Research and analysis

Outbreaks under monitoring: week 15 (week ending 12 April 2026)

Updated 16 April 2026

Disease or pathogen	Avian influenza A(H5N1)
Location	Cambodia
Status	Update
Reporting date	31 March 2026
Summary	On 31 March 2026, the Cambodian Ministry of Health (in Khmer) reported a human case of avian influenza A(H5N1) from Banteay Ampil district, Oddar Meanchey province in a 3-year-old child. This is the third avian influenza A(H5N1) case reported in Cambodia in 2026. Investigations found sick and dead poultry in the case’s home and in the village where they reside. The case was hospitalised and received medical care. Response activities by Cambodia’s cross-government health agencies are ongoing and include active case finding, contact tracing, and source investigation in both humans and animals. Oseltamivir has been offered to close contacts. In 2025, Cambodia reported 18 confirmed avian influenza A(H5N1) human cases, including 9 deaths.
Further information	Avian influenza: managing human exposures to incidents in birds or animals NaTHNaC country information page: Cambodia

Disease or pathogen	Plague
Location	United States of America (USA)
Status	New
Reporting date	7 April 2026
Summary	On 7 April 2026, the Apache County Public Health Services District, Arizona State, USA, reported a confirmed human case of plague. The individual has since recovered following medical care. In response, health authorities are assessing environmental risks to ensure appropriate response measures are in place. Health authorities consider the risk to the general public to be low. This is the first human case of plague in Apache County since 2015. In the USA, an average of 7 human cases of plague are reported annually. Most cases occur in western USA, particularly in the states of New Mexico and Arizona.
Further information	Plague: epidemiology, outbreaks and guidance Plague: interim guidance for clinicians NaTHNaC country information page: United States of America

Disease or pathogen	Crimean-Congo Haemorrhagic fever (CCHF)
Location	Pakistan and Senegal
Status	New
Reporting date	7 - 9 April 2026
Summary	On 7 April 2026, the Pakistan National Institute of Health issued an advisory for CCHF, due to the risk of disease transmission during Eid al-Adha as a result of increased human-animal contact. As of March 2026, 4 CCHF cases have been reported in Pakistan in 2026. On 9 April 2026, the Africa Centres for Disease Control and Prevention reported that in the week ending 29 March 2026, one confirmed human case of CCHF was reported from Dioffor, Fatick Region, Senegal. The case was a 28-year-old female who presented at a local health centre with symptoms on 25 February 2026. On 19 March 2026, samples taken from the case tested positive for CCHF. The case had no travel history in the 15 days prior to symptom onset. This is the second case of CCHF in Senegal in 2026, with the first case reported in February 2026 in the Tambacounda Region. Both Pakistan and Senegal report cases of CCHF annually. During 2025, 8 cases, including one death, were reported from Birkelane District in Senegal, whilst 82 cases, including 20 deaths, were reported in Pakistan. CCHF is not present in the UK, nor are there any identified established populations of Hyalomma ticks, the principal vectors of CCHF virus. Confirmed CCHF cases have been imported into the UK, including one fatal case in 2012 and one in 2014.
Further information	Crimean-Congo haemorrhagic fever: origins, reservoirs, transmission and guidelines HAIRS risk assessment: Crimean-Congo haemorrhagic fever NaTHNaC country information page: Pakistan and Senegal

Disease or pathogen	Mpox
Location	Pakistan
Status	New
Reporting date	10 April 2026
Summary	On 10 April 2026, media reported 14 mpox cases in Sindh, Pakistan, including 5 fatal cases amongst newborn babies. The fatal cases, all reported from Khairpur district, were described as involving infants with reduced immune capacity. In response, Sindh health authorities have established isolation wards in major and district headquarter hospitals across the province. The mpox clade type has not been reported. According to media, as of 14 April, 122 mpox cases (25 confirmed) and 9 deaths have been reported in Sindh in 2026. Historically, mpox cases reported in Pakistan since 2022 have been attributed to clade II. However, following the 2024 outbreak, one confirmed case of clade Ib mpox has been detected in the country as of 10 April 2026. Since 2024 and as of 31 March 2026, 45 cases of clade I mpox have been reported in the UK. Most of these cases have been directly or indirectly linked to travel to countries where clade Ib mpox is circulating.
Further information	Mpox: guidance NaTHNaC country information page: Pakistan