Medical Contact Group Newsletter

From the ECDC (European Centre for Disease Prevention and Control) Weekly Communicable Disease Threats Report, the US CDC, and the WHO: 

Current data indicates significant ongoing transmission of chikungunya in the Seychelles. The ECDC is advising travellers to take enhanced mosquito bite-prevention measures, as well as to consider vaccination in line with recommendations in their country of origin.

Still significant seasonal respiratory virus circulation in much of the Northern hemisphere, now with a decreasing trend, and mostly affecting people older than 65 years in terms of seriousness. Influenza A(H3N2) has been this season’s dominant strain. In some tropical and Southern Hemisphere regions, influenza activity has been reported outside the usual peak season. Globally, COVID-19 activity has been unremarkable. 

From the ECDC Weekly Communicable Disease Threats Report, the US CDC, and the WHO: 

• Various influenza and related:

• Japan has declared an early start of the influenza season. Elsewhere in the Northern hemisphere, namely in Europe, influenza circulation remains low. In Europe, there is widespread but decreasing circulation of SARS-CoV-2, with limited severity.
• So far in October there have been reports of one case of avian influenza A(H5N1) in Cambodia, and the second human case of avian influenza A(H5) since 2024 in Mexico City, while two new human cases of avian influenza A(H9N2) had been reported in China earlier in September. No extraordinary measures have been necessary.

• Ebola in DRC: 
  
  A total of 64 cases of Ebola virus disease haa been reported in Bulape, Kasai Province, DRC. The current risk for people travelling to the region is estimated to be low by the ECDC, due to low likelihood of exposure. Bulape is more than 1000 km by road from Kinshasa. 

• Chikungunya – world:
  
  According to a recent assessment by the WHO, given the ongoing outbreaks reported globally in 2025, including resurgence in some countries that had not reported substantial numbers in recent years, the potential for further spread remains significant. More here:

From the ECDC (European Centre for Disease Prevention and Control) Weekly Communicable Disease Threats Report, the US CDC, and the WHO: 

Chikungunya:  

Since the beginning of 2025, approximately 317,000 CHIKVD (Chikungunya virus disease) cases have been reported in 16 countries/territories in the Americas, Africa, Asia, and Europe. 

As reported last month, South America still accounts for the highest cumulative number of cases reported worldwide, with an ongoing outbreak in Bolivia in a region far from La Paz, and cases in Brazil and Argentina. In Europe, just last week, two countries reported new locally-acquired cases of chikvd: 45 in France and 22 in Italy.

The situation has been evolving in Asia now with an outbreak in China’s southeastern coastal province of Guandong (see US CDC map) – a total of 830 new cases were reported in the period 10-16 August. Since the start of the outbreak in July, at least 9,933 cases have been reported, mostly in the city of Foshan. Other nearby territories, such as Macao and Honk Kong have reported locally acquired CHIKVD cases associated with imported cases from Guangdong. According to the Chinese CDC, so far, cases have been mild with no deaths. Containment measures have been put in place, such as drones to identify sources of standing water, larvae-eating fish and community isolation for infected individuals. 

From the ECDC Weekly Communicable Disease Threats Report, the US CDC, and the WHO:

• Marburg virus disease (MVD) outbreak in Tanzania: The MVD outbreak in Rwanda was declared over last month. On 20 January, Tanzania declared an MVD outbreak in Kagera region where a previous outbreak occurred in March 2023. This time so far 10 cases have been reported, of which two confirmed and eight probable. Response efforts are ongoing: https://www.who.int/emergencies/disease-outbreak-news/item/2025-DON552

• Acute respiratory infections: There is high influenza activity in Europe as expected for this time of year, while SARS-CoV-2 activity is at very low level. It looks like influenza has peaked in the US as well earlier this month.
  

• Global outbreak of mpox: The global epidemiological situation of clade I and clade II mpox remains essentially unchanged with the virus circulating in multiple countries.

• Highly pathogenic avian influenza (HPAI) A(H5N1):
• Ohio is the US state with the most cases of H5N1 avian influenza in poultry, with some 3 million birds affected.
• Recent research has revealed signs of mammalian adaptation of viral strains circulating in cattle populations.
• Human infections with avian influenza viruses remain rare and sporadic, with no evidence of sustained human-to-human transmission so far. According to the US CDC, the risk to the general population remains low.

From the ECDC Weekly Communicable Disease Threats Report, the US CDC, and the WHO:

• Marburg virus disease (MVD) outbreak in Rwanda: 42 days after the last patient tested negative for the virus twice, as per the usual protocol for ending these types of outbreaks, the outbreak was declared over on 20 December. This outbreak resulted in 66 cases, with 15 deaths, mostly from a single cluster linked to healthcare facilities that treated the index case. The MVD fatality rate ranges from 24% to 88%. In this outbreak, the fatality rate was lower at around 23%.

• Acute respiratory infections complicated by malaria: This is the name now given by the WHO to an initially undiagnosed disease outbreak reported in early December in the Kwango province of the DRC, in a remote region that requires a 48-hour road trip to be reached from the capital, Kinshasa. The WHO has concluded that the outbreak has been caused by a combination of multiple acute respiratory infections complicated by malaria, malnutrition and limited healthcare access. Children under five have been disproportionately affected. Most cases tested positive for malaria. Common respiratory viruses were also detected, such as influenza A (H1N1) and parainfluenza viruses, rhinoviruses, and SARS-CoV-2. Coordination and infection prevention and control measures are to be strengthened. Further details here: https://www.who.int/emergencies/disease-outbreak-news/item/2024-DON547
  

• Global outbreak of mpox:
• Overall, the global epidemiological situation of clade I and clade II mpox is fairly stable.
• Outside the affected African countries, small household clusters of cases of MPXV clade Ib have been reported in the UK and Germany since October, the first US case was detected in November, and a case was reported in Belgium earlier this month.  All index cases had travelled to affected areas in Africa.

• Avian influenza:
• The first case of bird flu was confirmed in New Zealand in an egg farm early December. However, this was not a case of the H5N1 type circulating among wildlife around the world, rather a case of H7N6, which is considered unlikely to be transmitted to mammals.
• H5 bird flu is widespread in wild birds worldwide and is causing outbreaks in poultry and US dairy cow. So far there is a total of 66 confirmed human cases of influenza A(H5N1) in the US. One severe case was confirmed on 13 December in Louisiana following exposure to sick and dead birds in backyard flocks. On 18 December, the Governor of California declared a state of emergency in the state to further expand monitoring and contain and mitigate the spread of H5N1.
• Human infections with avian influenza viruses remain rare and sporadic, with no evidence of sustained human-to-human transmission so far.   According to the US CDC, the risk to the general population remains low.

From the ECDC Weekly Communicable Disease Threats Report, the US CDC, and the WHO:

• Marburg virus disease outbreak in Rwanda:
• No new cases of Marburg virus disease have not been reported in Rwanda since the end of October. All patients who were under care have recovered.
• Overall, by mid-November, 66 cases, including 15 deaths, had been reported. All cases seem to belong to one large cluster linked to healthcare facilities and one presumed index case.
• If no cases are reported in the 42-day period starting on 9 November 2024 the outbreak will be declared over.
• The US CDC has been performing enhanced public health screenings at three designated airports (JFKJ, ORD, IAD) to identify air travellers entering the US who might have Marburg symptoms or who may have come in contact with the virus while in Rwanda in the preceding 21 days.
• However, the US is no longer recommending that nonessential travel to Rwanda be reconsidered. The current updated recommendation is for travellers to practice enhanced precautions, which means the CDC Marburg in Rwanda Travel Health Notice level has been  lowered from 3 to 2 – details here: https://wwwnc.cdc.gov/travel/notices/level2/marburg-rwanda 
• Both the ECDC and the US CDC assess the risk from the Marburg virus outbreak in Rwanda to Europe and to the USA respectively, as s.

• Global outbreak of mpox:
• There have been no significant changes in the global epidemiological situation of clade I and clade II mpox.
• The WHO published on 28 November temporary recommendations agreed during the second meeting of the International Health Regulations Emergency Committee regarding the upsurge of mpox:
  https://www.who.int/news/item/28-11-2024-second-meeting-of-the-international-health-regulations-(2005)-emergency-committee-regarding-the-upsurge-of-mpox-2024  These recommendations are an addition to the  standing recommendations for mpox (see previous MCG update), which will be extended until 20 August 2025. The additional temporary recommendations mainly regard enhancing emergency coordination between countries, collaborative surveillance and laboratory diagnostics, clinical care and vaccination, financing and research. As for international traffic the focus is on provision of information to travellers and operators, without resorting to general travel and trade restrictions unnecessarily impacting local, regional or national economies.

From the ECDC Weekly Communicable Disease Threats Report, the US CDC, the Africa CDC, and the WHO:

• Global outbreak of mpox:
• Overall, more than 24,000 confirmed or suspected mpox cases due to both clades I and II have been reported from 14 African Union Member States since the beginning of the year. Similarly to previous weeks, although there is an increasing trend in cases of MPXV clade I reported by the DRC and Burundi, the epidemiological profile of the cases remains the same.
• No new countries have reported confirmed mpox cases due to clade I.
• No secondary transmission has been reported from the two clade I cases imported to Sweden and Thailand.
• The WHO has not changed its recommendation against implementing travel-related health measures specific for mpox. No international travel or trade restriction measures are recommended.

• Until now this year, a total of 14 human cases of avian influenza A(H5) have been reported in the US. Most of the cases involved individuals who had had direct contact with infected poultry or dairy cattle. The most recent case, from earlier this month, which was reported in the state of Missouri and detected through that state’s seasonal flu surveillance system, is the first instance without any documented exposure to infected animals, and it is still under investigation – it is not yet known whether the implicated virus is H5N1. The patient, who had underlying medical conditions, was hospitalized and treated with influenza antiviral medications, was later discharged from hospital and has recovered.
• The US CDC continues to assess the risk to the general public as low due to the absence of sustained human-to-human transmission. CDC updates here: https://www.cdc.gov/bird-flu/situation-summary/index.html
  

• COVID-19: WHO global COVID-19 dashboard with cases from the last 7 and the last 28 days here: https://data.who.int/dashboards/covid19/cases

• Oropouche virus (OROV) disease: This year and until 31 August, 9,852 cumulative confirmed cases of OROV disease have been reported in Brazil, Peru, Cuba, Bolivia, Colombia, and the Dominican Republic. Over 30 cases have been confirmed in the US - most in Florida and all linked to travellers returning from Cuba. Another 19 exported cases have also been reported in Spain, Italy and Germany. The risk of OROV disease for persons travelling to countries in the Americas where transmission is ongoing or has been reported is assessed by the ECDC as moderate. When travelling to regions where the virus is present, the use of insect repellent and other insect bite prevention measures are recommended. The US CDC also recommends that travellers returning from affected regions use insect repellent for three weeks after returning to prevent possible transmission to others via midges or mosquitoes.

From Airfinity’s curated analysis of various health and media sources, the US CDC, and the ECDC (European Centre for Disease Prevention and Control) Weekly Communicable Disease Threats Report:

• H5N1 infections have now been reported in a total of 185 dairy herds across 13 US states. Colorado is the first state to mandate weekly bulk tank milk testing.
• 25 human H5N1 cases have been detected globally: US (13), Cambodia (9), Vietnam (2), and Australia (1). There is a possible instance of human-to-human transmission in Texas, but outside the US all cases were most likely transmitted from bird to human.
• The US CDC have recommended that children under five, adults 65 years and older, and others at a higher risk of developing serious flu complications, should try and limit contact with animals that could carry influenza viruses at upcoming county fairs. Specific recommendations for fair exhibitors have been issued including reducing the time pigs, poultry, and cattle are on display to not more than 72 hours.
• There currently are several H5N1 vaccine pipeline candidates, eight of which mRNA-based. Meanwhile the US CDC have announced they will offer seasonal influenza vaccines to farmworkers.

• According to the CDC, Colorado has reported the first US case of influenza A(H3N2) variant (v) virus infection in 2024 in a person who attended an agricultural event. The person recovered without hospitalization. When an influenza virus that normally spreads in swine but not people is found in a person it is called a variant influenza virus. No additional cases or person-to-person spread have been identified. Since 2005, 517 variant influenza virus infections have been reported in the US, generally linked to pig exposure.
  

• COVID-19: Indicators of increased SARS-CoV-2 activity in healthcare settings have been observed in Europe since late spring. The overall impact on hospitals and mortality has been relatively low. Variant BA.2.86 and its subvariants, including KP.3, continue to dominate and are not expected to be associated with increased infection severity or to significantly reduce vaccine effectiveness.

• France has reported the first case of autochthonous chikungunya since 2017. The case was reported in the Greater Paris region and is also the first in the whole of EU/EEA since 2017. Previously, between 2010 and 2017, France had had 31 locally transmitted cases of chikungunya. In the Indian state of Tamil Nadu there is an ongoing surge of chikungunya infections, with over three hundred confirmed cases so far this year.

• Malaria has reemerged as a significant issue in Kokrajhar, Chirang, and Udalguri, three districts in Assam, India.

• Nigeria has reported almost five thousand cholera cases since the beginning of the year. Lagos state accounts for 65% of all suspected cases in the country.