Most people with H. pylori infection will never have any signs or symptoms but some people may be born with more resistance to the harmful effects. H. pylori infection may sometimes cause the following symptoms.
• An ache or burning pain in abdomen that may come and go; the pain may worsen when the stomach is empty it may go away upon eating or drinking milk or after taking an antacid.
• Loss of appetite
• Frequent burping
• Bloating of stomach
• Unplanned weight loss
A few of these signs and symptoms may require urgent medical help
• Abdominal pain which is severe or persistent
• Difficulty in swallowing
• Blood in stools (black coloured stools).
• Blood in vomiting (black coloured vomit)
Routes of Entry 
The exact way H. pylori infects someone is still unknown. H. pylori infection can be contacted through contaminated food, water, or utensils. H. pylori bacteria may be passed from person to person through direct contact with saliva, vomit or faecal matter
H. pylori is often contracted in childhood. Living conditions or environment may influence the risk for H. pylori infection such as :
•Lack of access to reliable supply of clean water.
•Crowded environment i.e more the numbers of persons living in a home, greater the risk.
•Living in unsanitary environment: Unhygienic conditions without good sanitation increases risk of H. pylori infection.
•Living with a close family member who has a H. pylori infection also increases the chance of H. pylori infection. .
Complications associated with H pylori infection 
Infection with H. pylori can lead to variety of upper gastrointestinal disorders, such as chronic gastritis, peptic ulcer disease, gastric mucosa-associated lymphoid tissue (MALT) lymphoma, and gastric cancer.
• Peptic Ulcers: H. pylori can damage the protective lining of the stomach and small intestine by compromising the mucus layer. This can allow stomach acid to create an open wound (sore /ulcer)
• Inflammation of the stomach lining: Chronic H. pylori infection can irritate the stomach; can eventually lead to loss of the normal gastric mucosal architecture, with destruction of gastric glands and replacement by fibrosis and intestinal-type epithelium leading to inflammation and a condition called gastritis.
• Stomach cancer: H. pylori infection is a strong risk factor for certain types of stomach cancer. Evidence shows that H pylori’s Infection increases the risk gastric cancer approx. upto ten folds via the sequence of atrophy and metaplasia
Diagnosis and Treatment:
Various tests are available for the detection of H. pylori [4, 5,6,7,8,9].
• Non- Invasive tests: Test samples such as blood, stools, breath samples, urine or saliva fall under non-invasive tests. These samples are tested for the presence bacterial antigens, detection of antibodies or urease activity.
• Invasive Tests : Invasive test is endoscopy i.e looking at the oesophagus, inner lining of your stomach and the first part of the small intestine (duodenum). Usually this testing is done in a hospital care. For this test the doctor insert a thin, flexible tube with a viewing probe to examine the inside of oesophagus, stomach and duodenum. Particular test suggested shall depend on an individual patient and clinical setting
• For routine diagnostic purpose, histological examination, culture and rapid urease test are used. Some non-invasive tests, such as the urea breath test and the stool antigen test, detect active infection of H pylori hence these are called ‘active tests’. Other non-invasive tests such as serology, urine, are markers of exposure to H. pylori but do not indicate whether the infection is active and are referred to ‘passive tests’.
1. Signs and symptoms of stomach cancer https://www.cancer.org/cancer/stomach-cancer/detection-diagnosis-staging/signs-symptoms.html accessed on 17th August, 2017.
2. Perry S, Sanchez Md, Yang S, et al. Gastroenteritis and Transmission of Helicobacter pylori Infection in Households. Emerging Infectious Diseases. 2006;12(11):1701-1708. doi:10.3201/eid1211.060086.
3. http://www.who.int/water_sanitation_health/dwq/gdwq3_11.pdf accessed on 8th September, 2017.
4. Brown LM. Helicobacter pylori: epidemiology and routes of transmission. Epidemiol Rev. 2000;22(2):283-97.
5. Helicobacter pylori. https://www.cdc.gov/ulcer/files/hpfacts.pdf accessed on 8th September, 2017.
6. Cochrane Database of Systematic Reviews. Non-invasive diagnostic tests for Helicobacter pylori infection(Protocol) Gurusamy KS, Yaghoobi M, Davidson BRGurusamy KS, et al. Non-invasive diagnostic tests for Helicobacter pylori infection.Cochrane Database of Systematic Reviews 2016, Issue 2. Art. No.: CD012080.DOI: 10.1002/14651858. CD012080 .accessed on 8th September, 2017.
7. Ricci C, Holton J, Vaira D. Diagnosis of Helicobacter pylori: invasive and non-invasive tests. Best Pract Res ClinGastroenterol. 2007;21(2):299-313.
8. Vaira D, Holton J, Menegatti M, et al. Review article: invasive and non-invasive tests for Helicobacter pylori infection. Aliment PharmacolTher. 2000 Oct;14Suppl 3:13-22.
9. https://www.niddk.nih.gov/health-information/digestive-diseases/gastritis accessed on 8th September, 2017.