Measles - Paraguay - Prevention is better than cure

Spread the Message

Read Time:8 Minute, 29 Second

2 February 2023

Situation at a glance

On 23 January 2023, the Paraguay IHR National Focal Point notified WHO of a measles case in a 14-month-old boy from Itapúa Department, who had onset of fever and rash on 15 September 2022. The case was notified as a highly suspected case of measles in September 2022, and on 11 October 2022, the case was laboratory confirmed by the Central Public Health Laboratory (LCSP. as per its acronym in Spanish) in Paraguay. Although the case had no history of receiving routine vaccination as per the immunization schedule, one dose of MMR (MMR1) was given on 12 September 2022 as part of measles vaccination campaign conducted in the affected department between November 2021 to 16 December 2022 . Due to the history of recent vaccination, the case samples were sent to United States Center for Disease Control and Prevention (US CDC) for further molecular analysis, which tested positive for measles and negative for measles vaccine strain on 10 January 2023. The case had no history of travel, however, 30 days prior to developing symptoms, he came into contact with a symptomatic family member, diagnosed as having an allergic reaction at the time, and who was a contact of a family member with a history of periodic travel to Buenos Aires, Argentina.

Control measures, such as strengthening surveillance activities, were implemented by the local and national authorities as soon as the case was notified in September 2022.

This is the first case of measles reported in Paraguay since 1998.

Description of the situation

On 23 January 2023, the Paraguay IHR National Focal Point notified WHO of a confirmed case of measles in Itapúa Department, Paraguay. Itapúa is close to the southern border of the country with Argentina. The case is a 14-month-old boy who had onset of rash and fever on 15 September 2022. He had no travel history and had received one dose of MMR vaccine (MMR1) on 12 September 2022. According to the information received, 30 days prior to onset of symptoms, the case was in contact with a 16-month-old child, a symptomatic family contact, diagnosed as having an allergic reaction including fever, rhinorrhea and skin lesions. This symptomatic family contact was a contact of a family member with a history of periodic travel to Buenos Aires, Argentina.

On 26 September 2022, a serum sample was collected and sent to LCSP which was reactive for measles by Immunoglobulin M ( IgM). On 11 October, a second serum sample was collected and sent to the LCSP and tested reactive for measles by IgM and IgG. Further, on 16 November, serum and urine samples were sent to the US CDC for confirmation, and additional molecular analysis was performed which tested positive for measles by reverse transcriptase – quantitative polymerase chain reaction (RT-qPCR) on 10 January 2023, and negative for measles vaccine strain.

In Paraguay, the official measles vaccination coverage for the first and second dose of measles, mumps and rubella vaccine (MMR) in 2021 was reported to be 56% and 55%, respectively, lower than the WHO recommended sustained homogeneous coverage of at least 95%. The last National MMR Vaccination Campaign was conducted from November 2021 to 16 December 2022 including the department of Itapúa.

This is the first case of measles reported in Paraguay since 1998.

Epidemiology of measles:

Measles is a highly contagious viral disease, which affects susceptible individuals of all ages and remains one of the leading causes of death among young children globally. The mode of transmission is airborne or via droplets from the nose, mouth, or throat of infected persons. Initial symptoms, which usually appear 10-12 days after infection, include high fever, usually accompanied by one or several of the following symptoms: runny nose, bloodshot eyes, cough, and tiny white spots on the inside of the mouth. Several days later, a rash develops, usually starting on the face and upper neck and gradually spreading downwards. A patient is infectious four days before the start of the rash to four days after the appearance of the rash. There is no specific antiviral treatment for measles and most people recover within 23 weeks.

Among malnourished children and immunocompromised people including people with HIV, cancer and treated with immunosuppressives, as well as pregnant women, measles can also cause serious complications, including blindness, encephalitis, severe diarrhea, ear infection, and pneumonia.

Measles can be prevented by immunization. In countries with low administrative vaccination coverage, epidemics typically occur every two to three years and usually last between two and three months, although their duration varies according to population size, crowding, and the population’s immunity status.

Public health response

The following public health measures were implemented by local and national health authorities:

Intensified epidemiological surveillance through active and retrospective institutional case finding, contact tracing, and monitoring of contacts.
Rapid assessment of vaccination coverage in the community, and if needed, rapidly deploying measles containing vaccine (MCV) in the field targeting those who have missed one or two doses of MCV. Additionally, in September 2022, a total of 181 people , between the age of one and 60 years and above, were surveyed in the surrounding area where the case was detected. Of these 181 people surveyed, 107 were vaccinated against measles and rubella, with a coverage of 59%.
Training was provided to health care providers on case management and measles surveillance.
Strengthening the laboratory networks.

WHO risk assessment

In 2016, the WHO Region of the Americas was the first Region of the World Health Organization (WHO) to be declared free of the endemic transmission of measles virus by the International Expert Committee (IEC) for documenting and verifying measles, rubella and the congenital rubella syndrome in the Americas. However, keeping the Region free of measles is an ongoing challenge due to the permanent risk of importation and reintroduction of the virus.

In 2021, five countries and territories (countries hereafter) have achieved ≥95% coverage for the first dose of MMR (MMR1) in the Region of the Americas, while 13 countries had MMR1 coverage of less than 80%. For MMR2, only two countries had ≥95% coverage and 36 countries had less than 80% coverage.

Several factors have contributed to the outbreaks of measles in the Region of the Americas occurring between 2017 and 2022, including lack of compliance with 2-dose measles vaccination coverage, influenced by the COVID-19 pandemic. During the same period, there are gaps in the performance of international indicators for integrated measles/rubella surveillance.

In Paraguay, risk of disruption to routine immunization activities remains due to both the COVID-19 related burden on the health system and decreased demand for measles vaccination because of physical distancing requirements or community reluctance. Disruption of immunization services, even for brief periods, can result in an increased number of susceptible individuals and raise the likelihood of outbreak-prone vaccine-preventable diseases (VPDs) such as measles.

WHO advice

WHO recommends strengthening efforts to implement the Plan of Action for the Sustainability of Measles, Rubella, and Congenital Rubella Syndrome Elimination in the Americas 2018-2023, with a focus on: 1) guaranteeing universal access to measles vaccination services; 2) strengthening the capacity of epidemiological surveillance systems for measles, rubella, and congenital rubella syndrome; 3) developing national operational capacity to maintain the elimination status; 4) establishing standard mechanisms for rapid response to imported measles, rubella, and congenital rubella syndrome cases, in order to prevent the re-establishment of endemic transmission in the Region’s countries.

To avoid the spread of measles beyond this case, WHO recommends maintaining sustained homogeneous coverage of at least 95% with the first and second doses of the MCV in all municipalities and strengthened surveillance to achieve timely detection of all suspected cases in public, private, and social security healthcare facilities.

WHO recommends strengthened surveillance particularly in high-traffic border areas to rapidly detect and respond to highly suspected measles cases.

WHO also recommends managing imported measles cases to avoid the re-establishment of endemic transmission through the activation of rapid response teams trained for this purpose, and by implementing national rapid response protocols when there are imported cases. Once a rapid response team has been activated, continued coordination between the national, sub-national and local levels must be ensured, with permanent and fluid communication channels between all levels. During outbreaks, it is recommended to establish adequate hospital case management in order to avoid nosocomial transmission, with appropriate referral of patients to isolation rooms (for any level of care) and avoiding contact with other patients in waiting rooms and/or other hospital rooms.

WHO recommends vaccination of at-risk populations (without proof of vaccination or immunity against measles and rubella), such as healthcare workers, persons working in tourism and transportation (hotels, airports, border crossings, mass transportation, and others), as well as international travelers. Implementing a plan to immunize migrant populations in high-traffic border areas, prioritizing those considered at-risk, including both migrants and residents, to increase vaccination coverage in order to increase population immunity.

WHO recommends maintaining a stock of the measles-rubella (MR) and/or MMR vaccine, and syringes/supplies for control actions of imported cases. Access to vaccination services should be facilitated, according to the national scheme, to foreigners; people from the same country who perform temporary activities in countries with ongoing outbreaks; displaced populations; indigenous populations, or other vulnerable populations.

WHO does not recommend any restriction on travel and trade to Paraguay, based on the information available on the current outbreak.

Further information

Citable reference: Citable reference: World Health Organization ( 2 February 2023). Disease Outbreak News; Measles – Paraguay. Available at: https://www.who.int/emergencies/disease-outbreak-news/item/2023-DON438