Kenya: Dengue Fever Outbreak - Emergency Plan of Action (EPoA) n° MDRKE048

Situation Report
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A. Situation analysis

Description of the disaster

According to the county department of health in Mombasa, the first Dengue cases were reported in early March 2021 with 24 cases testing positive out of 47 (51% positivity rate). In April, another 305 cases tested positive out of 315 (97% positivity rate). The adjacent Lamu county, has also reported a total of 224 positive cases from different health facilities where 59 are children under 5 years old. Cumulatively, 553 cases have been reported within the past 4 months of January, February, March and April, with a peak of cases being reported in April. No deaths have been reported so far within the two counties.

Health officials in Mombasa County have warned over the Dengue fever outbreak and directed all their health officials in sub-counties to initiate “targeted preventive and control measures”. The County Director of Public Health of Mombasa made a request for support to Kenya Red Cross on 26 April 2021 and the Chief Officer, Medical Services & Public Health, County Government of Lamu, on the 28 April 2021. In both counties, the cases are on the rise and urgent action needs to be taken to prevent an all-out outbreak which would endanger the lives of the population causing a health disaster. Public health officials are warning that more cases should be expected as the seasonal ‘long rains’ run through to the end of May, boosting mosquito populations. The scenario is that if this spread of Dengue is not addressed urgently, it will spread into adjacent counties.

The trend is hardly a reflection of the true situation in the counties since people who suffer the milder form of the disease are not seeking medical attention. Dengue symptoms are also like malaria and Chikungunya and therefore diagnosis in most health facilities is a challenge because of the lack of Dengue test kits. According to county level health structures, this has resulted in clinicians misdiagnosing cases especially in the rural and informal settlements where access to the correct diagnostics and medical services is a challenge.

In Lamu county for example, the county disease surveillance team is yet to update its emergency reporting tool to include Dengue fever. This means that data can only be captured using the monthly reporting tool. Another obstacle to early case detection and management is the shortage of testing capacity (both PCR and Rapid test kits). Currently PCR, samples must be taken from some 150 sub counties to the KEMRI-Well Trust laboratory in Kilifi County that neighbors both Lamu and Mombasa, which can significantly compromise quality of diagnoses.

Previous outbreak data and monthly trends show that annual upsurges are experienced after the short and long rainfall seasons with dual peaks in February and June. The usual trend is that the next peak would be June after the long rains have subdued, however, in this case, the virus is surging at the beginning of the long rains. Therefore, with the onset of long rains it will most likely make the situation worse as the conditions become more conducive for the mass spread of the disease vector. Hence, with the heavy rains expected, preventive measures need to be accelerated to reduce the impact of the disease. The Kenya Meteorological Department also predicts normal to above rainfall along the coastal counties of Kenya for the long rains of April-June and this will increase the vector population and in turn a surge in new cases. There is also concern about a new variant of Dengue fever. A specialized team of experts from the Ministry of Health has been deployed in Mombasa county on 4 May 2021 to investigate this new variant of Dengue fever.

Dengue is a viral infection that causes a wide spectrum of diseases, from subclinical disease (where the person may not have symptoms) to the development of hemorrhagic fever. In recent years, Dengue has rapidly spread in all regions, especially Asia and African subcontinents. Female mosquitoes mainly of the Aedes aegypti spread the disease, for which there are four subtypes. These mosquitoes are also vectors of Chikungunya, Yellow fever and Zika viruses. Dengue is widespread throughout the tropics, with local variations in risk influenced by rainfall, temperature, relative humidity, and unplanned rapid urbanization.

Dengue causes a wide spectrum of signs and symptoms. According to WHO, these can range from subclinical disease (people may not know they are even infected) to severe flu-like symptoms in those infected. Although less common, some people develop severe Dengue, which can be any number of complications associated with severe bleeding, organ impairment and/or plasma leakage. Severe Dengue has a higher risk of death when not managed appropriately.

Severe Dengue was first recognized in the 1950s during Dengue epidemics in the Philippines and Thailand. Today, severe Dengue affects most Asian, Latin American and Eastern African Indian Ocean coastal countries and has become a leading cause of hospitalization and death among children and adults in these regions.

The last Dengue outbreak in Kenya occurred between 2011 and 2014. Dengue has distinct epidemiological patterns, associated with the four serotypes of the virus. These can co-circulate within a region, and indeed many countries are hyper-endemic for all four serotypes (1,2,3 and 4). Kenya has previously (2011-2014 outbreak) reported three types of the virus (1, 2 and 3). Infected travelers frequently transport DENV from one place to another; when susceptible vectors are present in these new areas, there is the potential for local transmission to be established.

Below is the latest distribution of Dengue cases across the sub counties of Mombasa and Lamu from the health departments active case search by surveillance teams.

The current outbreak was first reported in January 2021 and is currently affecting two Coastal counties of Mombasa and Lamu. Mombasa County has six sub counties: Mvita (Island), Changamwe and Jomvu (mainland West), Kisauni and Nyali (mainland North) and Likoni (mainland South) with a total projected population of 1,208,333 for 2019 (Kenya National Bureau of Statistics (KNBS)). The county is among the smallest geographically with coverage of approximately 212.5km². It borders Kilifi County to the North, Kwale County to the South West and the Indian Ocean to the East.

Lamu County is in the Northern Coast of Kenya. The County capital is Lamu town. The County covers a strip of northeastern coastal mainland and the Lamu Archipelago. Lamu County has a population of 143,920 and covers a total of 6,167 km² (2019, KNBS). The County has two constituencies, Lamu West and Lamu East: Lamu West has the seven electoral Wards of Shella, Mkomani, Hindi, Mkunumbi, Hongwe, Witu and Bahari while Lamu East has three electoral wards of Faza, Kiunga and Basuba.