{"id":11445,"date":"2026-02-20T00:47:12","date_gmt":"2026-02-19T22:47:12","guid":{"rendered":"https:\/\/medilab.km.ua\/?p=11445"},"modified":"2026-04-20T18:53:25","modified_gmt":"2026-04-20T15:53:25","slug":"how-does-the-flu-manifest-itself-to-someone-who-is-at-risk-and-when-do-you-need-diagnostics","status":"publish","type":"post","link":"https:\/\/medilab.km.ua\/en\/how-does-the-flu-manifest-itself-to-someone-who-is-at-risk-and-when-do-you-need-diagnostics\/","title":{"rendered":"Influenza B: how it manifests itself, who is at risk and when diagnostics are needed"},"content":{"rendered":"<p data-start=\"75\" data-end=\"354\">Influenza B is a seasonal viral infection that causes waves of illness every year along with influenza A. Although influenza B does not cause pandemics, it can cause severe illness and serious complications, especially in children, the elderly, and patients with chronic diseases.<\/p>\n<p data-start=\"356\" data-end=\"542\">Understanding the characteristics of the influenza B virus, its transmission routes, symptoms, diagnostic and prevention methods allows you to reduce the risk of complications and the spread of infection during the seasonal peak.<\/p>\n<p data-start=\"544\" data-end=\"723\">According to <span class=\"hover:entity-accent entity-underline inline cursor-pointer align-baseline\"><span class=\"whitespace-normal\">World Health Organization<\/span><\/span>, influenza A and B viruses cause millions of cases of infection each year, and seasonal vaccination remains the primary method of prevention.<\/p>\n<h2 data-start=\"725\" data-end=\"754\">Features of the influenza B virus<\/h2>\n<p data-start=\"756\" data-end=\"837\">Influenza B virus circulates exclusively among humans. It has two main genetic lineages:<\/p>\n<ul data-start=\"839\" data-end=\"868\">\n<li data-start=\"839\" data-end=\"853\">\n<p data-start=\"841\" data-end=\"853\">B\/Victoria<\/p>\n<\/li>\n<li data-start=\"854\" data-end=\"868\">\n<p data-start=\"856\" data-end=\"868\">B\/Yamagata<\/p>\n<\/li>\n<\/ul>\n<p data-start=\"870\" data-end=\"1084\">Unlike influenza A, type B does not have an animal reservoir and is less likely to undergo drastic mutations. However, this does not mean that the course is milder - in some seasons, it is influenza B that causes the greatest number of hospitalizations among children.<\/p>\n<h2 data-start=\"1086\" data-end=\"1120\">Who is most at risk of getting sick?<\/h2>\n<p data-start=\"1122\" data-end=\"1162\">The following are at increased risk of severe disease:<\/p>\n<ul data-start=\"1164\" data-end=\"1321\">\n<li data-start=\"1164\" data-end=\"1183\">\n<p data-start=\"1166\" data-end=\"1183\">children under 5 years old<\/p>\n<\/li>\n<li data-start=\"1184\" data-end=\"1196\">\n<p data-start=\"1186\" data-end=\"1196\">teenagers<\/p>\n<\/li>\n<li data-start=\"1197\" data-end=\"1221\">\n<p data-start=\"1199\" data-end=\"1221\">people over 65 years old<\/p>\n<\/li>\n<li data-start=\"1222\" data-end=\"1233\">\n<p data-start=\"1224\" data-end=\"1233\">pregnant<\/p>\n<\/li>\n<li data-start=\"1234\" data-end=\"1255\">\n<p data-start=\"1236\" data-end=\"1255\">patients with asthma<\/p>\n<\/li>\n<li data-start=\"1256\" data-end=\"1275\">\n<p data-start=\"1258\" data-end=\"1275\">people with diabetes<\/p>\n<\/li>\n<li data-start=\"1276\" data-end=\"1321\">\n<p data-start=\"1278\" data-end=\"1321\">people with cardiovascular diseases<\/p>\n<\/li>\n<\/ul>\n<p data-start=\"1323\" data-end=\"1380\">In these groups, influenza B can cause serious complications.<\/p>\n<h2 data-start=\"1382\" data-end=\"1407\">How does influenza B develop?<\/h2>\n<p data-start=\"1409\" data-end=\"1557\">The incubation period is 1\u20134 days. The disease begins suddenly. A person may experience chills, body aches, and a sharp increase in temperature.<\/p>\n<p data-start=\"1559\" data-end=\"1584\">The main symptoms of influenza B:<\/p>\n<ul data-start=\"1586\" data-end=\"1734\">\n<li data-start=\"1586\" data-end=\"1609\">\n<p data-start=\"1588\" data-end=\"1609\">temperature 38\u201340\u00b0C<\/p>\n<\/li>\n<li data-start=\"1610\" data-end=\"1635\">\n<p data-start=\"1612\" data-end=\"1635\">severe headache<\/p>\n<\/li>\n<li data-start=\"1636\" data-end=\"1653\">\n<p data-start=\"1638\" data-end=\"1653\">muscle pain<\/p>\n<\/li>\n<li data-start=\"1654\" data-end=\"1670\">\n<p data-start=\"1656\" data-end=\"1670\">dry cough<\/p>\n<\/li>\n<li data-start=\"1671\" data-end=\"1687\">\n<p data-start=\"1673\" data-end=\"1687\">sore throat<\/p>\n<\/li>\n<li data-start=\"1688\" data-end=\"1710\">\n<p data-start=\"1690\" data-end=\"1710\">pronounced weakness<\/p>\n<\/li>\n<li data-start=\"1711\" data-end=\"1734\">\n<p data-start=\"1713\" data-end=\"1734\">anorexia<\/p>\n<\/li>\n<\/ul>\n<p data-start=\"1736\" data-end=\"1760\">In children, the following are often added:<\/p>\n<ul data-start=\"1762\" data-end=\"1796\">\n<li data-start=\"1762\" data-end=\"1772\">\n<p data-start=\"1764\" data-end=\"1772\">nausea<\/p>\n<\/li>\n<li data-start=\"1773\" data-end=\"1785\">\n<p data-start=\"1775\" data-end=\"1785\">vomiting<\/p>\n<\/li>\n<li data-start=\"1786\" data-end=\"1796\">\n<p data-start=\"1788\" data-end=\"1796\">diarrhea<\/p>\n<\/li>\n<\/ul>\n<h2 data-start=\"1798\" data-end=\"1858\">How is influenza B different from other respiratory infections?<\/h2>\n<div class=\"TyagGW_tableContainer\">\n<div class=\"group TyagGW_tableWrapper flex flex-col-reverse w-fit\">\n<div class=\"table-scroll\"><table class=\"w-fit min-w-(--thread-content-width)\" data-start=\"1860\" data-end=\"2102\">\n<thead data-start=\"1860\" data-end=\"1886\">\n<tr data-start=\"1860\" data-end=\"1886\">\n<th class=\"\" data-start=\"1860\" data-end=\"1869\" data-col-size=\"sm\">Sign<\/th>\n<th class=\"\" data-start=\"1869\" data-end=\"1878\" data-col-size=\"sm\">Influenza B<\/th>\n<th class=\"\" data-start=\"1878\" data-end=\"1886\" data-col-size=\"sm\">SARS<\/th>\n<\/tr>\n<\/thead>\n<tbody data-start=\"1916\" data-end=\"2102\">\n<tr data-start=\"1916\" data-end=\"1951\">\n<td data-start=\"1916\" data-end=\"1926\" data-col-size=\"sm\">Beginning<\/td>\n<td data-start=\"1926\" data-end=\"1937\" data-col-size=\"sm\">Sudden<\/td>\n<td data-start=\"1937\" data-end=\"1951\" data-col-size=\"sm\">Gradual<\/td>\n<\/tr>\n<tr data-start=\"1952\" data-end=\"1993\">\n<td data-start=\"1952\" data-end=\"1966\" data-col-size=\"sm\">Temperature<\/td>\n<td data-start=\"1966\" data-end=\"1975\" data-col-size=\"sm\">High<\/td>\n<td data-start=\"1975\" data-end=\"1993\" data-col-size=\"sm\">Often low<\/td>\n<\/tr>\n<tr data-start=\"1994\" data-end=\"2035\">\n<td data-start=\"1994\" data-end=\"2010\" data-col-size=\"sm\">Muscle pain<\/td>\n<td data-start=\"2010\" data-end=\"2022\" data-col-size=\"sm\">Expressed<\/td>\n<td data-start=\"2022\" data-end=\"2035\" data-col-size=\"sm\">Minor<\/td>\n<\/tr>\n<tr data-start=\"2036\" data-end=\"2068\">\n<td data-start=\"2036\" data-end=\"2048\" data-col-size=\"sm\">Weakness<\/td>\n<td data-start=\"2048\" data-end=\"2057\" data-col-size=\"sm\">Strong<\/td>\n<td data-start=\"2057\" data-end=\"2068\" data-col-size=\"sm\">Moderate<\/td>\n<\/tr>\n<tr data-start=\"2069\" data-end=\"2102\">\n<td data-start=\"2069\" data-end=\"2083\" data-col-size=\"sm\">Complication<\/td>\n<td data-start=\"2083\" data-end=\"2093\" data-col-size=\"sm\">Possible<\/td>\n<td data-start=\"2093\" data-end=\"2102\" data-col-size=\"sm\">Liquid<\/td>\n<\/tr>\n<\/tbody>\n<\/table><\/div>\n<\/div>\n<\/div>\n<p data-start=\"2104\" data-end=\"2180\">It is the abrupt onset and pronounced intoxication that help to suspect influenza B.<\/p>\n<h2 data-start=\"2182\" data-end=\"2204\">Diagnosis of influenza B<\/h2>\n<p data-start=\"2206\" data-end=\"2242\">Laboratory confirmation is required:<\/p>\n<ul data-start=\"2244\" data-end=\"2366\">\n<li data-start=\"2244\" data-end=\"2268\">\n<p data-start=\"2246\" data-end=\"2268\">in severe cases<\/p>\n<\/li>\n<li data-start=\"2269\" data-end=\"2294\">\n<p data-start=\"2271\" data-end=\"2294\">in young children<\/p>\n<\/li>\n<li data-start=\"2295\" data-end=\"2309\">\n<p data-start=\"2297\" data-end=\"2309\">in pregnant women<\/p>\n<\/li>\n<li data-start=\"2310\" data-end=\"2340\">\n<p data-start=\"2312\" data-end=\"2340\">if complications are suspected<\/p>\n<\/li>\n<li data-start=\"2341\" data-end=\"2366\">\n<p data-start=\"2343\" data-end=\"2366\">in case of hospitalization<\/p>\n<\/li>\n<\/ul>\n<p data-start=\"2368\" data-end=\"2387\">Diagnostic methods:<\/p>\n<ul data-start=\"2389\" data-end=\"2460\">\n<li data-start=\"2389\" data-end=\"2415\">\n<p data-start=\"2391\" data-end=\"2415\"><a href=\"https:\/\/medilab.km.ua\/en\/analysis\/infectious-disease-panel\/respiratory-illness\/flu-and-influenza-in-respiratory-syncytial-virus-pcr-qualitative-diagnosis\/\">PCR of nasopharyngeal swab<\/a><\/p>\n<\/li>\n<li data-start=\"2416\" data-end=\"2433\">\n<p data-start=\"2418\" data-end=\"2433\">rapid tests<\/p>\n<\/li>\n<li data-start=\"2434\" data-end=\"2460\">\n<p data-start=\"2436\" data-end=\"2460\">complete blood count<\/p>\n<\/li>\n<\/ul>\n<p data-start=\"2462\" data-end=\"2535\">PCR allows you to accurately determine the type of virus and distinguish influenza B from <a href=\"https:\/\/medilab.km.ua\/en\/flu-and-symptoms-diagnostics-treatment-and-prevention-of-seasonal-virus\/\">influenza A<\/a>.<\/p>\n<p data-start=\"2537\" data-end=\"2650\">Specialists <span class=\"hover:entity-accent entity-underline inline cursor-pointer align-baseline\"><span class=\"whitespace-normal\">Mayo Clinic<\/span><\/span> Laboratory diagnostics are recommended in the presence of risk factors.<\/p>\n<p data-start=\"2537\" data-end=\"2650\"><img decoding=\"async\" class=\"alignnone size-full wp-image-11447\" src=\"https:\/\/medilab.km.ua\/wp-content\/uploads\/2026\/02\/closeup-man-having-pcr-test-medical-clinic.jpg\" alt=\"laboratory PCR diagnostics of influenza B\" width=\"1200\" height=\"800\" srcset=\"https:\/\/medilab.km.ua\/wp-content\/uploads\/2026\/02\/closeup-man-having-pcr-test-medical-clinic.jpg 1200w, https:\/\/medilab.km.ua\/wp-content\/uploads\/2026\/02\/closeup-man-having-pcr-test-medical-clinic-300x200.jpg 300w, https:\/\/medilab.km.ua\/wp-content\/uploads\/2026\/02\/closeup-man-having-pcr-test-medical-clinic-1024x683.jpg 1024w, https:\/\/medilab.km.ua\/wp-content\/uploads\/2026\/02\/closeup-man-having-pcr-test-medical-clinic-768x512.jpg 768w, https:\/\/medilab.km.ua\/wp-content\/uploads\/2026\/02\/closeup-man-having-pcr-test-medical-clinic-18x12.jpg 18w, https:\/\/medilab.km.ua\/wp-content\/uploads\/2026\/02\/closeup-man-having-pcr-test-medical-clinic-600x400.jpg 600w, https:\/\/medilab.km.ua\/wp-content\/uploads\/2026\/02\/closeup-man-having-pcr-test-medical-clinic-150x100.jpg 150w\" sizes=\"(max-width: 1200px) 100vw, 1200px\" \/><\/p>\n<h2 data-start=\"2652\" data-end=\"2682\">Possible complications of influenza B<\/h2>\n<p data-start=\"2684\" data-end=\"2712\">Complications may include:<\/p>\n<ul data-start=\"2714\" data-end=\"2812\">\n<li data-start=\"2714\" data-end=\"2727\">\n<p data-start=\"2716\" data-end=\"2727\">pneumonia<\/p>\n<\/li>\n<li data-start=\"2728\" data-end=\"2739\">\n<p data-start=\"2730\" data-end=\"2739\">bronchitis<\/p>\n<\/li>\n<li data-start=\"2740\" data-end=\"2748\">\n<p data-start=\"2742\" data-end=\"2748\">otitis<\/p>\n<\/li>\n<li data-start=\"2749\" data-end=\"2760\">\n<p data-start=\"2751\" data-end=\"2760\">sinusitis<\/p>\n<\/li>\n<li data-start=\"2761\" data-end=\"2782\">\n<p data-start=\"2763\" data-end=\"2782\">aggravation <a href=\"https:\/\/medilab.km.ua\/en\/bronchial-asthma-as-a-diagnosis-and-control-of-chronic-respiratory-tract-infections\/\">asthma<\/a><\/p>\n<\/li>\n<li data-start=\"2783\" data-end=\"2812\">\n<p data-start=\"2785\" data-end=\"2812\">inflammation of the heart muscle<\/p>\n<\/li>\n<\/ul>\n<p data-start=\"2814\" data-end=\"2889\">Children may develop dehydration due to high fever and vomiting.<\/p>\n<h2 data-start=\"2891\" data-end=\"2911\">Treatment of influenza B<\/h2>\n<p data-start=\"2913\" data-end=\"2942\">Treatment for influenza B involves:<\/p>\n<ul data-start=\"2944\" data-end=\"3097\">\n<li data-start=\"2944\" data-end=\"2994\">\n<p data-start=\"2946\" data-end=\"2994\">antiviral drugs as recommended by a doctor<\/p>\n<\/li>\n<li data-start=\"2995\" data-end=\"3021\">\n<p data-start=\"2997\" data-end=\"3021\">antipyretics<\/p>\n<\/li>\n<li data-start=\"3022\" data-end=\"3052\">\n<p data-start=\"3024\" data-end=\"3052\">adequate fluid intake<\/p>\n<\/li>\n<li data-start=\"3053\" data-end=\"3073\">\n<p data-start=\"3055\" data-end=\"3073\">bed rest<\/p>\n<\/li>\n<li data-start=\"3074\" data-end=\"3097\">\n<p data-start=\"3076\" data-end=\"3097\">contact restrictions<\/p>\n<\/li>\n<\/ul>\n<p data-start=\"3099\" data-end=\"3224\">According to the recommendations <span class=\"hover:entity-accent entity-underline inline cursor-pointer align-baseline\"><span class=\"whitespace-normal\">FDA<\/span><\/span>, early initiation of antiviral therapy reduces the risk of complications.<\/p>\n<p data-start=\"3226\" data-end=\"3297\">Antibiotics are not used without a confirmed bacterial infection.<\/p>\n<h2 data-start=\"3299\" data-end=\"3322\">Influenza B prevention<\/h2>\n<p data-start=\"3324\" data-end=\"3398\">Seasonal vaccination includes components against influenza A and B. Annual vaccine:<\/p>\n<ul data-start=\"3400\" data-end=\"3498\">\n<li data-start=\"3400\" data-end=\"3429\">\n<p data-start=\"3402\" data-end=\"3429\">reduces the risk of disease<\/p>\n<\/li>\n<li data-start=\"3430\" data-end=\"3459\">\n<p data-start=\"3432\" data-end=\"3459\">reduces the severity of the course<\/p>\n<\/li>\n<li data-start=\"3460\" data-end=\"3498\">\n<p data-start=\"3462\" data-end=\"3498\">reduces the likelihood of hospitalization<\/p>\n<\/li>\n<\/ul>\n<p data-start=\"3500\" data-end=\"3531\">Additional preventive measures:<\/p>\n<ul data-start=\"3533\" data-end=\"3661\">\n<li data-start=\"3533\" data-end=\"3556\">\n<p data-start=\"3535\" data-end=\"3556\">regular hand washing<\/p>\n<\/li>\n<li data-start=\"3557\" data-end=\"3585\">\n<p data-start=\"3559\" data-end=\"3585\">avoiding crowds<\/p>\n<\/li>\n<li data-start=\"3586\" data-end=\"3613\">\n<p data-start=\"3588\" data-end=\"3613\">ventilation of premises<\/p>\n<\/li>\n<li data-start=\"3614\" data-end=\"3633\">\n<p data-start=\"3616\" data-end=\"3633\">good sleep<\/p>\n<\/li>\n<li data-start=\"3634\" data-end=\"3661\">\n<p data-start=\"3636\" data-end=\"3661\">balanced diet<\/p>\n<\/li>\n<\/ul>\n<h2 data-start=\"3663\" data-end=\"3710\">Why it is important not to carry influenza B &quot;on your feet&quot;\u00ab<\/h2>\n<p data-start=\"3712\" data-end=\"3850\">Neglecting treatment can lead to complications. Even if symptoms seem mild, the body needs rest to recover.<\/p>\n<p data-start=\"3852\" data-end=\"4074\">Influenza B is a serious viral infection that requires careful attention. Early diagnosis, appropriate treatment, and prevention can minimize risks and protect yourself and your loved ones during the season of increased morbidity.<\/p>","protected":false},"excerpt":{"rendered":"<p>Influenza B is a seasonal viral infection that causes waves of illness every year along with influenza A. Although influenza B<\/p>","protected":false},"author":627,"featured_media":11446,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-11445","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-zahvoryuvannya-ta-symptomy"],"_links":{"self":[{"href":"https:\/\/medilab.km.ua\/en\/wp-json\/wp\/v2\/posts\/11445","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/medilab.km.ua\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/medilab.km.ua\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/medilab.km.ua\/en\/wp-json\/wp\/v2\/users\/627"}],"replies":[{"embeddable":true,"href":"https:\/\/medilab.km.ua\/en\/wp-json\/wp\/v2\/comments?post=11445"}],"version-history":[{"count":0,"href":"https:\/\/medilab.km.ua\/en\/wp-json\/wp\/v2\/posts\/11445\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/medilab.km.ua\/en\/wp-json\/wp\/v2\/media\/11446"}],"wp:attachment":[{"href":"https:\/\/medilab.km.ua\/en\/wp-json\/wp\/v2\/media?parent=11445"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/medilab.km.ua\/en\/wp-json\/wp\/v2\/categories?post=11445"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/medilab.km.ua\/en\/wp-json\/wp\/v2\/tags?post=11445"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}