zika aims for reduction of fever and joint pain (paracetamol). Avoid aspirin and anti-inflammatory drugs (e.g. ibuprofen) as long as dengue fever is not excluded. There is no vaccine available.

In case of pregnancy and fever during or upon return from a Zika virus transmission area, blood and/or urine tests are indicated. In case of confirmed infection, the medical management should be discussed with the gynecologist and infectious/travel medicine specialists.

The risk of infection can be reduced by effective protection from mosquito bites during the day and in the early evening (long clothing, mosquito repellents, mosquito net).

When travelling in an area of increased risk (= declared epidemic) and in order to prevent possible sexual transmission of the virus, it is recommended to use a condom / Femidom during the trip and at least 2 months after return.

Due to the risk of fetal malformation, pregnant women are advised against travelling to areas at increased risk (= declared as epidemic) of Zika transmission at any time during pregnancy (in case of essential travel, a consultation with a travel medicine specialist is advised before departure). Women who wish to become pregnant should wait at least 2 months after their return (or that of their partner) from an area at increased risk of Zika transmission.

• Zika virus infection during pregnancy (any trimester) can cause fetal malformation.
• For most up-to-date information on Zika distribution and / or Zika outbreaks, please consult CDC Zika Travel Information: https://wwwnc.cdc.gov/travel/page/zika-information 

• Geschlechtskrankheiten sind ein weltweit verbreitetes Gesundheitsproblem und können durch Prävention, regelmässiges Testen und Behandlung in den Griff bekommen werden.
• Das Wissen um Risiken sowie Safer-Sex-Praktiken inklusive Kondomgebrauch sind wichtig. Falls Sie mehr dazu erfahren wollen, wie Sie sich während der Reise optimal schützen können, besprechen Sie dies mit einer Fachperson.
• Hatten Sie eine Risikosituation, ist es wichtig mit einer Fachperson so rasch wie möglich Rücksprache zu halten, um zu erörtern, ob eine HIV-Post-Expositions-Prophylaxe (PEP) durchgeführt werden soll, um eine Ansteckung mit HIV zu verhindern.
• Im Nachgang einer Risikosituation ist es wichtig sich auf Geschlechtskrankheiten testen zu lassen. Auch dann, wenn Sie keine Symptome haben.

• Brennen oder Juckreiz im Genitalbereich
  
• Schmerzhaftes oder häufiges Wasserlösen oder auch Schmerzen im Unterleib
  
• Ungewöhnlicher Ausfluss aus dem Penis oder der Vagina
  
• Wunden, Rötungen, Bläschen im Mund/Lippen oder Genitalbereich sowie Warzen im Intimbereich
  
• Manchmal auch Fieber (eher selten)
  

Wichtig: Eine STI kann auch ohne oder mit nur leichten Symptomen auftreten. Auch wenn Sie sich dessen nicht bewusst sind, können Sie andere anstecken. Deshalb ist es wichtig sich testen zu lassen.

• Beachten Sie die Safer Sex Regeln von Love Live. Dazu gehört auch bei jedem Anal- oder Vaginalverkehr Kondome zu verwenden.
  
• Denken Sie daran, dass es bei Oralverkehr auch zu Übertragungen von STIs kommen kann.  
  
• Lassen Sie sich impfen! Es gibt Impfstoffe zum Schutz vor HPV, Hepatitis A und Hepatitis B.
  
• Hatten Sie eine Risikosituation, ist es wichtig mit einer Fachperson so rasch wie möglich Rücksprache zu halten, um zu erörtern, ob eine HIV-Post-Expositions-Prophylaxe (PEP) durchgeführt werden soll, um eine HIV-Infektion zu verhindern. Am wirksamsten ist eine HIV-PEP innerhalb weniger Stunden danach.
  
• Es gibt auch weitere Präventionsmassnahmen für spezielle Situationen (Präexpositionsprophylaxe HIV-PrEP). Sprechen Sie mit einer damit erfahrenen Fachperson vor Abreise darüber.
  
• Denken Sie daran, dass Alkohol oder Drogen zu erhöhtem Risikoverhalten führen.
  
• Denken Sie daran, dass Sie eine weitere Person/bekannter Partner*in bei ungeschütztem Sex anstecken können, sofern bei Ihnen eine unbehandelte STI vorliegt.
  
• Menschen mit einer neu diagnostizierten STI sind angehalten ihre früheren Sexualpartner*innen zu informieren, damit auch sie behandelt werden können.

Durch Bakterien oder Parasiten hervorgerufen
Alle diese Krankheiten können geheilt werden. Wichtig ist dabei, frühzeitig zu testen und umgehend zu therapieren, um Komplikationen und v.a. weitere Übertragungen zu vermeiden.

• Syphilis
  Auch bekannt als Lues. Sie wird durch das Bakterium Treponema pallidum verursacht. Das erste Anzeichen ist eine schmerzlose Wunde an den Genitalien, im Mund, auf der Haut oder im Rektum, die hochgradig ansteckend ist und nach 3 bis 6 Wochen spontan abklingt. Da diese schmerzlos ist, nehmen nicht alle Patienten*innen diese Läsion wahr. Oft heilt diese Infektion jedoch nicht von selbst aus. In der zweiten Phase können Hautausschlag, Halsschmerzen und Muskelschmerzen auftreten. Unbehandelt kann die Krankheit im Verborgenen (latent) bleiben, ohne dass Symptome auftreten. Etwa ein Drittel der Infizierten mit unbehandelter Syphilis entwickelt im Verlauf Komplikationen. Diese Spätform wird als  sogenannt tertiäre Syphilis bezeichnet . In diesem Stadium kann die Krankheit alle Organe befallen: am häufigsten das Gehirn, die Nerven und die Augen. Die Infektion kann während der Schwangerschaft auf den Fötus und bei der Geburt auf das Kind übertragen werden.
  
  
• Chlamydia trachomatis
  Chlamydien können ungewöhnlichen Ausfluss aus dem Penis oder der Vagina, Unbehagen beim Wasserlösen und Unterleibsschmerzen verursachen. Oft treten keine Symptome auf. Unbehandelt können sie zu Unfruchtbarkeit führen und die Krankheit kann auf Sexualpartner*innen übertragen werden. Die Bakterien können auch während der Schwangerschaft auf den Fötus, oder während der Geburt auf das Kind übertragen werden und Augeninfektionen oder Lungenentzündungen verursachen.
  
  
• Gonorrhoe
  Auch bekannt als Tripper. Zu den häufigsten Symptomen gehören Ausfluss aus der Vagina oder dem Penis und schmerzhaftes Wasserlassen. Symptome müssen aber nicht immer auftreten. Sowohl bei Männern als auch bei Frauen kann Gonorrhoe auch den Mund, den Rachen, die Augen und den Anus infizieren und sich auf das Blut und die Gelenke ausbreiten, wo sie in eine schwere Krankheit übergehen kann. Bleibt sie unbehandelt, kann sie eine Beckenentzündung verursachen, die zu chronischen Beckenschmerzen und Unfruchtbarkeit führen kann. Die Krankheit kann während der Schwangerschaft auf den Fötus übertragen werden.
  
  
• Weitere bakterielle STIs: Mykoplasmen und Ureaplasmen. Diese können ebenfalls behandelt werden.
  
  
• Trichomoniasis
  Sie wird durch einen Parasiten verursacht, der mit einer einzigen Dosis eines Antibiotikums behandelt werden kann. Trichomoniasis kann bei Frauen einen übel riechenden Scheidenausfluss, Juckreiz im Genitalbereich und schmerzhaftes Wasserlassen verursachen. Bei Männern treten in der Regel weniger oder keine Symptome auf. Zu den Komplikationen gehört das Risiko einer vorzeitigen Entbindung bei schwangeren Frauen. Um eine Reinfektion zu verhindern, sollten beide Sexualpartner behandelt werden.
  
  

Durch Viren hervorgerufen

• HIV/AIDS - siehe Informationsblatt HIV-AIDS
  
  
• Herpes simplex Virus
  Im Lippen-Mundbereich, auch bekannt als Fieberbläschen, ist nicht heilbar. Herpes kann aber mit Medikamenten bei akuten Beschwerden kontrolliert werden. Die Symptome sind in der Regel schmerzhafte, wässrige Hautbläschen und finden sich an oder um die Genitalien, den Anus oder den Mund. Nach der Erstinfektion ruht das Virus im Körper und die Symptome können über Jahre hinweg wieder auftreten. Schwangere Frauen können die Infektion an ihre Neugeborenen weitergeben, was zu einer bedrohlichen Infektion führen kann.
  
  
• Virale Hepatitis (siehe auch Hepatitis Schweiz)
  
  • Hepatitis A (HAV)
    Hepatitis A ist eine durch Impfung vermeidbare Leberinfektion, die durch das Hepatitis-A-Virus verursacht wird. Das Hepatitis-A-Virus findet sich im Stuhl und im Blut infizierter Personen. Hepatitis A kann durch verunreinigtes Wasser und Lebensmittel sowie bei anal-oralen sexuellen Aktivitäten übertragen werden. Die Patienten*innen leiden an einer akuten und oft schweren Erkrankung, erholen sich aber allermeist spontan.
    
  • Hepatitis B (HBV)
    Das Hepatitis-B-Virus wird durch sexuelle Kontakte sowie durch den Kontakt mit anderen Körperflüssigkeiten, wie z.B. Blut, übertragen. Zur Übertragung kann es z.B. auch bei medizinischen Eingriffen oder Brennen eines Tatoos unter nicht optimalen hygienischen Bedingungen kommen. Hepatitis B kann eine schwere Leberinfektion verursachen, die sowohl zu einer sofortigen Erkrankung, als auch zu einer lebenslang andauernden Infektion führen kann mit möglicher Folge einer dauerhaften Lebervernarbung (Zirrhose) und Krebs. Schwangere Frauen mit Hepatitis B können das Virus während der Geburt auf ihr Kind übertragen. Zu Beginn der Infektion haben Sie möglicherweise keine Symptome.  Das Virus kann auf Sexualpartner*innen übertragen werden. Hepatitis B kann mit antiviralen Medikamenten behandelt werden, ist aber nur selten heilbar. Eine Impfung kann eine Hepatitis-B-Infektion verhindern.
    
  • Hepatitis C (HCV)
    In den meisten Fällen wird Hepatitis C durch den Kontakt mit infiziertem Blut übertragen. Seltener kann es durch analen Sexualkontakt oder von der Mutter auf das Kind während der Schwangerschaft und Geburt übertragen werden. Die meisten Infizierten sind sich ihrer Infektion nicht bewusst, weil sie keine Symptome entwickeln, aber diese chronische Infektion kann zu Leberzirrhose und Krebs führen. Hepatitis C kann behandelt werden, eine Impfung gibt es nicht.
    
    
• Humanes Papillomavirus (HPV)
  HPV ist die häufigste Geschlechtskrankheit. Es gibt eine Vielzahl verschiedener HPV-Typen, und einige von ihnen können Genital-, Anal- und Mundwarzen sowie Gebärmutterhals-, Penis- oder Rachenkrebs verursachen. Die Symptome können auch noch Jahre nach dem Sex mit einer infizierten Person auftreten. Zwei verfügbare Impfstoffe schützen gegen die wichtigsten HPV-Typen, die Gebärmutterhals-, Penis- oder Analkrebs verursachen.
  
  
• Zika - siehe Informationsblatt Zika
  In den meisten Fällen wird es vor allem durch Stechmücken übertragen. Es kann aber auch sexuell übertragen werden. Eine Ansteckung mit Zika während der Schwangerschaft kann bei dem sich entwickelnden Fötus Geburtsfehler wie Mikrozephalie (kleiner Kopf mit neurologischen Ausfällen) verursachen. Die einzige Möglichkeit, eine sexuelle Übertragung des Virus während der Schwangerschaft zu verhindern, besteht darin, Vorsichtsmassnahmen (Kondome) zu treffen oder Sex (mindestens 2 Monate nach der Rückkehr) mit jemandem zu vermeiden, der kürzlich in ein Risikogebiet gereist ist, auch wenn der Reisende keine Symptome hat.

• Love Life: www.lovelife.ch 
  
• Sexuelle Gesundheit Schweiz: www.sexuelle-gesundheit.ch 
  
• Hepatitis Schweiz: https://hepatitis-schweiz.ch/formen/was-ist-hepatitis 
  
• World Health Organization (WHO). Factsheets. Sexually transmitted infections (STIs). 14 June 2019:
  www.who.int/news-room/fact-sheets/detail/sexually-transmitted-infections-(stis) 
  
• Centers for Disease Control and Prevention (CDC). Factsheet: Information for Teens and Young Adults: Staying Healthy and Preventing STDs (2017): www.cdc.gov/std/life-stages-populations/stdfact-teens.htm 
  
• Centers for Disease Control and Prevention (CDC). How You Can Prevent Sexually Transmitted Diseases: www.cdc.gov/std/prevention/ 
  
• Centers for Disease Control and Prevention (CDC) Sexual Transmission and Prevention. Zika Virus: www.cdc.gov/zika/prevention/protect-yourself-during-sex.html 
  
• Centers for Disease Control and Prevention (CDC) Zika and Pregnancy; Pregnant Women and Zika (March 2021): www.cdc.gov/pregnancy/zika/protect-yourself.html