Beyond our Borders – March 2020
Communicated by: National Institute for Communicable Diseases
The ‘Beyond our Borders’ column focuses on selected and current international diseases that may affect South Africans travelling abroad.
1. Cholera: Yemen and Somalia
Yemen is currently suffering from a forgotten cholera crisis. Oxfam international (a confederation of 19 independent charitable organisations focusing on the alleviation of global poverty), warned of the high number of people infected with the disease with the approaching rainy season in April, while health care systems are on the verge of collapse. It noted that more than 56 000 suspected cases have already been recorded in the first seven weeks of 2020, roughly equal to the same period in 2019. The number of deaths from cholera in 2019 dropped to 1 025, less than half the number of fatalities in 2017. However, efforts to definitively beat the disease have been massively undermined by the war, which has decimated health, water and sanitation systems. Medical supplies are in chronically short supply and only around half the health facilities in Yemen are fully functional. Fluctuating exchange rates have pushed up the price of diesel, in turn increasing the price of trucking clean water to parts of the country where groundwater is unavailable. More than 17 million people struggle to get clean water.
Meanwhile, in Somalia, at least seven deaths and over 700 cases have been reported in a cholera outbreak, the United Nations (UN) said on Sunday 1 March 2020. A total of 732 cases was recorded across the country between 23 January and 25 February 2020. According to the UN’s Office for the Coordination of Humanitarian Affairs (UNOCHA), women and children under the age of five were most vulnerable, and they would need more help if acute watery diarrhoea (AWD)/cholera cases surge after the next rainfall season.
2. Measles: Central African Republic
The Central African Republic (CAR) has experienced an upsurge in measles cases as a result of outbreaks since 2019. The first case of measles was recorded in week 5 of 2019 (week commencing 28 Jan 2019), and the outbreak has continued through to week 7 of 2020 (week commencing 10 February 2020), with 18 health districts affected, including 12 newly affected in 2020. From 1 January 2019 through 16 February 2020, a total of 7 626 suspected cases, including 83 deaths, was reported. A large proportion of cases (72%) was below the age of five, and 18% of cases were aged between 5 and 10 years. A total of 1 167 samples from suspected cases were tested at the reference laboratory of the Institut Pasteur in Bangui, of which 180 were positive for measles using immunoglobulin M (IgM).
The low vaccination coverage for routine measles vaccine over the past five years (below 60% for the 1st dose at 9 months), the absence of a 2nd measles vaccine dose in the national immunisation schedule, and inadequate follow up campaigns, resulted in a high proportion of measles susceptible people. This has contributed to the ongoing epidemic. All 35 health districts of the CAR are at risk of a measles outbreak, and without adequate response, the epidemic could spread through the entire country.
In December 2019, the outbreak affected 8 health districts, and the country organised local measles vaccination campaigns that targeted children aged 6 – 59 months, in seven districts. Despite vaccination coverage of more than 95% after the campaign, as confirmed by the vaccination coverage survey, new cases are being recorded in these districts and neighbouring health districts in children aged from 5 – 15 years old. Based on the age distribution of cases as indicated by epidemiological investigations, the proposed vaccination strategy is to target the risk group (aged 6 months to 10 years) to help stop transmission.
3. Dengue: French Guiana, Guadeloupe, Martinique, and Saint-Martin
On 12 February 2020, the European Centre for Disease Prevention and Control (ECDC) reported an increase in the number of cases of dengue infection in French Guiana, Guadeloupe, Martinique, and SaintMartin. Dengue epidemics in these territories usually occur when there is a shift in the predominant circulating dengue virus (DENV) serotype, and non-immune populations (e.g. tourists, new immigrants, or people not previously exposed to the circulating serotypes) are exposed to the new serotype through human movements within the territories or across neighbouring countries. Local transmission occurs through the Aedes mosquito vector present on the islands and in French Guiana.
Health authorities in French Guiana, Guadeloupe, Martinique, SaintMartin, and Saint-Barthélemy are implementing the following measures: • Strengthening integrated vector management (IVM); • Enhanced surveillance of cases; • Updating clinical management guidelines; • Social mobilisation; and • Emergency risk communications.
4. Lassa fever: Nigeria
Lassa fever is endemic in Nigeria, and the annual peak of human cases is usually observed during the dry season (December–April). In week 10 of 2020 (1 – 8 March 2020), the number of new confirmed cases decreased from 85 cases in week 9, to 81 cases. The 81 newly confirmed and 364 newly suspected cases in week 10 indicate that Lassa fever virus transmission is continuing at a relatively high level, although declining somewhat. These cases were reported from 15 States. Cumulatively from week 1 to week 10 of 2020, 144 deaths have been reported with a case fatality rate (CFR) of 16.8%, which is lower than the CFR for the same period in 2019 (23.3%). The predominant age-group affected is 21-30 years. The male to female ratio for confirmed cases is 1:1.2.
Transmission of Lassa fever virus occurs when individuals are in contact with rodent reservoir host excreta, or are within healthcare facilities. The National Emergency Operations Centre (EOC) of Nigeria has been activated to coordinate response activities across states. Of the states with confirmed cases, eight of them have activated state-level EOCs.