Travel Health Alerts

Peak dengue season forecast; Flu uptick in tropical Asia

An increase in dengue fever cases is likely this year as the cycle of outbreaks takes an upward turn, according to the Department of Disease Control (DDC). The provinces of Mae Hong Son, Chiang Mai, Ubon Ratchathani, Tak and Si Saket are ranked highest for dengue incidence, while it has been reported that more adults are being infected this year. In neighbouring Laos, the capital Vientiane has registered the majority of the 18,000-plus cases this year and four of the 17 deaths. Other dengue-affected provinces are Luang Namtha, Saravan and Attapeu. Read more

GLOBAL flu data for the week to Aug 7 shows overall declines or normal inter-seasonal influenza activity in most regions, however increasing trends were reported in Cambodia, Malaysia, Singapore, Thailand (predominantly influenza A(H3N2)) and India (influenza A(H1N1)pdm09). Read more

Advice for travellers

: In most years, seasonal flu is the most common vaccine-preventable travel-related illness: it’s likely to be found aboard aircraft, in crowded airport terminals, and at your destination. Whether you are travelling within Australia or overseas, vaccination is highly recommended and travellers should also avoid close contact with people showing flu-like symptoms, and thoroughly washing hands using soap and water after using the toilet and before eating. Alcohol-based hand sanitiser is a convenient alternative if soap and water is not available.

New Ebola case in NE

A new Ebola virus disease (EVD) case has been confirmed in the city of Beni, in the NE province of North Kivu, and initial sequencing has linked it to the 2018-2020 outbreak in the same area. The infected person had been hospitalised for treatment of other medical conditions and was only tested for EVD post-mortem. Preliminary analysis published in virological.org suggests transmission occurred ‘from a persistently infected survivor or a survivor who experienced a relapse’. All contacts are being monitored and, according to reports, 59 of the 60 healthcare workers treating the woman were vaccinated. Read more

Advice for travellers

Ebola virus disease is a severe viral haemorrhagic fever found in humans and other primates (such as monkeys, gorillas, and chimpanzees). It spreads through families and friends in close contact with blood and infectious secretions of people with obvious symptoms and, as such, presents a low risk to tourists to the affected countries. Read more about Ebola virus disease.

2nd local dengue case in Occitanie

Insecticide fumigation is being carried out in the town of Andrest, in the SW region of Hautes-Pyrénées (Occitanie), after a locally acquired case of dengue fever was confirmed. The town’s mayor told local media that this year they had been plagued by swarms of the invasive mosquito species Aedes albopictus, a dengue fever vector. Last month a local dengue fever infection was reported in Perpignan, the capital of Pyrénées-Orientales département. Read more

Advice for travellers

Dengue fever is common in most tropical or sub-tropical regions of the world. The virus is spread by daytime-feeding Aedes mosquitoes and to avoid it and other insect-borne diseases, travellers should apply an insect repellent containing an effective active ingredient, such as DEET, Picaridin or oil of lemon eucalyptus (PMD), to exposed skin when outdoors during the day. In addition, cover up with long-sleeved tops, long pants, and shoes and socks around dawn and dusk, as well as other times when the mosquitoes are active.

Lassa fever cases in capital

Surveillance of fever and vomiting symptoms in patients at a clinic in the capital Conakry earlier this month has resulted in six confirmed Lassa fever cases and a further probable infection being detected. The cases were either from Conakry or Kindia (a city 90kms to its NE), and monitoring of contacts is underway in greater Conakry and Kouroussa. Read more

Advice for travellers

Lassa fever is an acute viral illness that occurs in sub-Saharan West Africa, notably in Nigeria, Guinea, and Liberia. As many as 300,000 cases and 5,000 deaths occur each year. However, Lassa is a remote risk for most travellers. Rodents shed the virus in urine and droppings and it is spread between humans through direct contact with the blood, urine, faeces, or other bodily secretions of an infected person. For 80% of people infected, Lassa fever is mild or has no observable symptoms. The remaining 20% can experience severe, often fatal, multisystem disease. Read more about Lassa fever.

Mosquito-borne infection rates increase

As the monsoon season heads into its third month, health authorities are ramping up vector control measures due to rising cases of dengue fever and/or chikungunya in the states of Karnataka, West Bengal and Maharashtra (Pune). While in Mumbai (Maharashtra), it’s increasing rates influenza and malaria in the community that are concerning doctors in some quarters. Assam’s toll from Japanese encephalitis (JE) infections continues to mount, with 77 deaths from more than 375 cases recorded since the beginning of July. Lastly, health authorities in the state of Mizoram have confirmed their first JE case in a man from the capital, Aizawl. Read more

Advice for travellers

A mosquito-borne virus, JE is generally found in many parts of Asia, the Indian subcontinent, Southeast Asia, China, Indonesia and PNG, and more recently, in areas of southern and eastern Australia. In Asia, it is mainly found in rural areas around rice paddies where pigs, wading birds and humans live closely together, however it does also occur in or near cities. The risk to short-stay travellers who confine their travel to large urban centres and use appropriate mosquito bite avoidance measures is low. The recommendations for vaccination are itinerary-specific. Read more on JE.

COVID-19 update

The latest WHO epi update noted that while new COVID-19 case numbers had fallen by 24 percent and deaths by six percent for the week, fatalities over the previous month had risen by 35 percent. The Western Pacific and SE Asia were the only regions to record an upswing in deaths, logging increases of more than 60 percent in Japan and South Korea and between five and 28 percent in India, Thailand and Indonesia. On Aug 17, the WHO director-general observed that the current rate of 15,000 deaths per week is ‘completely unacceptable, when we have all the tools to prevent infections and save lives’. Read more

In related news:

- A CIDRAP article summarises a study on the comparison of incubation times for the original SARS-CoV-2 and its variants from a systematic review and meta-analysis, showing the duration ‘fell over time’. The study was published the week in JAMA Network Open.

Chikungunya acquired in Bali

A ProMED post details chikungunya infections contracted by four European travellers between March and June this year, with symptoms presenting either during their stay or on return home from holidays in Bali. The last confirmed outbreak of chikungunya in Bali occurred around five years ago in the northern regency of Buleleng. Read more

Advice for travellers

The symptoms of chikungunya fever are similar to dengue fever and both are transmitted by day-time feeding Aedes mosquitoes. Acute joint pain with a rash is typical of chikungunya and while fatal cases are rare, painful joints may persist for weeks or months after the acute phase has ended. There is no vaccine or prevention medication; using an effective, tropical-strength repellent to avoid insect bites is the best form of protection. Read more about chikungunya.

WNV toll climbs

After an early start to the West Nile virus (WNV) season in Italy’s north this year, the case count has risen to 228 (and 13 deaths) and a new risk area has been identified after the city of Pistoia in Tuscany registered its first human WNV infection. In news on a related zoonotic virus, routine surveillance of donated blood in Italy has detected an asymptomatic Usutu virus (USUV) infection in a resident of Piedmont. This is the third human USUV case confirmed, all from the country’s north (Piedmont and Friuli). WNV and USUV belong to the Japanese encephalitis antigenic complex, have overlying ranges and share the same life cycle – bird hosts and mosquito vectors. Humans are dead-end hosts. Read more

Advice for travellers

West Nile virus is endemic in Eastern Europe and the Mediterranean basin, with sporadic outbreaks reported in summer and autumn since the 1950s. Most human WNV infections (70-80%) are mild, subclinical or asymptomatic, but around 1-in-150 cases involve potentially severe neuroinvasive disease.  The virus is transmitted by Culex mosquitoes, which feed mainly around dawn and dusk. While the risk of infection for most travellers is generally low, those visiting regions reporting human cases, particularly the peak transmission season, should take measures to avoid mosquito bites. Europe’s outbreaks are generally not as severe or widespread as in other regions where the virus occurs, notably North America. Read more on WNV.

Cholera now reported in north

Confirmed cases from an outbreak of cholera in the country’s south now total 1358 with 55 deaths, and late last week the health ministry issued a cholera alert for a northern district, Nkhata Bay. Meanwhile the WHO reports that cholera continues to sicken residents living in three of Mozambique's provinces, however it has observed is a declining trend in new infections in the eight affected districts of Nampula, Sofala and Zambezia provinces. Read more

Advice for travellers

Cholera is usually spread in contaminated water. For most short-stay travel, the risk of infection is low. Travellers to regions where a cholera outbreak is occurring should adhere to strict personal hygiene guidelines and choose food and beverages with care. Read more about cholera.

VD polio in 3 countries, ramifications of VD polio spread

The latest GPEI update covered the detection of circulating vaccine-derived poliovirus type 2 (cVDPV2) in three countries: two cases in Niger (Dosso region), three in Nigeria (Zamfara state) and two in Yemen (Abyan and Ibb governates). Elsewhere, more media attention has been directed at the US polio case and positive wastewater testing reported this year in both the UK and USA, and the implications for international travel. One such article authored by Prof. Michael Toole of the Burnet Institute was published this week in The Conversation: ‘The latest polio cases have put the world on alert. Here's what this means for Australia and people travelling overseas’. Read more

Advice for travellers

Poliomyelitis is a potentially serious viral illness that is spread through contact with infected faeces or saliva. The risk to travellers is generally low, however vaccination is recommended for travel to affected regions and is a requirement for travel to/from some countries. If at risk, adults should have a booster to the childhood series. More on polio.

Suburban rabies risk; Dengue rates highest in west

News sources report that 25 deer inhabiting a suburban area of Colombo district have died of rabies infection recently. Residents of Homagama have been warned to avoid contact with remaining herds and to stop feeding them. Read more

THE WESTERN Division has recorded around half of the 50,000 dengue cases registered in Sri Lanka in the year to August - the end of the first of the two annual peak seasons (the second is November to January). The Division takes in the districts of Colombo, Gampaha and Kalutara. Financial constraints have limited vector control programs used in the management of the mosquito-borne infection. Read more

Advice for travellers

Rabies is present in most countries and all travellers should be aware of the importance of avoiding contact with wild and domestic animals, including bats. If bitten or scratched, urgent post-exposure treatment is required. Vaccination is generally recommended for longer stays, especially travellers planning to live in, or travel extensively through, rural areas and also for children; however the final recommendation is itinerary-specific. Read more on rabies.

Success against 4 neglected diseases

During a WHO AFRO Regional Committee meeting held earlier this week, the WHO director-general offered his congratulations to the government and people of Togo for their achievement in eradicating four Neglected Tropical Diseases (NTDs): Dracunculiasis, Lymphatic filariasis, Human African Trypanosomiasis and Trachoma. Read more  

Monkeypox cases top 44,000 globally

North America and Europe continue to report the bulk of new monkeypox infections, as reported in the Aug 23 WHO update, while the global 7-day average has fallen from over 900 new cases per day on Aug 15 down to 600 on Aug 22, according to Our World in Data. In the latest Technical Briefing issued by the UK health authorities on Aug 19, transmission in that outbreak continues mainly ‘within a defined sub-population, currently gay, bisexual and men who have sex with men (GBMSM) connected by sexual networks’. Strong evidence is lacking on ‘sustained transmission outside some sexual networks of GBMSM, although the increase in cases who are women requires close surveillance’ (moderate confidence). From the latest update for Australia (dated Aug 18): 89 cases have been reported - 40 in Victoria, 39 in NSW, three in both Qld and WA, and two in the ACT and SA. Local transmission has been confirmed in Vic and NSW, leading state health departments to issue advice on prevention to at-risk groups. Read more

Advice for travellers

Closely related to the smallpox virus, monkeypox has its origins in Central and Western Africa. Rodents are the suspected reservoir, with monkeys and humans as secondary or ‘spill-over’ hosts. People travelling in endemic countries can be infected by eating undercooked ‘bushmeat’ or handling infected animals, making infection a low risk in those regions. More recently, monkeypox has spread person-to-person around the globe, primarily through large respiratory droplets, but also via direct contact with skin lesions or body fluids (i.e. close or intimate contact) and indirect contact by way of contaminated bedding, clothes etc. Read more from the WHO on the current outbreaks of monkeypox.

Vivax malaria outbreak continues

An update a month after malaria outbreaks were declared in North East and West Coast Santo, South East Malekula, Epi Island and South East Vanua Lava advised that the case count has risen to 612 - a 90 percent increase on the entire 2021 total. Plasmodium vivax was identified in all cases, according to Health Promotions Vanuatu. Read more

Advice for travellers

Travelvax recommends that travellers planning a visit to malarious regions discuss their itinerary and preventative measures, including medication, during a pre-travel medical consultation. More on malaria.

Measles spreads countrywide

The measles outbreak that first started in unvaccinated children from a religious community in Manicaland has now spread to Harare, Midlands, Masvingo, Mashonaland (East, Central and West), Matabeleland North and South, and Bulawayo. More than 2,000 measles cases have now been recorded and there have been 157 related deaths. All children aged from six months to 15 years will be offered measles vaccination, ‘regardless of their vaccination status’. Read more

Advice for travellers

Measles occurs in developing and developed countries and unvaccinated travellers are at particular risk, both in transit and during their stay. While generally benign, infection can result in severe illness or death. Travelvax Australia recommends travellers check their immunisation status for measles and other childhood diseases such as diphtheria, whooping cough (pertussis) and mumps at least 6 weeks before departure. Read more about measles.