A total of 110 cases and 110 controls were recruited into the study. Participants were comparable in almost all demographic characteristics except for age as shown in Table .
Demographic characteristics of measles cases and controls, Zaka District, Masvingo Province, 2010
Of the 126 cases reported on the line list, all five specimens collected tested IgM positive and 5 community deaths were reported giving a case fatality rate of 4%.Three of the five deceased cases were males, all of them were unvaccinated, and all five cases belonged to the apostolic sect. The major complications reported by the deceased were diarrhoea, cough and croup.
The median age of cases was 10(Q1=7; Q3=16) years while that of controls was 16 (Q1=10; Q3=19) years. Majority of cases 70 (63.65%) belonged to the apostolic sect and 24(21%) were from orthodox churches as shown in Table . The most affected area was Ndanga and the least was Mukanganwi and Chikwanda as shown in Figure . The measles vaccination coverage for Zaka district was 75%. Ninety two (83.6%) of cases were not vaccinated and thirty two (29%) of cases were unvaccinated. Zaka district vitamin A supplementation coverage verified by the child health card was at 66.5%.
Distribution of measles cases by area of residence, Zaka district 2010.
There were multiple peaks on the Epi curve as shown in Figure . The index case had onset of symptoms on the 6th of May. Interventions (treatment of cases, mass vaccinations, health education, advocacy and contact tracing by environmental heath technicians) to the outbreak however started on the 3rd of June 2010 almost a month after the outbreak onset. The outbreak lasted for four months (May to August 2010).
Epi Curve showing the distribution of measles cases by time in Zaka District, 2010.
The most reported symptoms were koplik spots 104(94.5%), maculopapular rash 103(93.6%), red eyes 97(88.2%), coryza 55(50.8%), fever 110 (100%) and the least was cough 30 (27.3%). The other symptoms that were reported were vomiting 20 (18.2%), loss of appetite 15(13.6%), and fatigue 40(36.36%).
Out of the 110 cases that were interviewed 45(40.9%) reported seeking medical treatment for measles while 78(70.9%) of controls reported believing in medical treatment for measles. Sixty two (56.4%) of cases were treated for measles at home. Several methods were used for treatment of measles at home and these included herbs 57 (25%), holy water 10 (4.5%), prayer 5 (2.3%) and pain killers 3 (1.4%). There was no significant difference on knowledge of measles between cases and controls.
Okra was the most widely used substance for treatment of measles in Zaka with 57(51.8%) of cases using it. The least used treatment method was pain killers 3(2.7%).
Fifty eight (69.0%) sought treatment at the hospital while 42(31%) were treated for measles at home and 10 cases were treated at school. One hundred (91.8%) of cases sought treatment within three days of onset of illness while the rest of the cases (8.2%) sought treatment later than three days. The median duration for seeking treatment after onset of illness was three days (Q1=2; Q3=7).
In bi-variate analysis, not being vaccinated against measles OR 12.46(95%CI 6.20:25.31) and being below the age of 18 years OR 18.44(95%CI 4.27:79.64) and not believing in medical treatment for measles OR 1.83 (95%CI 1.40:2.40) were significant risk factors for contracting measles. as shown in Table .
Risk factors for contracting measles in, Zaka district, Masvingo Province, 2010
In multivariate analysis, factors that remained independently associated with contracting measles in Zaka district measles outbreak were, contact with a case AOR=41.14(95%CI: 7.47-226.54), being unvaccinated AOR= 3.96(95%CI: 2.58-6.08) and not receiving additional doses of vaccine AOR 5.48 (95%CI: 2.16-11.08.) as shown in Table .
Independent factors associated with contracting measles in Zaka district Masvingo Province, 2010
Zaka district had 99% of nurses post filled and every health centre being manned by at least one trained nurse. The District Nursing Officer post, community nurse post, Environmental Health post, pharmacy technician post, health information officer post, health promotion, nutritionist post and the District Medical Officer post were all filled while the laboratory scientist post was vacant. There were 44% environmental health posts filled in Zaka district.
Measles vaccine, thermometers, paracetamol, aspirin, amoxicillin capsules and syrup, tetracycline, oral rehydration solutions, intravenous fluids and needles as well as syringes and vitamin A were available.
Three vehicles were available at the district office and the Expanded Programme on Immunisation truck was in good condition at the time of the outbreak. However fuel was not available at the station. There were no Information Education materials (IEC) on measles readily available.
The district delayed notifying the province of the outbreak. In addition the district took long to do field investigations. The interventions that the district instituted were immunisation of apostolic sect children with the aid of the police and environmental health technicians who had information on sick children in the village and health education.
There was poor surveillance as the district officers did not analyse data and disseminate information. Poor team work was reflected by the failure of the district team to hold outbreak update meetings and some officers lacked current outbreak information like how many cases were recorded.
The most affected area was Danda village followed by Bota and the least was Mukanganwi village as shown Figure .