Kenya FELTP Residents: Dr. Irungu Karuga - Cohort 14, Dr. Ali Nur - Cohort 14, Richard Kihara -Cohort 14, and Dr. Elvis Oyugi - Field Coordinator participated in a measles outbreak from September 2018 in Madera County Kenya.
Measles is a highly contagious, vaccine-preventable, viral disease that causes significant mortality and morbidity in children under the age of 5 years (World Health Organization, 2018). In Kenya, two doses of measles containing vaccines (MCV) are administered at 9 months and 18 months of age in the routine immunization schedule. (GoK, 2013).
The National coverage for MCV1 and MCV2 in 2017 was reported at 89% and 35% respectively (GoK, 2013). In 2016, a supplemental immunization activity (SIA) was done using a combined Measles-Rubella (MR) vaccine. The vaccine was introduced into routine immunization program in the same year (Manakongtreecheep & Davis, 2017).
In 2018, measles outbreaks were reported in Kenya. A total of 404 cases were reported from January 2018 to Mid-September 2018. Among these cases, 20 (5.0%) were laboratory confirmed and 1 death (CFR=0.2%). The cases were reported in five counties; Mandera, Wajir, Garissa, Nairobi and Kitui.
Mandera had previous measles outbreaks in 2006, 2011 and in 2016 (Eziakonwa-onochie, 2016; International Federation of Red & Societies, 2006; Red & Societies, 2011). In 2018, the first outbreak began in January in Mandera East with a confirmed case from Lafey Sub county on 8 January 2018 with a total of 103 cases reported and with 4 laboratory confirmations. A second outbreak began in June in Mandera West and Mandera North Sub County. The September outbreak recorded 182 suspect cases reported of which 8 were sampled and tested, and 5 (2.74%) were laboratory confirmed with measles IgM antibodies.
Measles cases were reported in additional counties. The outbreak in Garissa mainly affected Dadaab Sub County, where the refugee camps are located. It began in January and is still ongoing with 47 suspect cases, ___ cases sampled and tested, and 9 laboratory confirmed. In Nairobi County, 22 suspect cases have been reported since July 2018 from Kamukuni County and 4 (3.8%) have been lab confirmed.
The Disease Surveillance and Response Unit (DSRU) was notified of the outbreaks and subsequently, the Ministry of Health constituted a team from DSRU and Kenya Field Epidemiology and Laboratory Training Program (K-FELTP) to carry out an investigation and assist in response and control of the outbreak in Mandera county.
As of 30 September 2018, Mandera County had a total of 286 (95.5%) suspected cases and 13 (4.5%) confirmed cases. There are likely to more undetected cases. Due to the highly communicable nature of measles virus, transmission is said to be ongoing hence additional epidemiologic investigation is necessary to identify more cases and to develop an optimally targeted outbreak response immunization plan with which measles virus transmission will be interrupted.
The residents role in the outbreak was to characterize measles cases through descriptive epidemiology, in Mandera County, Kenya, to estimate the extent of the ongoing cases, identify measles genotype through nasopharyngeal swab collection and urine samples in cases within 7 days of onset rash and to confirm measles virus infection among cases through IgM antibody detection and in cases symptomatic in the thirty days prior to identification.
Cases were actively searched from health facility records and community reports. Residents reviewed records of health facility outpatient registers (MoH 204A and 204B), inpatient files, inpatient registers (MoH 301), and monthly summary reports (MoH 705A and 705B).
In the communities, any person with a fever and rash, living in or visiting Mandera County at any point between January 1, 2018 and October 12, 2018, was identified as a probable case. For cases identified through record review, community visits were made and cases interviewed.
Household visits were aided by Community Health Volunteers (CHVs) who also doubled as translators. At the household, verbal consent was obtained for adults above 18 years, assent for children > 7 years and verbal consent from a guardian for children less than 7 years old. A structured questionnaire was then administered and samples collected from those who were eligible.
During the health facility and community visits, sensitization was done on measles transmission and prevention measures.
All additional cases were added to the line list.
Study population and period
The study was conducted among persons living in or visiting Mandera County, Kenya between January 1 and October 12, 2018. Data will be collected between 4 and October 12, 2018.
· Suspected measles case will be either 1) a person with fever AND maculopapular rash AND one of the following symptoms: cough OR coryza OR conjunctivitis; 2) any person in whom a clinician suspects measles, living in or visiting Mandera county at any point between January 1, 2018 and October 12, 2018.
· Lab-confirmed measles case- a suspected, investigated and sampled case with serological confirmation of recent measles virus infection (measles IgM +ve), who has not received measles vaccination in the 30 days preceding specimen collection, living in or visiting Mandera County at any point between January 1, 2018 and October 1, 2018.
· Epidemiologically linked measles case- a suspected case for whom no sample was provided and who is linked to a laboratory confirmed case, with 30 days or less separating the onset of the rashes of the two cases, and was living in or visited Mandera County at any point between January 1, 2018 and October 12, 2018.
· Clinically compatible measles case- a suspected measles case without adequate specimen taken and who is not linked epidemiologically to a laboratory confirmed case and was living in or visited Mandera County at any point between January 1, 2018 and October 12, 2018.
Data was collected using an electronic standardized questionnaire. The questionnaire was administered to caretakers of case-persons or case-persons identified through either a register review at the health facilities or at the community.
Variables of interest include:
- Socio-demographic factors: age, sex, residence, occupation and level of education
- Clinical information: rash onset date, symptoms, complications, hospital utilization, outcome, Laboratory information
- Vaccination history: number of doses of measles-containing vaccine received, date of last vaccination against measles
- Exposure and travel history
Specimen collection and laboratory testing
The team collected 5 ml of venous blood into a microtainer from persons fitting the suspect case definition and who experienced symptoms in the 30 days preceding the case investigation. The team separated blood cells from serum and let the clot retract for 30 to 60 minutes at room temperature. Centrifuge was at 2000 rpm for 10-20 minutes. Serum was decanted into a clean glass tube labeled with a case identifier and date of collection. Samples were transported using the triple packaging to the Kenya Medical Research Laboratory (KEMRI) national reference laboratory for testing. The samples were kept in a cool box at 4-8° C(WHO, 2010) during transport.
Nasopharyngeal swabs and urine samples were collected from all identified suspect cases who reported onset of rash within 7 days from date of interview. Samples were placed in 2mls of viral transport media (VTM), and placed in a cooling box at 4-8°C for transport to KEMRI laboratory for genotyping. A minimum volume of 50mls of urine will be collected in a sterile urine container and transported to the laboratory in a cool box at 4-8°C for processing(Controlled, 2018).
Data was transferred from the electronic tablets and entered into Microsoft Excel 2013 for cleaning. Epi Info 7.2 to be used for the analysis. A descriptive epidemiologic analysis was conducted. Measures of central tendency and dispersion for continuous variables were calculated, as well as frequencies and proportions for categorical variables. We will characterize cases in time, place and person. Epidemic curves will be used to show cases with their date of onset of the rash. Maps will be used to illustrate where the cases are from to show the extent of the outbreak. Age-specific, sex-specific and ward-specific attack rates will be calculated to estimate magnitude of the outbreak by dividing number cases by population at risk. Case fatality rates (CFR) will be calculated by dividing number of deaths that occur within 30 days of rash onset by the total number of measles cases.
Table 1: Measles cases by Sub County in Mandera County
Epidemic curve of suspected and confirmed line listed cases of measles, Mandera County, 2018
The epidemic curve below shows number of cases by date of rash onset. For cases that did not have a recorded date of onset, they substituted it with the date of visit to health facility. The first 2 cases occurred in Mandera East Sub County with onset of Rash on 4 January 2018. The first confirmed case occurred In Lafey with onset on illness on 8 January 2018. This was also the first cases in Lafey Sub County.
Clinical characteristics of suspected measles cases
None of the cases in the line list had any symptoms recorded besides the date of onset of the rash and clinical outcome.
Among the 378 cases line listed only 237 (62.7%) had vaccination history indicated. Of the cases who had a vaccination history indicated, 203 (85.7%) had not been vaccinated for any dose of MCV. The number of doses received was not indicated for any of the line listed cases. Among those aged below one year 18 (94.7%) had not been vaccinated, and those aged 1 to 4 years 51 (86.4%) had not been vaccinated as shown in figure below.
Figure : Proportion of unvaccinated line listed measles cases by age (years) in Mandera county, 2018
The overall attack rate for line listed cases in Mandera County was 26.0 cases per 100,000 population. By age, Children under 1 year had the highest attack rate at 50.0 cases per 100,000. Males had an attack rate of 28.8 per 100,000 population. Among the wards, Takaba North ward had the highest attack rate in Mandera County with 224.9 measles cases per 100,000 population. Mandera West Sub County had the highest attack rate among the sub counties with 100.3 cases per 100,000 population. Attack rates are shown in Table3 below.
Among the line listed cases, 1 (0.3%) deaths occurred. The death occurred in a 3 year old girl from Township village in Mandera East Sun County. Rash developed on 1st March 2018 and she was seen on 6th March 2018. No further clinical information, nor vaccination history was available for the cases.
The team observed there was very low awareness of MCV2 vaccine and administration of measles vaccine at age 6 months in outbreak situations among health care workers and the community.
· Local community practices for treatment of measles include:
o Fresh chicken/goat blood applied to the entire body treats the illness (see photos, Appendix 1).
o Wrapping of fresh goat skin helps ill persons.
o Provision of chicken/goat soup helps ill persons.
o Drinking camel milk helps ill persons.
· Local community beliefs about measles include:
o Water worsens the condition. Thus the sick are instructed to avoid drinking water or bathing.
o Eating mutton will lead to death for the sick.
o There is another form of measles that has “internal” manifestations that does not exhibit the characteristic rash. Therefore, other febrile illnesses maybe attributed to measles despite absence of rash.
· There were many suspected chicken cases in the outpatient registers. This was also observed during the field visits
· Health facilities within the areas visited were sparsely populated with long distances and rough roads noted. Some villages were very far away from health facilities and no outreach services had been rendered since March 2018. The communities in hard to reach areas requested for resumption of outreach services as it was the only source of health services for them. . The teams encountered some very sick individuals in dire need of medical attention.
· In the last three months of the outbreak, the sub county health management teams (SCHMTs) reported no support for the measles outbreak response.
· Documentation was quite poor in the outpatient registers with missing variables for almost all the records,
· IDSR reporting was done by all the public health facilities. However, none of the private health facilities were reporting via IDSR system.
· There was a community report of a community death in a pregnant woman who was reported to have a severe febrile illness and a rash in Gofa village. Gestation could not be established for the pregnancy. She was reported not to have had attended any ANC clinic. The pregnant woman was reported to have had a maculopapular rash, fever, cough, red eyes and difficulty in breathing. She is also reported to have come in contact with a girl who had suspected measles. The girl had travelled to Gofa village from a neighboring town, Ramu, where measles cases had also been reported. Gofa village is reported not to have had any measles cases prior to the arrival of the girl from Ramu. The pregnant woman was attended to by some family members at her house without improvement. She had not visited a health facility, nor had she been attended to by a health care worker. The illness was reported to have lasted for 2 weeks. The death occurred around 26th September 2018.
· Majority of the cases occurred in those aged below 15 years.
· All wards in Mandera West Sub County reported cases except Lagsera.
· The highest attack rate occurred in children under 1 year of age and those residing in Takaba North ward in Mandera west Sub County. (or ward) of ___ sub county.
· There was very low coverage for MCV1 and MCV2
Public Health Actions taken
- Community sensitization about measles by the investigating team in Ardahallo, Kobe, Dandu, Did Koba.
- Health education of the community health volunteers and community health assistants about measles community case definition and how to differentiate measles from other febrile rashes especially chicken pox
- Addressed issues on data quality such as incomplete register entries.
- Sensitization of health care workers about measles detection, vaciination at 6months of age, sample collection, reporting and appropriate follow up was done.
- Case management was done for cases identified in hard to reach areas.
- Referral of measles cases, and other serious illnesses identified in the community to health care facilities for treatment.
The team recommended that there is;
- Need to strengthen routine immunization
- Need for a measles Outbreak response immunization (ORI) in Mandera County
- Sub Counties need to conduct integrated outreaches in hard to reach areas
- Need for IDSR training among health care workers and CHVs