Research and analysis

Infectious disease surveillance and monitoring for animal and human health: summary April to October 2022

Updated 1 August 2024

Interpreting this report

The UK Health Security Agency’s (UKHSA) Emerging Infections and Zoonoses (EIZ) team uses an integrated horizon scanning approach, which combines information on both human and animal health, to identify and assess outbreaks and incidents of new and emerging infectious diseases globally.

This summary provides an overview of incidents (new and updated) of public health significance, which are under close monitoring. The incidents are divided into 2 sections: Notable incidents of public health significance and Other incidents of interest. Notable incidents that the EIZ team have been monitoring are allocated an incident assessment rating (see Incident assessment key for descriptions). The report also includes a Publications of interest section, which contains new publications relevant to emerging infections, and a final section which focusses on Novel pathogens and diseases.

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Incident assessment key

Rating	Description
Deteriorating	Incident is deteriorating with increased implications for public health
No change	Update does not alter current assessment of public health implications
Improving	Incident is improving with decreasing implications for public health
Undetermined	Insufficient information available to determine potential public health implications

Notable incidents of public health significance

Cholera: global update

Event summary

On 19 October 2022, the World Health Organization (WHO) stated that since January 2022, 29 countries had reported cholera cases. This compares to fewer than 20 countries on average reporting outbreaks in the previous 5 years. Factors attributed to the increasing global trend include floods, droughts, conflict, population movements and limited access to clean water.

After more than 3 years with no reported cases of cholera in Haiti, on 2 October 2022, authorities reported 2 confirmed cases in the greater Port-au-Prince area. As of 30 October 2022, 3,030 suspected cases, 399 confirmed cases and 89 deaths had been reported from 6 departments. This outbreak, combined with ongoing crises related to gang violence and insecurity, has strained the country’s health system’s response capacity. In a report published on 12 October 2022, WHO assessed the overall risk for this outbreak as very high at the national level, moderate at regional level and low at global level.

An outbreak of cholera was reported in Lebanon on 6 October 2022, the first to be reported in the country since 1993. As of 28 October 2022, 1,225 confirmed and suspected cases, including 16 deaths, had been reported from 9 governorates. The outbreak was reported 6 weeks after a cholera outbreak was declared in neighbouring Syria. WHO states that responding to the outbreak may overwhelm the already fragile health system in the country, and that due to porous borders allowing free movement between Lebanon and neighbouring countries, the exportation of cholera cases is highly likely.

The current cholera outbreak in Malawi, which began in March 2022, is the largest cholera outbreak reported in the country in the past 10 years. Between 3 March and 31 October 2022, 6,056 cases including 183 deaths were reported from 27 of 29 districts in Malawi (case fatality rate of 3.0%), with active transmission ongoing in 23 districts. Flooding, due to extreme weather events in early 2022, has led to the displacement of a population with low pre-existing immunity that now lacks access to safe water and adequate sanitation conditions. WHO states that there is a continued risk for further increases in cases numbers and international spread. The risk of further spread of the disease is considered very high at national and regional levels.

In Syria, between 25 August and 22 October 2022, 24,614 cases of cholera were reported, including 2,204 confirmed cases and 81 deaths (case fatality rate of 0.33%). Syria’s health system has been repeatedly strained through concurrent emergencies and challenges that continue to affect the availability and quality of health services across the country.

Other

On 19 October 2022, WHO reported that due to a strained global supply of cholera vaccines, the International Coordinating Group temporarily suspended the standard 2-dose vaccination regimen in cholera outbreak response campaigns, using instead a single-dose approach.

Incident assessment

The incident is deteriorating with increased implications for public health.

COVID-19: global update

Event summary

By the end of October 2022, WHO had reported over 627 million coronavirus (COVID-19) cases and over 6.5 million deaths globally. Over 12.8 billion vaccine doses had been administered globally, as of 26 October 2022.

Incident assessment

No change – update does not alter current assessment of public health implications.

Further information

WHO’s global weekly epidemiological updates.

ECDC’s weekly surveillance summary for European countries.

UKHSA’s national COVID-19 surveillance reports.

Polio: global update

Wild polio virus type 1 (WPV1)

Between 1 January and 25 October 2022, a total of 29 cases of WPV1 were reported to the Global Polio Eradication Initiative, with 2 cases reported from Afghanistan, 7 from Mozambique and 20 from Pakistan. WPV1 remains endemic in 2 countries: Afghanistan and Pakistan.

Circulating vaccine derived polio virus (cVDPV)

As of 25 October 2022, 48 cases of acute flaccid paralysis (AFP) caused by cVDPV type 1, with symptom onset in 2022, have been reported globally. Cases were reported from the DRC (29 cases), Madagascar (8 cases), Malawi (3 cases) and Mozambique (8 cases). This is an increase in cases compared to 2021 and 2020, when 16 and 35 cases had symptom onset in the reporting year, respectively.

As of 25 October 2022, 400 AFP cases of cVDPV type 2 (cVDPV2), with symptom onset in 2022, had been reported from 14 countries. The DRC has seen an increase in cases so far in 2022 (160 cases) compared to previous years (28 cases in 2021 and 81 cases in 2020). On 8 July 2022, WHO was notified of a case of cVDPV2 with AFP from Tamanrasset Province, southern Algeria. This represents the first cVDPV2 case identified in the country. As of 25 October 2022, the global number of cases with symptom onset in 2022 remained lower than the total numbers seen in 2021 (682 cases) and 2020 (1,081).

In March 2022, a case of cVDPV type 3 was confirmed in Israel in an unvaccinated child who had developed AFP. This was the first case of poliomyelitis to be reported in Israel since 1988. Testing found genetic links to strains detected in environmental samples from Jerusalem and Bethlehem taken between September 2021 and January 2022. No further AFP cases were identified in Israel, as of 25 October 2022.

Other updates

In July 2022, an AFP case of VDPV2 was reported in New York State in the US. The case was unvaccinated and had no recent history of international travel. This is the first case of poliomyelitis reported in the US since 2013. In recent months, poliovirus has been detected in environmental samples from the US (New York State), the UK (London) and in sewage samples collected between January to June 2022 from Israel (Jerusalem District); the viruses were found to be genetically linked. No human case associated with VDPV2 has been reported in the UK. Poliovirus identified in the UK and the US was classified as ‘circulating’ VDPV2 due to multiple mutations and continued detection over an extended time period.

Incident assessment

No change – update does not alter current assessment of public health implications.

Mpox: global update

Event summary

In May 2022, cases of mpox (then termed monkeypox) began to be identified in countries not considered endemic for the disease. This was the first time that sustained transmission of mpox was identified without direct or immediate epidemiological links to West or Central Africa. Clade IIb (B.1 lineage) is the mpox strain associated with this outbreak. Globally, a total of 77,264 confirmed cases, 3,622 probable cases and 36 deaths had been reported to WHO by the end of October 2022 from 109 member states. Outside of endemic countries, the outbreak has mainly been in men who have sex with men. Males between 18 and 44 years of age account for 79.6% of cases (where data is available). A decrease in the number of cases globally has been observed since a peak in August 2022.

In the UK, the first cases of mpox associated with this outbreak were confirmed on 6 May 2022. As of 31 October 2022, 3,552 confirmed cases and 149 highly probable cases had been reported, with the majority of cases (3,378 confirmed and 149 highly probable) being located in England. Since a peak in mid-July 2022, the number of cases in England has been declining.

WHO assesses the global risk of this outbreak as moderate.

Incident assessment

Improving – incident is improving with decreasing implications for public health.

Other incidents of interest

Infectious diseases

Acute hepatitis of unknown aetiology

On 5 April 2022, the UK notified WHO of 10 cases of acute hepatitis of unknown aetiology in children. Cases have since been reported in multiple countries. As of 8 July 2022, 35 countries in 5 WHO regions had reported 1,010 probable cases which fulfilled the WHO case definition, including 22 deaths. A decrease in the number of cases has been observed since a peak in late April 2022. A possible association with adenovirus infection has been identified, although other causes remain under investigation. As of 4 July 2022, samples from 258 out of 274 cases in the UK had been tested for adenovirus, of which 170 (65.9%) were positive.

Avian Influenza A(H3N8)

In April 2022, a human case of avian influenza A(H3N8) was identified in China. The case, a 4-year-old child from Henan Province, developed fever and shortness of breath. No further cases were detected among contacts. WHO assessed the risk of disease spread at national, regional and international levels as low.

In May 2022, a second human case of avian influenza A(H3N8) was reported in a 5-year-old boy residing in Hunan Province, China.

These 2 cases are the first ever human cases of avian influenza A(H3N8) to be reported globally.

Avian influenza A(H5N1)

In April 2022, a human case of avian influenza A(H5N1) was reported in Colorado, US. The case had been involved in culling poultry infected with avian influenza A(H5N1) at a farm. The patient recovered and did not require hospitalisation. This is the first human case of avian influenza A(H5N1) to be reported in the US.

Spain reported 2 human cases of avian influenza A(H5N1) among poultry workers on a farm in Guadalajara, where avian influenza A(H5N1) infection had been confirmed in poultry. The first case tested positive in September 2022 and the second in October 2022. Neither case experienced any symptoms and there was no evidence of human-to-human transmission. Both cases were likely infected through exposure to infected poultry or contaminated environments.

Avian influenza A(H5N6)

Between April and October 2022, 7 cases of avian influenza A(H5N6) were reported in mainland China, bringing the total number of human cases reported so far in 2022 to 24. One case each was reported from Henan, Jiangsu, Sichuan and Jiangxi provinces, while 3 cases occurred in Guangxi Province (in April, July and September 2022). Since 2014, a total of 81 human cases of avian influenza A(H5N6) have been reported from mainland China.

Crimean-Congo haemorrhagic fever (CCHF)

As of 29 October 2022, Afghanistan had reported 103 confirmed and 264 suspected CCHF cases during 2022. There had been 15 associated deaths reported.

In July, an individual tested positive for CCHF in Côte d’Ivoire, following consumption of meat from a sick ox.

Iraq has reported a higher number of CCHF cases in 2022, compared to previous years. As of 7 August 2022, 287 confirmed cases, including 52 deaths, were reported by WHO, although media sources report 299 confirmed cases. In 2021, 33 confirmed cases were reported.

Mauritania reported an outbreak of CCHF in February 2022 in Hodh.

In El Gharbi Region, as of 27 April 2022, 7 cases had been reported, including 2 deaths. Additionally, 3 cases, including 2 deaths were reported between 29 August and 31 October 2022, bringing the total number of cases identified in 2022 to 10, as of 31 October.

On 12 August 2022, Senegal confirmed an outbreak of CCHF in Podor District, Saint-Louis Region. The index case had a history of recent travel to Mauritania. As of 28 August 2022, 5 cases and 2 deaths had been reported.

In July 2022, Spain confirmed 2 cases of CCHF in Bierzo, León Province, one of which was fatal. One case of CCHF had previously been reported in León Province in 2021.

South Africa has reported 3 cases of CCHF so far in 2022, as of the end of October. Of these cases, 2 were in Western Cape Province and one in Eastern Cape Province. A total of 221 confirmed CCHF cases have been confirmed in South Africa since 1981.

Media reported several cases of CCHF in Turkey during 2022, including 12 cases in Sivas, 8 cases in Erzincan, 4 cases in Tokat, 2 fatal cases in Yozgat, a fatal case in Bingöl and a suspected case in Malatya.

Uganda reported 5 confirmed cases of CCHF, including one death, between 12 July and 15 October 2022.

Dengue

In 2022, São Tomé and Príncipe reported the first outbreak of dengue to ever be identified in the country. Between 15 April and 31 October 2022, 1,019 cases and 6 deaths were reported. Laboratory testing identified the predominant serotype as dengue virus serotype 3 (DENV-3).

In 2022, Bangladesh reported the second-highest number of dengue cases since 2000, when records first began. As of 31 October 2022, 38,024 cases were reported, with 21,932 of these occurring in the month of October. Rohingya refugee and Forcibly Displaced Myanmar Nationals camps in Cox’s Bazar experienced an increase in cases which started at the end of May 2022.

An increase in dengue cases has been observed in Pakistan following severe flooding in June 2022. As of 27 September 2022, 25,932 confirmed cases and 62 deaths had been reported. There is high population movement between Pakistan and neighbouring countries such as Iran and Afghanistan, which means that the international spread of dengue cannot be ruled out.

Nepal has been experiencing an increase in dengue cases which began in August 2022. As of 28 of September 2022, 28,109 cases, including 38 deaths among confirmed cases, had been reported. Dengue is recurrent in Nepal, meaning that the population may be at risk of re-infection.

Corynebacterium diphtheriae

An increase in cases of Corynebacterium diphtheriae was identified among migrants in Europe in 2022. As of 26 October 2022, 129 cases had been reported in Europe, the majority of which (100 cases) presented with cutaneous diphtheria. In the UK, 14 cases were reported. The European Centre for Disease Prevention and Control published a risk assessment in October 2022, and proposed that the increase in cases could be due to an increase in migrants travelling from countries endemic for diphtheria, transmission in reception centres, and/or increased transmission in countries of origin.

Hantavirus

As of 28 August 2022, 38 hantavirus cases and 6 deaths were identified in Argentina during 2022. The type of hantavirus is not reported for nearly all cases. The confirmed cases include an individual in Chubut who developed symptoms in August 2022 and was a household contact of a previous fatal case that occurred in July 2022. Whole genome sequencing confirmed Andes virus in both cases. It is considered highly probable that human-to-human transmission occurred between the 2 cases.

As of 16 October 2022, 23 confirmed hantavirus cases and 5 deaths were reported in Chile during 2022. The type of hantavirus was not reported. In total, 37 hantavirus cases were reported in Chile during 2021.

Hepatitis

An outbreak of hepatitis E continues in Bentiu internally displaced persons camp (IDP) in Unity State, South Sudan. In 2022, South Sudan’s Ministry of Health, together with Médecins Sans Frontières, vaccinated approximately 25,000 people. This vaccination campaign represents the first time globally that the hepatitis E vaccine has been used in response to a public health emergency. From January 2019 to 30 October 2022, 3,548 hepatitis E cases were reported in Bentiu IDP camp.

Japanese encephalitis

As of 25 August 2022, 30 confirmed cases and 10 probable cases of Japanese encephalitis had been reported in Australia in 2022, including 6 deaths among confirmed cases. The outbreak represents a geographical expansion of the area affected by Japanese encephalitis virus; this is the first time that locally-acquired human cases have been identified in mainland Australia since 1998. In the last 10 years, only one locally acquired case had been reported in Australia, in the Tiwi Islands, Northern Territory.

Lassa fever

In April 2022, the Ministry of Health and Public Hygiene of Guinea declared a Lassa fever outbreak in Guéckédou Prefecture. A total of 2 confirmed cases were reported during this outbreak. An additional outbreak of Lassa fever was detected in Guinea in September 2022, in Conakry and Kindia prefectures. A total of 18 confirmed cases, one probable case and 2 deaths were reported. In late September 2022, a single case of Lassa fever was confirmed in Nzérékoré Prefecture, which was not known to be epidemiologically linked to the previous cases.

In 2022, as of 23 October 2022, a total of 156 cases of Lassa fever, including 52 confirmed cases and 17 deaths among confirmed cases (case fatality rate of 33%), had been reported in Liberia. In 2021, 112 suspected and 24 confirmed cases (15 deaths) were reported as of 21 November.

In Nigeria, there were 7,183 suspected and 958 confirmed cases of Lassa fever reported between 1 January and 30 October 2022. A total of 176 deaths have been reported amongst confirmed cases (case fatality rate of 18.4%). This is an increase in the number of reported cases when compared to the same period in 2021 (3,495 suspected, 403 confirmed cases and 89 deaths amongst confirmed cases, with a case fatality rate of 22.1%). Enhanced surveillance across the country has improved case detection.

In April 2022, one imported case of Lassa fever was reported in South Africa, in an individual with recent travel history to Nigeria. No further cases were identified.

Malaria

Between January and August 2022, over 3.4 million suspected cases of malaria, including over 170,000 confirmed cases, were reported in Pakistan, compared to 2.6 million suspected cases reported in 2021. The risk at a national level was assessed by WHO as very high considering that flooding affected the national health systems capacity, with rapid assessments indicating that 1,543 health facilities had been damaged.

Marburg virus disease

In July 2022, Ghana reported an outbreak of Marburg virus disease. A total of 3 confirmed cases (2 deaths) were reported, all of which were epidemiologically linked. The outbreak was declared over on 16 September 2022, and was the [first time that cases of Marburg virus disease had been identified in Ghana](https://www.afro.who.int/countries/ghana/news/ghana-reports-first-ever-suspected-cases-marburg-virus-disease.

Measles

Large outbreaks of measles continue to be reported globally, particularly from parts of Asia and Africa. From May to October 2022, the countries reporting the highest number of measles cases globally include India (11,055 cases), Yemen (7,914 cases) Somalia (7,397 cases), Zimbabwe (4,861 cases) and Pakistan (3,270). Other countries reporting large outbreaks include Ethiopia, Liberia, Indonesia, Nigeria and Angola.

Middle East respiratory syndrome coronavirus (MERS-CoV)

Between 29 December 2021 and 31 October 2022, 4 MERS-CoV cases were reported in Saudi Arabia: 2 cases in Riyadh (with symptom onset in December 2021 and June 2022), one case in Gassim (with symptom onset in March 2022) and one case in Makka Al Mukarramah (with symptom onset in April 2022).

In Oman, one MERS-CoV case was reported in April 2022, from Al Dhahira Governorate. This was the first case to be reported from Oman since February 2019.

Between 22 March and 3 April 2022, 2 MERS-CoV cases were reported in Doha, Qatar.

Overall, 6 of the 7 MERS-CoV cases reported contact with camels; exposure history was reported as unknown for one case from Saudi Arabia.

Plague

In the DRC, 615 suspected cases of bubonic plague had been reported in 2022, up to 9 October. In total, 10 deaths have been reported, resulting in a case fatality rate of 1.6%. In comparison, in 2021, 138 suspected cases and 14 deaths were reported (case fatality rate of 10%).

During the reporting period, cases of plague were also reported in by the media in various countries. One case of bubonic plague was reported in July 2022 in Must District, Mongolia. A fatal case of bubonic plague was reported in Ambatolaona, Madagascar in October 2022. In China, a case of bubonic plague was reported in July 2022 in Ningxia Hui Autonomous Region and 2 cases of pneumonic plague were reported in Tibet in October 2022.

West Nile virus

The West Nile virus transmission season in Europe generally occurs from June to November each year. As of 26 October 2022, Italy, Greece and Serbia had reported relatively high numbers of cases compared to previous years. Italy reported 573 cases, Greece reported 283 cases and Serbia reported 226 cases.

Yellow fever

As of 26 August 2022, 8 countries in the WHO Africa Region had reported confirmed yellow fever cases in 2022: Central African Republic (11 cases), Cameroon (8 cases), DRC (4 cases), Kenya (3 cases), Chad (2 cases), Republic of the Congo (2 cases), Uganda (2 cases), and Ghana (1 case). The Eliminate Yellow fever Epidemics (EYE) strategy classifies 27 countries in the Africa Region as high-risk for yellow fever. WHO reports that vaccination coverage in the region is suboptimal and not high enough to confer population immunity.

Publications of interest

Infectious diseases

COVID-19

Findings from a recent Nature Communications publication suggest that minimal adaptation of SARS-CoV-2 was required for onward transmission in mink and deer following human-to-animal spillover.

Ebola virus disease

A study carried out in Liberia reports that older age, decreased illness severity, elevated total serum Immunoglobulin G3 and human leukocyte antigens -C*03:04 allele expression may be risk factors associated with persistence of Ebola virus in the semen of survivors.

Malaria

Findings from a phase 1/2b trial suggest that a booster of the R21/Matrix-M vaccine maintained high efficacy against malaria. The vaccine has now progressed to phase 3 trials, with the aim of attaining licensing in 2023.

Marburg virus disease

A recent publication suggests that the incubation period of Marburg virus disease may be longer than previously considered. Previous evidence suggested that the incubation period of Marburg virus disease had an average of between 5 to 10 days (range 3 to 21 days). However, 2 cases which occurred during the 2004 to 2005 outbreak in Angola had an incubation period of at least 23 and 26 days. In 2022, 2 cases in Ghana had incubation periods of 21 to 24 days and 25 to 28 days.

Mpox

Researchers report that the 2022 global outbreak strain of mpox virus diverges from the original strain (isolated from cases in Nigeria during 2018 and 2019) by 50 single nucleotide polymorphisms, and that such a divergence might represent accelerated evolution.

Characteristics of mpox cases identified in Italy suggest close physical contact in sexual networks has played an imported role in transmission in the 2022 outbreak.

West Nile virus

In 2022, West Nile virus activity started earlier than usual in Italy. A recent publication described a newly introduced West Nile virus lineage 1a, which was first identified in the country in 2021, co-circulating with West Nile virus lineage 2.

Zika

A global study of Zika virus incidence from 2011 to 2019 found the age-standardised incidence rate was highest in 2015 (20.25 cases per 100,000 population) and decreased to 3.44 cases per 100,00 population in 2019. Most Zika virus infections were reported from Latin America.

Other

An article was published in September 2022 on simian haemorrhagic fever virus (SHVF), a type of simian arteriviruses. Simian arteriviruses are endemic in wild African primates and can cause haemorrhagic fever in macaques. The study demonstrates that the CD163 receptor is used by SHFV for cellular entry. The cellular proteins required for SHFV replication are also functional in human cells. However, no human cases of infection with simian arteriviruses have been identified to date.

A recently published study predicts that by the year 2070, under climate change and land-use scenarios, virus species will aggregate in new combinations at high elevations, in biodiversity hotspots, and in highly populated areas in Africa and Asia, and states that this ecological transition may already be under way. Furthermore, a publication from August 2022, reports that 58% of infectious diseases have been aggravated by climatic hazards.

Novel pathogens and diseases

Langya henipavirus

A correspondence piece published in August 2022 identified Langya henipavirus, a new henipavirus, which was associated with febrile illness in 26 people between 2018 and 2021 in China. The individuals all reported recent contact with animals. There was no evidence of human-to-human transmission. The virus was detected in shrews in the region, suggesting that they may be a natural reservoir for the virus.

Candidatus Anaplasma sparouinense

In August 2022, researchers reported a case of human infection with a novel Anaplasma species, called Candidatus Anaplasma sparouinense. The affected individual resided in the rainforest of French Guiana and was retrospectively diagnosed based on testing of samples taken in October 2019 and May 2021.

Authors of this report

Alethea Charlton
Bláthnaid Mahon
Michael Reynolds