Research and analysis

NOIDs causative agents: week 49 (week ending 7 December 2025)

Updated 9 December 2025

The list of causative agents that laboratories must notify the UK Health Security Agency (UKHSA) about has been expanded to include additional notifiable organisms. These became reportable under the Health Protection (Notification) (Amendment) Regulations from 6 April 2025.

Publication of the additional causative agents will begin at a later date, once reporting development work has been undertaken to include them.

This report contains statistics of formal notifications of causative agent test results to UKHSA from diagnostic laboratories in England, under Regulation 4 of the Health Protection (Notifications) Regulations 2010.

The number of notifications in this report reflects test results provided from laboratories to UKHSA before UKHSA interprets or applies standardised case definitions to these test results. Individual test results will not always result in a confirmed diagnosis of a disease, therefore the notifications in this report should not be considered counts of cases and should be interpreted with caution.

Epidemiology reports including confirmed case numbers using standardised case definitions are published separately on a per pathogen or pathogen-group basis.

Laboratories in England have a statutory duty to notify UKHSA of the identification of the following causative agents:

  • Bacillus anthracis
  • Bacillus cereus
  • Bordetella pertussis
  • Borrelia spp
  • Brucella spp
  • Burkholderia mallei
  • Burkholderia pseudomallei
  • Campylobacter spp
  • Carbapenemase-producing Gram-negative bacteria
  • Chikungunya virus
  • Chlamydophila psittaci
  • Clostridium botulinum
  • Clostridium perfringens
  • Clostridium tetani
  • Corynebacterium diphtheriae
  • Corynebacterium ulcerans
  • Coxiella burnetii
  • Crimean-Congo haemorrhagic fever virus
  • Cryptosporidium spp
  • Dengue virus
  • Ebola virus
  • Entamoeba histolytica
  • Escherichia coli O 157
  • Francisella tularensis
  • Giardia spp
  • Guanarito virus
  • Haemophilus influenzae (invasive)
  • Hanta virus
  • hepatitis A
  • hepatitis B
  • hepatitis C
  • hepatitis D
  • hepatitis E
  • influenza virus
  • Junin virus
  • Kyasanur Forest disease virus
  • Lassa virus
  • Legionella spp
  • Leptospira interrogans
  • Listeria monocytogenes
  • Machupo virus
  • Marburg virus
  • measles virus
  • mpox virus
  • mumps virus
  • Mycobacterium tuberculosis complex
  • Neisseria meningitidis
  • Omsk haemorrhagic fever virus
  • Plasmodium falciparum
  • Plasmodium Knowlesi
  • Plasmodium Malariae
  • Plasmodium Ovale
  • Plasmodium Vivax
  • polio virus
  • Rabies virus
  • Rickettsia spp
  • Rift Valley fever virus
  • Rubella virus
  • Sabia virus
  • Salmonella spp
  • SARS coronavirus
  • Shigella spp
  • Streptococcus group A (invasive)
  • Streptococcus pneumoniae (invasive)
  • Varicella zoster virus
  • Variola virus
  • Vibrio cholerae
  • West Nile virus
  • Yellow fever virus
  • Yersinia pestis

Statutory notifications of causative agents, grouped by root organism

Totals for the current week compared to the previous 5.

Week notification received 2025/44 2025/45 2025/46 2025/47 2025/48 2025/49
Arboviruses            
West Nile Virus - 2 - - - -
Bacillus            
Bacillus cereus 15 14 26 23 21 22
Bordetella            
Bordetella pertussis 2 2 5 1 3 6
Borrelia            
Borrelia burgdorferi 34 41 39 20 38 21
Borrelia other named - - - 1 - -
Borrelia sp 24 7 3 5 5 7
Brucella            
Brucella sp 1 2 2 3 2 1
Campylobacter            
Campylobacter coli 43 31 31 28 24 18
Campylobacter fetus - 1 - 1 4 -
Campylobacter gracilis - 1 1 - - -
Campylobacter jejuni 298 330 312 277 217 246
Campylobacter other named 3 1 1 1 1 1
Campylobacter rectus - - - 1 1 -
Campylobacter sp 1,031 1,002 977 877 918 852
Campylobacter upsaliensis 1 - 1 1 - 1
Campylobacter ureolyticus (bacteroides corrodens) - 1 - - 1 1
Chikungunya virus            
Chikungunya virus 1 1 2 - 1 1
Clostridium            
Clostridium perfringens 40 42 36 41 55 38
Coronavirus            
Coronavirus 20 31 24 27 32 54
Human coronavirus 229e - - 6 - 5 3
Human coronavirus nl63 - 1 1 - - -
Human coronavirus oc43 - - 1 1 1 -
SARS-CoV-2 antibody indeterminate 6 4 - - - -
SARS-CoV-2 antibody void 10 20 12 6 - -
SARS-CoV-2 coronavirus (COVID-19) 1,526 1,400 805 638 708 790
SARS-CoV-2 coronavirus (COVID-19) indeterminate 67 36 42 24 28 71
SARS-CoV-2 IgG antibody negative 12 5 8 5 2 6
SARS-CoV-2 IgG antibody positive 71 48 60 48 49 50
SARS-CoV-2 total antibody negative 4 8 12 4 8 8
SARS-CoV-2 total antibody positive 32 36 45 15 37 19
Corynebacterium            
Corynebacterium diphtheriae 3 7 8 2 2 4
Corynebacterium ulcerans 1 1 - - - -
Coxiella            
Coxiella burnetii 1 - - - - 1
Cryptosporidium            
Cryptosporidium cuniculus 1 - 2 2 - -
Cryptosporidium felis - 1 - - - -
Cryptosporidium hominis 27 17 13 8 1 -
Cryptosporidium parvum 36 20 35 28 18 8
Cryptosporidium sp 52 54 34 45 62 82
Entamoeba            
Entamoeba histolytica 1 4 1 3 2 4
Escherichia            
Escherichia coli O 157 13 10 14 11 10 7
Flaviviruses            
Dengue virus 3 12 9 3 6 3
Giardia            
Giardia intestinalis 1 - 1 - - -
Giardia sp 146 138 137 143 123 145
Haemophilus            
Haemophilus influenzae 58 76 66 46 74 68
Hepatitis viruses            
Hepatitis A 18 18 19 17 32 11
Hepatitis B 247 232 290 241 234 252
Hepatitis C 223 254 235 228 206 246
Hepatitis D 10 10 2 3 3 6
Hepatitis E 33 26 53 21 39 25
Influenza virus            
Influenza A 3,416 3,906 3,489 3,841 6,927 9,129
Influenza B 44 51 43 56 72 45
Influenza indeterminate 6 5 11 15 9 12
Influenza ungrouped 84 95 61 88 148 216
Legionella            
Legionella longbeachae - - - - - 1
Legionella pneumophila 7 11 8 5 4 1
Legionella sp 3 7 3 7 4 5
Leptospira            
Leptospira interrogans - - 1 - - -
Listeria            
Listeria monocytogenes 3 3 2 10 4 3
Mycobacterium            
Mycobacterium tuberculosis 116 114 83 98 80 88
Neisseria            
Neisseria meningitidis 32 28 35 35 27 41
Orthopoxvirus            
Mpox virus positive 10 7 15 19 12 12
Paramyxoviruses            
Measles virus 10 8 14 7 25 11
Mumps virus 8 5 7 4 2 5
Plasmodium            
Plasmodium falciparum - - - 3 14 -
Plasmodium malariae - - - - 2 -
Plasmodium ovale - - - - 3 -
Plasmodium vivax - - - - 2 -
Polyomavirus            
Polyomavirus BK 67 60 60 49 63 70
Polyomavirus JC 10 13 15 14 7 2
Polyomavirus untyped 66 6 17 16 12 10
Rickettsia            
Rickettsia prowazekii - - - - 1 -
Rickettsia rickettsii - - - - 1 -
Rickettsia spotted fever - - - - - 1
Rubella virus            
Rubella virus 3 6 2 1 1 1
Salmonella            
Other salmonellas 64 61 54 62 46 21
Salmonella bareilly 7 5 - 7 5 -
Salmonella chester 5 8 5 5 - -
Salmonella enterica 6 - 5 - - -
Salmonella enteritidis 75 71 73 70 40 11
Salmonella infantis - - 7 6 - -
Salmonella java 7 - 7 - - -
Salmonella mikawasima 6 - - - - -
Salmonella newport 8 11 8 13 5 -
Salmonella saint-paul 7 - 5 - - -
Salmonella sp 31 24 17 39 102 134
Salmonella typhi and paratyphi 15 9 10 13 14 6
Salmonella typhimurium 43 31 44 23 13 9
Shigella            
Shigella boydii 2 4 2 2 1 1
Shigella dysenteriae 2 - - 1 - -
Shigella flexneri 17 21 20 19 15 7
Shigella sonnei 41 49 35 34 36 25
Shigella sp 98 99 80 66 72 68
Streptococcus            
Streptococcus group A 41 42 71 57 40 55
Streptococcus pneumoniae 140 127 123 99 100 141
Vibrio            
Vibrio cholerae 1 1 - - 1 4

Carbapenemase-producing Enterobacterales (CPE)

For all Carbapenemase-producing Gram-negative organisms, the reports are de-duplicated by first mention of organism species and resistance mechanism by person in a rolling 52-week period.

Note: the numbers presented here do not include specimens that have been referred to the Antimicrobial Resistance and Healthcare Associated Infections (AMRHAI).

Week notification received 2025/44 2025/45 2025/46 2025/47 2025/48 2025/49
Citrobacter              
Citrobacter spp IMP - 1 1 - - -
  KPC 1 - 1 1 1 -
  NDM 6 2 - 4 1 -
  OXA48 3 3 1 3 - 1
  VIM 1 - - - - -
  Other - - - 1 - -
Enterobacter              
Enterobacter cloacae complex IMP 2 - - 5 - -
  KPC 6 3 4 3 4 -
  NDM 10 3 4 10 6 1
  OXA48 6 1 2 2 5 1
  VIM 1 - - - - -
  Other 1 1 - 3 1 -
Other enterobacter spp NDM 1 1 - - - -
  OXA48 - - - 1 - -
Escherichia              
Escherichia coli IMP - - 1 - - -
  KPC 2 8 - 4 3 1
  NDM 14 12 32 15 11 7
  OXA48 17 21 31 32 23 9
  VIM - - - 1 - -
  Other 1 1 3 3 3 1
Hafnia              
Hafnia alvei OXA48 1 - - - - -
Klebsiella              
Klebsiella aerogenes IMP - 1 - - - -
  OXA48 - 1 - - - -
  Other 1 - - - - -
Klebsiella oxytoca KPC 1 - 1 1 - 1
  NDM - 2 - - - -
  OXA48 - - - 1 - -
  VIM - - - - 1 -
  Other - - - - 1 -
Klebsiella pneumoniae IMP - - - 1 - 1
  KPC 9 8 8 11 13 2
  NDM 11 9 13 10 8 -
  OXA48 16 12 15 13 11 1
  Other 2 3 3 1 2 -
Klebsiella variicola OXA48 - 1 - - - -
Other klebsiella spp KPC - 1 - - - -
Leclercia              
Leclercia adecarboxylata KPC - - - - 1 -
  NDM - - - - - 1
  Other - - - - - 1
Proteus              
Proteus mirabilis NDM - 2 1 5 1 -
  OXA48 - - - 1 - -
  Other - 1 1 1 1 -
Providencia              
Providencia rettgeri (proteus rettgeri) NDM - - 1 - - -
Raoultella              
Raoultella ornithinolytica OXA48 - 1 - 1 - -
  Other - 1 - - - -
Other Raoultella spp KPC 1 - - - - -

Other carbapenemase-producing Gram-negative organisms

For all Carbapenemase-producing Gram-negative organisms, the reports are de-duplicated by first mention of organism species and resistance mechanism by person in a rolling 52-week period.

Note: the numbers presented here do not include specimens that have been referred to.

Week notification received 2025/44 2025/45 2025/46 2025/47 2025/48 2025/49
Acinetobacter              
Acinetobacter baumannii IMP 1 - - - - -
  NDM 1 - - 1 1 -
  Other - - 1 1 - 1
Other acinetobacter spp NDM - - - 1 - -
Pseudomonas              
Pseudomonas aeruginosa IMP - 1 - 1 - -
  NDM - 2 - - 1 -
  VIM - 2 1 - 2 -
  Other 1 2 1 2 3 -
Pseudomonas putida group NDM - - - - 1 -
  VIM - 1 1 - - -
Other pseudomonas spp NDM 1 - - - - -
Other              
  NDM - 1 - - - -
  OXA48 - - - - 1 -
  Other 1 - - - - -