Research and analysis

NOIDs causative agents: week 1 (week ending 4 January 2026)

Published 5 January 2026

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 2025/48 2025/49 2025/50 2025/51 2025/52 2026/01
Arboviruses            
West Nile Virus - - - 1 1 -
Bacillus            
Bacillus cereus 21 22 20 15 17 12
Bordetella            
Bordetella pertussis 3 6 4 2 2 2
Borrelia            
Borrelia burgdorferi 40 22 32 26 19 26
Borrelia sp 4 6 4 4 8 6
Brucella            
Brucella sp 2 1 2 3 1 -
Burkholderia            
Burkholderia mallei - - - - 1 -
Campylobacter            
Campylobacter coli 25 19 16 20 13 10
Campylobacter fetus 4 - - - 1 -
Campylobacter jejuni 224 279 296 283 240 146
Campylobacter other named 1 1 2 - 3 2
Campylobacter rectus 1 - - - - -
Campylobacter sp 955 825 894 849 639 645
Campylobacter upsaliensis - 1 - 1 1 1
Campylobacter ureolyticus (bacteroides corrodens) 1 1 1 1 1 -
Chikungunya virus            
Chikungunya virus 1 1 2 2 - -
Clostridium            
Clostridium perfringens 58 38 32 31 51 34
Coronavirus            
Coronavirus 33 54 77 95 95 113
Human coronavirus 229e 5 3 5 - 2 3
Human coronavirus hku1 - - 1 - - 1
Human coronavirus nl63 - - 3 - 1 2
Human coronavirus oc43 1 - 2 1 5 3
SARS-CoV-2 antibody void - - - - 2 2
SARS-CoV-2 coronavirus (COVID-19) 767 791 1,351 623 543 651
SARS-CoV-2 coronavirus (COVID-19) indeterminate 28 71 50 35 10 14
SARS-CoV-2 IgG antibody negative 2 6 10 7 4 4
SARS-CoV-2 IgG antibody positive 49 50 77 38 26 24
SARS-CoV-2 total antibody negative 8 8 - - 12 12
SARS-CoV-2 total antibody positive 37 19 19 7 43 15
Corynebacterium            
Corynebacterium diphtheriae 2 4 6 5 4 3
Corynebacterium ulcerans - - 1 1 - -
Coxiella            
Coxiella burnetii - 1 1 - - -
Cryptosporidium            
Cryptosporidium cuniculus 1 - - - - -
Cryptosporidium hominis 2 6 10 11 3 -
Cryptosporidium parvum 20 34 36 33 13 2
Cryptosporidium sp 58 50 37 28 35 34
Cryptosporidium ubiquitum 1 - - - - -
Entamoeba            
Entamoeba histolytica 2 5 4 4 3 2
Escherichia            
Escherichia coli O 157 13 11 4 6 3 2
Flaviviruses            
Dengue virus 6 3 3 3 4 1
Giardia            
Giardia intestinalis - - - 1 1 -
Giardia sp 124 145 124 148 84 84
Haemophilus            
Haemophilus influenzae 80 68 62 71 53 58
Hepatitis viruses            
Hepatitis A 35 12 14 12 13 3
Hepatitis B 241 272 253 256 161 194
Hepatitis C 213 270 232 592 152 176
Hepatitis D 4 6 5 4 2 4
Hepatitis E 39 26 33 31 24 19
Influenza virus            
Influenza A 7,010 9,226 9,527 7,851 6,033 6,031
Influenza B 73 46 71 51 47 56
Influenza indeterminate 9 12 18 7 23 38
Influenza ungrouped 148 219 218 318 228 140
Legionella            
Legionella longbeachae - 1 - - - -
Legionella pneumophila 4 2 7 12 4 2
Legionella sp 4 4 6 3 - 5
Listeria            
Listeria monocytogenes 4 3 7 2 6 4
Mycobacterium            
Mycobacterium tuberculosis 94 98 90 107 72 65
Neisseria            
Neisseria meningitidis 27 40 40 25 28 26
Orthopoxvirus            
Mpox virus positive 12 12 6 8 2 4
Paramyxoviruses            
Measles virus 25 11 11 9 7 8
Mumps virus 2 5 9 5 3 3
Plasmodium            
Plasmodium falciparum 14 - - - - 1
Plasmodium malariae 2 - - - - -
Plasmodium ovale 3 - - - - -
Plasmodium vivax 2 - - - - -
Polyomavirus            
Polyomavirus BK 71 73 75 79 53 40
Polyomavirus JC 7 2 18 7 15 8
Polyomavirus untyped 12 10 13 14 9 8
Rickettsia            
Rickettsia prowazekii 1 - - - - -
Rickettsia rickettsii 1 - - - - -
Rickettsia spotted fever - 1 - 1 1 -
Rickettsia tsutsugamushi - - 1 - 1 -
Rubella virus            
Rubella virus 1 1 1 2 2 2
Salmonella            
Other salmonellas 53 65 58 42 16 15
Salmonella agona - 5 - - - -
Salmonella bareilly 6 - 8 - - -
Salmonella enterica 5 - - 5 - -
Salmonella enteritidis 62 56 43 41 16 9
Salmonella kentucky 6 - - - - -
Salmonella newport 6 - - 7 - -
Salmonella saint-paul 8 - - - - -
Salmonella sp 39 23 30 49 71 81
Salmonella stanley 5 - - - - -
Salmonella typhi and paratyphi 14 10 11 7 5 5
Salmonella typhimurium 22 22 28 17 12 -
Salmonella virchow - - - 5 - -
Shigella            
Shigella boydii 1 1 1 1 2 -
Shigella dysenteriae - 2 1 - - 1
Shigella flexneri 19 12 28 12 10 12
Shigella sonnei 46 35 27 42 11 11
Shigella sp 59 52 41 35 36 41
Streptococcus            
Streptococcus group A 43 58 57 48 57 62
Streptococcus pneumoniae 105 151 143 189 163 223
Vibrio            
Vibrio cholerae 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 2025/48 2025/49 2025/50 2025/51 2025/52 2026/01
Citrobacter              
Citrobacter spp KPC 1 - 1 - 1 -
  NDM 1 - 2 2 1 -
  OXA48 - 4 2 1 2 -
  Other - - 1 - 1 -
Enterobacter              
Enterobacter cloacae complex IMP 2 - 3 2 2 1
  KPC 4 5 4 4 3 -
  NDM 8 6 4 15 7 1
  OXA48 5 8 6 4 11 1
  VIM - - - 1 - -
  Other 1 1 - 2 1 1
Other enterobacter spp NDM - - - 1 - -
Escherichia              
Escherichia coli IMP - 1 - - - -
  KPC 4 4 3 3 3 1
  NDM 12 25 15 15 17 4
  OXA48 26 28 22 21 14 7
  VIM - 1 - - - -
  Other 3 3 1 1 2 1
Escherichia marmotae NDM - - - 1 - -
  Other - - - 1 - -
Klebsiella              
Klebsiella aerogenes NDM - - - 1 - -
  OXA48 - 2 - 1 1 -
  Other - - - - 1 -
Klebsiella oxytoca IMP - - - - 1 -
  KPC 1 1 3 1 - -
  NDM 1 - - - - -
  OXA48 - 2 1 - - -
  VIM 1 - - - - -
  Other 1 1 - - - -
Klebsiella pneumoniae IMP - 2 1 - - -
  KPC 15 12 5 1 4 1
  NDM 10 7 5 10 10 1
  OXA48 13 10 15 13 6 -
  VIM - 1 1 - - -
  Other 1 3 2 2 - -
Klebsiella pneumoniae subsp ozenae KPC 1 - - - 2 -
Klebsiella variicola KPC 1 - - - - -
  OXA48 - - - - 1 -
Leclercia              
Leclercia adecarboxylata KPC 1 - - - - -
  NDM - 1 - - - -
  Other - 1 - - - -
Morganella              
Morganella morganii OXA48 - 1 - - 1 -
Pantoea              
Pantoea septica OXA48 - - - - 1 -
Proteus              
Proteus mirabilis NDM 1 - 2 - 1 -
  Other 2 - 1 - - -
Raoultella              
Raoultella ornithinolytica OXA48 - - 1 - - -
  Other - - 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 2025/48 2025/49 2025/50 2025/51 2025/52 2026/01
Acinetobacter              
Acinetobacter baumannii IMP - 1 - - - -
  NDM 1 - - 1 - -
  Other - 1 - 1 - -
Pseudomonas              
Pseudomonas aeruginosa IMP 1 - 1 - - -
  NDM 1 2 - 1 1 -
  VIM 2 1 - 1 - -
  Other 3 1 3 1 2 1
Pseudomonas alcaligenes VIM - - - - 1 -
Pseudomonas putida group NDM 1 - - - - -
Other              
  KPC - - - - 1 -
  NDM - - - 1 - -
  OXA48 1 - - 1 - -