Monkeypox is a rare disease that is caused by an infection from the monkeypox virus. This virus belongs to the Orthopoxvirus genus in the family Poxviridae. The Orthopoxvirus genus also includes variola virus (the cause of smallpox), vaccinia virus (used in the smallpox vaccine), and cowpox virus. Monkeypox, just like smallpox developed like other known pox-forming diseases (pustules that eventually break open, ulcerate, crust over, and some pox form scars on the skin

Monkeypox was first discovered in 1958 when two outbreaks of a pox-like disease occurred in colonies of monkeys kept for research, hence the name ‘monkeypox.’ The natural reservoir of monkeypox remains unknown. However, African rodent species are suspected to play a role in transmission.

Monkeypox was first identified in humans in 1970 in the Democratic Republic of Congo (then known as Zaire) in a 9 -year -old boy in a region where smallpox had been eliminated in 1968. Since then, the majority of cases have been reported in rural, rainforest regions of the Congo Basin and western Africa, particularly in the Democratic Republic of Congo, where it is considered to be endemic. In 1996–97, a major outbreak occurred in the Democratic Republic of Congo. Since then, monkeypox has been reported in humans in other Central and Western African countries.

There are two different genetic groups (clades) of the monkeypox virus, i.e., the Central African and Western African. Human infections with the Central African monkeypox virus clade are typically more severe compared to those with the West African virus clade, and thus have a higher mortality ratio. Person–to–person sporadic cases is recorded for the Central African monkeypox virus and limited to the West African monkeypox virus.

In the year 2003, monkeypox cases were confirmed in the United States of America (47 cases), marking the first reported occurrence of the disease outside of the African continent. Most of the patients were reported to have had close contact with pet prairie dogs which were infected by African rodents that had been imported into the country. Soon afterward, other cases were recorded both in the United Kingdom (3 cases) and in Israel (1 case) back in 2018.
Sporadic cases of monkeypox have been reported from West and Central African countries, and with increasing awareness, more countries are identifying and reporting cases. Since 1970, human cases of monkeypox have been reported from 10 African countries – the Democratic Republic of the Congo, Republic of the Congo, Cameroon, Central African Republic, Nigeria, Ivory Coast, Liberia, Sierra Leone, Gabon, and South Sudan.

Monkeypox Epidemic in Nigeria

Nigeria experienced her first case of human monkeypox in the year 1971, and a second case was reported, in 1978 (1 case).

In 2017, Nigeria experienced the largest documented outbreak, approximately 40 years since the country had last confirmed cases of monkeypox.  Between Sept. 22, 2017, and Sept. 16, 2018, 122 confirmed or probable cases were reported from 17 states. There were seven deaths, a 6% case fatality rate. Infected individuals were aged 2 days-50 years, and 69% were male.

According to reports from the Nigeria Centre for Disease Control (NCDC), as of the end of September 2019, 15 new suspected cases of the monkeypox virus were reported in 6 states – Lagos (5), Rivers (2), Akwa Ibom (3), Zamfara (1), Delta (1), Imo (2) and Federal Capital Territory, FCT (1). Five of these 15 fifteen suspected cases were confirmed positive for monkeypox in three states – Lagos (3), Rivers (1), and Akwa Ibom (1).

Although no death was recorded during that time, a total of 81 suspected cases were reported in 2019 of which 39 confirmed cases were recorded in nine states (Bayelsa, Lagos, Delta, Rivers, Akwa Ibom, Enugu, Anambra, Cross River, and Oyo) and one death. Of the confirmed cases, 59% were from two states, Delta (28%) and Lagos (26%). The most affected age group was 21-40 years; 84.6% of confirmed cases were male (male to female ratio = 2.6:1).

According to the World Health Organization’s latest report, it shows that from January to June 22, 2022, 50 countries across five regions have reported a cumulative total of 3,413 confirmed cases with over 90 percent recorded in non-endemic countries.

Also, according to the report, the WHO European Region topped the infection rate with 2,933 cases, representing 86% of the total cases, followed by the American Region with 381 (10%), and Africa coming third with 82 cases (2% of global cases) reported from six countries, with Nigeria topping the list with 50 confirmed cases (1 death). Nigeria is followed by the Democratic Republic of the Congo, the Central African Republic, Ghana, Cameroon, and Congo.

Since the beginning of the outbreak in September 2017 through July 10, 2022, Nigeria has recorded a little over 800 cases of monkeypox, having seen a 3% (25) case fatality ratio among confirmed cases. The disease is predominantly in men aged 31 to 40 years, and there has been no evidence of sexual transmission of monkeypox.

In summary, monkeypox is a disease endemic in Africa that spread to the rest of the world and has been declared by WHO a pandemic.